"Masters of the Universe" was spacier than we expected. And we're loving it.

Spoiler Alert: We will be talking about specific details from "Masters of the Universe," if you haven't seen it yet, be forewarned

If you haven't caught up with He-Man since the '80s, it's a genre mashup of sci-fi, fantasy, comedy, action-adventure, with a healthy dose of retro '80s vibes sprinkled in. Think Guardians of the Galaxy meets Lord of the Rings.

But, while all of these elements co-exist spectacularly in the new live-action film, it is chock-full of outer space. You even get to meet He-Man's mom, a NASA astronaut!

"Masters Universe is famously, famously sort of this wacky, you know, unhinged blend of sci-fi and fantasy and all these kinds of crazy things mixed together, and so sci-fi in space is a big part of that," director Travis Knight told Space.

1. An 80's-tastic trip through space

Within the first few moments of "Masters of the Universe," it's clear that things are going to get space-y.

These early moments in the film not only establish Eternia's place in space, but take the viewer on a cosmic trip that really sets the tone and lets you know what kind of fun you're in for.

2. He-Man's mom is a NASA astronaut!

In the "Master's of the Universe" canon, it turns out that He-Man's mom is an astronaut.

"A lot of people aren't aware of this, but He-Man's mother, Queen Marlena, is actually a NASA astronaut," Knight told Space.

But beyond just being canon, Knight actually hid an easter egg in the film that hints at Queen Marlena's spacefaring background.

"If you look very, very carefully in the back, there's a scene very, very early on [in the film] where Adam is talking with his mother in the royal chambers. If you look in the background, you will see her NASA astronaut helmet," Knight added.

3. Eternia is an exoplanet!

According to He-Man lore, this exoplanet, or planet outside of our solar system, lies at the exact center of the universe. And at the center of the planet lies a "starseed," or a fictional remnant from the universe's creation.

Now, Eternia is very much unlike any exoplanet scientists have ever discovered. Not only is there flowing water and rolling green hillsides, but the planet is bustling with life including the mythical Griffin flying overhead.

Judging from a few scenes, the planet might also have some strange interior caves.

4. Teela "folds space"

"Ship, fold space!" Teela tells her spaceship that she takes to rescue He-Man (and the sword) from Earth back to Eternia. "Folding space and getting weird," the ship replies.

While no sci-fi space travel is perfectly scientific, this moment is a fun nod to the fabric of spacetime, and traveling great distances in a short amount of time by traveling through that fold in what we can only imagine is something like a theorized wormhole.

5. Spaceships (and, of course, spaceship battles) galore

Teela's space-folding spaceship is far from the only incredible spaceship or space plane we get in this film.

None of the ship designs are entirely different from what you may have seen in other science fiction films – in fact, one tiny ship that He-Man rides out of the back of another ship looks pretty much like a jet ski with some space-y paint thrown on it. But this movie provides no shortage of awesome adventures and battles on and between spaceships.

6. A possible Star Wars nod?

Keep your eyes peeled during one particular spaceship chase scene through the forest.

It seems heavily inspired by, and perhaps a cheeky nod to, the speeder chase scene in Star Wars: Episode VI – Return of the Jedi. Am I seeing things? Let us know if you see the inspiration in this scene.

7. Adam loves his telescope

While living on Earth, Adam (or He-Man) has a telescope pointing out of his bedroom window.

That telescope even has a NASA sticker on it. With his memories from Childhood, Adam is obsessed with his old life on Eternia, and it seems like this telescope is likely placed facing out his window as he spends his time searching the night sky for any sign of his home planet.

Perhaps he used our best telescopes guide to get his setup?

8. Brian May is here?!

Legendary Queen guitarist and astrophysicist Brian May was even invited to the He-Man party. May delivered some seriously epic guitar stylings to the movie's score.

May's cosmic and searing guitar solos can be heard across the track Eternia on the soundtrack composed by Daniel Pemberton.

9. Eternia has auroras

He-Man's home world has auroras, or colorful light displays in the night sky that occur when charged solar particles interact and react with a planet's atmosphere.

In fact, in one scene, we even see Skeletor sending a message to He-Man and the gang through an aurora.

10. Aliens galore

Eternia is home to more creatures than just He-Man and Skeletor. This planet has a wide variety of aliens that come to life with a variety of prosthetics, makeup, props and costumes.

Reminiscent of the variety of aliens in any Star Trek series, Eternia has everything from a blue pig man serving as a henchman to Skeletor to a "moss man" who meets his untimely demise.

The new 'Masters of the Universe' movie is in theaters from today (June 5, 2026). You can watch the original "He-Man and the Masters of the Universe" on Amazon Prime Video.

Earlier this month, the U.S. Department of Defense released what it termed "new, never-before-seen files" on unidentified anomalous phenomena (UAP), tagging it as a historic effort in transparency.

The UAP release came courtesy of the Trump administration's Presidential Unsealing and Reporting System for UAP Encounters, or PURSUE for short.

The posting involves 158 files — documents, photos and videos from NASA, the FBI, Defense Department, and State Department. Additional files are forthcoming, to be issued by the Department of Defense (DoD) "on a rolling basis." In a press statement, DoD Secretary Pete Hegseth remarked that his department is in lockstep with President Trump to bring unparalleled transparency regarding the government's understanding of UAP.

"These files, hidden behind classifications, have long fueled justified speculation — and it's time the American people see it for themselves," Hegseth said.

But just what are we seeing here? Space.com reached out to specialists to unravel what's behind sightings of UAP — or, as they used to be known, unidentified flying objects (UFOs).

'A useful beginning'

For some, there is a "so what" — maybe a ho-hum — reaction to the UAP data release. Those familiar with UFO records, documents, or even astronaut sightings note that almost all of the "never-before-seen" files have long been known.

"I would view this first tranche as a useful beginning in what I hope becomes regular releases of documents not previously available, well documented sighting investigations and videos that aren't stripped of all necessary information," said Mark Rodeghier, president and scientific director of the J. Allen Hynek Center for UFO Studies.

Many of the FBI and other government files were already available, Rodeghier said, but fewer redactions and centralized access are still valuable.

"They allow researchers to check details more carefully and better reconstruct how official agencies received, evaluated and sometimes simply filed away UFO reports," Rodeghier added.

"Short videos and unresolved case summaries can be intriguing, but without the supporting metadata, investigative history and analysis, they are hard to evaluate," he said. "The real test will be whether future tranches provide complete case files, not just provocative fragments. True transparency means context, not just clips."

Similar in view is Robert Powell, an executive board member of the Scientific Coalition for UAP Studies.

"Recent government UAP disclosures have been valuable. They have confirmed that the public and the media regard this phenomenon as a matter of genuine importance," Powell said.

"But redacted files and the absence of credible scientific evaluation are not answers. They are a mandate," said Powell. "Academia and the scientific community can no longer afford to leave this field to institutions that operate in secrecy. The science of UAP must be conducted in the open, by those whose obligation is to the scientific evidence," he said.

More questions than answers

Also taking on "does it matter and who cares" is Alejandro Rojas, a consultant for Enigma Labs, a group appraising UAP via the use of cutting-edge technology and social intelligence.

"The UAP transparency movement didn't start with this administration," said Rojas. "It's been building in Congress for several years, driven by bipartisan oversight and persistent public pressure. What we're seeing now is the continuation of that effort, not the origin of it," he said.

As for the recent DoD release, "it feels somewhat unfinished," Rojas said. "There are many cases with minimal context, missing sensor data, and little accompanying analysis, as if the priority was getting something out the door rather than something useful."

But imperfect data released publicly, Rojas added, is still more valuable than perfect data sitting in a vault. "Even a messy dataset reveals patterns over time, and every case added to the public record is one more data point researchers and citizens can work with. The question is what comes next, because this release raises more questions than it answers," he said.

Missing: context and data

On the lack of context and data, Rojas said that, for any meaningful scientific analysis, you need more than a grainy infrared clip and a one-paragraph summary.

"These reports are largely missing the basics — coordinates, sensor parameters, altitude, speed confirmation. Many cases appear to have been flagged as UAP simply because there wasn't enough data to identify them, rather than because they exhibited genuinely anomalous behavior," said Rojas.

"That's not a criticism of the release," he added, "it's just the reality of what we're working with. Real analysis requires real data, and hopefully future releases include more of it."

Enigma Labs has built a website offering anyone  — researchers, journalists, curious members of the public  — the opportunity to search and explore these files as they come out, rather than hunting through a government portal.

"We're also collecting public sighting reports and giving people a community to discuss and analyze what's being released," Rojas added. "The goal is to make this process as open and accessible as possible, because transparency only works if people can actually find and use the information."

Real and inexplicable phenomena

For the first time in history, the White House and a number of government agencies "have acknowledged that there is a real and inexplicable phenomena occurring on a global basis that demands attention," said Michael Gold, president of Redwire Space, a space and defense company focused on advanced technologies.

Gold has experience delving into uncanny oddness in the skies. He served on NASA's UAP Independent Study Team that ran from 2022 to 2023. He said he's particularly grateful that the DoD (which the Trump administration has unofficially rebranded the Department of War) and NASA acknowledged that the object in the Apollo 17 imagery was real and unknown.

"The most powerful words in science are 'I don't know,' and I appreciate NASA and the Department of War being modest enough to acknowledge when a good explanation doesn't currently exist," said Gold. "Acknowledging anomalies is the first step to discovery, and is how scientific progress is made."

Gold emphasized that it's important to acknowledge the unprecedented nature of the White House's treatment of UAP. "I would like to compare the White House release to similar actions by prior administrations, but I can't, since there are none," he said.

The Trump administration and the agencies involved, Gold said, "should be applauded for supporting transparency despite what I'm certain were incredible and historic challenges to not just releasing information, but even just treating the UAP issue with the seriousness that it deserves."

Beginning, not an ending

In his 2024 testimony before Congress, Gold urged NASA to conduct a review of its archives for UAP.

"Another recommendation I made to Congress and supported by the NASA UAP Independent Study Team was for UAP to be added to NASA's Aviation Safety Reporting System [ASRS]," said Gold.

ASRS provides the U.S. Federal Aviation Administration with confidential data relative to safety anomalies. ASRS has provided the federal government with hundreds of thousands of confidential reports and has successfully operated for years, Gold said.

If UAP were added to the anomalies that ASRS collects, Gold said, every commercial pilot, crew member, and even passengers could act as sensors for UAP, providing a treasure trove of data.

"I hope that more files will be released soon that will show even more definitively anomalous behavior," Gold concluded. "I expect we are at the beginning, not an ending, of a very important moment in the history of science."

The Apollo photos really shouldn't have been part of the big UFO drop.

Last Friday (May 8), the Pentagon released its first batch of declassified "UFO files," responding to a directive that President Donald Trump issued in February.

Many of the 158 files focus on recent sightings by advanced U.S. military sensors — a "misshapen and uneven ball of white light" flying over Syria in October 2024, for example, and a small, bright dot cruising through a field of windmills in that same year. But some of them go back decades — all the way to the 1940s in several cases. (There has apparently been a slight cull or consolidation in the past week; there were 161 files when the drop was first announced.)

The older material includes 14 files related to NASA's human spaceflight programs — two from the Gemini 7 mission to Earth orbit in December 1965, one from Apollo 11 in July 1969, six from Apollo 12 in November of that year, four from Apollo 17 in December 1972 and one from crewed flights to the Skylab space station in 1973 and 1974.

The Apollo 11 file is a "technical crew debriefing," in which astronauts Neil Armstrong, Buzz Aldrin and Michael Collins discuss a few strange things that they saw and experienced during their historic mission. Aldrin, for example, states that he saw "what I thought were little flashes inside the cabin" — a phenomenon that he attributes to "some sort of penetration" or perhaps static electricity.

There are crew debriefings from Apollo 17 and Skylab, too, as well as other transcripts and/or audio excerpts from Gemini 7, Apollo 12 and Apollo 17. The UFO file drop also features photos captured on the lunar surface during those latter two missions, with the Pentagon highlighting supposedly mysterious features.

For example, one Apollo 17 photo "contains three 'dots' in a triangular formation in the lower right quadrant of the lunar sky that is clearly visible upon magnification of the image," its description reads. Another, captured during Apollo 12, "features five highlighted areas of interest, labeled 'Area 1' through 'Area 5,' above the horizon, in which unidentified phenomena are visible."

These photos and transcripts got a lot of attention shortly after last Friday's drop, with outlets like CBS News and Fortune discussing the material. Some of these stories used verbs like "reveal," which is a bit misleading, because this old NASA material has been publicly available for decades.

A number of folks have pointed this out. "Every single image released today from Apollo has simply added yellow boxes to images that have otherwise been public for half a century," astrophysicist Grant Tremblay noted on X on May 8.

"I am making no comment on aliens or UAP here, and am happy to see the release. But a bunch of serious people are suggesting that the Apollo stuff is 'newly declassified,' and that is simply not true," he added in another X post on that same day. (UAP, short for "unidentified anomalous phenomena," is the U.S. government's preferred term for UFOs these days.)

In a May 9 X post, Tremblay guided followers to the Project Apollo Archive on Flickr, inviting them to see the photos in bulk there. Such a perusal will reveal that many Apollo images sport "film defects," he added, highlighting a likely cause of the lunar "UFOs."

Graphic designer Jason Major, a space fan and veteran processor of space imagery, made a similar point.

"This is dumb. There are blue spots, specks, scratches, flares, and bits of crud in almost ALL of the Apollo photos. They were TAKEN WITH FILM CAMERAS IN SPACE — not to mention chemically developed and then scanned by various methods over the course of six decades," Major wrote in a May 8 X post about the Pentagon UFO-file drop.

This isn't to say that you should ignore the files or dismiss folks who are interested in them; some UAP observations are genuinely mysterious, and keeping an open mind is generally a good thing.

But keep a little perspective, too, and know that people have been poring over the Apollo material for longer than most of us have been alive.

Delivering a refreshing fusion of science, pop culture, history, and esoteric humor, renowned astrophysicist, lecturer, and best selling author Neil deGrasse Tyson takes us on a whirlwind tour of UFO culture and speculations on how first contact might actually happen in his latest book, "Take Me To Your Leader: Perspectives on Your First Alien Encounter" (Simon Six, May 12).

It's the perfect pocket-sized hardback that offers up Tyson's witty thoughts regarding alien abductions, UAP sightings, and flying saucer lore, as seen through his unique commonsensical delivery, and we’ve got the prologue exclusive to share with both believers and non-believers.

Tyson admits in our sneak peek below that "Ever since childhood I've wanted to be abducted by aliens." While as far as we know that's not occurred quite yet, the esteemed host of StarTalk does provide some sound practical advice that just might come in handy when entertaining alien kind.

"I saw so much swirling around," Tyson told Space.com. "The level of interest given to UFOs, rebranded as UAPs of course, as it ascended into the halls of Congress, at that point I said to myself as an educator, scientist, and as an alien enthusiast, that I thought I needed to step into the ring. I wanted to go in there and anchor conversations that people were having. To anchor it in the physics of the universe, so that when you do think about aliens you have some way to imagine it that has some kind of authenticity with the laws of the universe."

What Tyson has unwittingly accomplished in this enticing book is to present a solid case for him being the perfect candidate for Earth's official ambassador should E.T. ever come calling! And we can honestly think of no better representative ourselves!

"At no time do I say things like 'the supposed observation' or 'the supposed abduction.' I'm taking everything at face value and asking other questions related to it. When you were abducted, did you steal anything from the craft so you can show it to people? No. Did you take photos? Everyone has a high-resolution data-taking device in their pocket. Are you using that? I'm encouraging people to just get better data than simple eyewitness testimony."

In a world easily startled by sensationalism, Tyson here becomes a cool, gentle voice of reason amid the unchecked fascination with the topic of alien visitation and the stark reality of what humanity's reaction might be. Proper etiquette and protocol might be the difference between an enriching cultural exchange that could alter the trajectory of our species, or a disastrous instance of miscommunication as seen in films such as "The Day The Earth Stood Still" or "Mars Attacks."

"Because the public thinks eyewitness testimony constitutes evidence. Perhaps in the court of law, but not in the court of science, nor in the court of psychology, where they've known from the beginning of the susceptibility of the retelling of an objectively true event once it's filtered through the human sensory system. What I'm saying is if you want people embrace what you're saying, I need more than your eyewitness testimony to do so."

Hollywood has also helped foster the notion of extraterrestrial hookups in countless movies, from "War of the Worlds," "Invasion of the Saucer Men," and "Communion," to "Close Encounters of the Third Kind," "E.T. the Extraterrestrial," and "Fire In The Sky." These cinematic scenarios provide a framework to further the notion of cultural acceptance towards the idea of otherworldly visitors and how it might all play out.

"The evil alien trope is … here they are, they come across the galaxy, they clearly have more advanced technology than we do, and they kill us, enslave us, they have their way with us," Tyson notes. "So here is how we think aliens will behave based on suppositions. However, it's exactly how we know we've behaved to ourselves. This whole evil alien trope seems to me to be a mirror held back to how our civilization has interacted with itself. When a more advanced part of civilization encountered one that was less technologically advanced, it's never boded well."

For Tyson, this fun project was the ideal marriage of his scientific expertise, the physics and the astrophysics aspects, with his prominent presence in pop culture.

"I’m a big consumer of pop culture because I think it makes me a better educator," he adds. "I have places to touch and reach when I'm explaining something to others. And I can pivot it onto some pop culture thing that they know about or they've heard about. It makes for the transfer of knowledge, wisdom, and insight of science much easier if I can attach it to something you already care about or already know about. The fact that all of these films and TV shows that are referenced in there, are all part of my background, tells me that this book may be unique.

"If you're a successful academic you're kind of not watching sit-coms or 'SpongeBob Squarepants.' The fact that I am doing it, when I’d rather be in the lab, is so I can be more effective, and in this book it all came together. From early episodes of 'The Twilight Zone' to Superman and the Great Gazoo popping in and out of existence."

Prologue except for Neil deGrasse Tyson's "Take Me To Your Leader":

Ever since childhood I've wanted to be abducted by Aliens. My interest in the night sky began at age nine, after a first visit to New York City’s famed Hayden Planetarium, an attraction within the American Museum of Natural History. Growing up in the City, with persistent air pollution, light pollution, tall buildings, and endless evening distractions, were it not for the Hayden Planetarium, I’d have no relationship with the night sky at all.

After a few years, I joined the local amateur astronomer's club,* and with my telescope, I’d look for occasions to be alone, at night, under clear skies. The more alone I was and the more secluded the observing site, the greater my desire for a beam of light to come down from the sky and take me away. This sentiment was especially stoked at the summits of mountaintops, surrounded by low-lying clouds below, at observatories in the Chilean Andes, where I obtained data for my PhD thesis. Just me, my telescopes, and the universe. The desire to be abducted was driven entirely by my cosmic curiosity and not by some suppressed need to escape civilization and leave Earth behind.

As a professional astrophysicist, I am not alone in this interest. We've all done the calculations. We know the size of the observable universe — more than 90 billion light-years across. We know the age of the universe — 13.8 billion years. We know how many galaxies it contains — as many as a trillion. We know how many stars populate those galaxies — approximately 10,000,000,000,000,000,000,000 (ten sextillion), give or take a few. We can estimate how many planets and moons might orbit those stars — multiply by ten. We know the chemical ingredients of life — hydrogen, oxygen, carbon, nitrogen, and of course "other." We know how common they are — among the most common on the cosmos. And we know how quickly life began — organisms have thrived for 95 percent of Earth's timeline, starting when Earth was cool enough to sustain complex molecules.

We know these numbers well, which prevent any of us from imagining a universe not teeming with life. We desperately want to find them. Or maybe it is they who will find us. If that happens, and the space Alien demands, "Take me to your leader!" what will you do? What should you do? Our collective assumption is that the Alien wants to meet the person in charge of things: The President. The Prime Minister. The Monarch. The Pope. Or whoever happens to be the head of state. But plenty of other people are also “in charge of things, especially multibillionaires and captains of industry. Not knowing anything in advance about human civilization, but eavesdropping on our cultural norms before arrival, the Aliens might just as easily conclude that decade by decade, pop culture icons were also, or exclusively, in charge, such as Clark Gable, Walt Disney, Marilyn Monroe, Elvis Presley, the Beatles, Michael Jackson, Michael Jordan, Beyonce, Taylor Swift.

For the Aliens to have reached Earth at all, from any place outside our solar system, we can reliably conclude they’re more advanced than we are, in every way. So, maybe you should not seek out your actual leaders, be they political, cultural, or religious. Perhaps you should instead seek out people who have high scientific and technological expertise. You might also hide from the Aliens everybody who thinks Earth is flat, as well as all others who deny what science is and how and why it works. This would also be the wrong time to convince them that your God created the universe and that humans, not Aliens, are created in His image. We want to leave the friendliest impression possible on our space visitors, whatever their intentions, be they plunderous, nefarious, or simply curious.

In science, skepticism is foundational to our profession, so we uphold standards of evidence that some interpret as disinterest or even denial. Don’t take it personally, it’s how any and all objective truths have ever been established in this world. Think of "Take Me to Your Leader" as a book of etiquette and insights for your next close encounter, or perhaps a scientifically infused user’s manual with helpful hints from an astrophysicist who wants to meet the Aliens as badly as you do.

* The New York Amateur Astronomers Association is the oldest in the country, founded in 1927.

Excerpted from "Take Me To Your Leader: Perspectives on Your First Alien Encounter" by Neil deGrasse Tyson. Copyright © 2026 by Neil deGrasse Tyson. Reprinted by permission of Simon Six/Simon & Schuster. All Rights Reserved.

UFO enthusiasts just got a big old bone to sink their teeth into.

The Pentagon released its first tranche of declassified "UFO files" on Friday (May 8), responding to a directive that President Trump issued in February.

The new release consists of 161 files, most of which are PDFs recounting investigative reports and eyewitness testimonials (including from a few Apollo astronauts, who saw some strange things near the moon). But there's also quite a bit of imagery, including nearly 30 videos, which feature a range of intriguing unidentified flying objects — or unidentified anomalous phenomena (UAP), as they were recently rebranded.

Space.com combined all of those newly declassified videos into a supercut, which you can see above or via Space.com's YouTube channel. And the new footage is definitely worth a look.

For example, one submission from U.S. Central Command features five seconds of imagery captured in Syria by a full-motion video (FMV) camera in October 2024.

"An accompanying mission report, DoW-UAP-D32, described the UAP as consisting of a 'misshapen and uneven ball of white light,' and reported that a 'light/glare halo effect' occurred at the top of the FMV feed," Pentagon officials wrote in a description of the video.

Another video, submitted by U.S. Indo-Pacific Command, features a nine-second observation gathered in 2024 by an infrared sensor aboard an unspecified U.S. military platform.

"The sensor focuses on an area of contrast that resembles a football-shaped body with three radial projections: one oriented vertically, and two oriented downward at a 45-degree angle relative to the major axis of the main mass," Pentagon officials wrote in a description of the video.

Another 2024 infrared video from the same command has a more artistic feel, and not just because it's considerably longer (100 seconds). It shows a small, bright dot cruising through an array of windmills, looking like a wanderer lost in a ghostly forest of monstrous mechanical trees.

The Pentagon does not attempt to explain the UAP featured in these videos. Indeed, the accompanying text features the following disclaimer: "Readers should not interpret any part of this description as reflecting an analytical judgment, investigative conclusion, or factual determination regarding the described event’s validity, nature or significance."

And, of course, "unidentified" does not necessarily mean "alien" where UAP are concerned. Experts stress that there are a variety of possible earthly explanations for such observations, from advanced drone technology to software bugs and instrument issues.

Releasing the files will get more eyes on UAP footage, which military officials say is a good thing.

"The materials archived here are unresolved cases, meaning the government is unable to make a definitive determination on the nature of the observed phenomena," the Pentagon wrote on the new UFO files website. "This can occur for a variety of reasons, including a lack of sufficient data, and the Department of War welcomes the application of private-sector analysis, information and expertise."

And there will be more files coming soon, according to that page: "Given the scope of this task, the Department of War will be releasing new materials on a rolling basis as they are discovered and declassified, with tranches posted every few weeks."

Alien Day was this past Sunday (April 26), and to celebrate one of the best sci-fi horror franchises of all time, HBO Max has just added the special editions of the first four Alien movies onto the streaming service.

Founded by 20th Century Fox back in 2016, Alien Day is an honorary occasion for fans to connect with everything "Alien"-related, from movies to comic books to video games. It's aptly named after LV-426, the infamous planetoid that the interstellar towing vessel USCSS Nostromo set down upon to discover the derelict spaceship and its insidious contents in the classic 1979 feature film.

With Disney+/Hulu's "Alien: Earth" working on its second season, a sequel to director Fede Álvarez’s "Alien: Romulus" supposedly in development, and Ridley Scott hinting about a possible follow-up to his "Alien: Covenant," there’s a lot of life left in the 47-year-old franchise. Plus, 2026 marks the official 40th anniversary of director James Cameron's gung-ho second franchise entry, "Aliens."

One fantastic way to revisit the "Alien"-verse today is to leap over to HBO Max, which now has all nine "Alien" films available to stream, including their fun crossovers with the Predator world. But the real allure here is the brood of Director's Cuts, Assembly Cuts, and Extended Editions of the first four "Alien" movies: 1979's "Alien," 1986's "Aliens," 1992's "Alien 3," and 1997's "Alien: Resurrection."

Let's examine what makes each of these alternate versions so special as a proper salute to Alien Day 2026!

"Alien: The Director’s Cut" (2003)

Director Ridley Scott considers his 1979 theatrical cut of "Alien" to be the definitive version of the movie, but this rendition adds a little bit more bite to the Hollywood sensation that kickstarted it all. It's really a very mild recut, and well worth a watch if you're already familiar with the seminal sci-fi film at all.

First and foremost — and our personal favorite addition — is in the scene where Ripley, Dallas, Kane, Lambert, and Ash are trying to translate the repeating transmission emanating from the derelict craft on LV-426. Here, the sound effect for the extraterrestrial message seems more unsettling than in the groaning "voice-like" theatrical release, which underscores Ripley's line in both cuts that it "doesn’t sound like any radio signal I’ve heard." The difference is purely a matter of preference, but we still opt for the sinister repetitive hissing noise in this newer cut.

Secondly, it includes the "egg morphing" scene where Dallas and Brett are discovered cocooned in the xenomorph’s hive deep in the bowels of the Nostromo, and Ripley decides to torch the nest with the flamethrower to put the pair out of their agony.

The Director’s Cut is actually a minute or so shorter than the Theatrical Cut, since Scott and his cinematic instincts had to trim away a few bits to accommodate these five minutes of deleted scenes. It quickens the pace, shortens some slower corridor tracking shots, and gives you one jolting death scene for Dallas and Brett, which answers the question of their ultimate fate after being snatched by the immense insectoid alien.

One absent scene we’ve always been partial to is Kane’s space burial, where his body is ejected out into the cold black void.

"Aliens: Director’s Cut" (1991)

As far as alternate versions of the first four "Alien" movies go, this 1991 tinkered with entry is the most enjoyable of them all, as it adds a full 17 minutes of blistering action and excitement to an already-loaded original Theatrical Cut.

Most notable is the extended sequence at the Hadley’s Hope colony on LV-426 in the beginning that sees Newt's family taking a little weekend cruise out to investigate the derelict craft. In hindsight, this was NOT exactly a great idea for the clan.

Also wedged into this cut is Ripley being told by Carter Burke that her daughter, Amanda, passed away while she was adrift in space before being picked up in the Narcissus escape shuttle by a salvage crew and taken to Gateway Station. We get to see a digital printout featuring an image of Amanda Ripley as a senior citizen and feel the intense emotional reaction her mom has to this sad news.

Our favorite scene in this revised edition is the robotic sentry guns attempting to fend off an encroaching army of xenomorphs as we watch the ammo counters rapidly count down to zero.

Cameron milks this awesome sequence for all its worth, and the adrenaline rush is palpable as those smoking weapons do their best to strike down creeping creatures until the last bullet fires.

Sure, all this meddling does muck up the pacing somewhat, but who cares? We’ll take the longer, bumpier ride anytime!

"Alien 3: The Assembly Cut" (2003)

No "Alien" film is less immune to controversy than this polarizing third entry into the storied franchise. It's notorious for killing off poor Newt and Hicks from the start, and its depressing dankness due to the setting — a remote, prison colony on the hostile world of Fiorina “Fury” 161.

Known for the incessant studio meddling, incomplete screenplay, and insurmountable on-set creative differences, "Alien 3" has been disowned by its now-famous director, David Fischer. This was Fincher’s first feature film, and the severe stress of its production has been well-documented over the years. He obviously had zero involvement in this newer studio-mandated reconstruction.

With that said, the Assembly Cut is the far superior version and tacks on an astonishing 37 minutes of added runtime. It was initially offered in 2003’s deluxe Alien Quadrilogy home video DVD box set. Seven minutes were slashed from the Theatrical Cut, but what new inclusions we’re given — like the extended shuttle recovery scenes on Fury 161 where Charles Dance’s Dr. Clemens roams the bleak beachhead and finds Ripley washed up on the sand — add a ton of atmosphere and context.

This is a case where both versions are imperfect but offer an interesting compare-and-contrast experience to expose how different editorial decisions can make or break a flawed finished film. There are multiple character moments inserted that provide far more backstory, plus a visceral swap-out of the dog being a host vessel for the violent alien birth with a much bloodier ox impregnation scene.

Another significant difference is in Ripley’s sacrificial dive into the molten metal in the finale. In the Theatrical Cut, there’s a disturbing chestburster shot that was reportedly part of a studio-led reshoot, where the Assembly Cut simply has her plunge to her death before the infant’s ugly alien head ever appears. All told, this upgraded remaster feels substantially less disjointed but still quite disturbing.

"Alien Resurrection: Special Edition" (2003)

We have a particular fondness for this fourth entry from French filmmaker Jean-Pierre Jeunet, if only for its weird Euro flair, the superb underrated score by John Frizzell, and that hideous baby hybrid creature known as the Offspring that gets sucked out of the spaceship like a thick sticky meat-shake crying out for help.

Besides a changed opening title sequence depicting what might be xenomorph jaws transforming into a toothy bug, here the cloned Ripley 8 of "Alien Resurrection" has more instances when her mutated strength is on display, and some nice dialogue between her and Winona Ryder’s android character, Call, where Ripley 8 explains her existential thoughts, xenomorph hatred, and faded Newt memories.

This cut was also included in the Alien Quadrilogy release in 2003, but it’s not quite as severe a makeover as "Alien 3" received. At most, we're given roughly seven minutes of bonus screentime that delivers prolonged pieces of character dialogue. It's all nice, but none of it is essential.

But we saved the best for last, as the ending here is altered from Ripley 8 and Call simply looking down from the Betty upon the Earth. Instead, we see them landing on the post-apocalyptic ruins of our home planet to have a quiet sit-down for a spell, as the camera pulls back to reveal the ravaged city of Paris, France.

We may already be signaling other intelligences beyond our solar system, without even trying.

Kunyu City, in the Xinjiang Uygur Autonomous Region of northwest China, hosts huge sprinklers that are irrigating over 1,317 acres (533 hectares) of winter wheat fields on the southern edge of the Taklamakan Desert. Then there's the world's largest cluster of solar farms, a megaproject that covers 235 square miles (639 square kilometers) in Qinghai, China, high on the isolated Tibetan Plateau.

And Earth is dotted with many other humongous, human-made structures like these. To an alien eye, they may be tell-tale signs of intelligent goings-on, betraying our existence and hinting at our capabilities.

Visible signaling

People who want to reach out to E.T. have long recognized the communication potential of such "megastructures." In the nineteenth-century, for example, multiple folks advanced proposals for broadcasting "we're here" messages via visible signaling.

One popular type of proposal involved displaying supposedly meaningful figures on parts of our planet that would be visible from the extraterrestrial target of choice.

In these plans, recalled Douglas Vakoch, president of Messaging Extraterrestrial Intelligence (METI) International in San Francisco, huge diagrams would be etched on large expanses of land here on Earth. For example, a visual representation of a right triangle could be shown, he said, with a square attached to each side of the triangle to illustrate diagrammatically the Pythagorean theorem.

By clearing gargantuan stretches of forest, Vakoch said, such geometrical concepts could be seen by intelligent aliens scanning the sunlit side of the Earth. This intended, symbolic representation of the Pythagorean theorem would be huge enough to be seen from the moon — even by inhabitants of Mars.

Hello, lunarians!

Vakoch said that among the early proponents of displaying pictures to communicate with extraterrestrials was the illustrious mathematician Karl Friedrich Gauss. In 1826, he was credited with suggesting such an approach for communicating with potential lunarians, inhabitants of Earth's moon.

"It was Gauss whose idea of inscribing the Pythagorean theorem in Siberian forests has often been touted as an early proposal for communicating with lunarians, although it's unclear whether Gauss actually said this, or whether it's only attributed to him," Vakoch told Space.com.

Similarly, there were thoughts of perhaps creating large canals in the Sahara Desert filled with kerosene, then torched to flash a similar transmission from the dark side of Earth, the METI expert explained.

Strip malls and data centers

Vakoch's favorite early proponent of interstellar communication is Francis Galton, an English polymath (and, less admirably, the originator of eugenics during the Victorian era). In 1896, Galton published an article in the "Fortnightly Review" called "Intelligible Signals Between Neighbouring Stars."

"Signals have to be devised that are intrinsically intelligible, so that the messages may be deciphered by any intelligent man, or other creature, who has made nearly as much advance in pure and applied science as ourselves," Galton emphasized.

So a bottom line: Are we viewed by other starfolk as a bunch of busy beavers terraforming our own planet while inadvertently waving to other worlds? If we build a big enough strip mall or AI data center, maybe we'll find out.

Spend too long in the "Star Trek" — or indeed "Star Wars" universes — and you might start believing that every alien species is a human being with a few prosthetics glued to their faces. But while this approach certainly makes life easier for filmmakers, it doesn't quite live up to that old Vulcan maxim about "infinite diversity in infinite combinations".

So we reckon Mr Spock would approve of Rocky, Ryan Gosling's extra-terrestrial BFF in "Project Hail Mary", whose five limbs and complete lack of a face make him a rather more unconventional co-star.

Rocky's far from unique in the history of screen sci-fi, so we've rounded up 17 non-homo sapien-adjacent aliens who don't fit the genre's traditional two arms, two legs form.

We've also applied the caveat that entries have to be intelligent, which means no room for creatures like "Forbidden Planet"'s id monster and Cloverfield's New York-trashing guest.

But beyond those stipulations? Our only rule is the weirder the better.

1. Eridians

As seen in: "Project Hail Mary"

It's hard to tell whether Ryland Grace's alien BFF Rocky — so-named for his stone-like complexion — has a front or back, seeing as his five multi-purpose limbs appear to have equal, well, footing.

Perhaps more importantly, Erid's most famous son has no face and no eyes, meaning he instead "sees" the world via a form of echo-location. His mouth/anus can be found on his underside, in a set-up rather reminiscent of a starfish — as such, watching Rocky eat is not recommended for the squeamish.

Related: Sci-fi author Andy Weir explains the astrobiology behind 'Project Hail Mary' (interview)

2. Heptapods

As seen in: "Arrival"

This highly intelligent squid-like species has seven limbs, each containing seven "fingers".

Ambassadors "Abbott" and "Costello" don't appear to have any eyes, but communicate via unpronounceable sounds and a form of ink that creates linguistic pictograms. There's more to their language than initially meets the eye, however, as speaking it can facilitate a non-linear perception of time in its speakers.

Beat that, Duolingo.

3. The 456

As seen in: "Torchwood: Children of Earth"

Named after the radio frequency they use to communicate with Earth, the so-called "456" only appear shrouded in thick mist.

As such, it's hard to get a full handle on their physiology, but it's clear they have three heads and a tendency for flailing around and ejecting extremely noxious green goo from their mouths (or whatever the hell they are).

Worst of all, they like to hook themselves up to human kids to give themselves a chemical high.

4. Medusans

As seen in: "Star Trek"

The super-intelligent Medusans have evolved into non-corporeal entities, formless beings who travel the cosmos as hive minds and can communicate via telepathy. Unfortunately, their appearance is so hideous to ordinary flesh-and-blood creatures that looking at a Medusan is liable to induce madness and death.

A young Medusan named Zero did, however, become part of the USS Protostar crew in "Star Trek: Prodigy", giving themselves a physical presence by occupying a mechanical suit.

5. Starro

As seen in: "The Suicide Squad"

Seeing as it originated in space, it's remarkable how similar Starro looks to a standard Earth-based starfish, albeit with a very big eye at its center. The species is capable of growing to kaiju-like proportions, which is rather problematic as "Starro the Conqueror" is also smart enough to bear a grudge.

As well as dishing out city-smashing destruction with its interchangeable legs, the creature's spores are effectively baby versions of itself, capable of controlling — under Starro's direction, of course — any human they attach themselves to.

6. Rigellians

As seen in: "The Simpsons"

Usually sighted around Halloween, the octopus-like residents of Rigel 7 (e.g Kang and Kodos) have five tentacles (which they use for location), a single giant eye and a mouth that leaks saliva at a disgustingly prodigious rate.

They speak English — or technically Rigellian, which, by coincidence, is identical to English — and require special breathing apparatus to respire on Earth. They can also exchange long protein strands by holding hands, which is a neat trick.

7. Mysterons

As seen in: "Captain Scarlet and the Mysterons"

We've never seen the Mysterons' actual form. Instead, this Mars-based threat to planet Earth reveals its presence by projecting two green rings of light, usually accompanied by that famous, ominous "this is the voice of the Mysterons" catchphrase.

Whatever they look like, the Mysterons do have the ability to "reverse matter" (essentially, they can rebuild anything that's been killed or destroyed), which comes in handy any time you want to cause chaos by unleashing perfect human facsimiles on an unsuspecting world.

8. Spores

As seen in: "Invasion of the Body Snatchers"

Why go to the trouble of building spaceships when you can reach your destination by floating through the cosmos as spores? The Body Snatchers' plan for invading/infesting Earth is elegant in its simplicity, as they simply grow replacement humans in seed pods.

As soon as the original model falls asleep, they're replaced by a mindless pod person — and by the time anyone's noticed something's wrong, it's way too late to do anything about it. Genius.

9. The Thing

As seen in: "The Thing"

Even the Thing itself probably gets a tad surprised when it looks in the mirror, seeing as opportunistic shapeshifting is its favorite hobby. The fact that every single cell can operate as an independent organism makes it notoriously difficult to kill, especially as it has an uncontrollable urge to survive and spread.

Its intelligence is unclear — did the spaceship that crashes in Antarctica at the beginning of the film belong to the Thing, or its unfortunate host? — though the alien seems to have a pretty coherent plan for world domination: consume and destroy.

10. Brain bug

As seen in: "Starship Troopers"

"Brain bugs? Frankly I find the idea of a bug that thinks offensive," says a pundit on Federal Network TV, but he clearly has no idea what he's on about.

Klendathu's legions of arachnid drones and plasma-blasting giant beetles are all under the control of a species of giant arthropods that have somehow evolved into strategic masterminds.

The brain bug's intrinsic ick factor is undeniably high, but using their proboscises to suck thoughts directly from the brains of their unfortunate victims is a pretty neat party trick.

11. Mulefa

As seen in: "His Dark Materials"

Okay, they're not technically aliens — they hail from a parallel Earth much like our own — but the tapir-like Mulefa do fit our criteria of being both intelligent and distinctly non-human.

As well as inventing the wheel — they use seed pods to whiz around their homes — their eyes are capable of seeing dark matter (or Dust) — or as they call it, "Sraf".

12. The Masters

As seen in: "The Tripods"

Three really is the magic number for these wannabe alien overlords — they have three legs, travel around in three-legged vehicles (the eponymous Tripods), and even hail from a planet called Trion.

Appearance-wise, they're effectively heads on tree trunk-like legs, and thrive in hot, dense atmospheres and high gravitational fields.

13. Vashta Nerada

As seen in: "Doctor Who"

These microscopic creatures are pretty harmless on their own, but as soon as they swarm in their billions they're the "piranhas" of the air", and one of the best "Doctor Who" monsters.

Capable of stripping a human body to the bone in seconds — by the time you spot that telltale Vashta Nerada second shadow you're already done for — they have the ability to both reanimate corpses and communicate via neural relays in spacesuits. In other words, they're the tiny micro-organism that could.

14. Symbiotes

As seen in: "Venom"

Without a host, Marvel's Symbiotes (who hail from the planet Klyntar) are little more than sentient oil slicks. But when they latch onto a human (or other animal species), these parasites become something much more.

The Symbiote gets a functioning body, while the pay-off for the host is an impressive smorgasbord of superpowers. That said, the associated drawbacks include a penchant for expressing your inner monologues as very public arguments, and an insatiable urge to eat heads.

15. Mimics

As seen in: "Edge of Tomorrow"

Mimics have the hard-to-pin-down, CG-heavy, tar-like appearance of "Venom"'s Symbiotes, but without the quirky individuality. Instead, like the Arachnid society in "Starship Troopers", the Mimics utilize a hive mind system of government, with the big decisions managed by the so-called Alphas.

The Mimics' crucial USP, however, is that they’ve evolved the ability to transport themselves back in time, which is something of a cheat code in their ongoing war with humanity. It's no match for the power of Tom Cruise, though.

16. The Long One

As seen in: "Slither"

The alien threat in Slither looks like a bloated earthworm, but pure malice lurks beneath that unassuming exterior.

Once it's possessed the unfortunate Grant Grant, the "Long One" turns him into a vessel for propagating his offspring, who go on to infiltrate his fellow townsfolk, and forcibly welcome them into a hive mind with world domination on its mind. Weirdly, however, the worm/Grant hybrid remains dangerously obsessed with Grant's wife, Starla.

17. B'omarr monks

As seen in: "Star Wars"

One of the weirdest creations ever to come out of George Lucas's galaxy far, far away, these monks have voluntarily sacrificed their humanoid form in the name of their religion.

They believe that separating their minds from all physical sensation will bring them enlightenment, so they willingly have their brains removed and placed in nutrient jars. They're carried around by giant mechanical spiders, sometimes seen scuttling through the bowels of Jabba's Palace.

See Rocky is all his glory in "Project Hail Mary", which is in theaters worldwide now.

President Donald Trump has issued a statement that he will instruct the federal government to begin releasing all of its files related to UFOs, or UAP, as they're now known.

Just days after former president Barack Obama told podcast host Brian Tyler Cohen that he saw "no evidence" of alien life or a conspiracy to hide it while in office, Trump took to social media to make the announcement. "Based on the tremendous interest shown, I will be directing the Secretary of War, and other relevant Departments and Agencies, to begin the process of identifying and releasing Government files related to alien and extraterrestrial life, unidentified aerial phenomena (UAP), and unidentified flying objects (UFOs), and any and all information connected to these highly complex, but extremely interesting and important matters," Trump wrote on his Truth Social platform.

While many believers are hailing the announcement as another step toward disclosure, more skeptical observers point out that this is not the first time Trump has made similar promises, nor is it the first time members of the federal government have called for the release of UFO files specifically. Will this finally be the time we learn what alien skeletons are in the U.S. government's closet? Don't count on it.

The move from Trump follows many of the promises his administration campaigned on, including promising greater transparency from the federal government. Trump's administration has even gone so far as to call itself "the most transparent administration in history" in promotional videos on the White House website.

To that end, Trump has previously promised to release U.S. government files about some of the most conspiracy-theory-laden topics out there. Just last year, for example, Trump issued an executive order calling for the release of all of the files the U.S. government has on the assassinations of President John. F. Kennedy and Dr. Martin Luther King, Jr.

In November 2025, Trump also signed into law the Epstein Files Transparency Act, which called for the release of all unclassified records and documents related to Jeffrey Epstein, the financier indicted in 2019 for child sex trafficking.

But longtime observers point out that those moves by Trump came up short in terms of what was promised.

"Even if an official declassification order is issued regarding UAP/UFOs, what we learn from past releases like the JFK files and, more recently, Department of Justice files related to Jeffrey Epstein, is that much of the documentation will likely be released with significant redactions," Micah Hanks, a longtime researcher into the history of UFOs with relation to the U.S. intelligence community, told Space.com. "Further, some of the documentation may still be withheld altogether, based on national security concerns, which we have also observed in past releases."

The U.S. government has routinely blocked the release of documents, images and videos of alleged or reported UFOs due to the fact that releasing them could reveal sensitive capabilities of satellites, aircraft sensors, or other technologies.

The federal government has also declassified and released large tranches of UFO files before. But none of them contained a "smoking gun" that proved the existence of extraterrestrial visitation or that the U.S. government has concealed an alien presence on Earth.

"While the President's announcement is promising for those who have advocated for broader U.S. government transparency on such issues, it remains to be seen whether anything significant will result from this," Hanks said. "And as past releases have shown, we still have every reason to anticipate that the most sensitive information currently held by the U.S. intelligence community will remain secret."

Other skeptics say there could be an ulterior motive behind Trump's announcement. "I'd be delighted if some interesting UFO files get released, especially if those files contain evidence of aliens. It would be a huge step for science and our understanding of the universe," Mick West, a science writer who has published books on how to debunk sensational claims, told Space.com. "However, I suspect this is largely performative."

West said that leaked UFO videos and other historical documents show little more than ambiguous or misinterpreted data, or even the U.S. government's "embarrassing missteps" into researching pseudoscience or paranormal topics.

But many believers and UAP disclosure proponents remain optimistic.

"It would be fantastic if President Trump could provide us with more details on anomalous objects and how they might related to aliens, and I would be delighted to be involved in any further studies related to this topic," Harvard astronomer Avi Loeb said on his YouTube channel. Loeb has previously claimed that interstellar comet 3I/ATLAS could be an alien spaceship visiting our solar system.

Some members of Congress even took to social media to praise Trump's announcement. Representative Anna Paulina Luna (R-Fla.), who chairs the Task Force on the Declassification of Federal Secrets, thanked Trump in a post on X.

"As the Chairwoman of the Task Force that investigates these subjects, we are incredibly grateful for you doing this! I look forward to going through all the footage, photos, and reports with the public!" Luna wrote. The Florida congresswoman has previously stated that she has been shown evidence of interdimensional beings that can "actually operate through the time spaces that we currently have."

But many critics and skeptics are pointing out the timing of Trump's announcement. It coincides not only with Obama's statement about aliens earlier this week, but also with increased scrutiny on the president due to his former ties with Epstein and his appearance in documents in the U.S. Department of Justice's latest release of files related to the indicted sex trafficker.

One such critic, the comedian and talk show host Seth Meyers, called his shot last year. "We're just one Epstein story away from Trump announcing that UFOs are real," Meyers said in July 2025.

It's time to get tactical, as we're taking a look at the more bombastic side of sci-fi this time with our rundown of the ten best sci-fi action movies of all time (according to us, opinions may vary, etc, etc).

Sci-fi is the perfect setting for some bombastic action, as it allows filmmakers to lean into the impossible, crafting scenarios and set-pieces that wouldn't be possible in a movie set in the modern day. You can't just CGI in some aliens getting blown up and call it a day, though — it's all about the stakes, the tension, and the execution.

From epic showdowns to alien-blasting missions to defend the Earth, there's something for everyone here. We only have one rule. Everyone reads to the end; no one quits. Here's our ranking of the best sci-fi action movies of all time.

10. Starship Troopers

Release date: November 7, 1997 | Cast: Casper Van Dien, Denise Richards, Dina Meyer, Neil Patrick Harris | Director: Paul Verhoeven | Rotten Tomatoes: 72% critics / 70% audience

An interstellar war with a race of giant bugs that want to wipe out humanity? Oh, you better believe we want to know more. Starship Troopers sees the soldiers of the United Citizen Federation head to distant planets to destroy the gnarly-looking and incredibly vicious Arachnids and an even more upsetting Brain Bug (that I still can’t get out of my head).

A controversial release in 1997, in part due to its violence, it’s now considered a cult classic, popularized for its satirical view on militarism. And it was director Verhoeven who led the charge, famously behind other sci-fi classics of the 80s/90s, like RoboCop and Total Recall (which we’ll get into later on). No stranger to action, Verhoeven brought to life the book of the same name with a barrage of bug-blasting escapades in the 23rd century.

The result was a bombastic action movie with a dark sense of humour. It's packed with glorious one-liners, enormous battles, and — of course — Verhoeven's signature piece: a gratuitous shower scene to pump up the nudity. Hey, the man knows what he likes. The CGI and special effects hold up to this day, and even three decades on, nothing has really captured the awe-inspiring sense of scale that Starship Troopers managed.

9. Avatar

Release date: December 18, 2009 | Cast: Sam Worthington, Zoe Saldana, Sigourney Weaver, Stephen Lang | Director: James Cameron | Rotten Tomatoes: 81% critics / 82% audience

Maybe a controversial choice here, but the numbers don't lie. Avatar is famously the highest-grossing film ever, and the sequel, Avatar: The Way of Water, joins it in the top three. With Avatar: Fire and Ash on the way and looking to repeat that success, it's clear that people love James Cameron's blue sci-fi extravaganza.

With award-winning effects powered by ground-breaking 3D technology, the action scenes across the world of Pandora are epic. Whether it's Jake Sully and co flying in on their Ikran across vibrant landscapes, or the explosive N’avi versus Machine battles — where our lanky blue humanoids face off against the military descending on their sacred land — Avatar is always a feast for the eyes.

It's not just a pretty face, though; Avatar puts in the groundwork to make you care about its characters and stakes through excellent world-building and masterful pacing that you'd expect from a director of James Cameron's caliber, so by the time the bullets start flying, you're truly invested in the outcome.

8. Akira

Release date: July 16, 1988 | Cast: Mitsuo Iwata, Nozomu Sasaki, Mami Koyama, Taro Ishida | Director: Katsuhiro Otomo | Rotten Tomatoes: 91% critics / 90% audience

A little more leftfield for sci-fi action is the animated cult hit Akira. Biker gang leader Shōtarō Kaneda finds himself trying to help his childhood friend Tetsuo, who gets twisted up in a secret government project and acquires some… unusual abilities.

The only animated movie on our list, it depicts a 2019 Neo-Tokyo, wildly dreamt up from the 1988 release date. History has proven this future wrong (for now), but that doesn't make it any less compelling. There’s rival gang violence, anti-government protests, and dangerous resistance movements that Kaneda finds himself embroiled in.

The vibrant animations, thanks in part to the neon lights of a futuristic Tokyo, are the perfect backdrop to the fight scenes, and the energetic motorbike chases are the stuff of legends. Akira had a huge impact on the world’s view of anime and still brings relevance and inspiration over 30 years on.

7. The Fifth Element

Release date: May 7, 1997 | Cast: Bruce Willis, Milla Jovovich, Gary Oldman, Chris Tucker | Director: Luc Besson | Rotten Tomatoes: 71% critics / 87% audience

Bruce Willis fronts this bizarre and brilliant epic from director Luc Besson (yes, the guy who did Léon: The Professional). Willis plays Korben Dallas, a soldier-turned-cab driver who finds himself an integral part of a world-saving mission when the superhuman Leeloo (Milla Jovovich) drops from the heavens into his cab.

The Fifth Element has such a fantastic sense of style, with gorgeous sci-fi vistas, wacky rubber-faced aliens, and an iconic scenery-chewing bad guy in Gary Oldman's Jean-Baptiste Emanuel Zorg. And who can forget Chris Tucker's "hot, hot, HOT" performance as Ruby Rhod. And then on top of all of that, we've got the top-notch action scenes that you'd expect from a '90s Bruce Willis flick.

It’s over-the-top and kooky sci-fi, but if you’re into that — and we most certainly are — you’ll have a thoroughly enjoyable watch from start to finish. They really did make this one… perfect.

6. Inception

Release date: July 16, 2010 | Cast: Leonardo DiCaprio, Marion Cotillard, Joseph Gordon-Levitt, Tom Hardy | Director: Christopher Nolan | Rotten Tomatoes: 87% critics / 91% audience

In the midst of the Dark Knight trilogy, director Christopher Nolan also took on a mind-bending endeavour that had viewers questioning their grounding in reality. Inception sees Cobb (Leonardo DiCaprio) form a team to infiltrate a CEO’s mind via dream-sharing technology, only for Cobb’s own complicated history to threaten the team's survival.

It's on a slower burn than the other movies on our list, but there’s plenty of mind-bending, physics-defying action throughout Inception; most notably the hotel fight, which sees multiple layers of the dream world converging together as people are "kicked" back into reality. It's a wonderful crescendo of visual effects, action, and stakes, and the iconic, ambiguous ending is just the cherry on top of this Nolan classic.

5. Total Recall

Release date: June 1, 1990 | Cast: Arnold Schwarzenegger, Sharon Stone, Michael Ironside | Director: Paul Verhoeven | Rotten Tomatoes: 81% critics, 79% audience

Another of Verhoeven’s sci-fi successes and one of my favourite sci-fi movies of all time, Total Recall (the original, not the remake) is a slice of sci-fi action gold. It uses an excellent blend of practical effects and CGI to deliver a movie that feels of its time, sure, but also pulpy and real in a way that movies seem to have forgotten.

Arnold Schwarzenegger is Douglas Quaid, an ordinary man who signs up for a virtual vacation via an implanted memory of an adventure on Mars. Things quickly unravel when it turns out that Quaid has already been to Mars, and he quickly ends up embroiled in a manhunt that sends him back to the red planet.

Schwarzenegger delivers his trademark late 80s action and some truly iconic one-liners as Quaid uncovers a corporate conspiracy and battles against an array of villains, including his fake wife. Even 35 years on, it's an effortlessly enjoyable sci-fi action flick that others have topped. As Schwarzenegger himself put it: “Get your ass to Mars”.

4. Edge of Tomorrow

Release date: June 6, 2014 | Cast: Tom Cruise, Emily Blunt, Bill Paxton, Brendan Gleeson | Director: Doug Liman | Rotten Tomatoes: 91% critics / 90% audience

As the face of the Mission Impossible series, Tom Cruise is no stranger to the action genre, but he's also a dab hand at sci-fi with hits like Minority Report and, our favorite, Edge of Tomorrow.

As Major William Cage, Cruise plays an army public relations officer who finds himself up on the frontlines of war for humanity's survival against a vicious race of invading aliens known as ‘Mimics’. Cage dies only to discover that he's now stuck in a time loop that throws him back to before the battle starts.

Fortunately, he doesn’t have to do all this alone, and he’s joined by legendary warrior Rita Vrataski (Emily Blunt), who was previously stuck in the same time loop. It's basically the sci-fi action version of Groundhog Day, and the time loop allows for Cruise's character to grow even as the world around him repeats. Each loop, Cage learns a little bit more and gets a little bit closer to his goal. All he has to do is live, die, repeat.

3. Terminator 2: Judgment Day

Release date: July 3, 1991 | Cast: Arnold Schwarzenegger, Linda Hamilton, Robert Patrick | Director: James Cameron | Rotten Tomatoes: 91% critics / 95% audience

Oh, you can already hear that theme music, can't you? Dundun Dun Dundun! Terminator 2: Judgment Day is arguably the best sci-fi sequel of all time (we'll get to the other contender to that throne in a second). Set about 10 years after the original, Terminator 2: Judgment Day sees the return of Arnie as a T-800, but this time around, he's a reformed Terminator set on a mission to protect John Connor.

Unsurprisingly, that mission leads to a plethora of bombastic action scenes as they battle against the shape-shifting T-1000 (Robert Patrick). Terminator 2 has it all, with choreographed punch-ups and intense shootouts proving that Schwarzenegger really was the king of 80s action movies. And who could forget that chase scene down the canal?

Beyond all that, though, Terminator 2: Judgment Day understands when to slow things down. It's paced to perfection, with the final face-off between the two Terminators becoming a game of cat and mouse that echoes the ending of the original (albeit a lot hotter). It gets a slowly descending thumbs up from us.

Related: Terminator movies ranked

2. The Matrix

Release date: March 31, 1999 | Cast: Keanu Reeves, Carrie-Anne Moss, Laurence Fishburne, Hugo Weaving | Director: Lily & Lana Wachowski | Rotten Tomatoes: 83% critics / 85% audience

We may not know kung-fu, but we do know that The Matrix is one of the best sci-fi movies of all time. The story follows Neo (Keanu Reeves), a hacker who discovers that the world is not as it seems, leading him down the rabbit hole and into the Matrix.

What follows is one of the slickest, most stylish, and most late 90s-coded action movies of all time. It's a masterful blend of impeccable, choreographed martial arts, slow-motion bullet time gunfights, and physics-defying stunts. Joined by Trinity (Carrie-Anne Moss) and Morpheus (Laurence Fishburne), the trio battles against the sinister machine forces, led by Agent Smith (Hugo Weaving), as they battle for survival and try to figure out if Neo is The One.

The visual effects, acting, choreography, and story are all just… perfect, and with the unique directorial style of the Wachowski sisters thrown into the mix, we ended up with one of the greatest action movies of all time.

1. Aliens

Release date: July 18, 1986 | Cast: Sigourney Weaver, Michael Biehn, Carrie Henn, Paul Reiser | Director: James Cameron | Rotten Tomatoes: 94% critics / 94% audience

It had to be. Much like Cameron’s Terminator 2: Judgment Day, Aliens is the other contender to the best sequel ever throne, and another rare sequel that is arguably better than the original (though that one's hotly debated).

Ellen Ripley (Sigourney Weaver) returns decades after surviving the deadly incident on the Nostromo, trying to lead a normal life and forget about her extraterrestrial encounter. But, when a colony on LV-426 — the planet Ripley first found the xenomorph on — goes dark, she gets roped into joining a crack team of marines to mount a rescue mission.

That spicy little "s" on the end of the title tells you everything you need to know about this sci-fi action masterpiece. It's not one alien this time; it's a whole nest of them, complete with a hulking great queen. The marines' macho facade quickly fades as they're turned into an alien all-you-can-eat buffet cart, slowly being picked off despite their "state of the badass art" firepower.

The action is more claustrophobic than most entries on this list. It's less grand battles and more frantically firing pulse rifles down dark corridors, the muzzle flashes illuminating the increasingly terrified faces, the iconic pulse rifle sound mixing in the air with the screeches of dying xenomorphs. Add the epic soundtrack to that cacophony, and you get — in our humble opinion — the best sci-fi action movie of all time.

We could say more, but they ain't paying us by the hour, so saddle up and go watch Aliens. You won't regret it.

The search for life beyond Earth is one of the most profound quests in human history. It began not in laboratories, but in the minds of ancient stargazers who imagined other worlds teeming with beings like — or unlike — us.

Over centuries, this curiosity evolved into a scientific pursuit, blending astronomy, biology, chemistry, and philosophy into a single, thrilling endeavor: to find life elsewhere in the cosmos.

From Galileo's telescope to the James Webb Space Telescope, each technological leap has brought us closer to answering that age-old question. We've sent probes to Mars, listened for alien signals through SETI, and discovered thousands of exoplanets orbiting distant stars. Along the way, we've refined our understanding of what life is, how it might arise, and where it could thrive — even in the most extreme environments.

This quiz explores the milestones, theories, and missions that have defined the search for extraterrestrial life.

Whether you're a space science enthusiast or just curious about the universe's biggest mystery, this challenge will stretch your mind across time and space.

Try it out below and see how well you score!

For as long as humans have looked up at the night sky, we've wondered who, or what, might be looking back.

From ancient myths about gods descending from the heavens to 20th-century UFO sightings and today's hunt for exoplanets, the question of whether we are alone in the universe has never stopped captivating us. From microbial fossils on Mars to interstellar comets to mysterious signals in deep space, there is a timeless curiosity around extraterrestrials.

Journalist Becky Ferreira dives into this rich history in her new book "First Contact: The Story of Our Obsession with Aliens" (Workman Publishing, 2025). In a conversation with Space.com, Ferreira discusses the myths that shape our understanding of aliens (her newsletter dives into this further) and why real contact might look nothing like what Hollywood has taught us to expect.

Space.com: There are a lot of books about aliens out there. What made you want to add your perspectives to this tradition? 

Becky Ferreira: My editor for this book approached me with the idea, and when I saw it, I thought, "Oh aren't there so many alien books already?" But I should have known as a reporter that it's an inexhaustible subject.

For me, it also felt like the right time. There’s so much happening in the scientific search for alien life, but also more openness toward the UFO community and a posture of transparency from the government. I wanted the book to touch all those sides — the science, the pop culture, the history — and to do it in a short, visual, and kind of snarky way that invites people in.

Space.com: What is an alien trope you are tired of?

Ferreira: I love this question! Definitely the Messianic alien. And I’m sorry to the Superman fans! I like the new "Superman" movie, but I’m tired of stories where a superpowered being comes down to save humanity from itself. It’s not just aliens — it’s part of this larger myth we have that someone else will fix everything for us.

That idea goes way back — it’s basically a modern version of waiting for the gods, or the rapture. But I think it’s dangerous because it teaches us to wait for salvation instead of taking action ourselves.

I’d love to see more Robin Hood-type stories, where regular people, not superheroes, actually organize and make change for themselves. We need narratives that empower us, not ones that make us dependent on alien saviors.

Space.com: On the flip side, what kind of alien tropes would you like to see more of?

Ferreira: I love the truly strange aliens — stories like "Solaris" or "Arrival," where you have to completely rethink how you perceive the universe. Those stories feel more realistic to me, because if we do encounter intelligent life, it probably won’t think like us at all.

I’m fascinated by the idea of aliens who have a worldview that’s totally different, maybe even impossible for us to fully understand. Like the heptapods in "Arrival," who experience time all at once — that’s such a wild concept.

And honestly, I’d love to see more stories about microbes. What if we found a fossilized microbe on Mars that’s four billion years old? It’s tiny, it’s dead, it’s not a civilization — but it would completely change how we see life in the universe. Pop culture hasn’t really processed how monumental that kind of discovery would be.

Space.com: What is something you wanted to include in the book but couldn't due to narrative constraints or word limits? 

Ferreira: I finished the manuscript in January 2025, and of course all these fascinating discoveries happened right after — new exoplanet biosignatures, possible biosignatures on Mars.

There’s also a section on the rights of aliens that I wish I could have expanded. Like, what are the legal rights of a microbe on Mars? That sounds silly, but it’s actually a really important question. We’re doing all these astrobiological projects, and at some point we’ll have to decide how to treat what we find. You could write a whole book just about that.

Space.com: One of the hottest topics right now is Comet 3I/ATLAS, the newfound interstellar comet. You wrote about 'Oumuamua in your book — what do you make of this new one?

Ferreira: I think it’s the coolest thing ever! I couldn’t include it because of timing, but I’ve been obsessed. I love that we’re in an age where we can detect these interstellar objects at all. And with the Vera Rubin Observatory active I think by the end of the decade, we’ll have a whole census of them.

What’s exciting about 3I/ATLAS is that it’s like a time capsule — a piece of another star system passing through ours. Some scientists have even suggested it could be older than the solar system, which is wild. These are literal visitors from other worlds, and they help us see beyond our neighborhood. It’s like the universe is delivering us souvenirs from deep time.

Space.com:  If you could tell the public one thing about aliens — to clear up misconceptions or reframe the conversation — what would it be?

Ferreira: That our conception of aliens is human. I know that sounds obvious, but it’s so important. Aliens mean different things to different people, but the fascination itself is universal. Every culture has some story about beings from the sky — it’s part of who we are.

For people skeptical of UFOs, I get that — I used to be, too. But when I was researching this book, I realized a lot of those accounts are very persuasive. That doesn’t mean they’re extraterrestrial, but something happened. And I think it’s great that we’re finally talking about it without stigma.

For people skeptical of NASA or the government, I’d say: those institutions have extremely high standards for what counts as evidence. I don’t think they’re being secretive — they’re just careful. We’re all profoundly obsessed with aliens, but we need to give each other a little grace for what that means.

Because if we do ever find life out there, it’s going to change everything — spiritually, culturally, scientifically. And we’ll need everyone, skeptics and believers alike, to help us understand what that means for our place in the cosmos.

This article was originally published at The Conversation. The publication contributed the article to Space.com's Expert Voices: Op-Ed & Insights.

The TV series Alien:Earth has introduced a number of new creatures to the much loved, albeit terrifying, Alien franchise.

But how realistic are the new aliens? That's a question that we – a trio of scientists who are also great fans of the franchise and show – have tried to tackle with a ranking. To be clear, we are not trying to find flaws in the show. Like many fans we are simply having fun using science to analyze the creatures.

All species in the series draw inspiration from real living organisms and processes seen on Earth, but crank it up to the extreme. We therefore won't explore all those parallels, but instead focus on how plausible the organisms are in terms of underlying processes such as physics, chemistry, metabolism and evolution.

1. The tick

Our most plausible creature is the large blood-sucking tick. On Earth, the deer tick Ixodes do swell to the size of a walnut when feeding, which is not too different from the Alien:Earth tick. In the show, we see it attack the jugular and quickly take on a couple of pints of blood.

The perhaps surprisingly quick death of the unfortunate prey most likely results from hemorrhagic shock due to how quickly the blood is lost. It is possible that some sort of chemical agent (perhaps an anticoagulant, as has repeatedly evolved in blood predators on Earth) is also injected. We do see a defence mechanism in episode five where the ticks release an airborne toxin to prevent them being removed from their host. Chemical defenses like poisons and venom are common in animals and plants on Earth to deter predators.

In later episodes, we see it break containment (with the help of another alien) but we’ll assume it is simply seeking a body of water to lay its tadpoles in, rather than exhibiting intelligence. Horrifically, we see nothing that completely prohibits a life form like this.

2. D. plumbicare (the plant pod)

This creature, which as discovered and named in the show by the crew of the USCSS Maginot, benefits from not having been seen much (at the stage of writing, we have viewed the first six episodes). As the series progresses, it could move down our list. Initially, the character Kirsh questions whether it is flora or fauna. The science officer's analysis ultimately shows they classify it as a carnivorous plant. Its green color could indicate it also uses chlorophyll the way photosynthetic organisms like plants do on Earth.

However, a near spherical body is in fact the worst structure for photosynthesis. It lacks any of the surface area enhancing adaptations you’d expect from a photosynthetic organism, such as leaves. This would be particularly important given it appears to hang underneath covering structures like cave roofs. Perhaps this is why it needs to capture prey: rather than evolving more efficient light capturing mechanisms, it instead alternates between photosynthesis and predation, depending on the resources available.

This is known as mixotrophy in science, but is a feature only of single-cell organisms on Earth. "Carnivorous" plants are not mixotrophs as they merely source compounds like nitrates, potassium and phosphorus from captured insects, rather than carbohydrates. Animals are heterotrophic, meaning they get energy by consuming other organisms.

Some organisms, such as corals, have bacterial symbiotes – "friendly" parasites – that can photosynthesize energy for them from the sun, which could be the case here.

3. Trypanohyncha ocellus

T. ocellus is the lovable little eyeball octopus parasite. It attacks its host, removing an eyeball and then takes over entirely via connections to the brain.

This may seem like pure science fiction, but there are parasites on Earth that replace body parts and even control their host's behavior. However, the latter are usually relatively simple organisms, like the Ophiocordyceps fungus where taking over the brain of another animal is a necessary part of their life cycle. The behavioral changes these parasites induce are simple, such as moving the host towards light, water or the scent of a predator.

Toxoplasma gondii, for example, is a parasite that alters the behavior of mice, making them less avoidant of the smell of cat urine. The infected mice are therefore more likely to be eaten by cats, which then spread long-lasting parasite spores in their feces.

T. ocellus, in contrast, is very mobile, highly intelligent and strong, showing behavior like monitoring situations and distracting humans. This behavior is plausible with distributed ganglia (clusters of nerve cells) in the tentacles, similar to octopuses.

The length of these tentacles, however, exceeds that of similar structures on Earth, such as chameleon tongues, and is therefore somewhat implausible (but nevertheless incredibly cool). Our main issue here is why it needs to be parasitic at all – this is ultimately a formidable life form without requiring that.

4. The fly

First seen in episode 6, the fly appears to consume metal and metal ores and it pre-digests its food by spitting an enzyme, similar to flies on earth. Our main issue with it is that it's unclear whether this is a supplement (such as iron and other trace elements in our diet) or a main energy source.

There is a process on Earth known as chemolithotrophy (literally "rock eating") in which energy and biomass production can be harnessed by oxidation (removal of electrons from) of geochemicals – including iron, manganese and other metals.

On Earth, this is exclusive to single celled archaea such as Ferroplasma and bacteria such as Acidithiobacillus, organisms generally associated with very slow growth. Multicellularity is energetically demanding, not to mention flying, meaning metal oxidation is not a very plausible energy source for the fly.

Of course, the metal could simply be a supplement, albeit a very large one, needed to create a metallic shell. Biomineralization of iron compounds into the teeth of marine molluscs like chitons and limpets, who need hard teeth graze on rocky surfaces, is well documented. A similar mechanism could explain the hard metals in the Xenomorph's exoskeleton (which it needs to be able to scratch through the metal in a ship's hull).

5. The Xenomorph

The Xenomorph might come in at the bottom of this plausibility ranking, but it takes the top spot in our hearts/chests. The main problem with it is its impossibly fast growth rate, transitioning from a relatively small chest-burster to a fully grown adult in a very short period of time.

Very crudely, if we assume it has a similar metabolic efficiency to humans, and that it weighs roughly 100 kg, then it would need to consume and convert millions of calories of food (over a ton of pork-like meat) in what seems to be a few days at most. Of course, it could have a much higher metabolic efficiency than humans, though it would always be bound by the conservation of mass and energy. You can't acquire more biomass than you consume. And we never see it eat, not even its initial host.

Circumventing this would require an ultra dense (entirely hypothetical) energy source that it carries with it from the egg (Ovomorph). But energy has to enter the system at some point, implying the Queen would have to eat or capture huge amounts of energy somehow.

Another issue for the Xenomorph is that, if it did need to eat the huge amount of creatures it kills, it would rapidly deplete any prey resource and there would probably be no stable ecosystem that could support it. However, in the expanded universe, it seems that the Xenomorphs are artificial beings, created from a bio-weapon intended to obliterate an ecosystem, leaving a clean slate. In which case, they seem very effective.

This article is republished from The Conversation under a Creative Commons license. Read the original article.

A new study argues that conditions necessary for intelligent extraterrestrial life may be far less common than once thought.

Planets lacking plate tectonics and sufficient carbon dioxide and oxygen could make advanced civilizations like ours extremely rare, Manuel Scherf and Helmut Lammer of the Austrian Academy of Sciences suggested during a presentation at the Europlanet Science Congress and the Division for Planetary Science (EPSC-DPS) in Helsinki earlier this month.

According to their research, for a biosphere to persist long enough to allow for the evolution of complex life and subsequent advanced technology, an Earth-like planet needs to meet certain criteria.

First, there must be enough carbon dioxide to sustain photosynthesis and prevent atmospheric escape — but not too much that the atmosphere becomes toxic or traps too much heat. The key to this balance is plate tectonics, which regulate the amount of atmospheric carbon dioxide via the carbon-silicate cycle.

But plate tectonics won't maintain the biosphere forever. "At some point, enough carbon dioxide will be drawn from the atmosphere so that photosynthesis will stop working. For the Earth, that's expected to happen in about 200 million to roughly one billion years," Scherf said in a statement. Thus, a planet would also need a life-sustaining biosphere that lasts longer than the time it takes for technologically intelligent life to evolve. On Earth, that evolution took 4.5 billion years.

Second, a world must have a nitrogen-oxygen dominant atmosphere to develop an advanced civilization. Oxygen, in particular, is crucial not only for biology but also for technological advancement. For example, levels below about 18% oxygen could prevent the use of fire, which historically has been essential for metalworking and thus the development of advanced tools.

The team created models to compare the lifespans of biospheres with various atmospheric compositions to the amount of time it might take advanced civilizations to evolve. They concluded that if an advanced technological civilization were to exist in our Milky Way galaxy, the closest it would be to Earth is likely about 33,000 light-years away. Such a civilization would also have to survive for at least 280,000 years — and possibly much longer — for there to be any chance it overlaps with ours in time.

In other words, the odds are very slim that we coexist with another intelligent civilization in the Milky Way.

Despite the grim outlook, the authors encourage continued efforts, especially through SETI (the search for extraterrestrial intelligence). "Although ETIs [extraterrestrial intelligences] might be rare, there is only one way to really find out, and that is by searching for it," said Scherf. "If these searches find nothing, it makes our theory more likely, and if SETI does find something, then it will be one of the biggest scientific breakthroughs ever achieved, as we would know that we are not alone in the universe."

Fiction, by its very definition, isn't real. A character can have an entire lifetime of backstory, the politics and geography of their made-up homeworld a matter of record, but none of it would exist if writers, actors, artists and other creatives hadn't imagined it first. Pretend a pivotal moment from their past never happened, and history isn't actually being rewritten. A hero isn't going to sue anyone for defamation if they're suddenly reappraised as a villain.

Yet it sometimes feels as if sci-fi and fantasy "canon" in sci-fi and fantasy is the most sacred of sacred cows. Movies and TV shows frequently tie themselves in knots trying to avoid contradicting throwaway lines of dialogue uttered decades earlier. Fans — and I'll admit I've been as guilty of this as anyone — have always been happy to flag up inconsistencies in franchise lore, while the Marvel Cinematic Universe has built its entire brand on labyrinthine continuity. Lucasfilm even employs its own "Keeper of the Holocron" to stay on top of the vast timeline of a galaxy far, far away.

But while consistency is undoubtedly important, it shouldn't come at the expense of good stories. "Alien: Earth" showrunner Noah Hawley and the rest of the creative team seem to have realized this, as the show has adopted a much looser approach to canon than most of its genre counterparts.

The show is set just two years before the USCSS Nostromo crew touched down on LV-426, and brought something very nasty on board. However, "Alien: Earth" never worries about the fact that the catastrophic crash of the USCSS Maginot — as well as Prodigy and the three other non-Weyland-Yutani corporations ruling the world — have never been mentioned before. Nor does it get hung up on its unlikely chronology, or get sidetracked by the events of the Prometheus and Covenant missions that departed a few decades prior. The multipurpose black goo that displayed magical properties in Ridley Scott's prequel movies is, so far, conspicuous by its absence

Instead we've been introduced to a whole new ecosystem featuring acid-spewing bugs, and a freaky, parasitic eye on legs that may just be orchestrating the whole show. After being retconned as the result of a malevolent android's morally dubious experiments in "Covenant", the Xenomorph is — for now, at least — back to being a more evolution-adjacent apex predator.

Crucially, Alien: Earth has kept the key pillars that helped make "Alien" and "Aliens" all-time classics — the eggs, the Facehuggers, the acid for blood— and treated everything else as malleable. Other sci-fi sagas should probably take note.

Canon as we know it is a relatively new concept. When "Doctor Who" and "Star Trek" debuted in the 1960s, even the most forward-thinking writers would never have dreamed their ideas would still be impacting popular culture six decades later. There was no grand plan for the future — the Doctor wasn't revealed to be a Time Lord until the show was six years old — and the creatives were often making things up as they went. "Who" continuity remains a notoriously nebulous concept.

And despite George Lucas's earlier plans for the "Journal of the Whills", the original "Star Wars" trilogy was effectively a blank slate, in which he was free to tell any story he wanted. Even the prequels had minimal existing lore to dodge, with the numerous novels, comics and cartoons of the Expanded Universe occupying lower tiers of canon — pre-Disney, only the movies (and, to a lesser extent, the CG "Clone Wars") were gospel.

Even so, Lucas's reliance on the "from a certain point of view" principle still managed to wind up a significant portion of the fanbase. Why would Obi-Wan describe Yoda as "the Jedi Master who instructed me" if Qui-Gon Jinn was his teacher? How did Princess Leia remember her mom if Padmé died when she was just a few minutes old?But canon's a minor inconvenience when you're only dealing with a few movies. It's when you move into vast multimedia empires, straddling numerous interconnected films,TV shows, books, comics and cameos in "Fortnite" that it becomes a potential stumbling block.

Firstly, there's the heritage factor, as "Star Wars", "Star Trek", "Doctor Who" and every other legacy franchise have decided that nostalgia is their not-so-secret weapon. Often the impact is minimal — bringing one-off "Star Trek" character Roger Korby into prequel show "Strange New Worlds", for example — but leaning into existing canon can sometimes be a plotline's entire raison d'être.

Han Solo's sub-12 parsec Kessel Run was a casual, slightly nonsensical aside until it became a major set piece in "Solo: A Star Wars Story". Meanwhile, Omega (the Big Bad in the most recent "Doctor Who" finale) hadn't appeared on screen since 1983 Fifth Doctor story "Arc of Infinity" — a deep cut for all but the most hardcore of fans.

Much worse, however, is persisting with plotlines that don't work. Few TV shows get everything right from day one, and any long-running series will have — in fact, should have — some less successful stories in the back catalogue. It shows that they're trying to push the envelope, rather than just sticking to a formula.

Sometimes a franchise can make a minor course correction — the Leslie Knope of "Parks and Recreation"'s second season was subtly different to the Leslie Knope of the first — but other times it's best to just hold up your hands and consign an idea to the trash.

This is why we're unlikely to ever see anyone following in Tom Paris and Kathryn Janeway's footsteps by breaking the warp-10 barrier and turning into giant lizards, as they did in the infamous "Star Trek: Voyager" episode "Threshold". Writer Brannon Braga later described the story as a "royal, steaming stinker" and it was rumored to have been excised from canon. For similar reasons, the revelation that the Doctor is half-human on his mother's side has been conveniently brushed under the carpet since its one and only mention in the 1996 "Doctor Who" TV movie.

Arguably the smartest thing about "Alien: Earth" is the way Hawley's been picky about the essentials. Even the franchise's most strident fans would probably admit there hasn't been a significant addition to Xenomorph mythology since the Alien Queen reared her ugly head in "Aliens", four decades ago. But the decision to turn the TV show into a drama about child androids, feuding corporations and — crucially — an all-new menagerie of bizarre "Thing"-inspired fauna has given a 46-year-old saga a new lease of life, rather less reliant on its eponymous star beast — even Ridley Scott admitted after "Covenant"'s disappointing box office performance that, "I think the beast has almost run out, personally."

Cleverest of all, "Alien: Earth" has followed its path without (as yet) directly contradicting anything that's gone before, instead being selective about what to include and what to ignore. Anything that didn't make the cut? Well, maybe that's happening in a distant star system, on the other end of a lengthy voyage in hypersleep. (Or maybe it didn't happen at all.)

"Star Wars", "Star Trek", "Doctor Who" and the rest should all be watching with interest, because when you've got one eye on the past — even a freaky alien one with legs — it's hard to truly embrace the future. And besides, none of it is real anyway.

The final episode of "Alien: Earth"'s first season streams on Disney+ starting Wednesday Sept. 24.

How can the U.S. government restore public trust regarding unidentified anomalous phenomena (UAP) through transparency and offering whistleblower protections?

That was the core, mind-boggling question behind a Sept. 9 congressional House of Representatives hearing, held by the Task Force on the Declassification of Federal Secrets.

Representative Anna Paulina Luna (R-FL) is chair of that task force, swearing in witnesses that under oath discussed their experiences and knowledge about UAPs, a rebranded term attached, deserved or not, to unidentified flying objects (UFOs), as well as unidentified objects or phenomena in Earth's bodies of water or space.

Secrecy, stigma, dismissal

For too long, UAPs have been "shrouded in secrecy, stigma, and in some cases outright dismissal," Luna said in her opening statement.

"Today, I want to state clearly: this is not science fiction or creating speculation. This is about national security, government accountability, and the American people's right to the truth," said Luna. "Future generations will look back on this moment and ask what we did when presented with the unknown. Did we look away, embarrassed or afraid? Or did we pursue the truth with courage? I intend to be on the side of truth, transparency, and accountability," the lawmaker stated.

A transcript of the hearing and witnesses' prepared testimonies can be read on the U.S. House of Representatives' website.

Space.com asked several experts from leading research groups on UAPs/UFOs concerning the hearing and their take-away thoughts.

Wanted: nitty-gritty details

"The military witness reports were very good," said Robert Powell, executive board member of the Scientific Coalition for UAP Studies in Austin, Texas.

While it may not be apparent to the public or congress, Powell said that anyone who has studied the history of the subject knows that there have been hundreds of such reports by military witnesses that are equally as good.

So how do we move forward?

"Unless Congress is willing to push for the nitty-gritty details" by obtaining full videos, interviewing pilots involved in UAP incidents, and other reported events, "we will not progress," said Powell.

Powell said, in his view, the military will never release the necessary information to establish the presence of a non-human intelligence.

"That's because of their concerns for national security and whether one of our adversaries might learn something from UAP that they could use militarily against us," Powell said. "The resulting tendency to silo all information on UAP prevents moving forward with learning more. Only if Congress allocates funding to the scientific community and academia to study UAP will we make any progress," he concluded.

Science above all

"I find it frustrating that they, rightly, reiterate the importance of the role science can take in figuring out what is behind UAP, but do not apply it in these hearings."

That's the outlook from Alejandro Rojas, a long-time UFO journalist and a consultant to Enigma, a UAP/UFO sightings alert network.

"We have years of anecdotal sighting reports and claims of hidden government knowledge about alien visitation. What we need is evidence," Rojas said.

Rojas added that he found it also trying that the one organization that has been using science, the Pentagon's All-domain Anomaly Resolution Office (AARO), was pummeled in the hearing, without being represented.

"Having worked in the UFO field for so long, I am sympathetic to their [AARO's] effort. They have shown each step of their work analyzing previous videos, and although it is unpopular to demystify some of these reports, their scientific analyses have been sound," he said.

Preconceived notions

At the recent hearing, "the gripes of committee members came across as being frustrated with the organization that is using science and coming up with answers," sensed Rojas. "However, because they dislike the answers, they blame AARO, when in fact they genuinely do not want scientific analysis to dismantle their preconceived notions."

In the end, Rojas found the hearing disheartening.

"Instead of focusing on real issues and truly championing scientific investigation, the hearing comes across as a very political back-and-forth between the Oversight Committee and the Pentagon," said Rojas. "What gets lost is what we actually need, and that is data gathering and scientific evaluation of that data."

As a consultant with Enigma, Rojas said the group is collecting hundreds of reports, many with videos.

"What we need is a robust, transparent effort to analyze what we are collecting, and to build better sensor systems to gather more and better data on UAP," said Rojas. "If extraterrestrials are visiting us, it is not just the military that would be seeing them."

Credible and intriguing

Avi Loeb, head of the Galileo Project at Harvard, and director of the Institute for Theory & Computation, said he found the first-hand testimonies at the hearing "to be credible and intriguing."

Loeb's Galileo Project is an endeavor to bring the search for extraterrestrial technological signatures of other star folk from "accidental or anecdotal observations and legends" to the mainstream of crystal-clear, confirmed and systematic scientific research.

"I salute congresswoman Luna for chairing this important discussion within the Task Force on the Declassification of Federal Secrets in the U.S. Congress," Loeb said.

But does such a congressional hearing restore public interest in UAP?

"This discussion is not a matter of public relations in a popularity contest, but instead a topic of great relevance for national security and science," responded Loeb. "Once we all see credible evidence about the nature of UAP, we will be able to get to the bottom of it and everyone would agree on what it means."

Best path to new knowledge

Data collection is the goal of the Galileo Project under Loeb's leadership.

Does the astrophysicist believe that the U.S. government is hiding information? He replied that "as a scientist I respond to evidence and not to what people tell me. Scientific evidence is our best path to new knowledge."

The simplest way to tell the difference between a dogmatist and a genuine scientist, Loeb said, is to flood both of them with scientific-quality data.

"Whereas the dogmatist will shove anomalous data under the carpet of traditional thinking, an open-minded scientist will be thrilled to learn something new with an underlying sense of humility," advised Loeb. "Not only is nature more imaginative than we are, but it also does not care whether we figure it out. The insistence that everything in the sky is either icy rocks or human-made technologies will not rid us of cosmic neighbors, if they exist out there," he concluded.

Tone and testimony

"Overall, I was pleased with the tone and testimony in the hearing from the witnesses, and the often excellent questions from the Representatives," said Mark Rodeghier, president and scientific director of the Center for UFO Studies in Chicago, Illinois.

"The hearing hopefully provided more impetus to pass the crucial legislation necessary to answer questions we have about possible US government/contractor involvement with UAP that has been hidden all these years," said Rodeghier.

Rodeghier said the witnesses added additional experiences on the record of both UAP sightings and how the aftermath of those has been handled by the military, including treatment of those wishing to speak publicly.

Crucial legislation

Beyond moving Congress to pass the bills, Rodeghier advised getting witnesses into a SCIF, short for Sensitive Compartmented Information Facility. Located several levels beneath the U.S. Capitol, a SCIF is where lawmakers and witnesses hold closed interviews, far from the prying eyes of the public.

"I'm not sure what can be done with it [those interviews], but having it available is important," said Rodeghier.

Another Rodeghier recommendation is to have the head of AARO in a hearing this fall now that he has been on the job for a year. Lastly, there's need to work on getting the appropriate government agencies to provide modest funding for UAP research, which continues to be unavailable, he said.

Deep difficulties

Michael Cifone is the founding executive director of the Society for UAP Studies, based in Los Angeles, California. The group's mission is not to promote a single narrative but to advance careful scholarship, develop educational frameworks, and advocate for standards of evidence and data transparency.

The recent Congressional hearing on UAPs underscored, once again, "both the importance of the issue and the deep difficulties that have hampered its treatment for decades," said Cifone.

That handling of the topic within the government — whose aim since at least after World War II has been increasingly obsessed with national security and maintaining US military and strategic dominance, feels Cifone, "are guiding principles that are ultimately at odds with the inner operating directives of the sciences themselves: free, open, and therefore democratic exploration of self and world."

Mixed pool

"The UAP problem is not a mystery with one answer, but rather a somewhat unstable and chaotic amalgam of many overlapping realities, complicated by the unfortunate facts of the modern bureaucratic national security state," is a view that Cifone basically endorses.

"UAP reports are not a monolith," Cifone advised.

Instead, they are a mixed pool consisting of: (1) misidentified U.S. black projects, where cutting-edge aerospace programs are understandably shrouded in secrecy; (2) adversarial drones and surveillance platforms, which represent a genuine national security challenge; (3) a large number of ordinary misperceptions of balloons, satellites, or atmospheric phenomena; and (4) a small but stubborn residue of anomalous cases that resist explanation.

"This mixture makes the phenomenon difficult to study, not because of some grand cover-up, but because of the dysfunctional way information is handled inside the government," Cifone said.

Are we up to the task?

The UAP hearing, for all its frustrations, said Cifone, "at least signaled that Congress is beginning to take seriously the structural problems that have long clouded this issue."

From a safety standpoint, the "mixture hypothesis" is particularly important, said Cifone. If even a fraction of UAP reports involve advanced adversarial drones or unsafe incursions into U.S. airspace, then society is faced with an aviation and national security challenge that demands systematic response, he said.

"Let's see what data and frameworks we can establish that can handle UAP and associated phenomena/claims, and what philosophical/conceptual challenges remain, and if we're up to the task," Cifone said.

And for the other claims — crashes, bodies, and so on, Cifone concludes, "sure, but where's the beef?"

For researchers seeking answers to the question of whether we are alone in the universe, one event nearly half a century ago lingers even today — the so-called "Wow! Signal" detected back in 1977.

That strong, baffling radio episode was captured by Ohio State University's Search for Extraterrestrial Intelligence (SETI) project, also known as the "Big Ear." It has been viewed by some as one of the oddest radio transmissions from afar ever detected, also cited as compelling evidence for extraterrestrial intelligence.

The outburst was a strong narrowband radio signal received on Aug. 15, 1977 by Ohio State University's Big Ear radio telescope. Astronomer Jerry Ehman discovered the anomaly a few days later while reviewing the recorded data — writing on a computer printout "Wow!"

Unpublished observations, archival data

Jump ahead to today. Researchers from the Planetary Habitability Laboratory at the University of Puerto Rico at Arecibo are proposing a less extraterrestrial explanation. On-going assessments, led by Abel Méndez, are being pursued under the "Arecibo Wow!" Project, an initiative established to analyze unexplained radio signals from space in the search for extraterrestrial intelligence.

"We look at old archives with modern science methodologies. It's a bit like space archaeology," said Wow! Signal researcher Hector Socas Navarro, director of the European Solar Telescope Foundation and a staff scientist at the Instituto de Astrofísica de Canarias.

New clues

Researchers from that project have re-analyzed decades of previously unpublished observations and archival data from the Ohio State University SETI program. The result is the most precise characterization yet of the perplexing signal from afar and revealing new clues to its origin.

"Our newly derived properties may help finally pinpoint the source of the Wow! Signal," Méndez told Space.com. While the group's just-published paper focused on revising the known properties of the Wow! Signal, "we also discovered new properties that we look forward to sharing in an upcoming paper," he advised.

"We aim to archive and share all data from the Big Ear telescope by 2027, marking the 50th anniversary of the Wow! Signal," Méndez added.

Natural astrophysical origin?

In a recent posting on the Arecibo Wow! Project's website, Méndez underscored the team's output to date.

The research findings spotlight the prospect that the Wow! Signal was created by a natural astrophysical origin, Méndez and colleagues report. Also the work does make radio interference "an increasingly unlikely explanation," they add.

"This study doesn't close the case," Méndez points out. "It reopens it, but now with a much sharper map in hand."

Méndez and fellow researchers hypothesize that the Wow! Signal was caused by a sudden brightening of the hydrogen line in interstellar clouds, triggered by a powerful transient radiation source such as a magnetar flare or soft gamma repeater (SGR).

"Our results don't solve the mystery of the Wow! Signal," Méndez states. "But they give us the clearest picture yet of what it was and where it came from. This new precision allows us to target future observations more effectively than ever before."

Citizen science — join the search

The continuing research into the Wow! Signal has spurred the creation of the Wow@Home project. This initiative is a low-cost way that others can now actively search for similar signals and other rare cosmic events, including potential technosignatures of other star folk — in real time.

Wow@Home project officials found that the Wow! Signal was strong enough that even small telescopes could potentially detect similar signals.

Indeed, a network of small radio telescopes offers several distinct advantages compared to large professional observatories.

Low-cost systems can operate autonomously around the clock, "making them ideal for continuous monitoring of transient events or long-duration signals that professional telescopes cannot commit to observing full-time," Méndez and colleagues suggest.

Wow-like signal strength

Wow@Home is a cost-effective, engaging, and accessible, ideal for education, citizen science, and expanding participation in radio astronomy.

"A complete setup costs around $500, including a dedicated computer, but we are not selling these systems. Instead, we will provide recommendations for the necessary parts and offer free software to power the telescope and connect it to the Wow@Home network to search for transient events," a Wow@Home posting explains.

The software is built on analysis methods the project's developing to detect Wow-like signals in the archive data of professional observatories, as part of their Arecibo Wow! undertaking.

For more information on Wow@Home, visit the project's website. The group's recent research report is available on arXiv.org and will be submitted to the Astrophysical Journal.

Who's just a wee bit curious to discover exactly what's inside that crashed extraterrestrial mothership in Apple TV+'s riveting sci-fi show, "Invasion"? Yeah, us too.

After 2023's season 2 cliffhanger finale, that titanic derelict craft is just waiting to be investigated and, as this haunting new season 3 trailer shows, our international band of hardy survivors facing humanity’s extinction seems up to the task.

"Invasion" and its latest 10-episode outing lands back on Earth on Friday, Aug. 22, 2025, with a single episode premiere, followed by new chapters rolling out weekly each Friday until its Oct. 24, 2025, conclusion. This series has evolved into one of the finest offerings in Apple TV+'s extensive lineup of sci-fi sensations that also includes "Foundation," "Silo," "For All Mankind," and more. We can't wait to creep inside the behemoth spacecraft to explore.

Executive produced by Oscar-nominated and two-time Emmy-nominated filmmaker Simon Kinberg ("Deadpool," "X-Men: Days of Future Past," "The Martian") and David Weil ("Hunters"), "Invasion" season 3 will step into the unknown with the series' main group converging to devise a plan that will see them infiltrate the intimidating aliens fallen headquarters.

With the infestation of shapeshifting hunter-killers spreading across the globe, randomly slaughtering humans like cattle, these diverse strangers must forge a bond as they struggle to uncover a weakness in these uninvited creatures before time runs out.

In this enticing trailer, we see an elite crew of commandos formed to cross through the dead zone towards the wreckage of the downed mothership on a predictably doomed helicopter flight, with our connected heroes reluctantly recruited to join the team due to their psychic link to the aliens. We’re also treated to some unsettling imagery of crawling luminescent creatures inside their dark lair, showing the hidden horrors that have obviously evolved into more insidious lifeforms.

"What I saw is new, more powerful," reveals Shamier Anderson's Trevante. "And they’re not done."

"Invasion" season 3 arrives Aug. 22 exclusively on Apple TV+ with familiar returning faces that include actors Golshifteh Farahani, Shioli Kutsuna, Shamier Anderson, India Brown, Shane Zaza, and Enver Gjokaj. This season also introduces new series regular Erika Alexander.

There were some dark times, but the Predator movie franchise's health has been almost fully restored in recent years with Prey and Predator: Killer of Killers. Now, we're eagerly awaiting Predator: Badlands' arrival later this year. Dan Trachtenberg's third entry in the long-running sci-fi series is taking us to a faraway future — with trailers already revealing that it shares elements with the Alien movies — but we've also noticed more than a few similarities to the old (and forgotten) video game, Predator: Concrete Jungle.

While 'solo' Predator and Alien flicks were having some downtime in the 2000s, both franchises were kept alive with comic books, video games, and the two divisive Alien vs. Predator movies. The extended universe that surrounded the series grew much larger, and we got excellent games like Rebellion and Monolith's Aliens vs. Predator first-person shooters. Hot on the heels of those two and the first AvP movie, developer Eurocom got the chance to make a standalone Predator title targeting the 'ultimate alien hunter' power fantasy.

Though it never escaped PS2 and Xbox following bad reviews, Predator: Concrete Jungle gained a cult following, as no other Predator game had offered that gory action-adventure single-player experience that fans craved. It told an ambitious — and often silly — story full of twists and turns that made even Dark Horse's loopiest comics seem predictable.

With Badlands just around the corner, we revisited this overlooked 2005 game release and found more than one or two common points that suggest Trachtenberg has been digging deep into the franchise's history for his grand ideas.

Yautja outcasts

The most obvious connection is found in Badlands' Yautja protagonist, Dek. He's described as a young hunter who is an outcast after he fails his clan in some way. Now he's on a quest to regain his honor by hunting "the ultimate adversary" on a remote and ruthless planet. We've yet to learn more about the actual plot once the adventure gets going, but the setup alone instantly evokes Concrete Jungle's.

In Eurocom's game, a Predator nicknamed 'Scarface' is badly wounded by the mob in the year 1930 in New Way City. As a last resort, he sets off the self-destruct device we first saw in the original movie. While much of the city and his ship are destroyed, he fails to kill himself and protect Predator technology from reaching human hands, which leads to his clan exiling him to a desolate planet where insect-like creatures are at the top of the food chain.

There are some differences between the two stories, most notably in the time period they're set in. Concrete Jungle's story picks Scarface back up 100 years after the prologue — around 2030 — while Badlands is set much further into the future (we don't know the exact year, but humanity has space travel, synthetics, and terraforming courtesy of Alien's Weyland-Yutani).

Ultimately, Concrete Jungle is a story of redemption and humans messing with forces they don't understand. It echoes Prometheus and the "secret fire from the Gods" themes, beating the first of Ridley Scott's Alien prequels to the punch by over half a decade.

Predator: Badlands' Yautja lead is more of a rookie who will also have an unexpected synth ally, but we could see similar character arc and story beats throughout the film. Let's just hope the movie's 'final boss' will be more convincing than a human-Predator hybrid (yes, really).

The Alien connections

We know that the Weyland-Yutani corporation is present in Predator Badlands, marking the first step towards an inevitable Alien vs Predator crossover, but Concrete Jungle was out there name-dropping the Weyland Corp 20 years ago. At first glance, the game looks like an homage to Predator 2 with a cyberpunk twist, but things escalate quickly with a surprising tie-in to the previous year's Alien vs Predator movie.

The Xenomorphs appear as late-game foes in Concrete Jungle without much explanation as to their presence on Earth, but writer Grant Morrison (yes, comic book legend Grant Morrison) slips in a quick reference to Charles Bishop Weyland and his disappearance that heavily implies we're in the same universe as the movie. Perhaps Borgia Industries — the ruling corporation in Neonopolis following the 1930 disaster — picked up the Alien queen from the Antarctic waters?

The surprises keep coming in the closing moments, when a second Weyland appears and mentions the Yutani Corporation — we're pre-merger at this point, something Alien: Earth will also touch upon.

But perhaps the wildest reveal is that Isabella Borgia — a character from the prologue — shows up 100 years later, having apparently gained immortality after being covered in Predator blood. After Scarface takes her down, Weyland recovers her brain and jams it into a supercomputer. A supercomputer called MOTHER.

Predator: Concrete Jungle ended up being a stealth Alien prequel in many ways. The movie Aliens vs. Predator: Requiem would try a similar move with its cliffhanger ending and recovered Predator tech roughly two years later, but neither is, at least right now, considered canon. Despite that, Predator: Badlands is clearly establishing solid links between the two franchises, and rumors are floating around that a Predator will show up in the Alien Romulus sequel.

Whatever ends up happening in Predator: Badlands, it's clear that the 'powers that be' over at 20th Century Studios have been digging deep for inspiration, scouring the rich canvas painted by not only the Predator movies, but also comic books and video games over the years This might be the (conceptual) key to success filmmakers had been searching for, and we're delighted to see Trachtenberg and his peers leaning on often ignored works to boldly expand the series' cinematic possibilities.

Predator: Concrete Jungle is available to play on PS2 and Xbox if you're lucky enough to find a copy second-hand. Predator: Badlands will release in theaters on November 7, 2025. You can watch the rest of the franchise on Hulu (US) or Disney+ (UK).

"Alien: Earth" is landing soon.

From the stimulating looks of this bloody-good new trailer for the 8-episode "Alien: Earth" series from "Fargo" creator Noah Hawley's, the visionary filmmaker has no hesitation to terrify viewers when the ambitious sci-fi series hatches on FX and Hulu starting on Aug. 12, 2025.

Starring Sydney Chandler, Alex Lawther, Timothy Olyphant, Essie Davis, Samuel Blenkin, Babou Ceesay, David Rysdahl, Adrian Edmondson, Adarsh Gourav, Jonathan Ajayi, Erana James, Lily Newmark, Diem Camille, and Moe Bar-El, "Alien: Earth's" horrifying events play out in the year 2120 when the USCSS Maginot, a Weyland-Yutani deep space research spaceship, crashes on Earth in Prodigy City custodian of five deadly extraterrestrial lifeforms collected "from the darkest corners of the universe."

The plot focuses on Wendy (Chandler), a Prodigy Corporation-made humanoid robot synthetic and her hybrid tactical team that are dispatched to explore the crash site, search for survivors, and recover escaped specimens  —  including the notorious alien predator we all know as the eyeless, acid-spewing xenomorph.

"We don't lock them down … it will be too late," Timothy Olyphant's character Kirsh declares in the trailer. This atmospheric preview titled "Greener World" and paired with the somber song "A Greener World" by Gwilym Gold gives us a disturbing glimpse in the android-obsessed, corporate-run world of the 22nd century on Earth and the haunted house-like ship interiors. The final image of a dome-headed xenomorph crouching outside a forest cave is chilling!

"Alien: Earth" lands on FX and Hulu Aug. 12 and is executive produced by Noah Hawley, Ridley Scott, David W. Zucker, Joseph Iberti, Dana Gonzales and Clayton Krueger.

Aliens tend to fall into two distinct camps: those who want to zap us with lasers, and those who want to be our cool new intergalactic BFFs.

While the world-invasion types tend to grab the headlines with stunts like demolishing popular tourist destinations ("Independence Day") and vaporising the populace with death rays ("Mars Attacks!", "War of the Worlds"), the friendly aliens who come in peace are more likely to embrace humanity for all its flaws. Indeed, the 13 extra-terrestrials below have almost invariably left the world better than they found it, whether it's by saving the day, being an entertaining house guest, or expanding the fundamental limits of human consciousness.

So, with the live-action "Lilo & Stitch” remake and 'Elio’ now in cinemas, we celebrate a baker's dozen of pop culture's most memorable alien visitors, ordered by the date they first made contact with the people of Earth. And we also bring a warning from the cosmos — you may have a close encounter with a plot spoiler or two.

Superman (aka Kal-El)

• As seen in: numerous comics, movies and TV shows, including James Gunn's upcoming "Superman" movie
• Date of first contact: 1938

Few alien visitors have embraced Earth culture quite as readily as the son of Jor-El, who's spent a large chunk of his superhero career espousing values of "truth, justice, and a better tomorrow" (formerly "the American way"). Thanks to the effects of Earth's yellow sun on his Kryptonian physiology, Superman's enhanced strength, eye lasers, and ability to fly — not to mention his penchant for wearing his underwear outside his clothes — make him stand out from the crowd. Indeed, several recent stories (including the 2013 movie "Man of Steel") have explored how the world regards an alien who acts as a self-appointed peacekeeper.

But despite his unwavering devotion to protecting those in need — ignoring that bit in "Superman III" when he grew designer stubble and went bad — you can't help thinking he'd rather be settling down as Clark Kent, living out his happy-ever-after with Lois Lane.

Other friendly aliens from the DC stable include Supergirl, Martian Manhunter, and various members of the Green Lantern Corps.

Glordon

• As seen in: "Elio"
• Date of first contact: 2025

His dad, Lord Grigon, may be a power-hungry warlord with aspirations of seizing the peaceful Communiverse by force, but Glordon has no intention of joining the family business. He's certainly sceptical about spending the rest of his life in a robotic carapace, even though he'll be getting a state-of-the-art model featuring sophisticated weaponry, a lighter, and a cup holder.

A friendly, trusting demeanour makes this extra-terrestrial cross between a worm and a tardigrade the perfect best friend for Elio Solis, a human boy masquerading as Earth's ambassador to the cosmos. Sure, using his homespun silk to wrap Elio in a cocoon feels like an awkward way to say hello — especially for anyone who's seen Shelob in "The Lord of the Rings" — but there's no question the gesture comes from a good place.

Glordon wholeheartedly embraces his role as a "bargaining chip" in Elio's negotiations with his father, and besides, who wouldn't want a bestie who's not only fireproof, but also prepared to welcome you into his giant mouth whenever a river of lava heads your way?

Klaatu

• As seen in: "The Day the Earth Stood Still"
• Date of first contact: 1951

These days the poster for the original "The Day the Earth Stood Still" would probably be called out for false advertising. Giant robot Gort can be seen carrying a scantily clad woman while firing a laser from his eyes, recreating a scene that never actually happens in the movie.

Instead, Gort's boss, Klaatu (Michael Rennie), really does come to Earth "in peace and with good will", but ends up getting shot after a nervous soldier misunderstands his motives. In a highly topical move, Klaatu warns Earth's governments that the development of nuclear weapons has made the galactic community antsy, and subsequently turns off everybody's electricity for half an hour to prove he's not playing games. Of course, his message doesn't get across to everybody, and plenty see Klaatu as an interstellar busybody. Nobody can claim, however, that he didn't have our best interests at heart.

Keanu Reeves played Klaatu in a disappointing 2008 remake. Klaatu's famous catchphrase — "Klaatu barada nikto" — also inspired the names of several aliens in the "Star Wars" universe.

The Doctor

• As seen in: "Doctor Who"
• Date of first contact: 1963

Like Superman, the Doctor has devoted much of their professional life (or should that be lives?) to protecting the people of planet Earth. Every single one of the Time Lord's regenerations has displayed an uncanny knack for tracking down trouble, and doing what's necessary to sort it out — whether it involves a sonic screwdriver, reversing the polarity of the neutron flow, or some old-school monologuing. This modus operandi is a direct contravention of Gallifrey's strict non-interference policies.

But, given the unlimited wonders accessible to the owner of a TARDIS that can traverse all of space and time, the Doctor's ongoing obsession with Earth and its people (particularly the UK) seems slightly incongruous. Modern incarnations even manage to keep up with contemporary popular culture, particularly impressive for someone who's well over a thousand years old.

Unnamed alien visitors (Close Encounters of the Third Kind)

• As seen in: "Close Encounters of the Third Kind"
• Date of first contact: 1977

The most famous friendly alien to debut on the big screen in 1977 was undoubtedly Chewbacca but, seeing as everybody in "Star Wars"' galaxy far, far away is technically an extra-terrestrial, he doesn't really warrant a place on this list. The aliens from that year's other timeless sci-fi classic most definitely do, however, because this unnamed race of interstellar travellers arrive on Earth with an agenda of friendship, and a natural instinct for the theatrical.

Over the course of Steven Spielberg's movie, UFO sightings, toys coming to life, and visions of Devils Tower in Wyoming (subsequently recreated in mashed potato) gradually evolve into something more spectacular. The aliens' perfectly choreographed introduction culminates in a spectacular light show, accompanied by a musical symphony riffing on the most famous five notes in movie history. All in all, it's an extremely memorable way to say hello.

ET (aka The Extra-terrestrial)

• As seen in: "ET: The Extra-Terrestrial"
• Date of first contact: 1982

In the early stages of its development, "ET" was going to be alien visitation horror, but Steven Spielberg eventually changed tack to tell cinema's most beloved tale of a friendly alien coming to stay.

The movie's narrative drive comes from the marooned ET's efforts to "phone home", but it's his relationship with 10-year-old Elliott (Henry Thomas) and siblings Gertie (Drew Barrymore) and Michael (Robert MacNaughton) that provides the emotional punch. ET throws himself into Earth culture, watching daytime TV and bingeing fizzy drinks, while also bringing alien superpowers like instant healing and bike levitation to the party. All good reasons why there's not a dry eye in the house when he finally blasts off.

"Mac and Me" (1988) explored similar themes with more Happy Meal product placement, while John Carpenter's "Starman" (1984) did "'ET' for grown-ups" when Jeff Bridges' alien took the form of Karen Allen's late husband.

The Antareans

• As seen in: "Cocoon"
• Date of first contact: 1985

If "ET" was the quintessential alien movie for kids, "Cocoon" put a senior-friendly spin on visitors from outer space. In Ron Howard's film, a delegation from the planet of Antarea head to Florida to rescue some long-lost compatriots who've spent the last 10,000 years cocooned at the bottom of the Atlantic. Before heading home, they plan to replenish them in a swimming pool supercharged with special life force, but don't bank on a bunch of residents from a nearby retirement home taking unauthorised dips and rediscovering their youth.

The Antareans — luminescent beings of light beneath their human disguises — are surprisingly tolerant of the trespassing, even though it completely messes up the cocoons' recovery. They even agree to take the sprightly OAPs back to their homeworld for a shot at eternal life.

Contact aliens

• As seen in: "Contact"
• Date of first contact: 1997

You'd expect a film based on a novel by Carl Sagan to take a thought-provoking approach to aliens, and "Back to the Future" director Robert Zemeckis's adaptation does just that. SETI scientist Dr Ellie Arroway (Jodie Foster) picks up a radio signal from the star Vega, and realises it contains detailed instructions for building a machine that will allow one person to travel across the cosmos.

This being the Hollywood version of science — and despite the reservations of Matthew McConaughey's preacher — Arroway is also the person chosen to represent humanity on the maiden voyage. After reaching her destination, she meets an alien who's taken the form of her late father (David Morse), and tells her the sophisticated ETs got in touch to welcome humanity into the wider universe. Unfortunately, Arroway has no evidence of the meeting when she returns.

E 626 (aka Stitch)

• As seen in: "Lilo & Stitch"
• Date of first contact: 2002

Don't let Experiment 626's Disneyfied cuteness fool you. This alien was genetically engineered by morally dubious scientist Dr Jumba Jookiba as a super-intelligent weapon of mass destruction. When it escapes from exile, the creature crashes in Hawaii and goes incognito as a dog in an animal shelter — which is where he first meets a young orphan called Lilo.

Lilo names the creature Stitch and, realising that he's no ordinary dog, she attempts to domesticate a "pet" who causes constant (but comedic) disruption at home. Before long, however, a growing friendship gradually overcomes Stitch's more destructive instincts, and the titular duo form a tight partnership — which is for the best, seeing as Stitch remains a fugitive from the United Galactic Federation (not the one from "Star Trek").

Prawns

• As seen in: "District 9"
• Date of first contact: 2009

The aliens in "District 9" — pejoratively described as "Prawns" by the humans in the film — possess space-faring technology way beyond our own. Even so, when their ship arrives over Johannesburg in the early 1980s, the South African government immediately decides they're second-class citizens and relocates them to a camp called District 9. Lowly Department of Alien Affairs official Wikus van de Merwe (Sharlto Copley) is, like most humans, suspicious of the alien visitors, but forms an unlikely friendship with District 9 resident Christopher Johnson (Jason Cope) after he's infected by some alien goop.

Johnson may look like the product of Seth Brundle's experiments-gone-wrong in "The Fly" but he's also a very relatable dad trying to do the right thing for his son — and arguably much more sympathetic than any of the humans in the movie.

Paul

• As seen in: "Paul"
• Date of first contact: 2011

From "The X-Files" and "Dark Skies" to "Close Encounters of the Third Kind", plenty of TV shows and movies have riffed on the classic Roswell image of grey aliens with big black eyes. Few, however, have done it quite as successfully as "Paul" — the film even features a flashback to eponymous alien Paul (Seth Rogen) giving tips to a pre-"ET" Steven Spielberg, while sitting in an Area 51 warehouse that looks just like the one from "Raiders of the Lost Ark". Essentially, he claims to be the inspiration for some of the biggest sci-fi properties of the last 50 years. He even invented Fox Mulder.

Pop culture influences aside, Paul has refused to turn bitter despite the US government holding him hostage since his spaceship crashed in 1947. All these decades later he just wants to go home, and at heart is just a really good guy.

Heptapods

• As seen in: "Arrival"
• Date of first contact: 2016

"Star Trek" (a franchise that has plenty of friendly aliens of its own) has popularised the idea that most extra-terrestrial species look like humans — there's even an episode of "The Next Generation", "The Chase", that explains why Vulcans, Klingons, Cardassians and most other residents of the Alpha Quadrant look so alike. But in "Arrival" (based on Ted Chiang novella "Story of Your Life"), the heptapods who pay Earth a visit are so alien that we have to take a whole new approach to communication.

With governments and the military as sceptical as ever about the new visitors — have they learned nothing from "The Day the Earth Stood Still"? — linguist Louise Banks (Amy Adams) gradually cracks the heptapods' pictogram-based code. The aliens' language actually shifts the "speaker"'s perception of time, giving Banks spookily realistic premonitions of a daughter who hasn't yet been born, while offering the promise of a whole new frontier for humanity. Duolingo has a long way to go…

"Harry Vanderspeigle"

• As seen in: "Resident Alien"
• Date of first contact: 2021

It may not be immediately obvious, but "Harry Vanderspeigle" (his real alien name is tricky for humans to pronounce) has something in common with the aforementioned Stitch. Like the artist formerly known as Experiment 626, his original assignment involved destruction — namely, the elimination of the entire human race. But, after assuming the identity of a human doctor, getting some ad hoc medical training from "Law & Order", and setting up shop in a small Colorado town, this would-be space invader gradually comes to realise that, just maybe, we aren't so bad after all.

Harry's natural bug-eyed form suggests he's a fairly close relative of Paul, though he's able to adopt the very convincing disguise of genre legend Alan Tudyk ("Firefly", "I, Robot", "Rogue One").

If you want to meet a friendly alien yourself, the live-action Lilo and Stitch and Elio are in theaters now, and Superman will be in theaters in July.

Acclaimed New York Times bestselling novelist and Ph.D. roboticist Daniel H. Wilson ("Robopocalypse," "The Clockwork Dynasty," "The Andromeda Evolution") is one of the brightest minds in his field and an extremely good friend to have if some sort of robot uprising ever occurs around the globe.

His upcoming science fiction novel, "Hole in the Sky," lands on Oct. 7, 2025, from his longtime publisher, Doubleday. It depicts a most unusual alien first contact event on a Cherokee Indian reservation in Oklahoma, and has already been snapped up by Netflix and Aggregate Films for a feature film. Wilson will also act as an executive producer and adapt the screenplay from his own book.

Hollywood has a real appetite for Wilson’s brand of storytelling, and the Portland-based writer has at least a half-dozen Tinseltown projects in various stages of development.

"I had a book come out right when COVID started, so I switched over and started writing screenplays and television for a few years," Wilson tells Space.com. "Then we had a big strike, and so there was a great time to put on my novelist hat and go back and write a book. This really digs into two of my favorite things: where I’m from in Oklahoma, and robots and science fiction. I was really inspired to have a native take on first contact. You see so many alien invasion movies, and they’re really a dark reflection of what colonizers have already done to indigenous people. The aliens show up, and it’s like fear projection. They enslave people, they extract our resources, they destroy our monuments and our culture. It’s kind of the same story."

Wilson's thought process while composing this extraterrestrial arrival tale was focused on what the native perspective would be on the unknown, particularly the Cherokee perspective since he was raised in what's now the Cherokee reservation in North Tulsa.

"I'm a Cherokee citizen and I spent the summers with my grandparents on our original land allotment,” he explains. "It was about a mile or so away from this place called Spiro Mounds, which is the westernmost outpost of the Mound Builder civilization that disappeared thousands of years ago. But they've left these mounds all over the United States, and it's this ancient and mysterious place. Those tribes were the precursor tribes to all the tribes we know now.”

"Hole in the Sky" starts out with NASA's first observation of an interstellar object with its rapid approach and an impact on Earth that results in first contact.

"It's told through the lens of a by-the-books CIA weapons expert, the sort of person you'd expect to deal with this stuff, an anti-social NASA astrophysicist, and a really determined Cherokee father who lives in the place where this happens," Wilson adds. "All of these characters have a different perspective on the unknown. Typically, scientists want to understand it. Usually, they want to exploit it. Soldiers are afraid of the unknown, they want to destroy it. My native characters are comfortable with it. This guy lives with the unknown in his backyard. That was fun to tell that story and get to subvert that genre and put my own spin on first contact."

Mound Builders had a massive civilization on the scale of the Mayans, mainly in the Eastern portion of the United States. These earthworks were created anywhere it was useful to have a city, a place that had commerce and was easily defensible. As a result of these ancient people’s engineering, many mounds were eventually bulldozed over and major cities built atop them.

"We're talking about ten or fifteen thousand years ago, which plays into the story," says Wilson. "There's a lot of looking back to look forward. I ended up thinking a lot about what is indigenous technology. Right now, in Oregon, Washington, and California, they’re looking back at the way indigenous people dealt with their forests to prevent forest fires. They're trying to find that old knowledge to apply it now."

Netflix and Jason Bateman’s Aggregate Films were offered a draft of Wilson's book while the author and his agent pitched both the novel and the screenplay, which prompted constructive feedback that altered some elements of the story.

"I found the process really fun because film is so visual and you're thinking about how to make it super visual, and some of that can go into the book," he notes. "But in the book, you can go straight into people's heads and get into what they’re thinking. That’s something that’s harder to do in a film and get all the exposition out. We spoke to a lot of top-notch production companies, really amazing minds, and each had a territory to go out to, different studios they work with. Aggregate hit it out of the park, and we found a great creative partner.

"I'm excited because we’re shooting for an "Arrival"-level film. Obviously, "Contact" was an influence, but really this is much more along the lines of "Stalker," which is based on the book, "Roadside Picnic." Like movies that are smaller in scope but very deep and heartfelt. "Hole in the Sky" takes place in Oklahoma, and it's just as big of a character as anything in this film. It's literally going back to where I grew up, which is very fun."

"Hole in the Sky" will be published by Doubleday on Oct. 7, 2025.

The internet is absolutely full of myths and urban legends about space and just about everything else, so readers must be a skeptical these days.

From claims of aliens crashing on Earth and UFOs being hidden on military bases, to Mars being abnormally large and the moon turning green, space tends to attract some outlandish or at least highly unproven claims that should be vetted carefully.

Here are some of the biggest space myths and conspiracy theories that just won't go away.

1. The Apollo moon landings were fake

Twelve NASA astronauts walked on the moon between 1969 and 1972, but in the decades since Apollo 11 astronauts first set foot on the moon, many theories have been put forward claiming that the whole Apollo program was staged. However, the Lunar Reconnaissance Orbiter has since released photos of the landing sites as they appear on the lunar surface many years later.

Some of the questions moon landing deniers ask are "Why are there no stars in the sky in the moonwalkers' photos? Why are the U.S. flags fluttering on the surface? Why do you see footprints in the pictures, but no marks from the lunar modules that landed there?"

It turns out those questions are easy to answer than you may think.

There are no stars in the sky for the same reason you don't see stars during the day on Earth, according to NASA: The bright glow of daylight on the surface washes them out.

U.S. flags planted into the lunar soil had metal rods sewn in them to appear as though they were moving, according to NASA. Without these wires, the flag would have hung straight down, making for a pretty lackluster photo prop.

And the lunar modules, though heavier, didn't put prominent marks in the surface in some places because their mass was more evenly distributed than the astronauts' weight was in their boots.

2. NASA is a lie

Some people actually believe NASA's whole function is not to explore space, but to generate space-related hoaxes. (The Apollo moon landing is a famous example that we'll explore in the next slide.) People who believe this conspiracy, sometimes flagged with the hashtag "#NASAhoax" on social media, will say that amazing space pictures of Mars, Pluto and even Earth are fake, computer-generated imagery (CGI).

NASA was formed in 1958 "to provide for research into problems of flight within and outside the Earth's atmosphere, and for other purposes," according to the National Aeronautics and Space Act of 1958, which then-president Dwight D. Eisenhower signed into law shortly after the start of the space race against the Soviet Union.

Since then, NASA has launched hundreds of satellites into orbit around Earth, the moon and several other worlds. In fact, NASA spacecraft have orbited, flown by or landed on every planet in the solar system. NASA also sends astronauts into orbit, where they conduct research at the International Space Station (ISS).

If you're not convinced, you are free to travel to Florida's Space Coast to watch a rocket launch for yourself. It's also quite easy to see the space station and other satellites with your own eyes with the help of a satellite tracker.

3. The Earth is flat

This myth is so popular that there is even a group named after it: the Flat Earth Society. Members of the organization argue that the horizon is always at eye level, which they say would not be possible if the Earth were round. They also say there is no full movie of the Earth rotating from space — which is not true, as NASA has published multiple videos taken from satellites, including a live video of Earth from the ISS, which orbits our planet 16 times per day.

One way of demonstrating to yourself that the Earth is round is to consider how orbits of satellites work. Satellites constantly "fall" around the Earth as they are pulled around by our planet's gravity; they just need to be traveling fast enough at a high enough altitude to not slam into the atmosphere. Or, you can look at the amazing pictures taken by astronauts at the ISS.

4. Planet Nine will kill us

In April 2016, the New York Post tweeted, "A newly discovered planet could destroy Earth as soon as this month." The newspaper was referring to Planet Nine, a theoretical planet at the edge of the solar system. An accompanying video also claimed that the new planet would be throwing all sorts of asteroids and comets at Earth, which would supposedly end up pummeling our planet.

Although the existence of a ninth planet has not been confirmed, astronomers are actively looking for one to help explain motions of some objects in the icy Kuiper Belt, a vast region of icy objects beyond Neptune. If the planet is actually found, the planet will pose no threat to us, according to the California Institute of Technology's Mike Brown (who is one of the original backers of the Planet Nine theory).

5. Alien research is happening at Area 51

The 1996 movie "Independence Day" is one of the main sources of the Area 51 hoax, which claims that aliens and their technology — recovered from crashed flying saucers — are being studied secretly at a classified military base about 80 miles (130 kilometers) northwest of Las Vegas in the Nevada desert. Some people in the area around the base claim that they have seen strange lights or objects flying in or out of this area.

While the testing and development conducted at Area 51 is classified, the U.S. government has acknowledged its existence (although the CIA officially calls it "Homey Airport" or "Groom Lake").

A part of Edwards Air Force Base, the area was a known location for high-technology airplane flights in the 1960s and 1970s. It first served as a proving ground for Lockheed U-2 and A-12 OXCART spy planes as early as 1955. UFO sightings reported in the area were indeed unidentified objects, but only because the planes were top-secret — not because they were flown by aliens.

6. There is a killer planet known as "Nibiru"

Conspiracy theorists say another dangerous planet is Nibiru, which was first mentioned in the 1976 book "The Twelfth Planet," by Zecharia Sitchin. In the book, Sitchin translated ancient Sumerian cuneiform and claimed that the text is proof of a planet beyond Neptune called Nibiru that orbits the sun every 3,600 years.

Years later, self-proclaimed psychic Nancy Lieder claimed to have communicated with extraterrestrials who said Nibiru would collide with Earth in 2003. When that didn't happen, the date was moved to 2012 (and linked, of course, with the 2012 doomsday predictions). Of course, the collision never occurred, the world didn't end in 2012 and no astronomer has ever found a planet on a collision course with Earth.

7. There is a face on Mars

In 1976, NASA's Viking 1 spacecraft took a picture of what appeared to be a face on Mars. Immediately, some people said there must have been aliens on the Red Planet that left that face behind as evidence of their existence. NASA, however, pointed out that the suspected face is really just a pile of rocks casting shadows that resemble face-like features.

NASA followed up with better-resolution pictures taken from the Mars Reconnaissance Orbiter and the Mars Global Surveyor in 1998 and 2001, respectively. These new images made it quite clear that the "face on Mars" is nothing more than a trick of light and shadows on a completely normal Martian mound.

8. The moon Iapetus is an alien Death Star

Iapetus is a moon of Saturn that looks somewhat like the infamous Death Star in the "Star Wars" franchise, with a large crater that resembles the fictional weapon's superlaser focus lens. The Death Star is a planet-killing machine that destroys entire worlds with its outrageously powerful laser. It was prominently featured in the 2016 movie "Rogue One: A Star Wars Story," as well as in 1977's "Star Wars: Episode IV - A New Hope."

A Daily Mail article published in May 2016 claimed Iapetus is an artificial object crafted by aliens. As "evidence," the article cited a photo taken by NASA's Cassini spacecraft in 2004. In the photo, there's a line around the moon's equator that resembles the equatorial trench around the Death Star.

But this line isn't nearly as interesting as the Death Star's trench, which houses the battle station's engines, thrusters and docking bays. That line is nothing more than a mountain ridge, and Iapetus is actually just made up of boring old rock and ice. Cassini has flown by the moon to take pictures several times without being blasted by deadly alien lasers.

Saturn's moon Mimas, with it's giant crater Herschel, also looks surprisingly like the Death Star.

9. Saturn's hexagon is alien technology

Saturn's hexagon was first spotted when NASA's Voyager spacecraft flew by the giant, ringed planet in 1980. The bizarre, six-sided structure on the round planet's north pole caused quite the stir, because straight lines and polygons are not so common in nature.

Immediately after the Voyager returned its first images of Saturn's strange feature, even stranger theories arose to explain it, including that it was somehow related to alien technology, or perhaps even was a gateway to hell. The hexagon is not artificial, but rather a weird-looking hurricane at Saturn's pole.

NASA has done several flybys of this region with the Cassini spacecraft, studying the haze particles and other features of the storm, to try to learn more about its unusual properties.

10. Mars is as big as the moon

Originating in 2003, the infamous Mars hoax asserts that Mars was closer to Earth than it had been in the 60,000 years prior, and that the planet will appear as large as the full moon. What started out as a misconstrued email turned into a recurring rumor that gets reshared every August and, naturally, has spread to social media as it became more popular.

Although Mars is indeed relatively close to Earth in a cosmic sense, it will never be as large as the full moon. It will appear as a red dot in the sky, just as the ancient astronomers saw it. If you'd like to see Mars magnified, take out a telescope or look at one of NASA's spectacular Mars pictures.

11. The moon will turn green

In spring 2016, there was a rumor that the moon would turn green because several planets had aligned and caused an eerie glow, according to EarthSky. This was supposed to happen on April 20 and again on May 29 for the first time since 1596, the rumor alleged.

The moon never actually turned green, although it can appear red during a lunar eclipse, when the moon passes through Earth's shadow. In the same way sunsets often appear red, sunlight is scattered as it passes through Earth's atmosphere, casting a reddish shadow on the moon's surface.

Skywatching columnist Joe Rao debunked this green-moon myth. He pointed out that a full moon actually took place on April 22, 2016, and speculated that the April 20 date of the "green moon" might have to do with "National Weed Day," popularly known as 4/20. Considering that the last green moon supposedly happened 420 years ago as well, this doesn't appear to be a coincidence.

12. Earth will go dark for two weeks

In July 2015, a website called "NewsWatch33" wrote an article claiming that Earth would have 15 days of complete darkness that year. The website, which is actually a fake news site, was borrowing from an older version of the tale that has been circulating for years, according to debunking website Snopes.

As we all know, Earth did not actually experience that much darkness that year. (The article claimed that the alleged darkness was partly due to a Jupiter-Venus conjunction, which actually took place more than 500 million miles apart.) Darkness occurs when the Earth rotates, causing the sun to "set" on the local horizon. Brief periods of darkness can also happen when the sun is totally obscured during total solar eclipses, which occur rarely in any particular spot on Earth. But even during an eclipse, Earth is never completely in the dark.

13. Zero-gravity day will make you weightless

If you ever wanted to leap into the sky and soar like Superman, this hoax is for you. In late 2014 and early 2015, a widely shared story claimed that on Jan. 4, 2015, everyone on Earth would experience weightlessness due to a rare alignment of the planets. A doctored image of a purported tweet from NASA's Twitter account that went around on social media fooled a lot of people into believing the hoax.

But, of course, nobody floated off the surface of Earth that day. Earth's gravity is too strong for people to become weightless. The only way to experience weightlessness without going to space is to ride aboard a plane that performs parabolas, with some including a few seconds of weightlessness. This is sometimes nicknamed the Vomit Comet.

14. Alien spacecraft caused a mysterious explosion

Back in 2004, an expedition of Russian researchers working in Siberia claimed to have discovered "an extraterrestrial device" close to where the mysterious Tunguska explosion occurred. Scientists still aren't sure exactly what it was that blew up in the sky over Siberia that day in 1908, but the leading theory is that it was a large meteorite or an asteroid, according to Live Science.

The Tunguska incident flattened hundreds of square miles of forest, and signs of the destruction were visible even decades afterward. At the time, news reports claimed that evidence of aliens was found at the site, but this claim was never substantiated. "The Russian team stupidly stated long before they went to Siberia that the main intention of their expedition was to find the remnants of an alien spaceship," Benny Peiser, a researcher at Liverpool John Moores University in the U.K., told Space.com. "And bingo! A week later, that's what they claim to have found."

15. UFO was caught "refueling" at the sun

NASA has a fleet of sun-gazing spacecraft that keep an eye on space weather, especially during solar eruptions. In 2012, telescopic images appeared to show something in the shadows. On YouTube, some viewers said this could be a UFO that was refueling by using the solar plasma.

However, NASA pointed out that the feature is actually something called a "prominence," which has cooler and denser plasma than the outer atmosphere of the sun, or the corona. Scientists are still trying to figure out how solar prominences develop, but they're pretty sure it has nothing to do with aliens.

16. There is a ______ on Mars!

With NASA's Opportunity and Curiosity rovers regularly taking pictures of the Martian surface, viewers have the chance to check out what they're doing in almost real time. NASA puts the raw images online for the public to see. But over the years, some weird shapes have cropped up. In 2008, for example, the Opportunity rover appeared to photograph a female figure. Other photos have shown things shaped like animals, spoons or other items.

You can imagine that, with all of the rocks available on Mars, some of them would happen to look like familiar objects. In fact, the human brain tends to perceive meaningful images in random patterns — a phenomenon known as pareidolia.

When evaluating the claims, consider that the Martian environment is extremely harsh to life as we know it; the surface is baked with radiation, the "air" is mostly carbon dioxide and there's not much atmospheric pressure.

17. I just saw a bright UFO!

It's a familiar trope for police stations and astronomy writers. From time to time, somebody will call (or write) in to say they just saw a UFO in the sky. While UFO is the term used for any flying object that an observer cannot identify, many people claim that they are alien spaceships. They spotted a bright light around sunset, or saw a light moving around in an unfamiliar way.

While every situation is different, one common explanation for "UFOs" is actually another extraterrestrial object: Venus. Venus can be extremely bright when it's at its closest, because it's relatively near Earth. The planet is also extremely reflective because the sun's light bounces off the clouds. So before calling to say you've spotted a UFO, check your sky charts!

18. NASA can travel faster than light

If you've seen the "Star Trek" clips that show the Enterprise spaceship warping into another sector, you might have wondered how fast NASA is making progress on being able to move at the speed of light. The EmDrive has created years of speculation, with some breathlessly saying NASA must be on the verge of breaking the famed barrier.

In reality, NASA is downplaying the reports. The engine in question is a prototype that is producing some interesting results, such as appearing to create thrust when there was no reason for this to happen – and thereby violating Newton's Third Law of Motion. That said, NASA has not yet verified the results from these tests, and the engine has not been widely discussed in peer-reviewed research.

19. We've launched balloons into space!

With the advent of high-resolution, miniature cameras, several people have decided to strap these cameras on to high-altitude balloons and take pictures from up high. They've caught glimpses of blackness and, at times, taken interesting tiny passengers along (such as 1000 Lego minifigures). So they must be in space, right?

There's no way a helium balloon can get into space, according to the California Institute of Technology, and simple physics explains why. When a balloon rises into the sky, the air inside will expand in response to the dropping atmospheric pressure and eventually pop. Even Felix Baumgartner's stunning high-altitude balloon jump in 2012 was not actually from space, but from the stratosphere, which extends to roughly 31 miles (50 kilometers) above the Earth's surface.

At that altitude the air is thin enough to see the blackness of space, but thick enough to support special high-altitude balloons. The boundary between Earth's atmosphere and outer space is about twice as high as the upper limits of the stratosphere.

20. There are canals on Mars

Author Percival Lowell became one of space's first popularizers when he wrote many books for the general public back in the late 1800s and early 1900s. In these books and other writings, he said there were canals on Mars built by an intelligent civilization, perhaps to move water into desert-stricken areas. He claimed to have seen the canals in his own telescope, and produced several sketches that are still available on the internet today.

There are no artificial canals on Mars. Several spacecraft have flown by the planet or orbited it, and not one has caught signs of aliens from orbit. What they have seen, however, are smaller channels that were created by nature – likely from water, ice or other processes that cause erosion.

21. A star is flinging comets at Earth

A long-standing theory known as Nemesis supposes that there is some sort of "death star" on the outer edge of the solar system, whose orbital motions perturb comets in an icy region of objects known as the Oort Cloud. According to the myth, the star's gravity throws these comets toward the inner solar system, and these comets collide with Earth and cause mass extinctions once every 27 million years.

However, a 2011 study concluded that this idea is unlikely, because the comet strikes in recorded history haven't happened with any regularity. The pattern that was recorded in the hoax is actually a statistical artifact, or the result of researchers trying to find patterns in nature where they do not exist, the study's authors found.

22. There's life on Venus

Back in the 1970s and 1980s, the Soviet Union sent several uncrewed missions to study Venus. Ten of these Venera probes landed on the surface of Venus and were able to transmit data and images for a few minutes before succumbing to the planet's extreme atmosphere. In 2012, the Russian news service RIA Novosti reported that Leonid Ksanfomaliti, a scientist who worked on the Venera missions, suggested that the photographs showed living objects moving around on the planet's surface. (RIA Novosti ceased operations in 2013.)

These alleged life-forms on Venus are just an example of "letting your mind see patterns in low-resolution data that simply aren't real," Jonathon Hill, a research technician who processes images taken during NASA's Mars missions, explained to Space.com's sister site, LiveScience, in 2012.

According to NASA, the objects that appeared to be moving were actually camera-lens covers that automatically popped off of the cameras after landing LiveScience reports. These half-circle objects were seen in images from Venera-13 and Venera-14, two identical spacecraft that landed about 590 miles (950 km) apart. Both had two identical cameras — one in the front and one in the back — so it makes sense that the covers would appear in different places. Another photograph that Ksanfomaliti said was a scorpion is actually a blur in the image.

23. An asteroid is about to crash into Earth

This recurring rumor claims that a threatening "doomsday" asteroid is about to slam into our planet. An example from 2015 had an asteroid purported to hit Earth in late September, when it would supposedly wreak devastation from its impact point near Puerto Rico. NASA quickly dismissed the reports — which turned out, as usual, to be false. But that's not to say that asteroids will never hit our planet.

NASA and a network of monitoring telescopes across the world are cataloging all known asteroids wider than 459 feet (140 meters) across in line with a 2005 congressional mandate. (Smaller asteroids, if found, are also cataloged.) Of the space rocks discovered so far, NASA has not found a single asteroid that has a high probability of hitting Earth in the foreseeable future.

24. Aliens landed in Roswell, New Mexico

On a ranch in Roswell, New Mexico, so the story goes, an alien spacecraft crashed in 1947. While the accounts of exactly what happen vary, the legend claims that a disc or some sort of spacecraft was found on a ranch, and that the government quickly covered up the evidence.

While rumors of aliens circulated, some people speculated that the crash was just a plain old weather balloon that might not have been recognized by the local community. The U.S. military acknowledged the "spacecraft" was actually a weather balloon sent aloft as part of Project Mogul, which involved flying microphones on high-altitude balloons to listen for sound waves generated by possible Soviet Union nuclear tests.

25. Climate change isn't real

Earth is on an abnormal warming trend. Arctic ice is melting, the sea level is rising and temperatures are going to extremes in many locations around the world. Why is this happening? Anti-climate-change conspirators have many explanations: solar activity, radiation, the Earth's (and sun's) movements around the Milky Way, among other theories.

While there are many components of climate change, the fact that humans have contributed to it is indisputable, according to NASA. Temperature graphs show that the climate has not warmed this much, this quickly in all of Earth's history (as seen in geological records), and that the increase correlates with increased industrialization.

Additional resources

For more myths about space, you can read this article by How It Works magazine. Additionally, you can watch this video by BBC Earth Lab.

Bibliography

"National Aeronautics and Space Act of 1958 (Unamended)". National Aeronautics and Space Administration. https://history.nasa.gov/spaceact.html

"Modern myths of Mars". Proc. SPIE 6309, Instruments, Methods, and Missions for Astrobiology IX, 63090C (14 September 2006). https://doi.org/10.1117/12.676304

An advanced alien civilization may want to cruise around the galaxy, and the best way to do that is by steering their binary star system, a researcher proposes in a new paper.

Long-lived civilizations may have many motivations for wanting to move somewhere else in the galaxy. They may need to escape an impending supernova, for example. Maybe they need to scout our new natural resources. Or maybe they just feel like exploring.

Given the enormous distances between the stars, however, interstellar travel is tremendously difficult and time-consuming. So, instead of leaving their system, an intrepid alien species might decide to take their system with them. The main advantage of accelerating their own star would be that they get to keep it with them as they travel. They would do this by causing their star to either radiate or evaporate in just one direction, which would propel the star, along with all of its planets, to a new location in the galaxy.

Astronomers have investigated whether "hypervelocity" stars (which, as their name suggests, are stars with an extraordinarily high velocity) may have been purposefully launched by alien civilizations, but the known candidates show no signs of artificial interference.

Related: Astronomers Detect a Swarm of Tiny Objects Orbiting an Alien Sun

In a recent paper, Clement Vidal, a philosopher at the Vrije University Brussels in Belgium, pointed out that most stars are not solitary but rather belong to binary systems. This means we might be missing half of the potential artificially accelerated stars. Even better, binary systems offer many advantages over their solo counterparts, Vidal wrote in his paper, which has not been peer-reviewed or published in a scientific journal.

Vidal took a model system consisting of a neutron star with a low-mass star tightly orbiting it. This setup provides the most flexibility in steerability and thrust.

The alien civilization would have to figure out a way to eject material from the star. This could be from asymmetric magnetic fields or from some device that causes uneven heating on the stellar surface. No matter what, the goal would be to get the star to eject more material in one direction than another. This would create thrust, pushing the binary system in the opposite direction, Vidal explained.

If the civilization were to place the machinery on or near the neutron star, where the strong gravity could provide a ready source of energy, they could steer the binary system by carefully cycling the machine off and on. For example, if they activated the machine only at the exact same point in the orbit, they would send the binary system in one direction. If they left the machine activated slightly longer, they would adjust their course, pointing their movement in any direction they wished along the orbital plane.

They could even steer their system in new off-orbit directions by altering the direction in which their machine was pointed, effectively changing the orbit of the neutron star around its companion.

Amazingly, there are real systems in the universe that match these kinds of characteristics, like the "black widow" pulsar PSR J0610-2100 and the "redback" pulsar PSR J2043+1711. Both of those systems have significant accelerations. Although they are unlikely to be caused by alien engineering, they are worth looking into, Vidal concludes. At least, while they're still around.

This article was originally published at The Conversation. The publication contributed the article to Space.com's Expert Voices: Op-Ed & Insights.

Mike Sori is an Assistant Professor of Planetary Science at Purdue University.

On Oct. 14, 2024, NASA launched a robotic spacecraft named Europa Clipper to Jupiter’s moons. Clipper will reach the ice-covered Jovian moon Europa in 2030 and spend several years collecting and sending valuable data on the moon’s potential habitability back to Earth.

Clipper isn’t the only mission highlighting researchers’ interest in Jupiter and its moons.

On April 13, 2023, the European Space Agency launched a rocket carrying a spacecraft destined for Jupiter. The Jupiter Icy Moons Explorer – or JUICE – will spend at least three years on Jupiter’s moons after it arrives in 2031.

I’m a planetary scientist who studies the structure and evolution of solid planets and moons in the solar system.

There are many reasons my colleagues and I are looking forward to getting the data that Europa Clipper and JUICE will hopefully be sending back to Earth in the 2030s. But perhaps the most exciting information will have to do with water. Three of Jupiter’s moons – Europa, Ganymede and Callisto – are home to large, underground oceans of liquid water that could support life.

Related: SpaceX Falcon Heavy rocket launches NASA's Europa Clipper probe to explore icy Jupiter ocean moon (video)

Meet Io, Europa, Ganymede and Callisto

Jupiter has dozens of moons. Four of them in particular are of interest to planetary scientists.

Io, Europa, Ganymede and Callisto are, like Earth’s Moon, relatively large, spherical complex worlds. Two previous NASA missions have sent spacecraft to orbit the Jupiter system and collected data on these moons. The Galileo mission orbited Jupiter from 1995 to 2003 and led to geological discoveries on all four large moons. The Juno mission is still orbiting Jupiter today and has provided scientists with an unprecedented view into Jupiter’s composition, structure and space environment.

These missions and other observations revealed that Io, the closest of the four to its host planet, is abuzz with geological activity, including lava lakes, volcanic eruptions and tectonically formed mountains. But it is not home to large amounts of water.

Europa, Ganymede and Callisto, in contrast, have icy landscapes. Europa’s surface is a frozen wonderland with a young but complex history, possibly including icy analogs of plate tectonics and volcanoes. Ganymede, the largest moon in the entire solar system, is bigger than Mercury and has its own magnetic field generated internally from a liquid metal core. Callisto appears somewhat inert compared to the others, but serves as a valuable time capsule of an ancient past that is no longer accessible on the youthful surfaces of Europa and Io.

Most exciting of all: Europa, Ganymede and Callisto all almost certainly possess underground oceans of liquid water.

Ocean worlds

Europa, Ganymede and Callisto have chilly surfaces that are hundreds of degrees below zero. At these temperatures, ice behaves like solid rock.

But just like Earth, the deeper underground you go on these moons, the hotter it gets. Go down far enough and you eventually reach the temperature where ice melts into water. Exactly how far down this transition occurs on each of the moons is a subject of debate that scientists hope to resolve with JUICE and Europa Clipper. While the exact depths are still uncertain, scientists are confident that these oceans exist.

The best evidence of these oceans comes from Jupiter’s magnetic field. Saltwater is electrically conductive. So as these moons travel through Jupiter’s magnetic field, they generate a secondary, smaller magnetic field that signals to researchers the presence of an underground ocean. Using this technique, planetary scientists have been able to show that the three moons contain underground oceans. And these oceans are not small – Europa’s ocean alone might have more than double the water of all of Earth’s oceans combined.

An obvious and tantalizing next question is whether these oceans can support extraterrestrial life. Liquid water is an important piece of what makes for a habitable world, but far from the only requirement for life. Life also needs energy and certain chemical compounds in addition to water to flourish. Because these oceans are hidden beneath miles of solid ice, sunlight and photosynthesis are out. But it’s possible other sources could provide the needed ingredients.

On Europa, for example, the liquid water ocean overlays a rocky interior. That rocky seafloor could provide energy and chemicals through underwater volcanoes that could make Europa’s ocean habitable. But it is also possible that Europa’s ocean is a sterile, inhospitable place – scientists need more data to answer these questions.

Upcoming missions from ESA and NASA 

Europa Clipper and JUICE are set up to give scientists game-changing information about the potential habitability of Jupiter’s moons. While both missions will gather data on multiple moons, JUICE will spend time orbiting and focusing on Ganymede, and Europa Clipper will make dozens of close flybys of Europa.

Both of the spacecraft will carry a suite of scientific instruments built specifically to investigate the oceans. Onboard radar will allow Europa Clipper and JUICE to probe into the moons’ outer layers of solid ice. Radar could reveal any small pockets of liquid water in the ice, or, in the case of Europa, which has a thinner outer ice layer than Ganymede and Callisto, hopefully detect the larger ocean.

Magnetometers will also be on both missions. These tools will give scientists the opportunity to study the secondary magnetic fields produced by the interaction of conductive oceans with Jupiter’s field in great detail and will hopefully give researchers clues to salinity and volumes of the oceans.

Scientists will also observe small variations in the moons’ gravitational pulls by tracking subtle movements in both spacecrafts’ orbits, which could help determine if Europa’s seafloor has volcanoes that provide the needed energy and chemistry for the ocean to support life.

Finally, both craft will carry a host of cameras and light sensors that will provide unprecedented images of the geology and composition of the moons’ icy surfaces.

Maybe one day, a spacecraft will be able to drill through the miles of solid ice on Europa, Ganymede or Callisto and explore oceans directly. Until then, observations from spacecraft like Europa Clipper and JUICE are scientists’ best bet for learning about these ocean worlds.

When Galileo discovered these moons in 1609, they were the first objects known to directly orbit another planet. Their discovery was the final nail in the coffin of the theory that Earth – and humanity – resides at the center of the universe. Maybe these worlds have another humbling surprise in store.

In less than seven decades, humanity went from having no active flight technology to walking on the moon. It took only a little over a century to get from the first basic computer to a pocket-size device that enables widespread access to nearly the entire body of human knowledge within seconds. Based on that technological trajectory, there is a persistent assumption that our technological capacities are unbounded. 

This notion, along with the discovery that habitable worlds are common throughout the cosmos, has influenced a question that has perplexed scientists and others for decades: "Why is the universe so quiet?" This conundrum, which is said to have been proposed by physicist Enrico Fermi in 1950, is known as the Fermi paradox. If our solar system is young compared with the rest of the universe and humans could be capable of interstellar travel someday, shouldn't we have seen signs that other intelligent entities have spread throughout the cosmos by now? Basically, where are the aliens?

Perhaps we haven't encountered alien civilizations because there's a "universal limit to technological development" (ULTD) for every intelligent species in the universe and this limit sits well below a civilization's ability to colonize an entire galaxy, Antonio Gelis-Filho, a researcher in public policy at the Getúlio Vargas Foundation at the School of Business Administration (FGV EAESP) in Brazil, proposed in a recent paper published in the journal Futures. 

"If the ULTD hypothesis is correct, there has never been, there is not and there will never be something like an interstellar civilization, or anything similar to an 'interstellar conversation,'" Gelis-Filho told Space.com in an email. 

Related: Are we alone? Intelligent aliens may be rare, new study suggests

Based on the history of the rise and fall of human civilizations, the feasibility of constructing and running scientific projects that expand our knowledge and technology, and the apparent lack of technological intelligence elsewhere in the cosmos, Gelis-Filho thinks we should be careful about assuming the technological capacities of humans and other intelligent beings are limitless. 

The "uncrossable gap" 

Nobel prize-winning physicist Richard Feynman once said, "What I cannot create, I do not understand." The most straightforward interpretation of this is that our technology — what we can create — is constrained by our knowledge. 

There are, of course, natural limits to human technology. We can't travel in a straight line faster than the speed of light, for example. There may also be natural barriers to human knowledge — facts about the universe that are forever inaccessible to us due to the configuration of our biology. Sure, we have created technology that scaffolds our senses and cognition: Microscopes let us peer into the world of the small, telescopes provide a window into the world of the big, and computers crunch numbers and data that our individual minds are incapable of processing. 

However, the technologies and experiments that allow us to expand our knowledge are coming at an ever-increasing price. Projects like the Large Hadron Collider at CERN ($4.75 billion to construct and $286 million annually), the International Space Station ($3 billion per year), and the international effort to achieve nuclear fusion at ITER (an estimated $18 billion to $20 billion for construction) show that human efforts to probe our scientific horizons require increasing energy and resources. 

"If we are candid about it, the fact is that the last major fundamental advances in the science of the universe (macro- and micro-realms, cosmology and quantum mechanics) are almost a hundred years old," Gelis-Filho said. 

Sure, black holes and other phenomena are much better understood today than they were a century ago, but their theory is nowhere as consequential to human technology as relativity and quantum mechanics have been, Gelis-Filho contends.

Just "compare the scientific evolution from 1830 (no theory of evolution, no theory of electromagnetism) to 1930 (relativity and quantum mechanics already there) and from 1930 to 2024 (still no unifying theory) for us to perceive that the rate of advancement is slowing, to say the least," Gelis-Filho said. "Low-hanging fruits have already been picked. The remaining ones seem to be hanging from impossibly high branches." 

The growing price of probing the frontiers of human knowledge means we might decide the price is too high. Indeed, the European commission recently abandoned its plan to select a number of billion-euro flagship research projects, which included plans to convert solar and wind energy into fuels, and to bring cell and gene therapies into clinical settings. In such a case, the development of new technologies that leverage new breakthroughs in our understanding of reality will also come to a standstill, along with our dreams of becoming an interstellar civilization. 

Any intelligent civilization in the cosmos will have to face this same scenario, Gelis-Filho said. At a certain point, no matter how ingenious they become, they will have to make a decision: Do we build a particle accelerator as large as the Milky Way to test our new unifying theory, for example, or do we build necessary infrastructure for our civilization's survival? 

The ULTD hypothesis sustains that, even if a civilization decided to build such a machine to test the limits of their knowledge, they would discover that the levels of energy needed to perform experiments to facilitate a leap in scientific knowledge do not increase linearly. They would reach a point where their current technology would not allow them to cross the gap between one level and the next. 

"Since the laws of physics are the same throughout the universe, every single civilization will eventually clash against that 'uncrossable gap,'" Giles-Filho said. 

The cost of increasing societal complexity  

Gelis-Filho also thinks lessons from the rise and fall of human civilizations can be applied to this astrobiological context. Complex societies expand by adding layers of societal complexity to produce more "energy" to keep growing. However, after a certain point, complexity does not "pay for itself," and its returns will decrease, he said. 

"If we think of a hunter-gathering society, the number of social roles (chief, hunter, collector and so on) is minimal; in the Late Roman Empire, it was much higher and in our industrial society it is immensely higher," Gelis-Filho explained.

Of course, with added specialization, more complex societies can produce more. As people developed agriculture on Earth, for instance, the influx of food provided by the new technology led to new societal roles aimed at increasing production further. But as the level of complexity increased, so did the need for costly infrastructure to support it.  

Related: First contact with aliens could end in colonization and genocide if we don't learn from history

Gelis-Filho borrows his argument from Joseph Tainter, an archaeologist who studied many complex societies throughout history. Tainter  hypothesizes that, although the fatal blow to a society may vary (e.g., war, drought, epidemics or an astronomical event), the root cause is always the same: decreasing returns on complexity that have made the society fragile. 

"I have applied the concept to any technological society anywhere in the universe," Gelis-Filho said. "Advanced spatial technology demands legacy infrastructure to be developed. That infrastructure is just a part of societal complexity. … It is possible that many non-terrestrial societies have collapsed because of diminishing returns on societal complexity, even before clashing against the limits imposed by energy requirements to test scientific theories."

Cosmic messages in a bottle 

Despite all of this, Gelis-Filho doesn't rule out the possibility of receiving a message or signal from another intelligent civilization. The universal limit to technological development prohibits technological development beyond a level that prevents the organized, self-sustaining spread of a civilization beyond its solar system. 

"However, it does not preclude the existence of 'castaway technology,' like wandering dead space probes (just think about the Voyager 1 in a hundred thousand years, silently crossing our galaxy), isolated messages being received (the Wow! signal being a candidate) or even 'alien dead Voyagers' being retrieved by us (however improbable that event is)," he said. 

Such attempts to communicate with other intelligent civilizations across the vastness of space resemble "great cosmic bottle messages" — like a stranded captain of a sunken ship on a remote island trying to signal to the outside world with the rudimentary tools they have, Gelis-Filho explained. 

Giles-Filho's hypothesis is one possible explanation for why our attempts to observe an interstellar civilization have fallen short. Yes, we have been searching for signs that we are not alone in the cosmos for only a few decades. Maybe we haven't been looking long enough, in the right place or even for the right thing. The unambiguous detection of an intelligent alien civilization would obviously prove the ULTD hypothesis wrong, as would the sudden leap in knowledge that could facilitate the expansion of human civilization into the stars. Until then, the ULTD hypothesis provides a sobering reminder that our species' destiny is not a given.

Director Fede Alvarez ("Evil Dead," "Don't Breathe") hit a home run with the latest installment in the legendary "Alien" franchise when "Alien: Romulus" hit theaters back in August.

The film racked up a global box office total of $347 million and appeased "Alien" acolytes around the planet with its return to old-school scares and its nods to the first two installments in the series, 1979's "Alien" and 1986's "Aliens."

Now that its theatrical run has subsided, 20th Century Studios' "Alien: Romulus" will invade digital retailers (Prime Video, Apple TV and Fandango at Home) on Oct. 15. It will then sneak into your homes on 4K Ultra HD, Blu-ray and DVD on Dec. 3, complete with bonus featurettes, alternate and extended scenes, interviews with Fede Alvarez and Ridley Scott, VFX secrets, promo materials, behind-the-scenes content and much more.

Here's the full description of the impactful fright-fest:

"This truly terrifying sci-fi horror-thriller takes the phenomenally successful 'Alien' franchise back to its iconic roots. While scavenging the deep ends of a derelict space station, a group of young colonizers come face-to-face with the most relentless and deadly life form in the universe. Starring Cailee Spaeny, David Jonsson, Archie Renaux, Isabela Merced, Spike Fearn and Aileen Wu, 'Alien: Romulus' is directed by horror master Fede Alvarez from a screenplay by Alvarez and frequent collaborator Rodo Sayagues based on characters created by Dan O'Bannon and Ronald Shusett. Ridley Scott — who directed the original 'Alien' and the series entries 'Prometheus' and 'Alien: Covenant' — produces with Michael Pruss and Walter Hill."

Related: 'Alien: Romulus' is a visceral return to form for a venerable sci-fi franchise (review)

The 4K UHD presentation will also be available for purchase in a collectible limited edition SteelBook decorated with custom artwork and box packaging. 

Additionally, Xenomorph fans can honor director Ridley Scott's original 1979 sci-fi classic, "Alien," which celebrates its 45th anniversary this year, by grabbing a special Two-Movie Collection digital bundle pairing "Alien" and "Alien: Romulus" on Oct. 15.

Check out the total rundown of home video bonus features:

• "Return to Horror: Crafting 'Alien: Romulus'"
• "The Director’s Vision" – Discover how one of today’s greatest horror directors, Fede Alvarez, collaborated with master filmmaker Ridley Scott to craft a new, heart-pounding chapter in the "Alien" franchise.
• "Creating the Story" – Learn what inspired the story of "Alien: Romulus" and see the many easter eggs from previous Alien installments that you may have missed.
• "Casting the Faces" – Meet the stars of "Alien: Romulus" as they take us inside the hearts and minds of their characters. Explore the parallels between Rain and the iconic franchise heroine, Ripley, and learn how filmmakers brought back a face from the past.
• "Constructing the World" – Explore the massive, practical sets of "Alien: Romulus" that hearken back to the futuristic style established in the '80s and get up close and personal with a hoard of practically built facehuggers, chestbursters, and xenomorphs.
• "Inside the Xenomorph Showdown" – Experience the film's climactic zero-gravity sequence from every angle as filmmakers break down what it took to make the moment spectacular. From sets and performances, to wirework, stunts, and VFX, see how it all came together.
• "'Alien:' A Conversation" – A special conversation with Ridley Scott and Fede Alvarez for the "Alien" 45th Anniversary theatrical re-release.

This article was originally published at The Conversation. The publication contributed the article to Space.com's Expert Voices: Op-Ed & Insights.

Tony Milligan is a Research Fellow in the Philosophy of Ethics at King's College London.

The idea that aliens may have visited the Earth is becoming increasingly popular. Around a fifth of UK citizens believe Earth has been visited by extraterrestrials, and an estimated 7% believe that they have seen a UFO.

The figures are even higher in the US – and rising. The number of people who believe UFO sightings offer likely proof of alien life increased from 20% in 1996 to 34% in 2022. Some 24% of Americans say they’ve seen a UFO.

This belief is slightly paradoxical as we have zero evidence that aliens even exist. What's more, given the vast distances between star systems, it seems odd we'd only learn about them from a visit. Evidence for aliens is more likely to come from signals from faraway planets.

In a paper accepted for publication in the Proceedings of the International Astronomical Union, I argue that the belief in alien visitors is no longer a quirk, but a widespread societal problem.

The belief is now rising to the extent that politicians, at least in the U.S., feel they have to respond. The disclosure of information about claimed Unidentified Anomalous Phenomena (UAPs rather than UFOs) from the Pentagon has got a lot of bi-partisan attention in the country.

Much of it plays upon familiar anti-elite tropes that both parties have been ready to use, such as the idea that the military and a secretive cabal of private commercial interests are keeping the deep truth about alien visitation hidden. That truth is believed to involve sightings, abductions and reverse-engineered alien technology.

Belief in a cover-up is even higher than belief in alien visitation. In 2019, a Gallop poll found that a staggering 68% of Americans believed that "the U.S. government knows more about UFOs than it is telling."

This political trend has been decades in the making. Jimmy Carter promised document disclosure during his presidential campaign in 1976, several years after his own reported UFO sighting. Like so many other sightings, the simplest explanation is that he saw Venus. (That happens a lot.)

Hillary Clinton also suggested she wanted to "open [Pentagon] files as much as I can" during her presidential campaign against Donald Trump. As seen in the video below, Trump suggested he'd need to "think about" whether it was possible to declassify the so-called Roswell documentation (relating to the notorious claimed crash of a UFO and the recovery of alien bodies).

Former president Bill Clinton claimed to have sent his chief of staff, John Podesta, down to Area 51, a highly classified US Air Force facility, just in case any of the rumors about alien technology at the site were true. It is worth nothing that Podesta is a long-time enthusiast for all things to do with UFOs.

The most prominent current advocate of document disclosure is the Democratic Senate leader Chuck Schumer. His stripped back 2023 UAP disclosure bill for revealing some UAP records was co-sponsored by three Republican senators.

Pentagon disclosure finally began during the early stages of Joe Biden’s term of office, but so far there has been nothing to see. Nothing looks like an encounter. Nothing looks close.

Still, the background noise does not go away.

Problems for society

All this is ultimately encouraging conspiracy theories, which could undermine trust in democratic institutions. There have been humorous calls to storm Area 51. And after the storming of the Capitol in 2021, this now looks like an increasingly dangerous possibility.

Too much background noise about UFOs and UAPs can also get in the way of legitimate science communication about the possibility of finding microbial extraterrestrial life. Astrobiology, the science dealing with such matters, has a far less effective publicity machine than UFOlogy.

History, a YouTube channel part owned by Disney, regularly delivers shows about "ancient aliens." The show is now in its 20th season and the channel has 13.8 million subscribers. The NASA astrobiology channel has a hard won 20,000 subscribers. Actual science finds itself badly outnumbered by entertainment repackaged as factual.

Alien visitation narratives have also repeatedly tried to hijack and overwrite the history and mythology of indigenous people.

The first steps in this direction go back to Alexander Kazantsev's science fiction tale Explosion: The Story of a Hypothesis (1946). It presents the 1908 Tunguska meteorite impact event as a Nagasaki-like explosion of an alien spacecraft engine. In Kazantsev’s tale, a single giant black female survivor has been left stranded, equipped with special healing powers. This lead to her adoption as a shaman by the indigenous Evenki people.

NASA and the space science community do support efforts such as the Native Skywatchers initiative set up by the indigenous Ojibwe and Lakota communities to ensure the survival of storytelling about the stars. There is a real and extensive network of indigenous scholarship about these matters.

But UFOlogists promise a far higher profile for indigenous history in return for the mashing together of genuine indigenous stories about life arriving from the skies with fictional tales about UFOs, repackaged as suppressed history.

The modern alien visitation narrative has not, after all, emerged out of indigenous communities. Quite the opposite. It emerged in part as a way for conspiracy-minded thinkers in a Europe torn apart by racism to “explain” how complex urban civilizations in places like South America could have existed prior to European settlement.

Squeezed through a new age filter of 1960s counterculture, the narrative was flipped to value indigenous people as having once possessed advanced technology. Once upon a time, according to this view, every indigenous civilization was Wakanda, a fictional country appearing in American comic books published by Marvel Comics.

If all of this stayed in its own box, as entertaining fiction, then matters would be fine. But it doesn't, and they aren't. Visitation narratives tend to overwrite indigenous storytelling about sky and ground.

This is a problem for everyone, not just indigenous peoples struggling to continue authentic traditions. It threatens our grasp of the past. When it comes to insight into our remote ancestors, the remnants of prehistoric storytelling are few and precious, such as within indigenous storytelling about the stars.

Take the tales of the Pleiades, which date back in standard forms to at least 50,000 years ago.

This may be why these tales in particular are heavily targeted by alien visitation enthusiasts, some of whom even claim to be "Pleiadeans." No surprises, Pleiadeans do not look like the Lakota or Ojibwe, but are strikingly blond, blue-eyed and Nordic.

It is increasingly clear that belief in alien visitation is no longer just a fun speculation, but something that has real and damaging consequences.

This article is republished from The Conversation under a Creative Commons license. Read the original article.

The views expressed are those of the author and do not necessarily reflect the views of the publisher.

Alien: Romulus promises to cleverly mix the horror thrills of Ridley Scott's original 1979 masterpiece with the action-heavy 1986 sequel by James Cameron. If you're currently in the mood to get back into the iconic sci-fi series before it arrives, you'll want to read our in-depth examination of the Xenomorphs' many life stages and forms as seen in the movies.

The Alien movie franchise will soon expand with an Alien TV series too, which could keep the tradition of each creative team bringing their own sensibility to the universe alive. First, however, we've yet to see how Romulus strikes a balance between the first two classics while hopefully closing some of the gaps in the canon opened by Scott's Prometheus and Alien: Covenant, two divisive but fascinating prequels full of big ideas and bold swings.

Whether you're a newcomer to the Alien franchise or someone looking to get a full refresh before returning to theaters this summer, we recommend looking at our Alien movies in order and Alien movies ranked lists. There's also out best Alien games of all time list too, if you want to get in on the scares.

Egg

Of course, we can't start this exploration of the Xenomorph life cycle without the species' most basic form: the leathery (and rather large) eggs that were first seen in that memorable scene of the 1979 original. Characterized by their remarkable size and the 'goo' that covers them, as well as their four-lobed opening at the top, the alien eggs can seemingly lie dormant and wait for potential hosts (human, Engineer, or otherwise) for decades and maybe, given the Xenos' resilience and adaptiveness, even centuries.

Since the planned third entry of Scott's prequel trilogy never came to fruition and Romulus is taking the story to the period between Alien and Aliens, we don't really know the exact origin of the Engineer ship and the eggs inside it that the crew of the Nostromo found on LV-426 in the year 2122. 

We do know that Queens typically produce the eggs, but the original movie's novelization included the concept of 'eggmorphing' as the ultimate fate of Dallas and Brett, who'd been captured and cocooned by the Xenomorph roaming the Nostromo. The scene was reinstated partially in the movie's Director's Cut, and the eggmorphing process popped up again in other secondary Alien works, which is why many fans consider it a canonical ability of the species to reproduce and start the creation of a hive in the absence of a Queen.

Facehugger

Almost as iconic as the Xenomorph's main life stage is its facehugger form, which has become a mainstay of the movie series. Any living being that is caught by one of these is done for, as no non-lethal way to extract Xeno embryos and the ensuing chestbursters has been shown in the movies. 

The crab and spider-like facehuggers, whose fast movement and jumps are unsettling enough on their own, attach to a victim's face and release a strong paralytic chemical before latching on to their head with the legs. After the Xeno embryo is in place and can sustain itself inside the host, the facehugger detaches and dies. Any attempt to remove facehuggers is almost guaranteed to be fatal, as the parasite responds by tightening its grip on the victim and its acidic blood is as strong as that of an adult Xenomorph.

This stage of the life cycle is only skipped by the large Predalien, which was birthed from an impregnated Predator and first seen in Aliens vs. Predator: Requiem. That creature could directly produce and inject Xeno embryos into its victims, acting as the resulting hive's Queen.

Chestburster

The chestbursters represent the most unpredictable and fascinating stage of the aliens' life cycle, as what happens during this part of the evolution process defines the traits that shape the resulting Xenomorph. It seems that chestbursters are actually grown from the biological material of the hosts, which would explain why the resulting Xenos retain physical traits and even abilities from the living beings that unwittingly birth them later.

Typically, a chestburster violently erupts from the chest of its host, hence the nasty and disturbing nickname. It's at this stage when the Xenomorphs are most vulnerable, yet chestbursters are fast and silent once they escape their hosts' bodies. Once a secure location to cocoon and grow has been found, it'll become an adult Xenomorph in just a few hours.

Drone

The terrifying Xenomorph drone is the iconic alien in its most basic, recurrent, and memorable form — an almost perfect organism that's as lethal as it is industrious. Its main objective is to either grow or establish a hive, and will seek new hosts for gathering and impregnation, yet it can also kill any immediate threat to its integrity or the hive. Hosts other than humans produce different types of drones, such as the 'runner' birthed from a quadrupedal mammal on Fiorina 161 (Alien 3).

Drones are stronger and faster than a human, and are also extremely good climbers and jumpers. Moreover, like other adult Xenos, they appear to be able to survive even in the void of outer space. Its weapons are a piston-like tongue that is tipped with a second set of jaws, large claws, and the lance-like tip of its long tail. Even in death, they're savage, as any open wound will eject highly pressurized acid blood.

Warriors (and other adult Xenomorphs)

Once a hive is big enough, many drones will evolve into warriors, similar but more resilient Xenomorphs, often characterized by their 'ridged' heads. There are other subtypes which are tasked with more specific activities within and outside the hive. 

Much like drones, warriors and other subtypes retain the major DNA traits inherited from the hosts that birthed them, which means a Xenomorph hive and its population will be profoundly defined by the ecosystem that birthed it.

Praetorians could be considered an entirely different category, as they're considerably larger than other adult Xenomorphs (but still smaller than Queens). According to non-movie works, a handful of warriors are 'chosen' by the Queen and fed royal jelly, which leads to their transformation into the horrifying but majestic (due to the crown-like, flat crests) monstrosities tasked with protecting the leader of the hive.

Queen

The big boss and apex of the species is the Xenomorph Queen. Her highly iconic shape, coupled with the absolutely massive size for a terrestrial being, instantly granted Aliens' main villain a firm place among the best-ever monsters put on the big screen.

Queens are much larger and stronger than drones, warriors, and even praetorians. However, they're vulnerable while they're attached to the giant ovipositor that it uses to continuously lay eggs. They're not very fast, but can still surprise any unfortunate soul that isn't quick enough on their feet if they get agitated or are under extreme threat.

Video game and comic books have also introduced Empresses (Queens capable of ruling over several 'regular' Queens and their respective hives) and even the Queen Mothers, the absolute peak of the Xenomorph species, gigantic in size and far more intelligent than Empresses and Queens. As depicted in such works, the Queen Mothers can control all the Xenomorphs on a continent or planet. To this day, these definitive Xeno stages haven't been shown (or even referenced) in the movies, making them 'extended universe' additions.

Beyond the Xenomorph

Prometheus and Alien: Covenant, especially the former, put much of the focus on the Engineers and their other bioweapon efforts. Like it or not, the Xenomorphs in the current on-screen canon (which may clash with the Alien vs. Predator movies) are the product of the Engineers' experiments, much like mankind on Earth. The main weapon found by the unsuspecting humans and their Michael Fassbender-looking synthetics on LV-223 and Planet 4 was the 'black goo' that both created and destroyed life forms in unpredictable ways.

According to David's studies and experiments on Planet 4, an Engineer homeworld, the pathogen's primary purpose was to 'cleanse' planets of non-botanical life forms, yet the weapon proved to be more unstable than originally thought by its creators. Incompatible hosts were killed, and other beings were either mutated into monsters or became hosts for parasitic organisms similar to the Xenomorph facehugger. Unsurprisingly, those parasites also impregnated any living being that was big enough and produced alien lifeforms like the 'Deacon' on LV-223 and the 'Neomorphs' on Planet 4, which were remarkably close to the Xenomorphs as we know them.

While the main implication in Alien: Covenant is that David himself created the Xenomorph as seen in Alien and beyond after tinkering with the pathogen and the Engineers' scientific tools and knowledge, there are marked differences between the drones seen in the prequel and the one born from one of the eggs in LV-426. Moreover, the novelization of Covenant and some visual elements in the movie itself and the previous one offered enough wiggle room to consider that David could have simply revitalized an old Engineer bioweapon to create his own 'offshoot version' of the creature.

Word on the street is that Alien: Romulus might offer some answers for the remaining questions that the third Alien prequel was going to tackle, so maybe we'll end up with canon in a better place after Fede Álvarez's movie lands in August. However, the Alien TV series is supposedly set in a not-so-far future and on Earth, so chances are the flimsy lore will get even more complicated for diehard fans.

Xenomorph FAQs

A Quiet Place: Day One continues to terrorize theaters worldwide with strong box office numbers that are placing it even ahead of its two (mainline) predecessors, so we're likely to see more of the ferocious aliens that kill anything that makes a sound. However, there's much we don’t know about them yet and that information isn't really explored in the movies. In this article, we aim to answer your most burning questions.

As great as A Quiet Place: Day One turned out to be, it didn't really shine more light on the extraterrestrial invaders beyond one key scene we'll discuss later, so the two 'main' A Quiet Place installments are more important to understanding what these monsters from outer space are, how they live, and what their end goal is. A closer look at those two movies, coupled with interviews with the key creatives and behind-the-scenes trivia paints a clearer picture of the aliens' nature.

While we wait for official news on A Quiet Place Part III and whether or not it's directed by John Krasinski, there's a surprising video game based on the movies coming our way sooner rather than later, and its reveal trailer is thrilling. Way before that, an even more nightmare-inducing alien species will be returning to the big screen in Alien: Romulus.

Where are they from?

• A doomed world very different to ours.
• The aliens' planet was destroyed, but the creatures survived inside chunks of rock.
• Those rocks eventually crashed to Earth.

On Empire's podcast, all the way back in 2018, when the first movie was released, writer-director John Krasinski revealed much of the information that wasn't directly stated on-screen and confirmed numerous theories. Chief among them was the origin of the alien monsters, which he described as "predators" and "parasites" that "can’t be held back."

According to the filmmaker, the main idea behind the monsters, their design and unique capabilities is that they're "an evolutionarily perfect machine," only that they come from a planet very different from ours. Their doomed world had no living creatures that resembled anything on Earth and no light, at least not in the way that our system has light. As a direct result, they evolved to hunt by sound and protect themselves from harsh environments and conditions, which explains why they can't be hurt unless "they open themselves up."

Much like Krypton, the aliens' planet was destroyed, but most of the creatures managed to survive just fine floating adrift on (and inside) chunks of rocks across space for what we presume was a very long time. They're extremely resilient, seemingly don’t even need water and can survive the vacuum of outer space, so neither the destruction of the home planet nor crashing through Earth's atmosphere and on different points across the globe killed them off.

Biology

• Blind, but excellent hearing
• Heavily armored skin
• Extremely fast - up to 300 mph
• Can't swim
• Can't track prey in noisy environments

Echolocation completely replaced sight as the species evolved on their planet of origin. On top of that, the aliens' skin is nearly impenetrable and armor-like; possibly a sign of the unknown world having much harsher conditions and higher gravity than Earth. The density of their bodies, however, makes them bad swimmers, and it's been proven they can drown. Therefore, many communities of survivors were established on islands.

The creatures are slightly taller than humans; it’s their width that makes them bigger overall. The body posture kind of resembles that of gorillas and bats, and they seem to walk on their 'knuckles' rather than the end of their very long arms, which end on terrible three-finger claws used for hunting. In spite of their body density and very odd posture, they have proven to be extremely good climbers at fast speeds. On the ground, they can hit up to 300 miles per hour, so running away from them in a straight line and without turning their attention elsewhere is impossible.

Though their heads hide a large jaw filled with fearsome teeth, it doesn't appear to be used as a weapon. Moreover, it hasn't been confirmed whether they can smell or not. They’ve got several ears protected by the head and face's armor-like plates, and it's been reported they're so sensitive they can even detect small clocks – under normal conditions – from hundreds of meters (if not miles) away. However, their biggest known weakness comes from that strength: naturally noisy environments or phenomena, such as waterfalls and rainstorms, can hide noises that would usually attract them, plus certain high-frequency sound waves can render them almost completely helpless.

Do they eat humans?

• No, the 'Quiet Place' aliens don't eat humans.
• They didn't appear to eat anything at first.
• Day One showed them eating alien plants from the asteroids.

The most baffling thing about these aliens is that they don't kill for food. In fact, they don't seem to consume any terrestrial organisms. This is hinted at in the very first movie, and human corpses are seen mummified and largely intact in most cases. The creatures instinctively hunt down and silence any other animal or thing that’s too noisy for them.

So, how do they regain energy and stay fed? By and large, they seem to violate the laws of thermodynamics and physics, given their resilience to world-ending events and the vast emptiness of space, plus how fast and strong they are despite not consuming their prey for nutrients and energy.

A Quiet Place: Day One, however, shows the creatures eating alien plants that also came with the asteroids and survived the interstellar trip. It's safe to assume – unless stated otherwise in a future entry – that these plants can reproduce as quickly as (if not more than) the creatures, which can't eat anything on Earth because of incompatible biologies.

Behind the scenes

• Aliens have no official name, but they're nicknamed 'Death Angels'
• We have no idea how many there are on Earth

As it stands, the aliens don't have an official name in marketing materials or in-universe, but a newspaper clipping seen in the original movie calls them 'Death Angels,' which is kind of fitting given their long, almost wing-like, arms and the fact they fell from the sky.

The total population of 'Death Angels' on Earth hasn't been revealed either. We do know, however, that several asteroids hit U.S. soil, and their numbers in New York were far greater than in the less populated rural areas seen in the two mainline A Quiet Place movies. Their rate of reproduction and expansion hasn't been unveiled either, but the post-arrival timeline is only monthslong so far. Krasinski has stated in the past he's more interested in the more intimate stories happening during this apocalypse rather than making a traditional alien invasion movie, so we're not expecting to learn about global matters.

Another fun fact about the 'Death Angels' is that Krasinski himself also provided some motion capture for them, with ILM handling the CGI and adding a few extra touches to the final design that came from ancient bog bodies.

If aliens wrap their planets in potent greenhouse gases like we do, we'd be able to tell.

That's according to a recent thought experiment in which scientists identified five "artificial" greenhouse gases that, if abundant enough, can be spotted in the atmospheres of certain exoplanets using existing technology, including the James Webb Space Telescope (JWST). 

The gases, which include fluorinated versions of methane, ethane, propane, on Earth are known to be some of the most potent and persistent heat-trapping gases emitted by humans during various industrial manufacturing processes, like those used to produce semiconductors, for instance. Because these substances don't naturally form in large quantities — if we're going by Earth chemistry, at least — spotting them in an exoplanet's air would signal the presence of technologically-advanced species, scientists say.

On Earth, these gases are dangerous pollutants, and limiting their emissions is crucial to combat human-driven climate change. Their presence in an alien atmosphere may not necessarily be bad news, however.

"For us, these gases are bad because we don't want to increase warming," study lead author Edward Schwieterman of the University of California, Riverside, said in a recent statement. "But they'd be good for a civilization that perhaps wanted to forestall an impending ice age or terraform an otherwise-uninhabitable planet in their system, as humans have proposed for Mars."

Related: NASA space telescope finds Earth-size exoplanet that's 'not a bad place' to hunt for life

 Such intentional climate modification to create an Earth-like environment is known as terraforming. The idea of terraforming Mars has sprouted in almost every sci-fi story, and, in recent years, scientists too have proposed similar approaches to support long-term colonization. Ideas to warm Mars include thawing some of the ice in the planet's poles and releasing carbon dioxide trapped in its surface to buttress the planet's thin atmosphere like a warm blanket. Although, some remain skeptical about the concept. For instance, Paul Sutter, an astrophysicist at SUNY Stony Brook and Space.com contributor, wrote in a 2021 article that this type of terraforming effort probably won't work, crucially because Mars likely doesn't host enough carbon dioxide to trigger a decent warming trend.

More recently, Schwieterman and his colleagues simulated a planet in the TRAPPIST-1 system, which is a family of seven rocky planets about 40 light-years away from Earth in the constellation Aquarius; several of them are considered potentially habitable. The planet, TRAPPIST-1f, for example, circles its host star every nine days within its habitable zone.

If aliens were to terraform such a planet, the researchers found the JWST could identify the five greenhouse gases. One among them, sulfur hexafluoride, has a warming potential that exceeds carbon dioxide by 23,500 times. Minuscule amounts of this gas, which has a lifetime of at least 1,000 years, is sufficient to thaw an icy planet to a point where life-supporting liquid water flows on its surface, the researchers say. (Life as we know it, to be clear).

"The long lifetime makes these gases excellent technosignatures to systematically search for in comparison to shorter-lived signals," study co-author Daniel Angerhausen of ETH Zürich said in another statement. "These signatures might even outlive their civilization if their geoengineering experiments were to fail."

Other similar, fluorinated gases may hover in an Earth-like atmosphere for up to 50,000 years, so "they wouldn't need to be replenished too often for a hospitable climate to be maintained," Schwieterman said in the statement. 

That means if extraterrestrial life in frigid planets beyond our solar system pumps a bunch of greenhouse gases into their atmospheres to make their worlds more habitable, our existing telescopes might be able to spot them. Even if only one out of every million gas molecules sucked in infrared radiation from its host star, it would produce a tell-tale signature detectable with the JWST and other space-based telescopes, Schwieterman and his team found. 

"You wouldn't need extra effort to look for these technosignatures, if your telescope is already characterizing the planet for other reasons," said Schwieterman. "And it would be jaw-droppingly amazing to find them." 

These findings are described in a paper published June 25 in The Astrophysical Journal.

This article was originally published at The Conversation. The publication contributed the article to Space.com's Expert Voices: Op-Ed & Insights.

Michael Garrett is the Sir Bernard Lovell chair of Astrophysics and Director of Jodrell Bank Centre for Astrophysics, University of Manchester.

Artificial intelligence (AI) has progressed at an astounding pace over the last few years. Some scientists are now looking towards the development of artificial superintelligence (ASI) — a form of AI that would not only surpass human intelligence but would not be bound by the learning speeds of humans.

But what if this milestone isn't just a remarkable achievement? What if it also represents a formidable bottleneck in the development of all civilizations, one so challenging that it thwarts their long-term survival?

Related: Could AI find alien life faster than humans, and would it tell us?

This idea is at the heart of a research paper I recently published in Acta Astronautica. Could AI be the universe's "great filter" – a threshold so hard to overcome that it prevents most life from evolving into space-faring civilizations?

This is a concept that might explain why the search for extraterrestrial intelligence (SETI) has yet to detect the signatures of advanced technical civilizations elsewhere in the galaxy.

The great filter hypothesis is ultimately a proposed solution to the Fermi Paradox. This questions why, in a universe vast and ancient enough to host billions of potentially habitable planets, we have not detected any signs of alien civilizations. The hypothesis suggests there are insurmountable hurdles in the evolutionary timeline of civilizations that prevent them from developing into space-faring entities.

I believe the emergence of ASI could be such a filter. AI's rapid advancement, potentially leading to ASI, may intersect with a critical phase in a civilization's development – the transition from a single-planet species to a multiplanetary one.

This is where many civilizations could falter, with AI making much more rapid progress than our ability either to control it or sustainably explore and populate our Solar System.

The challenge with AI, and specifically ASI, lies in its autonomous, self-amplifying and improving nature. It possesses the potential to enhance its own capabilities at a speed that outpaces our own evolutionary timelines without AI.

The potential for something to go badly wrong is enormous, leading to the downfall of both biological and AI civilizations before they ever get the chance to become multiplanetary. For example, if nations increasingly rely on and cede power to autonomous AI systems that compete against each other, military capabilities could be used to kill and destroy on an unprecedented scale. This could potentially lead to the destruction of our entire civilization, including the AI systems themselves.

In this scenario, I estimate the typical longevity of a technological civilization might be less than 100 years. That's roughly the time between being able to receive and broadcast signals between the stars (1960), and the estimated emergence of ASI (2040) on Earth. This is alarmingly short when set against the cosmic timescale of billions of years.

This estimate, when plugged into optimistic versions of the Drake equation – which attempts to estimate the number of active, communicative extraterrestrial civilizations in the Milky Way – suggests that, at any given time, there are only a handful of intelligent civilizations out there. Moreover, like us, their relatively modest technological activities could make them quite challenging to detect.

Wake-up call

This research is not simply a cautionary tale of potential doom. It serves as a wake-up call for humanity to establish robust regulatory frameworks to guide the development of AI, including military systems.

This is not just about preventing the malevolent use of AI on Earth; it’s also about ensuring the evolution of AI aligns with the long-term survival of our species. It suggests we need to put more resources into becoming a multiplanetary society as soon as possible – a goal that has lain dormant since the heady days of the Apollo project, but has lately been reignited by advances made by private companies.

As the historian Yuval Noah Harari noted, nothing in history has prepared us for the impact of introducing non-conscious, super-intelligent entities to our planet. Recently, the implications of autonomous AI decision-making have led to calls from prominent leaders in the field for a moratorium on the development of AI, until a responsible form of control and regulation can be introduced.

But even if every country agreed to abide by strict rules and regulation, rogue organizations will be difficult to rein in.

The integration of autonomous AI in military defense systems has to be an area of particular concern. There is already evidence that humans will voluntarily relinquish significant power to increasingly capable systems, because they can carry out useful tasks much more rapidly and effectively without human intervention. Governments are therefore reluctant to regulate in this area given the strategic advantages AI offers, as has been recently and devastatingly demonstrated in Gaza.

This means we already edge dangerously close to a precipice where autonomous weapons operate beyond ethical boundaries and sidestep international law. In such a world, surrendering power to AI systems in order to gain a tactical advantage could inadvertently set off a chain of rapidly escalating, highly destructive events. In the blink of an eye, the collective intelligence of our planet could be obliterated.

Humanity is at a crucial point in its technological trajectory. Our actions now could determine whether we become an enduring interstellar civilization, or succumb to the challenges posed by our own creations.

Using SETI as a lens through which we can examine our future development adds a new dimension to the discussion on the future of AI. It is up to all of us to ensure that when we reach for the stars, we do so not as a cautionary tale for other civilizations, but as a beacon of hope – a species that learned to thrive alongside AI.

Originally published at The Conversation.

Elon Musk isn't convinced that aliens have ever visited Earth. 

The SpaceX CEO and founder sat down for a panel titled "How to save the human race and other light topics" at the 2024 Milken Institute Global Conference held in Los Angeles on Tuesday (May 7). During the conversation, the institute's chairman, financier Michael Milken, began by asking Musk how he feels about the well-known opening monologue to many "Star Trek" series, in which it is stated that the starship Enterprise's mission is to "seek out new life forms and new civilizations." Musk replied, "Yeah, that's the idea."

Musk elaborated, stating that if we send probes out into the universe, we might find "remains of long-dead alien civilizations." He then launched into an explanation about why he doesn't feel aliens have ever visited our planet.

Related: SpaceX's Starship will go interstellar someday, Elon Musk says

Musk told Milken that he is frequently asked if he believes aliens are among us here on Earth, acknowledging how widespread that belief is. "And for some reason, a lot of the same people who think there are aliens among us don't think we went to the moon, which, I'm like: 'Think about that for a second,'" Musk said to laughter from the audience.

Musk elaborated on why he doesn't believe aliens have visited our planet, stating that, even with the thousands of broadband spacecraft that SpaceX operates in low Earth orbit, he hasn't once seen any compelling evidence of either extraterrestrial life or any potential craft operated by non-human intelligence.

"I've not seen any evidence of aliens," Musk said. "And SpaceX, with the Starlink constellation, has roughly 6,000 satellites, and not once have we had to maneuver around a UFO. [...] Never. So I'm like, okay, I don't see any evidence of aliens."

But, like many people, Musk said that he's open to considering the possibility of alien visitation, if indeed there is any compelling proof. "If somebody has evidence of aliens, you know, that's not just a fuzzy blob, then I'd love to see it, love to hear about it," Musk said. "But I don't think there is."

The SpaceX CEO then pointed out how concerning the lack of any evidence of alien civilizations is for the future of humanity, opining that, even if an ancient civilization managed to last a million years, it should have easily been able to explore and settle the entire Milky Way galaxy.

"So, they haven't, so why not?" Musk asked.

"I think the answer might be, probably, is that that civilization is precarious, and rare. And that we should really think of human civilization as being like a tiny candle in a vast darkness. And we should do everything possible to ensure that that candle does not go out."

Despite having never had to move out of the way of a UFO, Starlink satellites do, in fact, regularly make avoidance maneuvers to dodge debris or other spacecraft. Between June 1, 2023, and Nov. 30, 2023, Starlink satellites performed 24,410 collision avoidance maneuvers, equivalent to six maneuvers per spacecraft, according to data collected by SpaceX reported to the U.S. Federal Communications Commission (FCC).

Happy Alien Day 2024!

"Alien Day" (April 26) has arrived, that annual occasion for all xenomorph acolytes to immerse themselves in the legends and lore of the storied "Alien" franchise that first hatched way back on May 25, 1979 to create one of the most frightening cinematic universes in Hollywood history. 

Officially promoted by 20th Century Fox beginning in 2016, Alien Day gets its name from the designation numerals of the LV-426 planetoid where "Alien's" space truckers discover a nightmarish derelict spaceship housing a horrifying secret. 

Related: Alien movies in order: chronological and release

Now for a limited time starting April 26, in honor of the 45th anniversary of 'Alien,' multiplex audiences can re-experience the sheer terror in a darkened theater once again, surrounded by petrified fellow patrons to witness the crew of the commercial towing vessel Nostromo being stalked by a marauding biomechanical creature with no conscience and concentrated acid for blood.

Directed by a youthful Ridley Scott from an original screenplay by Dan O’Bannon and Ron Shusett, "Alien's" stellar cast included Tom Skerritt, Sigourney Weaver, Yaphet Kotto, Veronica Cartwright, Harry Dean Stanton, John Hurt, and Ian Holm. Fans attending these special anniversary screenings will also be treated to an engaging conversation between Ridley Scott and Fede Alvarez, the director/writer of this summer's theatrical release, "Alien: Romulus."

In other Alien Day news, an upcoming documentary titled "Aliens Expanded" seeks to crack open the memories behind the making of James Cameron's 1986 "Alien" sequel and we have an exclusive chat with its director, British filmmaker Ian Nathan.

Here's the official description:

'Join the 'Aliens' cast & crew, including James Cameron (Writer & Director), Gale Anne Hurd (Producer), Michael Biehn (Hicks), Lance Henriksen (Bishop)  Mark Rolston (Drake), Jenette Goldstein (Vasquez), William Hope (Gorman) and Carrie Henn (Newt), on a deep dive into this science-fiction classic. Brimming with stories, insight, and wonderful personal detail, this four-hour documentary is the most passionate and sophisticated exploration of 'Aliens' ever made; a love letter to the people who made it and the communities who adore it, reflecting and enhancing the incredible legacy of this beloved epic."

London-born director Ian Nathan first saw "Aliens" when he was sixteen with his dad, in a hot cinema full to the brim, and he’s still not sure that he’s ever had an equivalent experience. His goal was to create an in-depth exploration of Cameron's iconic film and discover new info and insights along the way with the cast and crew.

"I was enslaved to that film, gripped like a vice," Nathan tells Space.com. "After the med-lab scene with the facehuggers, right up until the power loader, I had to remind myself to breathe. It was that thrilling. But I have come to understand that so much of that immersion is because James Cameron made me care so much about those characters. Beyond its place as a science fiction great, and a horror great, it is a perfect character piece. And even now, having seen it countless times, if I catch it on the box, I am there to the end, still willing them to survive." 

Having Cameron on board to share never-heard tales of his trials, tribulations, and purity of vision in making "Aliens" was a true masterclass in filmmaking for Nathan. When asked to recall his favorite scene in the 1986 classic, he's quick to respond.

"This is easy. I've known it since the night I first saw the film," he explains. "It's the crucial scene in the film, because this is when Ripley takes charge. Not because she wants to, but because she has to. She is a born leader. The marine incursion into the nest has gone to hell, chaos reigns, and Gorman is cracking up. Ripley is screaming at him. 'Do something!' Then she throws off her headset, secures Newt, and takes control of the APC. The drums kick in on the soundtrack and she rams that thing into the nest to rescue whichever survivors she can. It's Ripley's mission now." 

Fans can order "Aliens Expanded" by May 5 to get their name placed in the credits and score exclusive merchandise, with an expected June digital delivery date and physical copies coming in July.

How do you tell the difference between a spaceship and a space rock?  

For astronomers like me, this question has proved tricky — so tricky that we were very nearly fooled when the first recorded interstellar object, named 'Oumuamua, was spotted passing through the inner solar system in 2017.

Astronomers once thought that any object moving under its own speed, with no visible means of propulsion, would have to be artificial technology. We knew how 'Oumuamua should behave if it were an interstellar space rock, or so we thought, but in every way it acted the exact opposite. 

Related: 'Oumuamua: The solar system's 1st interstellar visitor explained in photos

As 'Oumuamua sped through the solar system, we only had a few weeks during which we were able to monitor it with our telescopes across the world. These observations showed that the object came from outside the solar system, and was extremely elongated and tumbling. 'Oumuamua displayed no comet-like tail but still moved under its own propulsion. 

Comets also move under their own propulsion, but they display beautiful tails caused by dust and ice blown off their surfaces, which also causes a rocket-like recoil. 'Oumuamua was different. Its mysterious flight through our solar system sparked whispers of an artificial provenance. Some astronomers even called it Rama.  

The true explanation, which we determined from its motion and the amount of energy it received from the sun, is just as strange: an entirely new kind of object. We call them "dark comets." Since we spotted 'Oumuamua, we have found a population of seven dark comets hiding among our solar system's asteroids. They get their name because they move like a comet, but display no dust tail.  

Visitors from beyond the solar system — interstellar travelers — have long been predicted by science fiction writers like Arthur C. Clarke, but in reality, it's not so easy to identify what we're seeing — or just how many interstellar space rocks, or spaceships, are in Earth's neighborhood at a given time. This difficulty came to a head as we rushed to make sense of 'Oumuamua, but with new telescopes like the James Webb Space Telescope (JWST) and the forthcoming Rubin Observatory Legacy Survey of Space and Time (LSST) in the Atacama Desert in Chile, we'll have the tools we need to make sense of future interstellar travelers — and expand our understanding of the cosmos.  

If only we'd had the JWST when 'Oumuamua was discovered, we would have been able to take more detailed images of the object and get information about how it looked in different wavelengths of light. By doing this, we could have better understood what was propelling it through space. We would have seen molecules like water or carbon dioxide that only show up at certain wavelengths and don't reflect sunlight. We routinely see normal solar system comets being propelled as their surfaces heat up and water and carbon dioxide ice transform into gas. We would have identified it immediately as a dark comet-like object. The good news is, if we spot another 'Oumuamua, we already have an approved JWST program to monitor it.  

Related: James Webb Space Telescope (JWST) — A complete guide

In the future, the JWST won't be the only powerful tool in our toolkit. The LSST, set to come online in the next year or so, should detect many more interstellar objects and be able to identify dark comets in our own solar system. Located in the Atacama Desert, a prime spot for viewing the heavens, the LSST will start scanning the entire Southern Hemisphere sky almost every night. The LSST will be able to spot much fainter objects than any of our surveys that currently monitor the entire sky for rapidly moving objects. It will be able to detect mysterious objects like 'Oumuamua that are dimmer, either because they are smaller or farther away from the Earth. The LSST will also be able to find many more smaller asteroids, and will be able to spot if they are dark comets and moving under their own propulsion. 

It's possible that when the LSST makes first light, we will start detecting interstellar objects on a monthly — or even weekly — basis. Some of these may be dark like 'Oumuamua, and some may be brighter with beautiful tails, like the second interstellar comet, 2I/Borisov.   

It may turn out that the sky close to the Earth is teeming with interstellar objects even smaller than 'Oumuamua, all of which were invisible up until now. These small interstellar visitors could quite plausibly be continuously whizzing through the Earth's neighborhood within the solar system. If that ends up happening, then the LSST might spot an interstellar target close enough for a dedicated space mission.  

Close encounters with an interstellar visitor will no longer be a topic reserved for science fiction writers. 

With the LSST and JWST, we have the tools to tell the difference between an intelligent visitor and an interstellar dark comet. Let's not get fooled. 

Darryl Seligman is a research associate in the Department of Astronomy at Cornell University. His research focuses primarily on theoretical and computational planetary science and astrophysics. 

It's called xenolinguistics: Looking at the science of extraterrestrial language. 

Biologists, anthropologists, linguists and other experts specializing in language and communication have begun to explore what non-human, off-Earth language might look like. 

Arguably, such thinking sparks thought about the fabricated Klingon language, the cosmic "Klingonese" chatter spoken by one the alien species on "Star Trek." There's even a thriving Klingon Language Institute, which was founded in 1992.

But you can put sci-fi aside, for scientists in the real world are investigating the possible forms that alien languages might take — and whether we might be able to understand them.

Related: The search for alien life

Off-Earth intelligence

Astrobiologist Douglas Vakoch is president of Messaging Extraterrestrial Intelligence (METI International) in San Francisco. He's co-editor with Jeffrey Punske of a new volume, "Xenolinguistics: Towards a Science of Extraterrestrial Language" (Routledge Taylor & Francis Group (2023).

The book is anchored in what is known about human language and animal communication systems, but it offers suggestions about what we may find if we encounter non-Earth intelligence.

For over six decades, researchers have been engaged in the search for extraterrestrial Intelligence (SETI), listening for signals with radio telescopes — and they could succeed tomorrow, Vakoch told Space.com. (METI, as its name suggests, concerns the possibility of communicating with alien intelligence — making meaningful contact.)

"We might be faced with understanding a message from an unknown civilization, and linguists could provide the key to cracking the code," said Vakoch. "The recommendations coming out of our new book are directly shaping how we will say 'Hello, universe.'"

Vakoch highlighted the importance of communicating our intentions as the hallmark and rationale for METI messages. "Another key question is whether universal grammar of the sort we see across languages on Earth will also hold true more broadly in the universe," he says.

As noted in the volume, one major point is that communication involves more than getting across the content of your message. "You also want to communicate your intention," said Vakoch.

Related: If aliens have visited the solar system, here's how to find clues they left

Start a conversation

One of the common objections to METI, Vakoch pointed out, is that we may alert hostile extraterrestrials to our existence and provoke an alien invasion. 

"In reality, any civilization with the capacity to travel between the stars also has the technology to pick up the accidental radio and television signals that have been leaking off into space for the past century," Vakoch said. 

So any aliens picking up our targeted messages won't be surprised to know we exist, Vakoch added. "But what will surprise them is that we're attempting to start a conversation. That's the whole point of METI — to get across our intention of making first contact."

Universal principles

Vakoch said that the aliens he is most interested in are the ones we can make contact with. 

"Those are the aliens who have developed the technology to transmit and receive radio signals. In the past, when scientists have sent interstellar messages, this shared technology has provided the foundation for crafting the messages." 

The messages we've sent into space so far have relied on possibly universal principles of math and science as a starting point, said Vakoch. "But maybe there's something more basic. Long before humans had math and science, we had language. Maybe the same is true on planets orbiting other stars."

In the end, Vakoch thinks, the idea that we must choose between either math and science, on one hand, or language, on the other, is itself too simplistic.

Core of language

Co-editor of the new xenolinguistics book is Jeffrey Punske, an associate professor and the director of undergraduate studies in linguistics at Southern Illinois University in Carbondale. 

What we define as the core of language may be fundamentally constrained by external considerations. If so, then it is almost certain that a linguistic, non-human intelligence would have the same core of language, Punske suggests. 

"However, there are many aspects of language that are universal to human language that cannot solely be attributed to such externals," he said. "Those aspects are likely products of the structure of human cognition. There is certainly no guarantee that a non-human intelligence would share our cognitive systems. Thus, while the underlying structure of language might be the same, the message might not be interpretable."

New perspective

Excited that scientists are beginning to think seriously about xenolinguistics is Bridget Samuels of the University of Southern California (USC). 

Samuels is conducting research in two areas that address where universal grammar may fit in the universe: How did language arise in our species, and what are the limits of variation in human language? 

"The study of animal communication has exploded in recent years, and it's given us a new perspective on how human language is, and isn't, unique," Samuels, the project director at USC's Center for Craniofacial Molecular Biology, told Space.com. "Also, how communication systems are shaped by the unique cognitive abilities of the organisms that use them, as well as by the environmental niches they inhabit." 

Invariant laws of physics

Those lines of inquiry, combined with a "third factor" in language design — factors that shape language beyond our genetic endowment and experience — have set the stage for theorizing in entirely new ways about universal grammar, Samuels said.

That theorizing has helped Samuels shape and share a prediction with Punske: "Some aspects of language syntax and externalization may even be shared by extraterrestrial languages, as they are constrained by invariant laws of physics."

By pondering language and animal communication in a cosmic context, Vakoch said, we are forced to rethink just how unique language is, even on our own planet — whether or not we ever make contact with extraterrestrials. 

"Xenolinguistics shows that human language may not have the privileged position we've always assumed," he said.

Hey, aliens! Lexington, Kentucky would be a good place to spend your next deep-space vacation.

This was the message that a group of Kentucky scientists, linguists and scholars recently beamed at the TRAPPIST-1 system, which lies 40 light-years from Earth and harbors multiple potentially habitable planets.

The missive represented the very first interstellar travel advertisement, according to VisitLEX, the group behind the effort.

Related: The search for alien life

VisitLEX's tourism team at the Lexington Convention and Visitors Bureau partnered with the Cornett ad agency to devise a playful campaign with sci-fi flavor. The team used a modified infrared laser to deliver a specially coded message, which was approved by the U.S. Federal Aviation Administration. 

Here are details from the VisitLEX press release:

"When the message reaches its destination in 2063, TRAPPIST-1 inhabitants will find a coded bitmap image with clues as to its origin and intent of the transmission. They'll also see bucolic photos of the Horse Capital of the World, noting the wide-open spaces perfect for landing a spacecraft. They'll learn why Lexington has the best food, bourbon and music on Earth — getting a taste via an audio recording from legendary blues musician Tee Dee Young."

If E.T. does eventually receive the message and pack their bags for our solar system, eager to take in The Bluegrass State's hospitality, thoroughbred race horses and bourbon industry, they'll have to cover 235 trillion miles (378 trillion kilometers) to get here. That's a bit of a trip, but who knows how fast their craft can go?

"We are targeting the TRAPPIST-1 system because we might actually get an answer in somebody's lifetime if there's somebody there watching," said astrobiologist and SETI (search for extraterrestrial intelligence) scientist Robert Lodder. "But the reason scientists have been interested in it lately is because of the large number of planets it has in what is considered to be the habitable zone. So, there could be life there. Why not send a signal and see if they answer?"

This message was sent last month from Lexington's Kentucky Horse Park museum and event center, during a festive evening ceremony that drew a sign-waving crowd. 

"The bitmap image is the key to it all. We included imagery representing the elements of life, our iconic Lexington rolling hills and the molecular structure for water, bourbon and even dopamine … because Lexington is fun!" added linguistics expert Andrew Byrd.

A new study calls for humanity to prepare for an encounter with extraterrestrial intelligence and examines the possible social consequences of such contact.

First of all, the consequences of first contact strongly depend on the way it takes place. The paper offers the view that first contact with alien life poses considerable risks for humanity. Additionally, a first contact event could also take place without being culturally recognized.

The intriguing new research paper is led by Andreas Anton of the Institute for Frontier Areas of Psychology and Mental Health in Freiburg, Germany.

Related: The search for alien life

Scenarios

Anton and colleagues serve up a set of scenarios:

• The signal scenario is the basis of SETI (search for extraterrestrial intelligence) programs, in which radio astronomers search for signs of alien civilizations. It assumes that radio telescopes can pick up artificial signals from the far reaches of space.
• The technosignature scenario envisions that future powerful telescopes will find evidence of past or present extraterrestrial technology.
• The artifact scenario assumes that one day, somewhere in our solar system (or even on Earth itself), we will come across the material remains — such as a space probe — of an extraterrestrial civilization.
• The encounter scenario involves the appearance of an alien spacecraft in near-Earth space that can be assumed, based on its flight maneuvers or other actions, to be controlled by intelligence, either biological or artificial.

Biological beings or artificial intelligence?

The prospect of an encounter scenario, the paper points out, raises an important question: Whether the alien technology is controlled by a biological life form or an artificial intelligence.

"A biological life form, we suspect, could potentially cause greater anxiety, as the immediate question would be what 'they' want here. It also has an inbuilt assumption that they have a relatively nearby base or have superfast travel (maybe faster than light) and would thus be very far ahead of us technologically," Anton and co-authors write in their paper. 

"However, the question of whether the encounter is with a biological life form or the emissaries of a machine civilization could remain unresolved for a long time," they add.

Be prepared

The paper concludes by acknowledging that the more we know about the universe and the further we penetrate into the cosmos through our own research activities, "the more likely it is that we will be confronted with alien civilizations, their signals or their legacies."

That being the case, the researchers suggest, humanity needs to be prepared as a global society for this scenario.

"In the political sphere, the question of how to deal with this discovery and possible communication with extraterrestrial civilizations would lead to a global discourse," they write in the paper. "International cooperation would be essential to develop a unified approach to dealing with this new reality."

 This research paper, titled "Meeting extraterrestrials: Scenarios of first contact from the perspective of exosociology," is available here. 

Humpback whale "conversations" provide valuable insight on how humans may one day communicate with life beyond Earth. 

Researchers from the SETI Institute, University of California Davis and the Alaska Whale Foundation recently "conversed" with a humpback whale named Twain using an underwater speaker and recorded a humpback "contact" call. Twain responded to the researchers' call by matching the interval variations between signals of each playback call over a 20-minute period. 

If you're having a Star Trek flashback, yes, this is awfully reminiscent of that one film in which the crew receives alien whale transmissions that can only be decoded underwater. And in fact, mirroring our sci-fi fantasies, this demonstration of interspecies communication has implications for the search for extraterrestrial intelligence, according to a statement from the SETI Institute. 

"We believe this is the first such communicative exchange between humans and humpback whales in the humpback ‘language,'" Brenda McCowan, lead author of the study from U.C. Davis, said in the statement. 

Related: Why are we still searching for intelligent alien life?

Much like how astronaut crews simulate missions to Mars or the moon on Earth, the Whale-SETI team is studying humpback whale communication systems to better understand how to detect and interpret signals from outer space. Their findings can be used to develop filters that can be applied to any extraterrestrial signals received, according to the statement. 

"Because of current limitations on technology, an important assumption of the search for extraterrestrial intelligence is that extraterrestrials will be interested in making contact and so target human receivers," Laurance Doyle, coauthor of the study from the SETI Institute, said in the statement. "This important assumption is certainly supported by the behavior of humpback whales."

Twain's response to each playback call showcases a sophisticated level of understanding and interaction. The humpback whale approached and circled the team’s boat upon hearing the contact call played via an underwater speaker. Matching the interval variations between each call mirrors a human-like conversational style, according to the study. 

"Humpback whales are extremely intelligent, have complex social systems, make tools — nets out of bubbles to catch fish — and communicate extensively with both songs and social calls," Fred Sharpe, co-author of the study from the Alaska Whale Foundation, said in the statement. 

Therefore, working with humpback whales offers a unique opportunity to study intelligent communication in non-human species. The team will apply principles of information theory to develop filters that can aid in processing extraterrestrial signals and the search for intelligent life beyond Earth.

Their findings were published Nov. 29 in the journal PeerJ.

Microscopic metallic spheres recovered from the Pacific Ocean are likely the result of manmade industrial pollution — rather than pieces of an interstellar meteor — according to several new studies.

Last summer, Harvard astrophysicist and extraterrestrial hunter Avi Loeb declared that several tiny, metallic balls dredged up from the bottom of the ocean were likely remnants from an interstellar meteorite, and could even contain signatures of alien technology. Now, independent analysis suggests the spheres have a much less distant origin: They are more likely a by-product of burning coal on Earth.

Related: 'Galileo Project' will search for evidence of extraterrestrial life from the technology it leaves behind

Loeb and his colleagues found the micrometer-sized spherules during an expedition off the coast of Papua New Guinea in search of fragments of a meteor that streaked through the atmosphere in 2014.

Based on the meteor's recorded speed, Loeb and his team said that it was likely interstellar in origin — and that it must have left debris in its wake. The dredged-up spheres, they suggested, are that debris, as their composition is different from that of most meteorites.

In several blog posts and a non-peer-reviewed paper posted to the preprint database arXiv, Loeb described the various "anomalous" properties of the metallic pellets. He zeroed in on five spherules in particular that contained a high percentage of beryllium, lanthanum and uranium. Loeb dubbed these five "BeLaU spherules". He and others have since speculated that the weird spheres might be evidence of alien technology.

But many scientists unrelated to the research took issue with these claims at the time — and now, several newly published studies poke additional holes in the supposed extraterrestrial origins of the spherules.

Interstellar rock, or manmade pollution?

First, there is some debate as to whether or not the meteor in question was actually interstellar. It was only recorded by U.S. military equipment, and some researchers say that it's possible the sensors made a mistake when recording its speed, according to a new non-peer-reviewed paper posted to arXiv on Nov. 13. However, even if the meteor's speed was correctly recorded, odds are low that any significant pieces of it would survive the fall through the atmosphere.

"If interstellar, practically none of the 2014-01-08 bolide would have survived entry," the authors of the new study — professors Steven Desch of Arizona State University and Alan Jackson of Towson University — wrote. "If it were traveling at the speeds that were reported (and necessary to be interstellar), then at least 99.8%, and probably > 99.9999% of it would have vaporized in the atmosphere, leaving insignificant quantities to be deposited on the seafloor."

Then, there's the issue of proving the spheres came from that particular meteor. Scientists don't know where or even whether the 2014 meteor landed; it would be extremely difficult to find tiny pieces of that exact specimen by searching the ocean within a 30-mile (48 kilometers) radius nearly 10 years after it appeared. On the other hand, little metal balls are ubiquitous on the seafloor. Some are micrometeorites shed by passing space rocks, but others are spewed out by volcanoes or produced by industrial activity. These naturally collect at the bottom of the ocean over time.

Finally, there is the question of the spheres' makeup.  If you start from the assumption that these particular pellets originated in space, then their composition does indeed seem unusual. However, as a recent paper published Oct. 23 in the journal Research Notes of the AAS points out, they match the profile of coal ash contaminants. Study author Patricio Gallardo, an astronomer at the University of Chicago, wrote that, because of this, "the meteoritic origin is disfavored."

Is it still possible that the spherules came from somewhere outside our solar system? Yes. But, based on the available evidence, it appears far more likely that they originated much closer to home, the new papers suggest. As NASA astrobiologist Caleb Scharf wrote on X, formerly known as Twitter, "Well, they did indeed discover evidence of a technological civilization…right here on Earth."

Loeb refutes critics

Loeb responded to these criticisms in a Nov. 15 blog post on Medium, arguing that the new papers cannot adequately assess the composition of the spherules without studying them directly.

He went on to quote team member Jim Lem of the Papua New Guinea University of Technology, writing: "The region where the expedition was carried, should have no coal mineralization. In addition, coal is non-magnetic and cannot be picked up by the magnetic sled that was used."

Loeb added that 93% of the collected samples have yet to be analyzed, cautioning critics not to jump to conclusions about their origins until all the data is in. To make definitive claims about the spherules' nature before they are properly analyzed in a peer-reviewed study would be "unprofessional," Loeb said.

Is there anybody out there in space?

It's a question we've all wondered. Given all of the advances in space telescopes, robotic missions to other planets and even the wild headlines related to UFOs and possible extraterrestrial visitation these days, the question can seem more pressing than ever. And for children, the question can feel frightening, fascinating and everything in between, given some of the sensationalism that surrounds the subject.

To help sort out fact from fiction, author and podcast host Laura Krantz has written "Is There Anybody Out There?: The Search for Extraterrestrial Life, from Amoebas to Aliens," a new book from Abrams Books for Young Readers coming out on Oct. 3, 2023. The book takes a rational look at the search for extraterrestrial intelligence, the flyby of interstellar object 'Oumuamua and even well-known examples of UFO lore like the July 1947 crash of either a flying saucer or a secret U.S. military balloon outside Roswell, New Mexico,

Space.com spoke with Krantz to learn about the book, her take on the UFO buzz these days and even some tips on how to talk to kids about aliens.

Related: The search for alien life

Space.com: First off, I have to say that this is a beautifully illustrated book.

Laura Krantz: I just love it. I love the colors. I love this sort of like blocky illustration style. I just I think it turned out really, really well. [Illustrator Rafael Nobre] has a good sense of humor, too. Like he's able to incorporate some of the funnier stuff into like, great photos. Like there's the scene of an alien trying to cook life, I just I love that one.

Space.com: What was the inspiration for the book?

Krantz:  The book is really a spin-off of the Wild Thing podcast. When I started doing the podcast, I wasn't really thinking about kids at all, I was thinking about adults. And I started getting letters from parents who were listening with their kids, teachers who were using elements of the podcast in their classroom to talk about like, evolution, DNA evidence and the scientific method. And I started talking to my agent, and she suggested doing a middle-grade nonfiction book, because that is really an area where teachers love this kind of information and resources for kids. 

But it's interesting to write this kind of stuff. Because when you're doing it for an adult audience, you assume they know what DNA is, they know what evolution is. They know what all these sort of terms mean, at least sort of obliquely. But when you're writing for kids, you're like 'Crap, I have to understand what this actually is, and be able to explain it in plain language!' So it was like getting a crash course in science education.

Space.com: Why do you think it's important for young people to read this book?

Krantz: I think one of the most important things about it is that [the question of alien life] kind of sits firmly in the gray area. There's no answer to the question "Is there anybody out there?" Just like there's no answer to the Bigfoot question. It's like, this is an area to explore. This is an area to think about things scientifically and wonder and hypothesize. And guess what? We don't have a solid answer. 

And in some ways, it's like teaching kids to be comfortable with the idea that there's no answer, because I think we are in a society now where things tend to be pretty black and white, good or bad, right or wrong, one side or the other side. And with this, you just kind of have to be like, 'There might be aliens out there; I can see both sides of this argument.' I can see all different ways this might go. And I still don't know for sure. And I think that that's valuable. 

And then I think the other thing, too, is it's helpful to help. It's helpful for kids to see how science works, that science has such a long timeline, that the work that was done in the '50s and '60s and '70s on space science, many of those scientists aren't around or won't be around to see where the sort of seeds that they planted end up. And I think that that's sort of important for kids to understand — that science is constantly building on itself and revising and resubmitting, and trying to figure it out as best as it can using the evidence at the time. I think those are two really valuable things. 

And then, also, space is cool.

Space.com: I read in your introduction like you were not familiar with the UFO topic before getting into this, right?

Krantz: What really caught my attention was, firstly, the 'Oumuamua story, which I just thought was fascinating. I mean, we guessed that there were things coming in from outside our solar system. But we hadn't really been able to say that for sure. And this is the first moment we were like, 'This thing is from very far away.' And I think that that's just kind of a cool thing to think about — like, this moment in time, we have this realization of just how big the universe is, and what kinds of things are traveling through it. 

And also seeing photos coming out of the James Webb Space Telescope. And granted this that was after this project was mostly finished. But it's hard not to look at those photos and just have your jaw drop with, you know, how amazingly beautiful and yet, kind of terrifyingly awesome they are. A lot of those photos make you feel very small and insignificant, which is, I guess, kind of a good reminder of our place. And in the grand scheme of things.

Space.com: What do you make of the current UFO buzz in the U.S. government?

Krantz: I saw how, like, crazy, everybody went over the AATIP program [an alleged U.S. Department of Defense UFO study program]. And when the announcement came out about that, like, people lost their marbles; the headlines on that were just constant. And so that was the moment where I was like, 'There's something to be done here on this' and sort of take my glancing interest in it and pull in these threads where it's obvious that this is a question that people think about a lot, even if it's not something we're talking about day to day.

I think that it's a perfect opportunity to apply some rational thought. So, for instance, the whistleblower who testified in front of Congress, he said that people told him that they had recovered bodies, but he hadn't seen them for himself. So that to me is the first red flag. It's like, if you're the whistleblower, you need to have been seeing some of the stuff, you can't just use hearsay. Generally, that's not admissible in court, from what I understand about legal proceedings. So I think that should be a rational thing. And in science, too, and in scientific inquiry.

I don't doubt that there's some weird stuff up in the sky, and that pilots are seeing things. I do think there needs to be a recording process for that, that does not have a stigma attached to it. 

Related: UFOs and UAP: History, sightings and mysteries

Space.com: What do you hope kids take away from the book?

Krantz: That wonder is a huge asset. I think it's so valuable. And I think we kind of beat the wonder out of people as they become grownups. It's like, there's these boxes, you have to check in these things you have to do and the wonder kind of slips by the wayside. But wonder is so important, because it gets you figuring out how your world works. And it gets you thinking about things from different perspectives. And scientifically, like the first step of the scientific method is, it's about wonder. Ask a question; what are you wondering? And I think that that is a really valuable thing for kids. 

And I also think it's a valuable thing for adults to wonder about the world around you, to wonder about what life is like for other people to just sort of have this curiosity and questions and continuing to maybe question your own thoughts on things and beliefs. And, you know, it extends beyond science. I think wonder is a skill that we sometimes lose as we get older.

"Is There Anybody Out There?: The Search for Extraterrestrial Life, from Amoebas to Aliens," is currently available for pre-order and will be released on Oct. 3, 2023.

UFOs and aliens are once again in the headlines this week.

Unfortunately, this is not because a mothership landed on the White House lawn, but because NASA released a long-awaited report published by the independent study team the agency commissioned to study unidentified anomalous phenomena (UAP). UAP is the new term for UFOs, encompassing not only unexplained things in the air but also in space, under water and everywhere in between.

However, the release of NASA's first UFO report wasn't the only story about possible non-human lifeforms to make headlines this week. According to Reuters, lawmakers in Mexico heard testimony this week about the presence of alien life on Earth that included two "corpses of extraterrestrials." These alleged alien corpses looked "white and like stereotypical depictions of aliens — big head, little body, three fingers," NPR reported.

The supposed alien mummies (well, the creepy ... whatever they are) were displayed by Jaime Maussan, a longtime UFO personality with a history of hoaxing alleged non-human remains. Despite Maussan's history of faking alien corpses and mummies, the story has now gone wide — so wide, in fact, that it was brought up during NASA's briefing about the new UAP report which took place on Thursday (Sept. 14). 

Related: NASA UFO report finds no evidence of 'extraterrestrial origin' for UAP sightings

During Thursday's briefing, BBC News Digital journalist Sam Cabral asked whether or not NASA has been in touch with Mexican authorities about "the rather sensational revelations" concerning the alleged alien mummies. In response, the chair of NASA's UAP study team, David Spergel, responded that if there is any evidence of alien remains, then those in possession of the material should make it publicly available for study.

"When you have unusual things, you want to make data public," Spergel said. "I think of this as like, NASA has one of the most valuable samples from outer space  —  lunar rocks  —  what do we do? We make them available to any scientists who want to work on this. 

"We don't know the nature of those samples that were shown in front of them," Spergel added. "If I was the Mexican government, if I would make a recommendation to the Mexican government — that's not our charge here, we're doing this for NASA — my recommendation [would be]: If you have something strange, make samples available to the world scientific community and we'll see what's there."

Dan Evans, assistant deputy associate administrator for research at NASA's Science Mission Directorate, chimed in to add that the entire point of NASA's UAP study team is to dispel the type of sensationalism and pseudoscience displayed for Mexican lawmakers this week. 

"I'll just add one of the main goals of what we're trying to do here today, is to move conjecture and conspiracy towards science and sanity," Evans said. "And you do that with data, as David says, and that's the whole purpose of this study."

As it turns out, Maussan has a history of wheeling out fake alien remains. Micah Hanks, Editor of The Debrief and a longtime UAP researcher, says that Maussan's latest alien body hoax is "unfortunately not the first time this sort of thing has happened." 

In 2015, Maussan organized an event in Mexico City marking the release of a blurry photograph depicting what appeared to be the remains of a small mummified humanoid alien. "However, once clear copies of the image were circulated online just hours after their unveiling at the event, it was quickly determined that the image actually depicted historic remains belonging to an indigenous American child which, decades ago, had been displayed for a time in a museum," Hanks told Space.com "Some of the individuals involved at the time issued public apologies on account of the child's remains being misrepresented in such a way."

It remains unclear what these most recent "alien mummies" might be, but an analysis of their physiology posted to social media suggests they have been assembled from parts of various mammals such as llamas. 

As Reuters reported, some of the other alleged alien corpses Maussan has presented over the years have turned out to be cobbled together from the remains of mummified children.

I was so confused in the opening minutes of The Greyhill Incident.

Was this space horror game meant to evoke found footage style? Or to be a dark commentary on politics in rural America? Or to bring in the "so bad that it's good" feelings common in the space horror genre?

I found myself figuratively (and literally) stumbling in the dark to find the plot of The Greyhill Incident, which I really wanted to love because it's an indie game and space horror — the perfect combo for me.

But somewhere in the game's opening minutes, I began to lose interest in the characters real fast. "Dad, we need to get out of this cursed place, I hate this neighborhood hole," says a preteen glaring at the 1990s-era television with poor signal. As if overcome by his confusing statement he just lay there, listlessly, as dad rambled something about not believing the government.

Eventually, I (in control of "Dad") got to go outside in search of ... something interfering with the TV. After I whacked Dad drearily against trees, trailers, anything but my objective in the cloistering dark, eventually I found my way and a blurry image emerged of a silver alien craft landing in a nearby field. Now, I thought, the story will get going. Sadly it only got worse from there.

Related: Best space horror games

Refugium Games describes the plot of 'The Greyhill Incident' as "a story-driven survival-horror game about an classic alien invasion [that] takes place during the early 90s." 

The early 90s is indeed an interesting setting for conspiracy-driven stories; without getting into details on this family-friendly site, there were a few unfortunate incidents involving survivalists that (like our characters here) had very negative opinions about the U.S. government.

I thought it would be interesting to see what aliens would add to that historical backdrop, but the conspiracists and extraterrestrials alike were forgettable in both shape and in character. Without spoiling too much of the plot, suffice it to say the aliens not only don't look scary, they also aren't too hard to kill. There's also a strange lack of motive to their actions, which perhaps is the point?

Other self-imposed limitations made the game very hard to navigate. Extremely dark settings and not infrequent graphic aberrations made it hard for me to make sense of anything. While I did watch The X-Files in the 1990s with poor TV reception (as my family didn't have cable) and am used to vague alien settings, the plot didn't make up for the things I was unable to see.

I do want to put in a word in favor for Refugium Games, however, because they're a small, indie developer and so many other big websites have had negative reviews about their new game. 

The team certainly worked hard on this, and after playing the game through, I honestly think with more development time to improve the plot pacing, voice recording, and bit of a graphics touch up would have moved the game to a decent game (at the least) instead of the mess that we currently have. And that may be already ongoing.

The developers have made changes in response to some of the early complaints that made gameplay even more difficult, including improvements to stealth, stamina and the flashlight. So stay tuned, and check in periodically — my review may be happily out of date down the road, but for now, I'd give this one a miss.

The Greyhill Incident is available now on Steam, PS5, and Xbox Series X/S.

Astronomers have now deduced what alien scientists might see when they gaze at the Milky Way from afar. The new results suggest our home galaxy is unusual but not unique, at least when it comes to chemistry.

Ever since U.S. astronomer Edwin Hubble discovered that our galaxy is just one among many galaxies about a century ago, researchers have wondered how special (or not) the Milky Way is in the universe, said study co-lead author Jianhui Lian, of the Max Planck Institute for Astronomy in Heidelberg, Germany.

"Finding ways to compare our home galaxy with more distant galaxies is what we need if we want to know whether the Milky Way is special or not," Lian said in a statement.

Related: The Milky Way galaxy may be a different shape than we thought

The fact that Earth dwells within the Milky Way means scientists know more about it than any other galaxy. For instance, the Milky Way is currently the only spiral galaxy in which astronomers can analyze large numbers of individual stars in terms of their locations, chemistry, temperature and other properties. Measuring how the levels of various chemicals have changed over the course of its history can in turn shed light on how the Milky Way and other galaxies may have grown and evolved over time.

However, until now, scientists had not analyzed how all these chemicals in the Milky Way might look from a distance. Doing so is key to comparing the Milky Way to other galaxies that astronomers have examined from afar.

"To the best of my knowledge, this idea of the 'alien's' view of the Milky Way is rather new," study co-lead author Maria Bergemann, an astrophysicist also at the Max Planck Institute for Astronomy, told Space.com. "I find it cool and out-of-the-box."

In the new study, the researchers depended on progress made in the past decade or so to analyze the Milky Way in a systematic manner. For example, the European Space Agency's Gaia spacecraft has tracked the brightnesses, motions and distances of nearly 1.5 billion stars in the Milky Way.

In addition, there is now much more and much better data for distant galaxies, making it easier to compare the Milky Way to them. For instance, the MaNGA survey analyzed nearly 10,000 galaxies in depth across 2,700 square degrees of the sky. (In comparison, the full moon as seen from Earth covers about 0.5 square degrees.)

The MaNGA survey examined how each galaxy's chemical composition varies from its center to its outer regions. Furthermore, modern simulations of galaxy formation and evolution can model the history of thousands of galaxies after the Big Bang to the present day. For instance, the TNG50 simulation from scientists in Germany and the United States models a cube of space that is more than 230 million light-years across, tracing the simultaneous evolution of thousands of galaxies across 13.8 billion years of cosmic history.

In the new study, the researchers set out to reconstruct what alien astronomers would see if they were to analyze the Milky Way to map the abundance of what astronomers call "metals" — all elements heavier than the hydrogen and helium that make 99% of all "normal" matter in the universe. (Mysterious dark matter is about six times more common than normal matter, however.)

Related: What is a spiral galaxy?

The Milky Way is shaped like a disk, so the scientists focused on how alien scientists would see the abundance of metals vary within the galaxy. As stars grow, the process of nuclear fusion that helps keep stars alive produces metals within the stars, and when massive stars die in supernova explosions, they expel those metals outward. As such, stars born earlier in time contain fewer metals, whereas later-born stars hold more. Mapping out which regions of a galaxy have stars with fewer metals or more reveals which regions formed its stars earlier and later.

The astronomers also had to account for how interstellar dust can smudge the view of the Milky Way from Earth. This involved combining their observations with known properties of dust and stars to reconstruct the real distribution of stars in the galaxy.

The scientists found that if they tracked the average metal content of stars from the Milky Way's core outward, it increased, reaching a metal content close to that of our sun at a distance of about 23,000 light-years from the center. (The sun lies about 26,000 light-years from the heart of the galaxy.) 

However, at greater distances from the Milky Way's core, the average metal content drops, reaching about one-third of the sun's value about 50,000 light-years from the galaxy's center.

To find out why this belt of metallicity exists, the researchers looked at stars based on their age group. They found that each age group followed a trend where there was greater metal content close to the Milky Way's core and less metal further out. However, older stars with much lower metal content are more abundant near the heart of the galaxy, while younger stars are more frequent farther out. Averaged out, this led to the pattern of metallicity the scientists detected.

The astronomers then compared the Milky Way with 321 galaxies in the MaNGA survey with masses similar to our galaxy that also feature similar amounts of stars. These galaxies are all also visible face-on, helping the researchers see how metal levels vary across each galaxy. The scientists used these same criteria to identify 134 Milky-Way-like galaxies in the TNG50 simulation.

All in all, the astronomers found that the Milky Way is not common but not unique among galaxies. Only about 1% of the galaxies in the MaNGA sample and 11% of the galaxies in the TNG50 simulation displayed a similar pattern of metals to the Milky Way. They noted that this discrepancy between 1 and 11% may be due to uncertainties in the MaNGA data and limitations of the TNG50 simulation's accuracy in modeling the universe.

In addition, the team found that the chemical nature of the Milky Way is rare among galaxies of its rough shape and structure.

"The main implication is that our Milky Way is not a typical Milky-Way-like galaxy," Bergemann said. "In other words, the Milky Way may have evolved differently, compared to others like it."

When it comes to why the Milky Way appears unusual, the scientists noted that the relative scarcity of metal-rich stars near our galaxy's center might be related to the formation of the so-called bulge, an approximately spherical region of older stars surrounding the galactic center out to a distance of about 5,000 light-years. The birth of the bulge likely depleted most of the hydrogen gas in the area, making later star formation much more difficult. 

But its also possible, the researchers said, that our galaxy's central supermassive black hole may have at some point become unusually active, spewing out particles and radiation that inhibited star formation.

Team members added that the relative scarcity of metals in the Milky Way's outer disk could also be explained by a number of different scenarios. For instance, our galaxy might have swallowed a smaller galaxy with gas that contained very few metals. This gas may have later served as the raw material for stars with fewer metals in the Milky Way's outer disk. The estimates that astronomers currently have for the extent of the Milky Way's outer disk may also be off, skewing how different the Milky Way appears compared with other galaxies.

In the new study, the researchers focused on iron, since this metal is relatively easy to measure in stars in the Milky Way.

"An interesting research direction would be to try measuring more chemical elements," Bergemann said. "For example, oxygen, a key element for life on Earth, can also be measured in other galaxies, and we will soon get a lot of data for the chemical evolution of oxygen in the Milky Way — for example from 4MOST [at the Paranal Observatory in Chile.] Another potentially crucial element is carbon."

The scientists detailed their findings online June 22 in the journal Nature Astronomy.

Could intelligent aliens be lurking at the heart of the Milky Way? 

A new search for extraterrestrial life aims to find out by listening for radio pulses from the center of our galaxy. Narrow-frequency pulses are naturally emitted by stars called pulsars, but they're also used deliberately by humans in technology such as radar. Because these pulses stand out against the background radio noise of space, they're an effective way of communicating across long distances — and an appealing target to listen for when searching for alien civilizations. 

Scientists described the alien-hunting strategy in a new study, published May 30 in The Astronomical Journal. Researchers led by Cornell University graduate student Akshay Suresh developed software to detect these repetitive frequency patterns and tested it on known pulsars to be sure it could pick up the narrow frequencies. These frequency ranges are very small, at about a tenth of the width of frequencies used by a typical FM radio station. The researchers then searched data from the Green Bank Telescope in West Virginia using the method. 

Related: Are aliens real?

"Until now, radio SETI has primarily dedicated its efforts to the search for continuous signals," study coauthor Vishal Gajjar of the SETI Institute, a nonprofit organization dedicated to the search for intelligent life in the universe, said in a statement. "Our study sheds light on the remarkable energy efficiency of a train of pulses as a means of interstellar communication across vast distances. Notably, this study marks the first-ever comprehensive endeavor to conduct in-depth searches for these signals."

The researchers are listening in to the middle of the Milky Way because it is dense with stars and potentially habitable exoplanets. What's more, if intelligent aliens at the core of the Milky Way wanted to reach out to the rest of the galaxy, they could send signals sweeping across a wide array of planets, given their privileged position at the center of the galaxy. Using narrow bandwidths and repeated patterns would be a prime way for aliens to reveal themselves, as such a combination is extremely unlikely to occur naturally, study co-author Steve Croft, a project scientist with the Breakthrough Listen program, said in a separate statement. 

The method uses an algorithm that can search through 1.5 million telescope data samples in 30 minutes. Though researchers did not find any telltale signs in their first search, they say that the speed of the algorithm will help improve searches in the future.  

"Breakthrough Listen captures huge volumes of data, and Akshay’s technique provides a new method to help us search that haystack for needles that could provide tantalizing evidence of advanced extraterrestrial life forms," Croft said. 

The Alien movies have been making outer space a scary prospect for over four decades now, and it appears the xenomorphs aren’t going anywhere anytime soon. We’ve now got the Alien: Romulus movie and the first-ever Alien TV series coming our way, but what about Alien video games? Well, they seem to be quite alive as well, although going back in time to dig up some killer entries is also a must in our opinion.

Following the success of Aliens: Dark Descent’s top-down tactics and Aliens: Fireteam Elite, fans of the Alien IP can look forward to even more xenomorph-y goodness. All-new projects are in active development across several studios, including a VR game titled Alien: Rogue Incursion. Disney, the new owner of the IP, as well as other Fox assets, is very much interested in keeping the xenos alive and spitting acid.

Mind you, the Predator franchise, first entangled with Alien in Dark Horse’s 1990 Alien vs. Predator comic series, isn’t getting nearly as much attention when it comes to video games. That’s even despite the decent success of Predator: Hunting Grounds (2020) and the huge hit that was Prey (2022), the Predator prequel we had always hoped for

For more sci-fi horror, we recommend checking out our up-to-date list of the best space horror games. We also have some thoughts about the rankings of the Alien and Predator movie series, as well as why and how Disney should reboot Alien vs. Predator.

Now, let’s go deep into the hive and show those bugs what flamethrowers and pulse rifles can do. Get tactical, marines!

10. Alien Resurrection

• Platforms: PS1
• Developer: Argonaut Games

We wouldn’t see another major Alien FPS until 2000’s Alien Resurrection, which, you guessed it, was intended to release alongside the 1997 movie of the same name. So, what’s up with that massive gap? Well, development didn’t go smoothly, and the game was stuck in development hell for quite a while before finally releasing in late 2000.

Somehow, it wasn’t hammered too hard by reviewers when it finally released. In fact, the years have been kind to one of the best-looking shooters on PS1. More specifically, the oppressive atmosphere is top-notch, and there are several playable characters spread throughout the story, each with their own weapons and special equipment.

9. Aliens vs. Predator: Extinction

• Platforms: Xbox, PS2
• Developer: Zono

The 2000s also led to an off-beat mix of real-time strategy and the Aliens vs. Predator IP. Developed by Zono, who already had experience with the genre, AvP: Extinction represents perhaps the weirdest big-budget release the Alien has ever been used for. It was a risk worth taking as there’s nothing out there quite like this game.

The focus was put on unit management and combat over base-building and the gathering of resources. Also, the entire game revolves around three campaigns which are light on actual storytelling, but shape each level and the starting conditions depending on the narrative. Each species plays very differently, so AvP: Extinction almost feels like three weird real-time strategy titles bundled into one.

A warning for those curious: it’s tough as nails.

8. Aliens: Infestation

• Platforms: Nintendo DS
• Developer: WayForward Technologies, Gearbox Software

The Alien franchise had been transformed into 2D sidescrollers before, but, nonetheless, it was strange to see a new one launch in 2011 and only for the Nintendo DS. The tie-in veterans at WayForward teamed up with Gearbox to craft a Metroid-like take on the IP, with a heavy focus on exploration and the “permadeath” of the colonial marines that the player controls. It’s “game over, man, game over” if the entire party is wiped out.

Like many other Alien games, Infestation’s story deals with the aftermath of Aliens and Alien 3, with a heavy focus on the U.S.S. Sulaco, which is adrift in space. To capture the movies’ slasher vibes, the developers created 20 unique characters to make sure their (more than likely) deaths resulted in gut-punches to the players.

Anyone into 2D action games with an emphasis on non-linear exploration should give this one a try. The sprite work is exquisite too which is a nice bonus for those who enjoy retro gaming.

7. Aliens: Fireteam Elite

• Platforms: PC, Xbox One/Series X/S, PS4/5, Nintendo Switch
• Developer: Cold Iron Studios

We already mentioned Aliens: Fireteam Elite in the intro, and we hadn’t forgotten about it. Mind you, it’s a game that could’ve used some extra polish and a bigger budget, but it’s got its heart where it matters. After the colossal disappointment that was Aliens: Colonial Marines (2013), Fireteam Elite felt like the co-op game we were promised around a decade ago. More surprisingly, many elements from Prometheus made it into the post-Aliens narrative, a creative choice that separates it from other Alien titles centered on the United States Colonial Marine Corps.

The character classes feel robust, and there are strong progression and customization systems in place to make Aliens and/or co-op shooter fanatics want to stick around past a single playthrough – that is no small feat when it comes to these games! With the addition of cross-play and solid post-launch content (both free and paid), Fireteam Elite is the go-to Aliens shooter at the moment.

6. Aliens vs. Predator (2010)

• Platforms: PC, Xbox 360, PS3
• Developer: Rebellion

AvP shooters had another shot at glory in 2010, and with Rebellion back developing the reboot of sorts. The full story is told across three different campaigns, following in the footsteps of Monolith’s AvP 2 instead of their 1999 game. As for the multiplayer, the offering of modes (both competitive and co-op) was pretty big, but the game struggled to find a sizable audience.

The most interesting thing about AvP 2010 is that Rebellion took some big swings with gameplay elements, such as melee combat, giving it a special flavor and a really visceral feeling in the moment-to-moment gameplay. Some shots missed their mark though, and the campaigns were a bit short, but it squarely delivered on the promise of more carnage between science fiction’s most famous horror icons. It also looks great to this day when maxed out on PC.

5. Aliens: Dark Descent

• Platforms: PC, Xbox One/Series X/S, PS4/5
• Developer: Tindalos Interactive

Shortly after Fireteam Elite reinvigorated the Alien video games scene, along came Aliens: Dark Descent from publisher Focus Entertainment. With a very different take on the source material, this time players can experience a real-time tactics game from a top-down perspective. While it’s definitely harder to get into than the rest of the games in this list, it’s quickly become one of our favorite approaches to the sci-fi franchise.

Long story short: Dark Descent has perfectly executed the feeling of being in command of a squad of colonial marines venturing into xenomorph-infested territory. The narrative hook is solid, and the progression systems that surround the nail-biting missions feel fresh in surprising ways. Command-based tactics and combat might not be everyone's cup of tea, but fans of the movie Aliens who are looking for a different type of game will find plenty to love here.

4. Aliens vs. Predator Classic 2000

• Platforms: PC, macOS
• Developers: Rebellion

1994 also saw the release of a strong Alien vs. Predator FPS on the Atari Jaguar, but it wasn’t until 1999 that Rebellion had a chance to truly wow players. Technology had come a long way in just a few years, and the full-3D graphics powered the ultimate Alien and Predator power fantasies, as well as super-tense human marine gameplay.

In early 2010, after several years of (legal) unavailability, AvP was re-released under the title Aliens vs. Predator Classic 2000. This version works on modern computers and has controller support as well as many other improvements. Moreover, it packs all the extra content released back in the day (and online multiplayer).

The storylines for each species are independent of one another and take players through original locations as well as iconic scenarios from the Alien movies. If you can grapple with the aged controls and old-school level design, this one shouldn’t be missed.

3. Alien vs. Predator (arcade)

• Platforms: Arcade
• Developers: Capcom

Though Alien vs. Predator games had already landed on Nintendo systems, the first big splash for the crossover IP was Capcom’s AvP arcade beat ‘em up. It’s considered to be one of the best games ever made within that genre, and we’re inclined to agree. It still looks gorgeous and packs quite a punch, with tight controls and level variety that aren’t all that common for that type of action game.

There are four characters available (the game can do three-player co-op): the Predator warrior and hunter, Major Dutch Schaefer (based on Arnold Schwarzenegger’s character from the original Predator movie), and Lt. Linn Kurosawa, a human cyborg expert in martial arts. They all work together to put an end to an alien infestation that has overrun a major city in futuristic California. It’s a breezy, wild ride which takes the best elements from the movies and comics released before 1994, and 100% a must-play – you’ll have to turn to emulation though.

2. Aliens vs. Predator 2

• Platforms: PC, macOS
• Developer: Monolith Productions

Although Monolith’s 2001 sequel to Rebellion’s classic hasn’t received a remaster nor a modern re-release, it remains the best Alien vs. Predator game ever. That might include being one of the best Alien games as well – the colonial marine campaign in particular is absolutely spectacular.

The jump in graphical fidelity was vast, and each of the three campaigns – interwoven this time around – feels meaty and challenging. More importantly, each species had a bigger arsenal of weapons and abilities to destroy their enemies and move around the levels. It all culminated with an excellent online multiplayer that some communities are still keeping alive to this day.

1. Alien: Isolation

• Platforms: PC, macOS, iOS, Linux, Android, PS3/4, Xbox 360/One, Nintendo Switch
• Developer: Creative Assembly

Of course, this list wouldn’t be complete without Alien: Isolation, the first-person horror game that dared to capture the magic of Ridley Scott’s original masterpiece. It truly felt (and still feels) like lightning in a bottle, and the fact it was developed by a studio with no prior experience with first-person titles made it even more anomalous.

Taking cues from indie horror hits from the early 2010s, such as Amnesia (2011), Creative Assembly was able to inject back some genuine horror and tension into an IP which had focused for far too long on action-heavy scenarios and colonial marines. The story takes places 15 years after the events of the first movie, following Ellen Ripley’s daughter, Amanda, as she investigates the disappearance of her mother aboard a space station that’s reliving the xenomorph terror.

Isolation isn’t just the best Alien game ever, but also one of the strongest installments of the franchise as a whole. It’s available on almost every modern platform, so there’s no excuse to skip it.

Imagine if one side of the Earth always faced the sun. Half of the planet would be stuck in perpetual daylight, the other shrouded in permanent night. 

But for aliens in other solar systems, our doomsday scenario may be their everyday — and life might get along just fine. In a new study, astronomers propose that extraterrestrial life could exist in so-called terminator zones, the border between light and dark halves of an exoplanet.

"These planets have a permanent day side and a permanent night side," Ana Lobo, an astrophysicist at University of California, Irvine (UCI) and lead author of the new work, said in a statement. "This is a planet where the dayside can be scorching hot, well beyond habitability, and the night side is going to be freezing, potentially covered in ice. You could have large glaciers on the night side."

Related: What really makes a planet habitable? Our assumptions may be wrong

This seemingly strange kind of planet is actually quite common, particularly around the dim small M dwarf stars that make up nearly 70% of all stars in our galaxy, the Milky Way. Around these smaller stars, exoplanets often become tidally locked, a gravitational phenomenon in which one side of the planet always faces the star. (Similarly, tidal locking is why Earth only sees one side of the moon.)

Astrobiologists often focus on ocean worlds since water is such a key ingredient for life. Lobo and collaborators, however, wanted to find new niches where life may be able to survive. "We are trying to draw attention to more water-limited planets, which despite not having widespread oceans, could have lakes or other smaller bodies of liquid water, and these climates could actually be very promising," Lobo said.

Through computer simulations, Lobo showed that terminator zones on planets with a significant amount of land — versus those covered entirely in oceans — could, in fact, support liquid water and therefore life. With too much water, however, everything evaporates, covering the surface in a thick cloud of vapor.

A slew of upcoming planet-hunting telescopes could search such terminator zones for signs of life, from the famed James Webb Space Telescope to the future Habitable Worlds Observatory, slated to take to the skies in the 2040s. 

The study was published March 10 in The Astrophysical Journal.

The story was originally published on Live Science.

Follow us on Twitter @Spacedotcom and on Facebook. 

Could an alien mothership be hovering around the solar system, sending out tiny probes to explore planets? According to a Harvard scientist and a Pentagon official, it's possible. 

In a draft paper, the pair said it is feasible an extraterrestrial spaceship could be in our galactic neighborhood, exploring the region by the means of "dandelion seeds" — small spacecraft that can gather and send back information, similar to the way humans send out spacecraft to explore planets.

Avi Loeb, an astronomer at Harvard University, and Sean M. Kirkpatrick, director of the Pentagon’s All-domain Anomaly Resolution Office (AARO) — established in July 2022 by the Department of Defense (DoD) to detect and study "objects of interest" — released the draft, Physical Constraints on Unidentified Aerial Phenomena, on March 7. It is not an official Pentagon document but was carried out in partnership with the DoD. It has not been peer-reviewed.

Loeb is known for his research into 'Oumuamua — an interstellar visitor from beyond the solar system. Astronomers first detected the cigar-shaped object in 2017 and originally thought it was a comet. However, its elongated shape, its lack of coma (the cloud of gases that envelope a comet), and the fact that it was accelerating away from the sun raised questions about the comet theory. Loeb suggested instead that 'Oumuamua was an alien spaceship. 

Six months before 'Oumuamua's close approach to Earth, a small interstellar meteor measuring around 3 feet (1 meter) wide smashed into Earth. This meteor, IM2, was not related to 'Oumuamua, but it got Loeb thinking. 

That coincidence inspired him "to consider the possibility that an artificial interstellar object could potentially be a parent craft that releases many small probes during its close passage to Earth, an operational construct not too dissimilar from NASA missions," Loeb told Live Science in an email. "These 'dandelion seeds'... could be separated from the parent craft by the tidal gravitational force of the sun or by a maneuvering capability."

In the draft paper, Loeb and Kirkpatrick looked at Unidentified Anomalous Phenomena (UAPs, the government's preferred term for UFOs) confined by known physics. The authors suggest the dandelion seed probes could reach Earth for exploration without being detected by astronomers as they would likely be too small to reflect enough sunlight for survey telescopes to detect.

"Equipped with a large surface-to-mass ratio of a parachute, technological 'dandelion seeds' could slow down in the Earth's atmosphere to avoid burnup and then pursue their objectives wherever they land," they wrote.

Aliens would likely want to explore rocky planets with an atmosphere in the solar system, the authors propose. From a distance, Venus, Earth and Mars would all look appealing, with Earth being of greatest interest once aliens found signatures of liquid water. The alien civilization that created the probes would not need to be on the mothership. It would be unlikely that it could even communicate with the probes. 

The alien civilization may not even exist anymore. Most stars in the galaxy formed billions of years before the sun. A habitable planet with intelligent life could have been sending out probes long before Earth formed. Searching for "resembles checking our mailbox for any packages that may have accumulated over time there, even if the senders are not alive anymore," Loeb said.

Since first suggesting 'Oumuamua was an alien spaceship, Loeb has faced criticism from the scientific community. One Perspective article published in Nature Astronomy in 2019 said the idea ‘Oumuamua was sent to Earth on purpose was "provocative" and "baseless."

In 2021, a letter published in the journal Astronomy & Astrophysics dismissed the idea on logistical impracticalities of interstellar travel: "Given the likely cosmological timescales required to traverse between stars, we conclude that it is unlikely that 'Oumuamua has been sent by an extraterrestrial civilisation and more likely that it is just an unusually shaped rock, which has happened to wander into the solar system."

Another study, published on March 22, 2023, explains 'Oumuamua's strange movements as the likely result of hydrogen off-gassing — again refuting the alien spacecraft theory. 

Still, the Pentagon has taken a renewed interest in studying unidentified objects over U.S. airspace in the previous year. Since the AARO's founding last summer, the office has opened more than 360 new investigations into alleged UAP encounters reported by U.S. military personnel. About half of these have been explained as "balloons or balloon-like entities," while the other half lack sufficient data to conclusively resolve.

Editor's note: This article was updated on Mar. 27 to correct a typo. A previous version of the story said most stars in the solar system are older than the sun; the text now reads "most stars in the galaxy." The sun is the only star in our solar system.

This article was originally posted on Live Science.

The truth is out there, and it’s coming to get us, if the best alien invasion movies are to be believed anyway. Maybe this is one time we don’t want to believe.

The matter of extra-terrestrial life has fascinated mankind for quite some time now, and the movie industry has made sure over the decades to make some serious profits thanks to the UFO craze. However, the subgenre has also evolved with time, giving birth to refreshing takes on alien invasion movies.

Now, what’s an alien invasion movie? Well, it goes beyond simply featuring alien lifeforms visiting Earth, so that throws stories such as E.T. or Arrival out of the window. The aliens have to be hostile. Okay, what about The Thing? One could argue it’s an alien invasion movie, but at the end of the day, it’s just a deadly organism that crash-landed on Earth long ago.

By limiting ourselves to hostile conflicts with entire alien species that want to take over Earth, we’ve come up with a pretty solid list of the best alien invasion movies (in no particular order, before anyone decide to invade our comments section). 

On the matter of aliens, you might want to check our extensive articles on the entire Alien and Predator movie franchises, and maybe meet some extra-terrestrial lifeforms (good and bad) yourself with the best space exploration games and space horror games. 

1. War of the Worlds (2005)

• Release date: June 29, 2005
• Cast: Tom Cruise, Dakota Fanning, Justin Chatwin, Tim Robbins

Based on H.G. Wells’ 1898 novel, Steven Spielberg’s take on The War of the Worlds is generally regarded as one of the lesser movies in his filmography, yet it managed to crack $600 million worldwide and has gained a solid following over the years thanks to its atypical blockbuster nature.

While we’ve seen several audiovisual reinterpretations of the famous novel over the decades, and most cinephiles would look back to the 1953 movie as the best one out of the bunch, there’s something about Spielberg’s version – maybe it’s the relentless grimness – that makes it incredibly attractive despite its many failings, underwhelming original ending included.

2. Edge of Tomorrow

• Release date: June 6, 2014
• Cast: Tom Cruise, Emily Blunt, Bill Paxton, Noah Taylor

Another Tom Cruise movie made it into our list, and with good reason: Edge of Tomorrow was one of the biggest surprises of 2014 thanks to a tight, action-packed script which masterfully mixed the alien invasion subgenre with time-travel shenanigans.

Based on Hiroshi Sakurazaka’s novel All You Need Is Kill, Edge of Tomorrow presents a near future in which most of Europe is occupied by an unstoppable alien species. Major William Cage (Cruise), a public relations officer, is forced to join an operation against the aliens, only to end up experiencing a time loop that could be the key to defeating the invaders. It’s both exciting and dark, but also a surprisingly funny rollercoaster ride. Don’t skip it.

3. Invasion of the Body Snatchers (1956)

• Release date: February 5, 1956
• Cast: Kevin McCarthy, Dana Wynter, Larry Gates, King Donovan

Here’s another instance of two widely known adaptations of the same book. Most sci-fi aficionados are familiar with the 1978 movie by Philip Kaufman, but going back to the 1956 adaptation – only two years after Jack Finney’s novel came out – is highly recommended.

Don Siegel’s movie remains one of the best political allegories of the 1950s and an excellent sci-fi reflection of North American society and the widespread mindset of those years in the States. Furthermore, it’s still a genuinely scary watch that feels way more focused than its 1978 counterpart.

4. Attack the Block

• Release date: May 11, 2011
• Cast: John Boyega, Jodie Whittaker, Nick Frost, Alex Esmail

Time for some sci-fi comedy! Attack the Block is one of the smaller (if not the smallest) movies on the list and an indie surprise that came from the UK. The story follows a teenage street gang who have to defend themselves – and their neighborhood – from ferocious alien creatures that emerge from meteorites. It’s got some important things to say about the marginalized British youth, and stays fun (and funny) until the credits roll.

While the movie underperformed at the box office, it received a largely positive critical reception and allowed both director Joe Cornish and actor John Boyega (now a Star Wars legend) to make the jump to much bigger movies. A sequel is now in development.

5. Independence Day

• Release date: July 3, 1996
• Cast: Will Smith, Jeff Goldblum, Bill Pullman, Judd Hirsch

Roland Emmerich’s magnum opus (yes, dumb plot points and all) is arguably the biggest alien invasion movie ever. While its 2016 sequel amplified the menace to ridiculous levels, the original flick has a distinct charm linked to its era which can’t be replicated. Moreover, its effective mix of practical and digital effects holds up.

The movie was also at the forefront of the large-scale disaster movie resurgence of the mid-late 1990s. It’s big and loud, adventurous and funny, and worked with a remarkably diverse cast – led by peak Will Smith and Jeff Goldblum – on top of everything. It was a winning combination that completely demolished the global box office of 1996. And that speech by Pullman is just *chefs kiss*.

6. Mars Attacks!

• Release date: December 13, 1996
• Cast: Jack Nicholson, Pierce Brosnan, Danny DeVito, Michael J. Fox

1996 ended with another big alien invasion blockbuster, though this one crashed and burned at the box office and struggled to convince the critics. However, Tim Burton’s zany and utterly deranged take on the subgenre found some love, and B-movie fanatics haven’t forgotten about it (and neither has pop culture).

This one is undoubtedly the wildcard of our list, but we’re fully committed to defending a movie with an unbelievable all-star cast having the time of their lives and embracing self-conscious humor, and filled to the brim with some of the strangest imagery in a Hollywood production ever. It’s hard not to smile when thinking about these invaders from Mars.

7. Signs

• Release date: August 2, 2002
• Cast: Mel Gibson, Joaquin Phoenix, Rory Culkin, Abigail Breslin

M. Night Shyamalan’s The Sixth Sense normally gets most of the attention when people talk about the “golden age” of the divisive director, but Signs remains one of his strongest works. And no, the infamous “water scene” does not ruin it. In fact, rewatching the movie while treating its aliens as literal demons actually works. Try it!

Backed by legendary producers Frank Marshall and Kathleen Kennedy, Signs feels like a homage to Steven Spielberg’s alien-centric movies at times, but Shyamalan took the premise to his own territory, heavily exploring the themes of faith and kinship on a small scale against the backdrop of a truly scary (but unexpectedly quiet) invasion.

8. The World’s End

• Release date: July 19, 2013
• Cast: Simon Pegg, Nick Frost, Paddy Considine, Martin Freeman

The final chapter in Edgar Wright’s Three Flavors Cornetto trilogy embraced the alien invasion subgenre with a unique twist which we won’t spoil here, but its influences are clear (and some of them can be found in this list). Unsurprisingly, it also has many tricks up its sleeve and puts humor above everything else.

The best thing about The World’s End is that it fully commits to its initial “pub crawl” premise even when things start to get a bit too weird, resulting in an off-beat sci-fi comedy that leads to a stupefying resolution and ultimately feels way more mature than the two previous entries of Wright’s iconic anthology.

9. They Live

• Release date: November 4, 1988
• Cast: Roddy Piper, Keith David, Meg Foster, Peter Jason

Hey, we kept The Thing out of this list, but that doesn’t mean we’ve forgotten about master of horror and campy action John Carpenter. Based on the 1963 short story 'Eight O’Clock in the Morning' by Ray Nelson, They Live is an excellent work of science fiction which helps understand much of the cultural and economic climate of the Reagan-era United States.

Of course, like most of Carpenter’s works, They Live also comes together as a paranoid action-horror flick full of cheesy but memorable one-liners and remarkable scenes that have grown more famous in pop culture as the years passed.

10. A Quiet Place 1 & 2

• Release date: April 6, 2018
• Cast: Emily Blunt, John Krasinski, Millicent Simmonds, Noah Jupe

Many would call A Quiet Place and its sequel “monster features”, but the latter made it clear they’re alien invasion movies as well. Born from a spec script by Bryan Woods and Scott Beck which actor-turned-filmmaker John Krasinski later rewrote, A Quiet Place has a simple but strong idea that has been mined twice to great success.

A post-apocalyptic world dominated by blind extra-terrestrial creatures with an acute sense of hearing was more than enough to get audiences on board, but the films’ strength lies in strong family drama and believable characters doing their best in really dire situations with no hope of saving the world on the horizon. No big heroics here, but let’s see where it all goes with the already-announced third instalment and spinoff.

Scientists have proposed another use for the world's largest gravitational wave observatory: scanning for the ripples in space-time left in the wake of gargantuan alien spaceships.

Gravitational waves ripple out when objects with mass move through space. Bigger objects — such as planets, neutron stars or black holes — produce more prominent gravitational waves. These space-time ripples were first directly detected in 2015, but since then, scientists have been getting better at spotting the waves as they lap at our cosmic shores. 

Now, new calculations published Dec. 5 to the preprint database arXiv suggest that the U.S.-based Laser Interferometer Gravitational-Wave Observatory (LIGO) can look beyond conventional sources for these space-time ripples. Colossal alien spacecraft traveling at high speeds, or pushed along by warp drives, would also produce the telltale vibrations, the authors said. 

Related: James Webb Space Telescope could help hunt for habitable alien worlds

The LIGO detector spots gravitational waves from the tiny distortions they make in space-time as they pass through it. Made up of two intersecting L-shaped detectors — each with two 2.48-mile-long (4 kilometers) arms and two identical laser beams inside — the experiment is designed such that if a gravitational wave passes through Earth, the laser light in one arm of the detector will get compressed while the other expands, creating a tiny change in relative path lengths of the beams arriving at the detector. The warpings of space-time that even the largest gravitational waves make, however, are minuscule — often the size of a few thousandths of a proton or neutron — meaning that LIGO is incredibly sensitive and requires strict maintenance and calibration.

To see how far this sensitivity could be stretched, scientists made calculations of the smallest object that would generate clearly detectable gravitational waves on Earth. It turns out, it would still be pretty big: To be detectable by LIGO, an alien mothership would need to weigh roughly the same as Jupiter, travel at one-tenth the speed of light, and be within 326,000 light-years of Earth.

Are spaceships of this scale and speed even possible? The researchers don't know, but they hope to squeeze down the ship size to more reasonable proportions as increasingly sensitive gravitational wave (GW) detectors, such as the European Space Agency's 2037 Laser Interferometer Space Antenna, are deployed. The physicists also noted that advanced alien warp drives would create gravitational wave patterns that would be distinguishable from natural sources and that, if detected, these alien waves could even provide humans with clues about how to reverse engineer the technology.

"This is because the shape of the GW signal is entirely dependent on the trajectory of the object," they wrote in the paper. "Thus, as a burst signal is detected, one can attempt to reason the qualities of the transportation mechanism present based on the shape of the GW signal."

Originally published on LiveScience.