Since the discovery of the first world beyond the solar system in the 1990s, astronomers have become adept at spotting extrasolar planets, or exoplanets. But while NASA's exoplanet catalog has burgeoned to over 6,000 confirmed entries, moons around these worlds, known as exomoons, have proved elusive.

In fact, we have failed to make a single confirmed discovery of an exomoon despite being certain that just as the planets of the solar system have their own natural satellites, worlds in other star systems must have them too.

Now, this controversial drought of exomoons may have become even more confusing and, frankly, weird. That is because while studying a strange star system called CD-35 2722 with the Very Large Telescope (VLT), astronomers have discovered an object that could be an exomoon, or it could be something that forces us to rethink our very definition of what a "moon" is and what a "planet" is.

The star CD-35 2722 is located around 73 light-years away and has around half the mass of the sun. It is orbited by a "failed star" or brown dwarf. These stellar bodies get their unfortunate nickname because they form like other stars but fail to gather enough mass to trigger the fusion of hydrogen to helium in their cores. In terms of mass, brown dwarfs are more massive than the largest gas giant planets, but smaller than the smallest stars, usually with around 13 to 80 times the mass of Jupiter, or around 0.013 to 0.08 times the mass of the sun.

The newly discovered object in CD-35 2722 is certainly moon-like, but rather than orbiting a planet as the moons in the solar system do, it orbits the system's brown dwarf.

"This system is somewhat hard to define using solar-system-based words like 'planet' and 'moon.' The exosatellite is clearly massive enough to be a planet, but it does not orbit a star, though it orbits an object that orbits a star," team leader Kevin Hoy of the Universidad Diego Portales and the Millennium Nucleus of Young Exoplanets and their Moons (YEMS) in Chile, said in a statement.

"Being the third wheel in this system makes us want to call it a moon, even if it is nothing like the small, rocky moons we have in our system."

The team's research was published on Wednesday (July 22) in the journal Nature.

Erm... It's definitely an exosatellite

The team currently isn't able to definitively claim this object in CD-35 2722 is an exomoon, because that would require really nailing down a new definition of what a moon is.

"The satellite we report is a giant gaseous body orbiting a highly massive companion, itself several times the mass of Jupiter. We have a clear delineation between the planets and the sun in the solar system, so defining things like moons is simple," team member Alice Zurlo of the Universidad Diego Portales said. "In the CD-35 2722 system, where we are blurring the lines between stars, planets, and moons, the whole thing becomes more complicated to describe."

Zurlo and colleagues can, however, confidently claim this is an exosatellite, meaning it is a first-of-its-kind detection no matter what the future holds for its classification.

It is hoped that the Extremely Large Telescope (ELT) currently under construction in Chile, will make a massive impact in the hunt for exomoons, and now, other exosatellites.

Until these objects begin to be uncovered, one thing this discovery re-emphasizes is something that astronomers have been gleefully discovering ever since the first exoplanet was spotted: planetary systems come in a variety of diverse, weird and wonderful forms.

A rocky planet orbiting in the habitable zone of a sun-like star may look like a perfect place for life to thrive — but not if it's too small to hold onto its atmosphere.

So, we may wonder: How much smaller Earth could be and still have its delightfully breathable atmosphere? How small could an exoplanet be to sustain life as we know it?

With these questions in mind, University of California Riverside planetary scientist Michelle Hill and her colleagues recently simulated what happens to the atmospheres of different sizes of rocky worlds. The worlds tested were similar to Earth and orbited in the habitable zones around sun-like stars. It turns out for a world to maintain an atmosphere long enough for life to gain a foothold (a few billion years at minimum), it needs to be at least as big as Mars.

Narrowing down the search for life

The habitable zone — the area around a star where temperatures are right for liquid water to exist on a planet's surface — is prime real estate in the hunt for alien life. It's also a tough neighborhood for exoplanet atmospheres, because the closer a planet is to a star, the more ways in which radiation and stellar wind will try to strip away an atmosphere.

This is why Hill and her colleagues recently simulated how long it would take rocky, Earth-like planets of various sizes, in the habitable zone of a star like our sun, to lose their atmospheres. In other words, how much smaller could Earth, or a similar planet, be and still keep an atmosphere?

The answer turns out to be that an atmosphere-sustaining planet needs to be about 80% as wide as Earth, but could technically be as small as 60%. This offers astrobiologists a clue about which planets to focus on in the search for habitable worlds and signs of alien life.

"The plethora of exoplanets creates an interesting challenge in the search for potentially habitable planets," wrote Hill and her colleagues. "Of the many targets in the habitable zones of their star, which are the best candidates for follow-up observations with the aim of detecting biosignatures?" In other words, astrobiologists now have almost too many planets to choose from and not enough telescope time to search them all. So, it's time to narrow the search.

One way to do that is to figure out which planets are most likely to be habitable — and for life as we know it, that habitability means having an atmosphere.

Modeling atmospheres — and volcanoes

Hill and her colleagues' "Smaller Than Earth Habitability Model" simulates the fate of atmospheres around digital versions of Earth. Some of the simulated worlds are exactly like ours but smaller, with the same chemical makeup and the same proportions of core, mantle and crust. Others have slightly different amounts of carbon, larger or smaller cores, or different starting temperatures. The model traces what happens to these worlds over a few billion years, based on two things: how quickly stellar wind and radiation strip away gas from the planet's atmosphere and how quickly volcanoes pump out gas (mostly carbon dioxide) to replace it.

The model is how the team realized a scaled-down version of Earth needs to be at least 80% as wide as true Earth (0.8 Earth radii) to maintain an atmosphere in the long run. Smaller planets tend to lose gas faster than volcanic eruptions can replace it.

That's because smaller planets have less gravity and weaker magnetic fields with which to hold onto their thin envelopes of gas. They also don't usually release enough gas from within to make up for the loss. Their mantles — the churning layer of magma beneath the crust — tend to release less volcanic gas over time, and their upper layers cool and harden much faster. The latter process cuts off volcanic eruptions much earlier in a planet's lifespan.

Smaller planets clinging onto atmospheres

By changing some of Earth's parameters, the team managed to get planets as small as 0.6 Earth radii to maintain a stable atmosphere. Carbon was the key: planets with more carbon in their mantles tend to release more carbon dioxide gas in eruptions, and that turns out to be the biggest factor (other than size) in whether a planet keeps its atmosphere.

"Carbon dioxide is a heavy molecule," Hill and her colleagues wrote, "which can make it a difficult molecule to lose. We focus on a pure carbon dioxide atmosphere as a best-case scenario for atmospheric retention." Of course, that's only a best-case scenario for some relatively simple forms of life, so your astrobiological mileage may vary.

It took tons more carbon than Earth contains to make a significant difference to the fate of a planet's atmosphere — but because it's theoretically possible for a planet to form with that much carbon in its makeup, that's useful knowledge. Planets with relatively smaller cores, and therefore relatively thicker mantles, also had better luck on the atmospheric retention front. Starting with a larger supply of radioactive elements, which decay and release heat into the surrounding rock, helped keep the mantle molten and the volcanic gases churning skyward.

Starting with a cooler mantle also helps — which sounds surprising. You'd think a hotter mantle would be more likely to spew volcanic gases into the atmosphere. Yet, a cooler mantle takes longer to start erupting in earnest, which means the planet gets to hold onto its reservoir of gases until its star is older and more settled.

Newborn stars are prone to violent bursts of radiation and plasma, which would sweep away the volcanic gas as fast as it erupted. With a cooler mantle and later eruptions, the planet gets to keep more of the erupted gas.

A second chance for airless worlds

There's still hope of life for smaller worlds.

Even planets that lose their initial atmospheres entirely — instead of gradually replacing them with things like carbon dioxide and methane — might have a second chance to build a new atmosphere.

Hill and her colleagues suggest that one way for a planet to regain its lost atmosphere could be comet and asteroid impacts, which might deliver volatile elements like hydrogen, oxygen and carbon. These elements can combine to form all sorts of atmospheric gases.

Such impacts could be especially helpful if they happen later in the star system's life, like after the star is past its youthful phase of intense flares.

"While smaller planets face greater challenges in retaining atmospheres, our model suggests that they can develop atmospheres under the right conditions," wrote Hill and her colleagues, so, "even those that initially lose their atmospheres should not be immediately discounted as potentially habitable worlds."

What's next?

Future simulations using the Smaller Than Earth Habitability Model could study worlds around smaller, cooler stars called red dwarfs — stars like TRAPPIST-1, which is home to at least seven rocky planets, with three of them in the habitable zone. These stars make up about 75% of the stars in our galaxy, and their relatively dim light makes it easier for telescopes like the James Webb Space Telescope (JWST) to capture images of starlight filtering through the atmospheres of planets that pass between Earth and their host stars.

Hill and her colleagues also hope to explore what happens to atmospheres around tidally-locked planets, or planets where tidal forces keep the interior hot and seismically active, similar to Jupiter's moon Io.

The researchers published their work in June in The Planetary Science Journal.

This might be the closest we've gotten to finding a planet that could support life: Astronomers have detected an atmosphere around an Earth-like, rocky planet orbiting in the habitable zone around its star, a monumental first.

The rocky planet, called LHS 1140 b, is 48-light-years away from Earth and according to this new research, it has an atmosphere that contains helium. It is also the first rocky planet to have an atmosphere be detected directly. This is the first rocky planet to be found with an atmosphere that is also in the habitable zone, meaning it's at the right distance away from its star for liquid water to potentially exist on the planet. As we continue to search the cosmos for planets that can be considered "habitable," this planet checks more boxes than almost anything we've ever seen.

"We have actually detected directly the helium present in the atmosphere itself, and that's the first direct detection for any rocky exoplanet, which is really exciting … and then there's this added bonus that it's in the habitable zone, which is super exciting for astrobiology and habitability and searching for life," lead author Collin Cherubim, who recently earned his Ph.D. from Harvard University, told Space.com. "It feels kind of surreal."

What's this planet like?

Let's explore this planet and the system where it "lives."

This exoplanet, or planet outside of our solar system, was first discovered in 2017 by a team led by astronomer Jason Dittmann who is now a co-author on this new discovery.

"This planet was found like 10 years ago, and we're just now saying, okay, that's an atmosphere," Dittman told Space.com. "We're slowly narrowing the gap and checking these boxes … we're finding a planet that's rocky, a planet that's of the right temperature and now … it's like okay, we finally found one that has an atmosphere."

And being a rocky planet, "there's definitely a surface … it's made of rocks," Dittman said. What does the planet's surface look like? We can't say yet, but the researchers who found this planet's atmosphere think there's a good chance it could have water.

While it orbits a red dwarf star, which is smaller and cooler than the sun, it orbits closer than we do to our star, maintaining a temperature that keeps the planet in the "Goldilocks zone" where liquid water could exist on its surface.

"It probably also has a lot of water," Cherubim said. "If it has some amount of atmosphere that can provide a bit of a greenhouse effect, which we know that it does now … it will very likely be what we consider to be habitable conditions on Earth, and conditions that would likely support liquid water."

So is it Earth-like? While it's certainly not an Earth copy, this planet can be considered Earth-like in two main ways, Cherubim shared. One: its overall composition. The planet is rocky, likely with an iron core and (now we know) it has an atmosphere. And two: the planet's temperature is just right for liquid water, which is necessary for life at least as far as we understand it on our planet.

Finding an atmosphere

The discovery of the first exoplanet was confirmed just over 30 years ago. Since then, scientists have found over 6,000 exoplanets and counting. And while a few rocky planets have been found in their star's habitable zone, it wasn't until now that an atmosphere has been confirmed around a rocky planet in the habitable zone.

One reason why scientists have had a hard time finding such planets with atmospheres is their stars. LHS 1140 b orbits the most common type of star, a red dwarf, which is about one-third the size of our sun. This type of star remains active for a lot longer than stars like our sun. This activity means it releases bursts of extreme radiation like solar flares and coronal mass ejections. And typically, the extreme radiation around these stars totally strips the atmospheres from the planets orbiting them, so astronomers have wondered if planets orbiting these stars can have an atmosphere at all.

"This discovery is a big deal because it's showing that at least this rocky planet has retained an atmosphere over billions of years," Cherubim said. It's "a bona fide, robust way of saying yes, atmospheres can survive on rocky exoplanets."

It's possible that other gases beyond helium are in the planet's atmosphere, and it's possible that some of its atmosphere was previously stripped away by its star's radiation. But the red dwarf that this planet orbits is roughly 6 billion years old, a few billion years older than the age at which their extreme radiation activity begins calming down. So while some helium is still slowly escaping the planet's atmosphere over time, the team expects the planet to retain an atmosphere, Dittman shared. After all, even Earth's helium is slowly escaping our own atmosphere.

The proof is in the atmosphere

To prove that this planet has an atmosphere, the team started with a prediction that Cherubim made during graduate school. It all started with a theoretical model and a sneaking suspicion that there must be rocky exoplanets with atmospheres other than Earth.

"This came out of a very specific prediction from a planetary evolution model that I actually developed myself, from scratch, from first principles, for my Ph.D. as a theorist, and I made a very specific prediction about this planet," Cherubim said. "And then I went out and did a pretty unexpected, weird thing using this technique that's typically reserved for observing giant planets, and I used it for a rocky planet, which nobody has done before.

"And lo and behold, I made this measurement that was actually consistent with my prediction. And it was really nice to kind of close the whole loop of the scientific method."

The team took the theoretical model that Cherubim developed in graduate school and put it to the test using the Warm Infrared Echelle (WINERED) Spectrograph on the Magellan Observatory in Chile. And with their observations, they were able to see LHS 1140 b and another planet both transit, or pass in front of, their star in the same night. With this spectrographic data, they could identify the signatures of molecules in the atmospheres of these planets as they passed in front of the star. And while one planet yielded no results, this planet showed a direct, undeniable helium signature.

Are there aliens?

When looking at a planet that is rocky, has an atmosphere, and is in the habitable zone (meaning it could have liquid water), the question of life comes up quite quickly.

But the researchers don't have enough data to make that conjecture. "I'm not claiming this planet has life," Cherubim made clear. With further investigation, scientists could better understand what else might be in this planet's atmosphere, and they could confirm if it has water. Further observations might not be able to confirm habitability or identify any life on the planet, but they could at least help us to better understand planets like this.

With this being the first planet of its kind discovered, further exploration will help us to put the pieces together. But it is certainly a major step forward in the eternal human quest to answer the question: are we alone?

This work was described in a study published in the journal Science.

It has taken over ten years, but astronomers have finally won a prolonged game of cosmic hide-and-seek with a planet hiding around the star Beta Pictoris. The extrasolar planet, or exoplanet, is known as Beta Pictoris d. It is found 63 light-years away and has two planetary siblings, which were caught some time ago.

This new exoplanet is 100 times fainter than its sibling Beta Pictoris b, which was the first planet discovered in the system. That makes Beta Pictoris d the faintest exoplanet ever seen from Earth.

Like its previously discovered sibling, Beta Pictoris d is a gas giant. However, unlike Beta Pictoris b and Beta Pictoris c, it is much further away from its parent star and is thus much cooler than its siblings. The newly discovered world is also smaller than the previously seen world around Beta Pictoris. While both Beta Pictoris b and Beta Pictoris c have around 10 times the mass of Jupiter each, Beta Pictoris d has only around 2.4 times the mass of the solar system's most massive world. That makes it one of the lightest exoplanets ever directly imaged by a ground-based telescope.

"Planet d, it seems, has been playing a game of hide-and-seek with us for over a decade, and only now can we say ‘found you!’" team member Jayne Birkby an astronomer at the University of Oxford in the UK, said in a statement.

The discovery of Beta Pictoris d helps clear up a puzzle regarding a disk of dust and debris in this planetary system, which is theorized to be made of the leftovers of planet formation. That is because this newly found world has exactly the right mass and location needed to explain both the odd shape of this debris disk and its location.

11 years of hide-and-seek

The team behind this discovery wasn't initially looking for a third planet around Beta Pictoris. Instead, they were simply attempting to learn more about the system's first planet.

"This was a serendipitous discovery," team co-leader Ben Sutlieff, an astronomer at the University of Edinburgh said. "We initially wanted to look more at a known planet in the system, Beta Pictoris b, to see how it changed over time."

That was until they spotted telltale signs of another planet around the same star. Delving back into 11 years of archival data, the team found the third planet lurking in various images.

To consider how impressive it is to directly image a planet outside the solar system, consider that of the over 6,000 worlds in NASA's exoplanet catalog, less than 100 were discovered using direct imaging. Such detections are so tricky because they require picking out the thermal glow of a planet from the glare of its parent star.

Catching a direct image of an exoplanet as faint as Beta Pictoris d is a major step forward for this technique.

"The new planet is 100 times fainter than Beta Pictoris b, the famous planet in the same system, making it the faintest exoplanet ever imaged directly from Earth," team co-leader and European Southern Observatory researcher Markus Bonse said.

The discovery of Beta Pictoris d makes the Beta Pictoris system just the second in which more than two worlds have been directly imaged. The first was HR 8799, which is located around 133 light-years away.

"Systems with multiple directly imaged exoplanets are the 'holy grails' of discoveries, because they can teach us a lot about what different exoplanets are like in the same formation environment," Sutlieff said

Thus, the discovery of Beta Pictoris d via direct imaging should encourage further direct imaging of planetary systems which may also harbor faint planets. This is an investigation that could be picked up by the Extremely Large Telescope (ELT), currently under construction in the Atacama Desert of northern Chile.

"Planets seem to have friends," team member Beth Biller, of the University of Edinburgh in the UK, said. "Many of the famous directly imaged exoplanet systems seem to have multiple giant planets in the same system, and likely there are even more lower-mass planets hiding in these systems that might be revealed with instruments on the ELT."

The team's research was published on Wednesday (July 15) in The Astrophysical Journal Letters.

Clouds formed from vaporized rock could create the ultimate thermal insulation on one of the most common types of exoplanets discovered so far — the sub-Neptunes — raising temperatures so high that these worlds' solid surfaces melt and turn into oceans of magma.

"This work takes us one step closer to answering the question of what these mysterious worlds are made from," said astronomer Luis Welbanks, of Arizona State University, in a statement.

Sub-Neptunes are planets larger than Earth but smaller than Neptune. They are especially mysterious since we do not have a world of this type in our solar system. They are thought to contain a rocky core surrounded by a deep atmosphere, but not much else is known about their composition and structure. Their atmosphere could be hydrogen-rich like Jupiter's, or it could be abundant with water vapor and carbon-based organic molecules. In some cases, they might even be habitable under the hycean world paradigm, wherein a thick hydrogen atmosphere encases a global ocean of liquid water.

The James Webb Space Telescope (JWST) is busy probing the atmosphere of several sub-Neptunes to try and learn more about their bulk composition because their atmosphere should be representative of what such planets are made from, but results so far have been inconclusive.

Atmospheres of sub-Neptunes are deep and dense, meaning crushing pressures close to the boundary between the atmosphere and the solid body of the world can turn minerals into vapor that forms clouds. These minerals include aluminium oxide, iron, magnesium silicate, manganese sulfide, potassium chloride, sodium sulfide and zinc sulfide.

Using detailed computer simulations, a team led by Sagnick Mukherjee of Arizona State University explored what effect these clouds could have on both the surface and atmosphere of a sub-Neptune.

They showed that when these mineral clouds form deep down, they act as efficient insulating blankets that trap heat (and lots of it) leaking out from the core of the planet.

"Among the sub-Neptunes currently being studied with JWST, we were amazed to find that cloud-driven heating can raise the temperature at the planet's atmosphere–interior boundary by roughly over 1,400 to 2,600 degrees Celsius [2,550–4,712 degrees Fahrenheit]," said Mukherjee.

At the same time, because heat is being prevented from escaping, the upper atmosphere cools noticeably.

With all that heat retained close to the surface, the rock begins to melt.

"For some of the planets we modeled, that extra heat is enough to melt the planet's surface, creating a magma ocean," said team-member Matthew Nixon of Arizona State University.

These potential magma planets include GJ 1214b, which orbits a red dwarf star 48 light-years away. At one time it was thought to be a cool water-world, but JWST's discovery in 2025 of metallic vapors and carbon-dioxide haze in GJ 1214b's atmosphere rule this out, and now it seems that its surface, undetectable beneath the thick atmosphere, could be completely molten.

However, the presence of magma oceans opens up possibilities for more complex atmospheric chemistry. Gas seeps out of the magma and diffuses into the atmosphere, in theory enriching it in oxygen, silicon hydride and silicon monoxide, while going the other way the magma absorbs ammonia, methane and water vapor from the atmosphere. In other words, the atmosphere becomes enriched by material from underground, while also becoming depleted in some gases that astronomers would expect to see in greater abundance.

This means that JWST's attempts to learn about the bulk composition of a sub-Neptune exoplanet from the spectrum of its atmosphere could be skewed by this exchange of gases between a magma ocean and the atmosphere. The extra heating deep down will also impact the future of these sub-Neptune planets, since the extra heat will keep their lower atmosphere bloated and prevent the planet from contracting over billions of years.

If the findings are correct, they could place a huge obstacle on sub-Neptunes being habitable. Even if the boundary between the atmosphere and solid body of the planet isn't hot enough to form magma, it would still render the surface too hot to support liquid water or life.

The findings were published on July 8 in Astrophysical Journal Letters.

NASA's exoplanet-hunting spacecraft TESS (Transiting Exoplanet Survey Satellite) has a new method for detecting worlds beyond the solar system. The technique relies on a phenomenon introduced by Einstein in his 1915 theory of gravity, general relativity, called gravitational microlensing.

The exoplanet in question is called Gaia23bra b. The first hints of this exoplanet were found in 2023 by the now-retired Gaia space telescope via the slight brightening of a star caused by a microlensing event.

TESS usually spots planets by the tiny drop in the light output from their parent star as they cross, or transit, its face. This technique is most effective for very large gas giants that orbit close to their star, so it most likely wouldn't work for Gaia23bra b, which has 1.6 times Jupiter's mass but orbits its star at a similar distance to Jupiter's orbit around the sun. Additionally, the transit method employed by TESS usually has a search radius of around 150 light-years. Gaia23bra b, however, orbits an orange dwarf star about 80 percent the size of the sun that is located 40,000 light-years away. Thus, to confirm the existence of this world, TESS had to learn a new trick.

"When TESS launched, no one expected it to ever be capable of finding this kind of planet," team member Diana Dragomir of the University of New Mexico said in a statement. "The discovery implies that there are probably other so-called microlensing planets hiding in TESS's data that we hadn't previously thought to look for."

Microlensing and the hunt for exoplanets

To understand what microlensing is, first we have to consider what general relativity says about the effect of objects with mass on space itself. Mass causes the very fabric of space and time, united as 4-dimensional spacetime, to warp. Gravity arises from that curvature. The greater the mass, the more extreme the warping and thus the greater the force of gravity.

Here is the cool part: light usually travels in a straight line, but when the very fabric of spacetime is curved, it has to follow that path. So when light from a background object passes a foreground object, the light bends around it. The bigger the mass and the closer to that mass the light passes, the more its path is curved. That means light from the same source can reach our telescopes at different times. This causes an amplification of the background source.

This phenomenon of gravitational lensing has been used to great effect to study ancient galaxies that would usually be too distant and faint to see when they are gravitationally lensed by foreground galaxy clusters.

Obviously, planets have a heck of a lot less mass than clusters of galaxies, but they can still cause a slight gravitational lensing effect. That is micro-lensing, and it can be used to hunt planets.

Of the around 6,000 known exoplanets, only around 5 percent have thus far been discovered using microlensing. That is compared to around 75% found using the transit method TESS usually depends upon.

Gaia23bra b was first hinted at when it acted as a gravitational lens, passing between Earth and a background star, causing the ever-so-slight brightening of that star. The exciting thing about TESS successfully using microlensing is that this offers a complementary technique of exoplanet detection capable of detecting planets that the transit method might miss.

"With microlensing, we can find smaller planets with greater orbital distances, including worlds in the habitable zone of their star and even farther away," team member Mallory Harris of the University of New Mexico said. "Microlensing events happen once, and they're gone — they don't repeat. I like to joke that we'll probably find the first Earth analog with microlensing, and then wave at it as it goes by because we'll never see it again.

And, if you will excuse the pun, the future is bright for microlensing. That is because it is one of the techniques that NASA's next project, the Nancy Grace Roman Telescope, will use.

Roman will scour the very heart of the Milky Way where stars are tightly packed together, hunting microlensing events which should be common in such a dense stellar region. NASA scientists predict that this will lead to Roman discovering around 1,000 microlensing exoplanets on top of the estimated 100,000 transiting worlds it is predicted to detect.

"This is a bit like a preview of the microlensing NASA's Nancy Grace Roman Space Telescope will do. The key to Roman's microlensing survey is its dense time coverage targeting the galactic bulge," team member Michael Fausnaugh of Texas Tech University said. "The TESS mission uniquely provides these rapid observations for stars in other parts of the galaxy, and pairing the two opens up prospects for understanding planet formation in a diverse population of stars.

"Since microlensing finds solar system-like planets, this offers a new chance to understand how planetary systems like our own vary in different regions of the galaxy."

The team's research was published on July 1 in The Astrophysical Journal Letters.

Astronomers have used the James Webb Space Telescope (JWST) to observe an oddball gas giant exoplanet orbiting a dead star, a white dwarf, located some 80 light-years away. This "life after death" system gives scientists a portentous vision of what the solar system may look like in around 6 billion years after the sun has exhausted the hydrogen in its core, shed its outer layers, and left behind a smoldering white dwarf stellar remnant.

Prior to the final stages of that transformation, our star will have become a red giant, swelling out to many times its original radius, swallowing the inner rocky planets including Earth but leaving the outer planets  — although changing them irrevocably. Reflecting this, the white dwarf at the heart of this research is orbited by a Jupiter-sized exoplanet, designated WD 1856 b.

As WD 1856 b orbits its dead parent star, it crosses or "transits" the face of this white dwarf, known as WD 1856+534. By observing these transits with the JWST, the team was able to measure the mass and temperature of this Jupiter-like planet while also observing the composition of its atmosphere. To their surprise, they found WD 1856 b is hotter than expected. They also discovered how this planet came to have such an unusually tight orbit around its host white dwarf star.

"We're used to looking back in time when we use telescopes, but this is the first time we have been able to look forward to what might happen to the outer planets around the remnant of a sun-like star; it's like using a time machine to peer into the distant future of our solar system," team leader Ryan MacDonald from the University of St Andrews in Scotland said in a statement. "This is just the beginning of our exploration of planets orbiting dead stars with Webb, and the search for further planets orbiting white dwarfs is ongoing.

"Our results show that stellar death is not the end  — some planets experience a vibrant and lively future after the death of their star."

The team's research was published on Wednesday (July) in the journal Nature.

Survivor planet is a real oddball

The gas giant WD 1856 b was first discovered in 2020 by NASA's exoplanet-hunting spacecraft TESS (Transiting Exoplanet Survey Satellite) and the Spitzer Space Telescope. TESS detects exoplanets using the tiny dips in starlight they cause as they transit their host stars, blocking starlight.

This was the first intact planet ever discovered closely orbiting a white dwarf. What immediately stood out about WD 1856 b was how close its orbit is to its white dwarf host. The orbit is around 2% the size of Earth's orbit around the sun and takes just 1.4 Earth days to complete.

"The planet is quite the oddball. It's about the size of Jupiter, but the white dwarf it orbits is the size of Earth, so the planet is seven times larger than its star," MacDonald said.

The planet couldn't have always been in such a close orbit to its star. If it had, it would have been obliterated when the star transformed into a red giant before shedding its puffy outer layers and leaving behind a white dwarf.

"The big question is how WD 1856 b ended up where it is today, and there are two theories," team member Christopher O'Connor of Northwestern University said. "One is that the planet was swallowed by the host star as it was dying, and managed to survive on the inside. The other is that the migration took place due to the gravitational effect of other objects in the system. The white dwarf is part of a triple star system, and the outer companion stars could have influenced WD 1856 b's orbit."

The clue that allowed the team to differentiate between these migration mechanisms was the temperature of WD 1856 b, which at 260 degrees Fahrenheit (127 degrees Celsius) is about 240 degrees hotter than it would be if its only source of heat were the light from its white dwarf parent star.

With no energy available to warm the planet to these temperatures, the team reasoned that the temperature must be a residual effect of prior warming either from being engulfed by the red giant or during an inward migration. Using observations of the planet's mass of between four and 11 times that of Jupiter, the team was able to model how it would have cooled over time.

MacDonald and colleagues determined that WD 1856 b was likely heated up around 3 billion to 5.5 billion years ago. Its host star has been a white dwarf for longer than that, which means the exoplanet was safe during the star's destructive red giant phase, and moved into its tight orbit afterwards.

"As the planet moved inwards, its interactions with the strong gravity of the white dwarf will have caused it to warm up considerably, and it has been cooling ever since," O'Connor said.

The results indicate that Jupiter could move closer to the sun after the violent drama of its red giant phase and the destruction of the inner solar system. The findings also demonstrate the incredible observing power of the JWST and how the $10 billion space telescope is still discovering things no other instrument can.

"White dwarfs like WD 1856 are exceptionally dim compared to the planet-hosting stars we normally observe with the JWST," team member Victoria Boehm of Cornell University said.

"To make things even harder, the planet's transit only lasts 8 minutes, so it's very much if you blink you miss it! Capturing enough light to see WD 1856's spectrum, while also doing so quickly enough to not miss the transit, is something only Webb can do."

A potentially habitable rocky world has been found in the habitable zone around a red dwarf just 25 light-years from us.

However, faced with a hostile wind of radiation from its host star, it remains unclear whether this new exoplanet supports an atmosphere, or the possibility of life. Nevertheless, astronomers are celebrating the discovery.

"This one's exciting," said Paul Robertson of the University of California, Irvine, in a statement. "It's one of our closest cosmic neighbors. Twenty-five light years sounds like a long way, but the Milky Way is about 100,000 light years across, so in that respect it's our next-door neighbor."

The planet, designated GJ 3378b, orbits the faint red dwarf star in the constellation of Camelopardalis, the Giraffe. It was discovered in 2024 by French astronomers using the Canada–France–Hawaii Telescope in Mauna Kea, but American astronomers have revised those initial findings, revealing that the planet is possibly more like Earth than we realized.

All we know for sure is the mass and the orbit of GJ 3378b. We do not yet know whether it is like Earth or not – it could have land and sea and clouds and life, or it could be airless and cratered.

The planet is not seen to transit, or pass in front of its star, blocking its light from our vantage point. Instead, GJ 3378b was detected by the effects of its gravity tugging on its parent star. This causes the star to wobble around the center of mass that it shares with the planet, a wobbling that is betrayed by a Doppler shift in the star's light that can be measured by its spectra, the wavelengths of light that it emits.

When it was discovered in 2024, its mass was measured to be 5.26 times the mass of Earth, putting it in mini-Neptune territory of being a larger, mostly gaseous world. However, by taking a second look at the planet using two different telescopes, Robertson's team was able to show that the planet's true mass is 2.3 times the mass of Earth. This means that it is closer to being a rocky super-Earth instead.

Furthermore, the same observations found that GJ 3378b's orbital period is 21 days, not the 25 days that had originally been measured. This means that the planet is closer to the star than had been thought, sitting comfortably within the habitable zone where temperatures will be suitable for liquid water on the surface of a planet with an atmosphere. So from that point of view, the chance of GJ 3378b being habitable, if not inhabited, seems fair.

"This super-Earth gets about 90% of the radiation from its host star that Earth gets from its sun, so it's right in the sweet spot," said Robertson.

One significant problem, however, is that red dwarfs spit out harmful torrents of radiation in fierce gusts of their stellar winds, which can strip away a planet's atmosphere. This raises the question, does GJ 3378b even have an atmosphere?

Currently there is no way to tell. The James Webb Space Telescope (JWST) has been probing for atmospheres around other rocky worlds orbiting red dwarfs, such as those in the TRAPPIST-1 system. It does so by transit spectroscopy, where an atmosphere wrapped around a planet absorbs some of the star's light filtering through it, leaving dark absorption lines in the star's spectrum.

Unfortunately, GJ 3378b does not transit its star. This means that astronomers will have to wait until the 2040s, when NASA's Habitable Worlds Observatory will hopefully launch, to answer the question of whether GJ 3378b really does have an atmosphere or not.

Still, astronomers are hopeful. GJ 3378b is right on the edge of the zone where planets are expected to be seriously battered by radiation, meaning it could have escaped the worst. If so, there might be more than just an atmosphere for the Habitable Worlds Observatory to discover.

"The ultimate goal is biosignatures," said University of Texas at Austin astronomer Michael Endl in a separate statement. "We really want to know, are we alone in the universe? We are still in the reconnaissance phase of our solar neighborhood, trying to find the planets around the nearest stars because those will be the easiest ones to detect a biosignature on."

"This planet brings us one step closer to knowing all of our neighbors and, ultimately, which might be hospitable for life."

The findings were reported on June 30 in The Astrophysical Journal.

Hot Jupiters are some of the most extreme planets in the universe, blazing gas giants like Jupiter or Saturn that exist so close to their stars that they complete orbits in a matter of days. Now, new research may rewrite the definition of these planets that make the solar system look a little bit mundane.

The extrasolar planet, or exoplanet, at the heart of this rethink is CoRoT-2 b, a world with 3.5 times the mass of Jupiter and 1.5 times the size of our solar system's largest planet, located around 696 light-years away. It orbits its star in just 41 hours or so.

What is so strange about CoRoT-2 b? Most hot Jupiters are tidally locked, meaning they have one side that permanently faces their stars, a "dayside," and a "nightside" that faces out into space in perpetuity. However, a new investigation of CoRoT-2 b seems to show that this hot Jupiter isn't tidally locked, and that is a big surprise, one that challenges all our assumptions about these extreme exoplanets.

"I really like looking at the weird ones — finding planets that don't fit the standard picture — and doing some mystery solving," team leader Aurora Kesseli of the NASA Exoplanet Science Institute (NExScI) said in a statement.

"Now we can see that a one-size-fits-all model does not work, even for planets that we've been studying for a long time. Every time we look at another hot Jupiter, we learn something new to help refine our models, which are useful for understanding not only hot Jupiters, but for all types of exoplanets."

The cosmic dance of hot Jupiters

For rocky planets, tidal locking would result in an incredibly hot dayside and a much cooler nightside, divided by a perpetual sunset. However, the situation for gas giants is somewhat more complicated because of their swirling atmospheres.

This means while hot Jupiters have day and night sides, they usually possess large hot spots on the dayside, shifted slightly towards the direction of their rotation and their orbit around the host star. CoRoT 2b defies this expectation too, possessing a hotspot in the opposite direction of its orbit. Kesseli and the team investigated three possible reasons for this abnormality.

"The conditions for tidal locking are important for astronomers to understand because the habitable zone for planets around M dwarfs is within the tidal locking zone, where we expect tidal locking to happen pretty quickly," Kesseli said. "The way that a planet rotates greatly affects how the planet distributes its heat, and therefore affects its habitability, so for a planet that is tidally locked, the temperatures, winds, and climates are going to look completely different than those of a planet that is not tidally locked."

Measuring the velocity of CoRoT-2 b, Kesseli and colleagues found that one day on this hot Jupiter is about three Earth days, which is almost twice as long as its year which lasts around 1.5 Earth days. This means that its day is much shorter than its year; by the time CoRoT-2 b completes one rotation, it has made almost two orbits of its parent star.
"I was very pleasantly surprised when I tried a bunch of methods, and I was like, 'Aha! This is actually like one of the three hypotheses!' Seeing the data pretty clearly pointing towards one of them was just really exciting," Kesseli said.

The next step for Kesseli is to discover what is causing the slow rotation of CoRoT-2 b.

"Hot Jupiters are the first type of planet where we have been able to really explore and refine our models of their climates," said Kesseli. "With the next generation of telescopes like the Habitable Worlds Observatory and the Extremely Large Telescope, we’ll be able to do more in-depth measurements across more planets, maybe even potentially habitable ones."

The team's research was presented at the 248th meeting of the American Astronomical Society in Pasadena, California, and has been published on the paper repository site arXiv.

What is rarer than discovering a "super-puff" planet with densities much (much) lower than those of the solar system gas giants? Discovering two orbiting the same star.

That is exactly what astronomers have done, finding two extrasolar planets, or exoplanets, that are super-puff siblings orbiting the same star. Both planets, designated TOI-791 b and TOI-791 c, have densities lower than that of cotton candy, making them the lightest exoplanets ever seen.

"Only a handful of these super-puffy planets are known, and it is even rarer to find two in the same system," team leader George Dransfield of Oxford University said in a statement. "Their extremely low densities make them fascinating targets for understanding how planetary systems form and evolve."

The two planets orbit a dwarf star called TOI-791, which is located around 1,110 light-years from Earth. Both planets are around the same size as Jupiter, but the solar system's most massive planet has a density 28 times greater than TOI-791 c and 35 times greater than TOI-791 b.

The low density of these exoplanets aren't their only remarkable quality, however. The super-puff siblings are also locked in a rare dance that sees the inner planet complete five orbits as the outer planet completes three orbits. This is known as a 5:3 mean-motion resonance.

As TOI-791 b and TOI-791 c complete this orbital tango, they gravitationally tug on each other, causing changes in their transits of their parent star, with transits representing the moments these planets cross the star's face from our vantage point. These transits are some of the longest ever seen, lasting 11 hours per planet, and were integral to discovering the worlds.

If you cross me....

TOI-791 b and TOI-791 c were first identified as candidate planets in 2019 and 2023, respectively, when the Planet Hunters citizen scientist group assessed data from NASA's exoplanet-hunting spacecraft TESS (Transiting Exoplanet Survey Satellite).

TESS hunts planets using the transits they make of their host stars from its position around Earth. These planetary transits cause a tiny dip in light from the star that TESS can detect.

Dransfield and colleagues then measured the size and density of these planets using data from telescopes across the globe, including the ASTEP (Antarctic Search for Transiting ExoPlanets) telescope at Concordia Station in Antarctica, to discover the planets are rare super-puff gas giants.

The discovery could help solve the puzzle of how super-puff planets actually form. The prevailing theory suggests super-puff planets form in distant, cold regions in the disks of gas and dust that surround their parent stars. This allows gas to accumulate around small solid cores, leading super-puffs to gather vast atmospheres of hydrogen and helium.

Further investigation of TOI-791 b and TOI-791 c could help sort between this formation route and other birth mechanisms for super-puffs.

"This system offers a unique laboratory for understanding how super-puff planets form and evolve," team member Amaury Triaud of the University of Birmingham said in the statement. "We propose to carry out space-based observations using the James Webb Space Telescope to assess if the puffy atmosphere contains carbon, nitrogen, and oxygen-bearing species, revealing new insight into how these unusual planets formed."

The team's research was published on Thursday (June 25) in the journal Monthly Notices of the Royal Astronomical Society.

A new planetary habitability model could make the search for aliens more efficient by quickly identifying rocky worlds unlikely to sustain the atmospheres needed for life as we know it.

The software, called the Smaller Than Earth Habitability Model (STEHM), allows astronomers to screen exoplanets before committing valuable telescope time to detailed observations. Developed by researchers at Stanford University, the model assesses whether a rocky planet can build and retain an atmosphere over billions of years — a prerequisite for life as we know it, according to a statement from the university.

Astronomers searching for life beyond Earth face a daunting challenge: thousands of exoplanets have already been discovered, and billions more are thought to exist throughout the Milky Way — roughly one for every star in the galaxy. As powerful new telescopes come online, researchers increasingly need ways to identify which worlds are worth closer study.

"The only way that we're going to ever find out if there are signatures of life out there is by observing the atmosphere of these planets," Michelle Hill, lead author of the study who developed STEHM, said in the statement.

Traditionally, scientists have focused on whether a planet lies within its star's habitable zone, the region where temperatures may allow liquid water to exist on the surface. But location alone does not guarantee habitability. A planet without a substantial atmosphere may be unable to maintain stable temperatures, shield itself from radiation or support surface water, the researchers said.

STEHM adds a second layer to this assessment by estimating whether small rocky planets can generate and retain atmospheres over geologic timescales. The model links a planet's size to its ability to hold onto atmospheric gases, helping identify a lower size threshold for potentially habitable worlds.

To build STEHM, Hill used the ExoPlex planetary simulation code to model six rocky worlds ranging from half Earth's size to Earth-size, testing how planetary structure, volcanic activity, internal heat and stellar radiation affect atmospheric survival. The model was validated using Venus and Mars, correctly reproducing Venus's thick carbon dioxide atmosphere and Mars's long-term atmospheric loss.

The results suggest that rocky planets at least 80% the size of Earth can retain atmospheres for 10 billion years or more when orbiting within habitable zones around sun-like stars. Smaller planets generally lose their atmospheres more quickly, though worlds around 70% of Earth's size may still be habitable under favorable conditions. Atmospheric longevity also depends strongly on initial carbon content and heat-producing elements that drive volcanic activity, allowing STEHM to serve as a size-based filter for identifying the most promising habitable worlds.

"Maybe there's life on other planets under the ground, but we are never going to be able to see it because we can't send something to those exoplanets," Hill said in the statement. "The best chance we've got is looking for signs of life by analyzing atmospheres from afar."

By narrowing the field of candidates, STEHM could help astronomers focus on the most promising planets for life while avoiding wasting resources on unlikely targets. The approach may be especially useful as next-generation missions, such as the European Space Agency's PLATO space telescope, expand the catalog of rocky exoplanets around nearby stars. Researchers hope the model will help prioritize which of these planets merit follow-up observations.

STEHM not only addresses where life beyond Earth could occur, but when it might, by modeling whether exoplanets can actually hold onto atmospheres over geologic timescales — a key prerequisite for life to take hold in the first place.

"Maybe the answer to why we haven't found any life yet is that we're so early in the grand scheme of what has been created through the lives and deaths of stars," Hill said in the statement. "Maybe we're one of the first."

Their findings were published June 4 in the Planetary Science Journal.

Using NASA's exoplanet-hunting spacecraft TESS (Transiting Exoplanet Survey Satellite), scientists have discovered a planetary system that scientists are calling "improbable." It could change how we think about the mechanisms behind planet formation.

The reason for the unusual arrangement of this planetary system is a failed star or brown dwarf designated TOI-201 c. Objects like this get the slightly unfair nickname of "failed stars" because, despite forming from a collapsing cloud of gas and dust like other stars, they fail to gather enough mass to trigger nuclear fusion of hydrogen to helium in their cores. Brown dwarfs have masses between 13 and 80 times that of Jupiter, or 0.013 to 0.08 the mass of the sun. That puts them right between the most massive planets and the smallest stars.

TOI-201 c is on a highly elliptical orbit, taking 2,881 days to orbit its star, which has resulted in planets including a super-Earth named TOI-201 d and a warm Jupiter named TOI-201 b, forming in a narrow zone within its orbit, something that isn't just new to astronomers; it is completely unexpected based on planetary formation models.

The 5.8-day orbit of TOI-201 d and the 53-day orbit of TOI-201 b are both perfectly aligned with the orbit of the brown dwarf. The brown dwarf creates gravitational instability at distances equivalent to the distance between Mars and the sun, but this didn't prevent planets from forming in the system.

"This discovery provides a crucial insight into how planets form even around massive, eccentric objects," team member and INAF researcher Aldo Bonomo said in an emailed statement.

The system challenges the idea that gas giant planets form at distances equivalent to 2 to 3 times the distance between Earth and the sun in the disks of gas and dust that surround stars during their infancy.

"The presence of the brown dwarf on such an elliptical orbit forced the planets to form and survive by occupying the innermost and hottest edges of the primordial disk," team member Luca Naponiello of the National Institute for Astrophysics (INAF) said in the statement. "Furthermore, the data show that during the close approach of the brown dwarf, the warm Jupiter undergoes strong and sudden variations in its transit timing, bearing witness to an intense and vigorous dynamic interaction currently underway between the two giants."

The system was discovered by TESS using a rare mono-transit event, which describes a planetary body making one crossing of the face of its star, causing a dip in starlight. This was followed by an observing campaign conducted from the ground.

It is extremely rare to discover objects like TOI-201 c with such long and eccentric orbital periods using transits they make of their parent star. This brown dwarf is the first one of these objects to have its mass confirmed, making it an important step forward in astronomy.

"It [TOI-201c] is the transiting object with the longest orbital period for which the mass is known," Naponiello said.

The team's results were published on Wednesday (June 17) in the journal Nature.

Using the James Webb Space Telescope, astronomers have discovered that the well-known "Pink Planet" harbors a salty surprise and an exotic atmospheric chemistry. The discovery marks an advancement in the study of cold objects beyond the solar system.

Initially discovered in 2013, GJ504b orbits a sun-like star located around 57 light-years from Earth. With a mass around 25 times that of Jupiter, this Pink Planet may not be a planet at all despite its moniker. It may instead be a brown dwarf, a failed star that formed like a star but was unable to gather enough mass to achieve the nuclear fusion of hydrogen to helium in its core. Thus, astronomers refer to it as a "planetary-mass companion," which means a planet-size object orbiting a parent star.

GJ504b remains one of the coldest planetary-mass companions discovered using ground-based telescopes, with a temperature of around 550 degrees Fahrenheit (290 degrees Celsius). Although, that still makes it hot enough to bake bread. Now, James Webb Space Telescope (JWST) data reveals it has a key ingredient for bread making too: salt located in its atmospheric clouds, unlike anything astronomers have seen before.

"The Pink Planet is the coldest companion ever discovered using ground-based instruments," team leader Aneesh Baburaj of Northwestern University said in a statement. "Many teams all around the world performed follow-up observations to study its light, but it was too faint for ground-based instruments. That made it a perfect target for JWST.

"When we finally obtained its spectrum, it immediately looked interesting. But once we started digging deeper into the data, we realized it was not like anything we have analyzed before."

The Pink Planet is cold and old

The team studied this planetary companion by measuring its faint electromagnetic radiation emissions and filtering out the bright glare of its parent star.

They found the relative coolness of the Pink Planet is a result of the planet's age. Both gas giant planets and brown dwarfs are born blisteringly hot but cool off as they get older. This new research estimated that GJ504b is between 2.5 billion and 4 billion years old.

Breaking down light from the Pink Planet into individual wavelengths, the team was also able to determine its chemical composition. This is possible because elements absorb and emit light at characteristic wavelengths, meaning they leave "fingerprints" on light passing through their atmospheres.

"In the past, other astronomers observed the companion for an entire night with some of the biggest telescopes in the world to obtain a spectrum," Baburaj said. "And they could not see the object. With JWST, our entire observation took around two hours, and we were successful."

The JWST data revealed a rich cocktail of chemicals in the atmosphere of the Pink Planet that included water, carbon dioxide, methane, and ammonia. However, these observations didn't match modeling of the planetary companion's atmosphere until the team factored in something completely unexpected: clouds of salt deep in the atmosphere.

"We ran simulations with clouds, and the results aligned with what we know about cold planets," Baburaj said. "We tried three different types of clouds, and salt clouds fit best. When we accounted for salt clouds, it subdued the signature of molecules hidden deeper in the companion’s atmosphere. Then, the results became physically possible.

"This is the first time we've found that salt clouds are critical to explaining the spectrum of an object. It's a good reminder to account for clouds in our models."

Though this mystery may be solved, there are still questions surrounding GJ504b that will only be solved with further investigation. The Pink Planet seems to be unusually rich in elements heavier than hydrogen and helium, which astronomers call metals. This means the team still can't pin down the origin of the Pink Planet; did it form like a planet, or like a star?

That means they aren't quite ready to determine if GJ504b is a gas giant planet or a brown dwarf... or should that be Pink Dwarf?

The team's research was published on Thursday (June 18) in The Astronomical Journal.

Astronomers have a cosmic mystery on their hands, investigating a celestial crime scene to determine if a distant star has eaten a super-Earth exoplanet. The star may have had an accomplice — a failed star or "brown dwarf" companion — which may have steered the unfortunate planet toward its fiery doom.

The team charged with investigating this mystery first discovered hints of the crime when they found the star, TOI-5882, located around 1,300 light-years away, is surprisingly rich in the element lithium.

"You are what you eat, right?" team leader Brooke Kotten of the University of Michigan said in a statement. "We know that there's much more lithium in planetary material than there is in stars. So if a star eats a planet, it's going to take on a bunch of lithium."

So-called engulfment events such as this one occur very rapidly, on a timescale of a few days to a couple of weeks, which means catching stellar beings in the act of enjoying a planetary meal is extremely rare. Thus, astronomers have to act as cosmic crime scene investigators to reconstruct these events with the evidence at hand.

"That's what makes this field so exciting. You really are solving a mystery," Kotten said. "We can't just watch the crime happen, so we have to work with all the clues we're given to figure out whodunit."

One of the aims of these investigations is to discover the ways in which a star can devour a planet. One of the most common engulfment scenarios happens when a star runs out of hydrogen at its core at the end of its main sequence lifetime. This results in it swelling out to up to 100 times its original diameter, engulfing its attendant planets during its so-called red giant phase. This will occur in the solar system in around 5 billion years when the sun will puff out to around the orbit of Mars, swallowing the inner rocky planets, including our own.

However, Kotten and colleagues know this isn't what has happened in the TOI-5882 system, as this star hasn't yet become a red giant. Instead, the researchers think the sun-like star had assistance from its brown dwarf companion.

Companion brown dwarf of partner in crime?

Brown dwarfs get their slightly unfortunate nickname of "failed stars" because, despite forming from collapsing clouds of gas and dust, just like stars, they fail to grow to the masses needed to trigger the nuclear fusion of hydrogen to helium in their cores, the process that defines what a main-sequence star is. They're quite mysterious by existing in this sort of limbo between planet and star.

This particular brown dwarf has around 20 times the mass of Jupiter, or around 2% of the mass of the sun. That's not massive enough to trigger nuclear fusion, but is massive enough for it to have enough of a gravitational influence over planets orbiting TOI-5882. That means the team suspects this brown dwarf could have perturbed the orbit of this unfortunate planet enough to send it plummeting into its star.

This is something the scientists will need to investigate further. They may not have enough information yet to determine this planet's cause of death, but they do have some evidence that helps them identify the kind of world it would have been before it was obliterated. This comes from observations of the chemical composition and lithium content of 62 stars with similar ages and masses to TOI-5882.

"Lithium atoms delivered by planetary engulfment to a star are like sports fans arriving at a stadium," team member Seth Jacobson of Michigan State University said. "There may already be a few early arriving fans present, representing the initial amount of lithium in the stellar atmosphere, but they are quickly outnumbered."

From the lithium abundance they measured, the team has determined that this planet was a so-called super-Earth with a mass somewhere between two times that of our planet and the mass of the solar-system ice giant Neptune, which is around 18 times as massive as Earth.

"The fact that we can look at a star 1,300 light-years away and say with confidence, 'This star has more lithium than you would expect,' is a testament to both the precision of modern instrumentation and the hard interpretive work that goes into making sense of that signal," said Melinda Soares-Furtado, a senior author of the study and assistant professor at the University of Wisconsin. "And it's not like you have to cherry-pick the data to make it stand out. It's robust. No matter how you slice it, TOI-5882 is so enriched in lithium it shows up as being at least in the 97th percentile."

Soares-Furtado added that TOI-5882 is one of the few stars she has seen demonstrating evidence of planetary engulfment, although a few of the other stars in the control sample were enriched in lithium, albeit not to the extent of TOI-5882. That leaves another mystery for the team to solve, something that Soares-Furtado may well be quite content with.

"When I was growing up, I dreamed about becoming a private investigator," she said. "I think that explains a lot about where I ended up. I do feel like a detective."

The team's research was published on Monday (June 15) in The Astrophysical Journal.

Astronomers have discovered chemical differences between binary stars that indicate one is a cosmic cannibal that has devoured at least one planet.

Binary stars should have the same chemical composition because each star is formed from the same vast cloud of gas and dust; however earlier this year the team behind this new research discovered that the two stars of HD 81809, located around 101 light-years away, are chemically different. One of the stars, HD 81809B, has a much greater concentration of elements heavier than hydrogen and helium, which astronomers call "metals," at its surface than its binary partner HD 81809A.

This new research suggests that the reason for the metal enrichment of HD 81809B is that this star has consumed an exoplanet which was between 50 and 75 times the size of Earth.

"This is the first binary system to be found with this chemical difference, which is very unusual," team leader Nuno Moedas of the Technical University of Denmark told Space.com. "Binary systems are 'like siblings' in that they are born from the same molecular cloud, meaning they have the same chemical composition. As with siblings, some differences in element abundances can appear due to physical processes. However, these differences will be much smaller than those of HD 81809."

Moedas added that there are only two possible explanations for the differences between HD 81809B and HD 81809A.

"One is that the stars are not 'real siblings' and were born from different molecular clouds containing different elements," Moedas said. "The other explanation is that star HD 81809B suffered a more drastic event during its evolution, such as ingesting a planet, which could have changed its chemical composition."

There is a "smoking gun" piece of evidence that planetary engulfment is the correct explanation for the metal enrichment of HD 81809B, however.

"It could be very hard to distinguish the two scenarios, but the main evidence for a planet's engulfment is the high abundance of lithium in HD 81809B that is not normal," Moedas said. "Lithium is a very volatile element, and it is easily destroyed in stars, so we expect very low abundances of this element when observing stars. For the case of HD 81809B, the most viable explanation for the large presence of lithium is an ingestion of a planet."

The team isn't quite sure how HD 81809B came to feast on one of its planets, but Moedas suggests it could be the result of gravitational interactions between the binary stars disrupting the orbit of the unfortunate planet, resulting in it falling into one of its stars. The question also remains of how many planets HD 81809B has devoured.

"We can only estimate the amount of planetary material required, which we find to be 75 times the mass of Earth. It is possible that the star ingested three planets, each 25 times more massive than Earth," Moedas said. "The event happened a few million years ago, and there are physical processes in the star that will 'clean up' the evidence and try to make the star's chemical abundance similar to that before the event."

Because of the physical processes within HD 81809B, the team can't tell much more about the planet, or planets that were devoured. However, there is a possibility that this information may be recovered from a dusty disk of debris detected in this system.

"We still do not know the exact location, but if it is around the secondary star, it could be the remains of a planet falling into the star," Moedas said. "We could use this to understand the composition of the planet. However, we are far from being able to study this debris disk with the current instruments we have. We probably still need to revisit this system, as there is still a lot we don't know.

"There is a lot to discover."A pre-peer-reviewed version of the team's research appears on the paper repository site arXiv.

If you thought summer here on Earth could get pretty brutal, spare a thought for the extrasolar planet, or exoplanet, designated HD 80606 b. Using the James Webb Space Telescope, astronomers have discovered that this gas giant exoplanet, located 217 light-years away, is being roasted by its host star.

The planet, it seems, really puts the "hot" in "Hot Jupiter," a category of gas giant planets that come so close to their stars that they can complete an orbit in a matter of days, sometimes even hours.

The 111-day orbit of HD 80606 b brings the exoplanet so close to its host star that the James Webb Space Telescope (JWST) saw its temperature soar to an incredible 1,100 degrees Fahrenheit (600 degrees Celsius). This causes an extreme change in the chemistry of this world, which makes it an ideal case study for the JWST.

"Hot Jupiters are already considered some of the most extreme exoplanets we know of, but even among that population, HD 80606 b is one of the most extreme," team leader Tiffany Kataria of NASA's Jet Propulsion Laboratory in Southern California said in a statement. "We typically think of hot Jupiters as hot gas giants sitting right next to their stars, but this planet's highly eccentric orbit creates a completely different beast."

Who ordered the roasted exoplanet?

Kataria and colleagues investigated HD 80606 b, its temperature and its chemistry using a technique in astronomy called spectroscopy, which breaks light down into individual wavelengths. This can reveal a world's chemistry because elements absorb and emit light at characteristic wavelengths.

Thus, when light from a star passes through the atmosphere of a planet, the chemicals in that atmosphere leave their fingerprints on this spectrum.
Using the JWST's MIRI (Mid-Infrared Instrument), the team observed this Hot Jupiter before, during, and after its close approach to its parent star, HD 80606. This required a great deal of planning given the extremely elliptical orbit of HD 80606 b.

This isn't the first time astronomers have studied HD 80606 b, the roasted exoplanet was previously investigated using NASA's now-defunct Spitzer Space Telescope.

"Spitzer did amazing work on this exoplanet, and now the JWST is building on that legacy by enabling us to drill down to distinguish specific chemical signatures like methane and carbon dioxide, which is just amazing progress," team member Ryan Challener of the Cornell Center for Astrophysics and Planetary Science said in the statement. "There's so much to learn from this one dataset here — we really are just getting started deciphering what the JWST has to tell us."

The JWST has followed that work to present a far more detailed picture of this exoplanet than before. In fact, the $10 billion space telescope has revealed that HD 80606 b is even more violent than anticipated.

"The JWST has shown that the planet’s increase in temperature was even more extreme than we anticipated based on Spitzer data," Kataria said.

The team's findings were presented Tuesday (June 16) at the 248th meeting of the American Astronomical Society in Pasadena, California.

Imagine a world where the weather forecast calls for winds blowing at 11,000 miles per hour (18,000 kilometers per hour) and nighttime showers of liquid metal, rubies and sapphires.

This is the chaotic reality astronomers have pieced together for WASP-121b, an "ultra-hot Jupiter" that ranks among the most extreme planets known beyond the solar system.

The gas giant orbits its host star at such a punishingly close distance that a single "year" there lasts just 30.5 hours. At that proximity — so close that if it got any closer, stellar gravity would start ripping it apart — the host star's immense tidal forces have warped the planet from a sphere into a football-like shape. Temperatures on its dayside climb high enough to vaporize metals, while previous studies have suggested that iron may condense and fall as rain on the cooler nightside. Now, astronomers using the James Webb Space Telescope (JWST) have added another piece to the world's meteorological portrait.

By tracking subtle changes in starlight passing through WASP-121 b's atmosphere as the planet crossed in front of its star, researchers detected differences between atmospheric conditions at dawn and dusk, according to the study.

"With its unprecedented observational quality, JWST gives us the most detailed glimpses into distant planets to date," study lead author Cyril Gapp of the Max Planck Institute for Astronomy in Germany, said in a statement.

"By measuring how star light absorption changes as WASP-121 b rotates, we probe its atmosphere longitude by longitude," Gapp said.

The observations suggest that the planet's evening terminator — the region rotating out of daylight — is hotter than its morning counterpart. The finding is consistent with powerful winds transporting heat from the planet's intensely hot dayside toward its cooler nightside, researchers say.

Because WASP-121 b is tidally locked to its star, one hemisphere permanently faces the star while the other remains in darkness. Yet, during a transit, the planet rotates just enough from JWST's vantage point for different regions of its atmosphere to come into view.

By examining how the atmospheric signal changed over time, Gapp and his team found that the evening side absorbed slightly more starlight than the morning side, the study reports. The researchers also detected changes in signals associated with water vapor and carbon monoxide, which they interpret as evidence of temperature differences across the atmosphere.

The hotter evening side appears warm enough to break apart water molecules in the upper atmosphere, the study notes. The cooler morning side, meanwhile, may be partially obscured by clouds made of silicate minerals, although the study notes more sophisticated models will be needed to determine whether such clouds are indeed present.

The findings add to a growing body of research of turbulent weather on WASP-121 b, including recent data from the Very Large Telescope in Chile that revealed complex, layered and violent wind patterns and jet streams spanning half the world.

Previous observations with the Hubble Space Telescope also found evidence that magnesium and iron were escaping from the planet's atmosphere, likely driven by intense ultraviolet radiation from its host star.

The team's new technique could eventually be applied to other ultra-hot planets, allowing astronomers to compare atmospheric conditions across a broader sample of distant worlds, the study notes.

The study was published Wednesday (June 10) in the journal Nature Astronomy.

A team of scientists is astounded to have discovered that bright and turbulent regions of galaxies — called active galactic nuclei, which are powered by feeding supermassive black hole engines — could be the birthplace of millions of planets. And these regions are brilliant. They often outshine the combined light of every star in their wider home galaxy.

Active galactic nuclei (AGNs) occur when supermassive black holes are surrounded by vast amounts of gas and dust that swirl around them in flattened, platter-shaped clouds called accretion disks. These accretion disks gradually feed some matter to the black hole. Meanwhile, other matter is channeled to the poles of the black hole, from where it is blasted away as high-energy plasma jets travelling at near-light speeds. The immense gravity of the central supermassive black holes, which have masses of millions or even billions of times that of the sun, generates intense friction in the gas and dust within accretion disks, causing them to glow brightly across the electromagnetic spectrum.

The discovery is so surprising because even though AGNs are rich with gas and dust — the building blocks of planets — the turbulent conditions within the disks wouldn't generally be considered ideal for forming planets. However, the edges of these disks may have temperatures and conditions akin to the planet-forming protoplanetary disks found around infant stars. Over time, could enough dust clump together and grow into planets?

To investigate this possibility, these scientists created a computer model of a supermassive black hole and its accretion disk and added data about the conditions at the edges of these disks. They then observed how rapidly dust clumped together and how the budding planets grew over millions of years.

"We discovered millions of Jupiter-mass planets could form at a distance of tens of parsecs [one parsec is around 3.3 light-years] from supermassive black holes, which are also AGNs," team member and University of Colorado Boulder researcher Bhupendra Mishra told Space.com. "These are dust giants exceeding Jupiter's mass. They will look like lava balls."

Mishra added that because the disk around an AGN supermassive black hole is more gas-rich compared to those that would exist around a star like the sun during its infancy, the potential of planet formation is enhanced from a few possible worlds around stars to maybe millions of planets around a supermassive black hole. He explains that the underlying mechanism of planet formation around supermassive black holes would be a phenomenon called "streaming instability" that allows multiple large filaments of dust to form. These are the birthplaces of vast amounts of planets. That eventually leads to millions of planets lurking in the outskirts of an AGN disk.

However, such planets may fly the nest quite quickly. The team's estimate confirms that these are stable planets — but while these planets will survive, they will likely migrate radially away from the supermassive black hole and the edge of the AGN.

"We were astonished! This has not been found in AGN disk context before using a streaming instability model," Mishra said. "My colleague Wladimir Lyra, an astronomy professor at New Mexico State University (NMSU), is world-renowned in the field of planet formation, and we both were totally amazed when we noticed this mass and size range of planet formation."

Mishra added that the outskirts of AGN disks are not very well understood, meaning the team's findings could help develop a much clearer picture of the hearts of active galaxies. Of course, it is early days for the team's theory, and the detection of planets around supermassive black holes would be a helpful confirmation of the team's conclusion. A useful tool in this investigation would be the curvature and the amplification of light from a background object that happens when a massive foreground object sits between it and Earth, a phenomenon known as gravitational lensing.

"Gravitational lensing could help to identify the cluster of these planets in the outskirts of the AGN disk. However, finding such an AGN is not easy unless we get lucky," Mishra concluded. "I believe we could detect these planets, but we have to study this model further."

A preprint version of the team's research is available on the paper repository site arXiv.

"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.

Vast clouds of soot that form in the pressure cooker of mysterious mini-Neptune exoplanets may hold the truth about these worlds' origins.

"It's like you have a natural diesel engine in the deep atmosphere of a planet," lead author of a study about this research, Jeehyun Yang of the University of Chicago, said in a statement.

Yang did his Ph.D. in chemical engineering, studying the exhausts of combustion engines before transitioning to study the chemistry of exoplanet atmospheres. The exhaust fumes of diesel engines are filled with black smoke made up of honeycomb-shaped particles called PAHs — polycyclic aromatic hydrocarbons. PAHs are among the most common carbon-based compounds in the cosmos, and are frequently produced whenever we burn something. (That black char on your burned toast? That's made of PAHs too.)

When it comes to chemistry, some exoplanet atmospheres are more enigmatic. Take the mini-Neptunes — worlds in the size range between Earth and Neptune that are found orbiting close to their star. Despite their being the most common type of exoplanet found so far, debate continues to rage over the nature of these mid-size worlds. Are they miniature versions of hydrogen-rich gas giants like Jupiter? Are they literally smaller versions of Neptune and Uranus, rich in volatiles such as water? Or could they be habitable hycean worlds, with a dense atmosphere of hydrogen concealing a global ocean?

Nobody knows for sure, and their characteristics could be varied enough that all three may apply. What is agreed upon, however, is that the mini-Neptunes did not form as close to their star as they are seen now; instead they formed farther out before migrating in. If we could answer how far out they formed, it could tell us what kind of world they are likely to be.

Unfortunately, probing the chemistry of these worlds' atmospheres doesn't help much, because these atmospheres seem to be opaque, hiding the true composition of the planets. Scientific consensus is that this opaqueness is caused by hazy banks of clouds that are masking the atmospheres, but what kind of aerosol particles are in the clouds?

When Yang saw the featureless spectra that the James Webb Space Telescope (JWST) was producing whenever it looked at a mini-Neptune, he noticed a distinct curve in the data that he recognized instantly as like the curve seen in the spectra of soot from a combustion engine.

PAHs can form when carbon, hydrogen and oxygen react at high temperatures, often combined with high pressure, just like the conditions deep in the atmosphere of some mini-Neptunes. Yang suspects that the same reactions that take place in a combustion engine could be occurring naturally within certain mini-Neptunes, producing PAHS that amalgamate as clouds of soot that then rise higher into the atmosphere, perhaps driven upwards by thermal convection currents. What we would then see as an opaque atmosphere would in actual fact be hazy, planet-spanning clouds of soot.

While the soot would explain why the JWST sees featureless spectra, it could also help solve a much more profound mystery: where did mini-Neptunes form and migrate in from?

Planets form in disks of gas and dust whose properties vary with distance from their central star. Take our solar system for instance. Heavier metallic and silicate materials were found in the disk closer to the Sun, while lighter gases and frozen volatiles such as water-ice and carbon dioxide-ice were found farther out, and this is replicated in the inner planets being rocky, Jupiter and Saturn being formed of the light gases hydrogen and helium, and Uranus and Neptune being rich in frozen volatiles.

Determining the ratio of carbon to oxygen in a mini-Neptune's soot could act as a measure of how far out from their star they formed, and therefore what their bulk properties are likely to be. We'd finally be able to differentiate the various possible types of mini-Neptunes. It might also provide clues as to why, despite being one of the most common types of planet in the galaxy, there are no mini-Neptunes in our solar system.

If Yang's findings, conducted with his Chicago colleagues Eliza Kempton and Arjun Savel, are accurate, then they show how a cross-disciplinary approach can provide fresh answers.

"As far as I know, this is the first time anyone has applied chemical engineering to the field of exoplanet study," said Yang. "I think it's a great case study that shows why having people from all different backgrounds can help us untangle these mysteries."

The findings were published on May 18 in The Astrophysical Journal Letters.

Astronomers have discovered the first evidence of magnetic fields around planets beyond the solar system, and they did so by studying the worlds' high-speed, violent winds. This marks the first direct measurement of exoplanet magnetic field strength, and represents a major step forward in exoplanet research.

Because life on Earth was made possible thanks to our planet's magnetosphere protecting it from harmful solar radiation, the research could also be beneficial to the hunt for life beyond the solar system.

Using the Very Large Telescope (VLT) and the Gemini North telescope, the team behind this discovery measured the speed of winds of seven extremely hot Jupiter-like gas giant exoplanets that are tidally locked to their stars, meaning they have a permanently raging hot "dayside" and a cooler, space-facing "nightside." The team found winds racing at speeds of between 4,470 miles per hour (7,194 kilometers per hour) and a staggering 15,530 mph (24,993 kph). For comparison, the fastest winds recorded on our solar system's Jupiter reached only around 930 mph (1,496 kph). The scientists think it is the magnetic fields of these exoplanets that are governing these winds.

Astronomers have discovered the first evidence of magnetic fields around planets beyond the solar system, and they did so by studying the worlds' high-speed, violent winds. This marks the first direct measurement of exoplanet magnetic field strength, and represents a major step forward in exoplanet research.

Because life on Earth was made possible thanks to our planet's magnetosphere protecting it from harmful solar radiation, the research could also be beneficial to the hunt for life beyond the solar system.

Using the Very Large Telescope (VLT) and the Gemini North telescope, the team behind this discovery measured the speed of winds of seven extremely hot Jupiter-like gas giant exoplanets that are tidally locked to their stars, meaning they have a permanently raging hot "dayside" and a cooler, space-facing "nightside." The team found winds racing at speeds of between 4,470 miles per hour (7,194 kilometers per hour) and a staggering 15,530 mph (24,993 kph). For comparison, the fastest winds recorded on our solar system's Jupiter reached only around 930 mph (1,496 kph). The scientists think it is the magnetic fields of these exoplanets that are governing these winds.

"This breakthrough opens a completely new window on exoplanet research. It’s the first time we can compare the magnetic environments of other worlds — a key step toward ultimately understanding which planets can stay alive, keep their water, and perhaps even, one day, host life as we know it," team member Julia Seidel, an astronomer at the Laboratoire Lagrange, Observatoire de la Côte d’Azur, France, said in a statement.

The hotter the planet, the more savage its winds

The team wasn't even really thinking about magnetic fields starting this research. The initial aim was to discover if all hot planets had winds that behaved the same. However, the researchers' curiosity was piqued when they discovered that wind speeds seemed to vary with the temperature of a planet. Strangely, the team found that the cooler the world was, the faster and more violent its winds were.

"This is totally counterintuitive because, all things being equal, hot planets have more energy to accelerate the winds!" team member Vivien Parmentier said in the statement. "Something must happen that slows down the wind speeds for hotter objects."

Parmentier and colleagues concluded that this counterintuitive, inverse relationship between temperature and wind speed was the result of global magnetic fields on these worlds. These fields work as a brake, slowing down charged particles. That means wind speeds could be used to infer the strength of these exoplanets' magnetic fields.

The team found the seven exoplanets had magnetic fields around four times as strong as that of the solar system gas giant Saturn and around half the strength of the magnetic field of Jupiter. This means these worlds could also feature stunning and dramatic colorful auroras that put Earth's northern and southern lights in the shade.

"Here on Earth, we know the beauty of the northern and southern lights, where particles from the sun hit our magnetic field and are guided toward the poles, colliding with gases in the atmosphere to produce colourful displays of green, pink, and purple," team member Bibiana Prinoth of the European Southern Observatory (ESO) in Garching, Germany, said in the statement. "I like to imagine that some of these worlds have a sky filled not only with stars, but with vast curtains of colourful light dancing across a planet that’s half in perpetual day and half in endless night."

The team's research was published on Tuesday (June 2) in the journal Nature Astronomy.

How do you weigh a planet you can't see from many light-years away? Astronomers may have the answer — and it involves "reading between the rings," aka the bright beautiful dusty structures that newborn exoplanets create around their young stars.

Planets in general are born from the dust, gas and tiny fragments called "planetesimals," that surround young stars. As a result, in their relative youth, these worlds are found still embedded in this natal-material swirling around in plate-like structures called protoplanetary disks. However, recent observations have revealed that as these infant exoplanets orbit their parent stars, they also carve lanes in this disk of gas and dust.

While such rings have been used to determine the presence of exoplanets around stars, this new research suggests a way to use those grooves to actually assess the characteristics of exoplanets, too.

"We've long understood that the rings could be created from concentrated dust that piles up just beyond the orbit of young, embedded planets, but we've been so far unable to link features of these rings to planet masses," team leader Amena Faruqi of the Astronomy and Astrophysics Group at the University of Warwick in the U.K, said in a statement. "By reading 'between the rings,' we have now found a way to reconstruct the masses of the planets that create the rings, even when those planets are too faint or too embedded to observe directly.

"These bright rings are not just beautiful structures — they are essentially planetary fingerprints."

Investigating a dusty star system

The first step taken by Faruqi and colleagues involved using computer simulations to assess how the masses of exoplanets would create distinct shapes for the rings in protoplanetary disks. They discovered that the width of dust rings and the location of the brightest point in that ring are key in assessing the characteristics of cloaked exoplanets.

Excitingly, the relationship between a planet's mass and the peak brightness of the dust ring it creates holds regardless of what wavelength of light the system is imaged in — as well as regardless of the size of the dust grains in the ring. That means astronomers don't need to know the exact conditions around an infant star to assess the mass of its exoplanets.

The scientists tested their new technique by applying it to a planetary system located around 370 light-years away called PDS 70, which astronomers have been studying with the Atacama Large Millimeter/submillimeter Array (ALMA), an array of 66 radio antennas located in northern Chile.

"One of the strengths of this work is that it doesn't stay in the realm of theory — we've been able to take these simulation results and apply them directly to real observed systems," Jessica Speedie of Massachusetts Institute of Technology (MIT) said in the statement. "Using the PDS 70 system as an observational laboratory in particular enabled a real verification of the approach, giving us confidence that these methods are genuinely ready to be applied widely as soon as possible."

PDS 70 was a useful test subject for the team because it possesses at least two exoplanets, PDS 70 b and PDS 70 c, and has been directly imaged. The technique delivered an estimated mass for PDS 70 c in line with current estimates of around 7.5 times the mass of Jupiter. The team's results also delivered some surprising insights into the processes that surround planet-formation as well as raising questions that astronomers will be keen to answer.

"Another striking result of the simulations is that, in typical discs, more massive forming planets can trap as much as 20 times the mass of Earth of dust within these rings," Ralph Pudritz of the Department of Physics and Astronomy at McMaster University said in the statement. "This confirms ALMA observations — but raises the question of why new planets have not been detected in the trapped dust and pebbles of the ring. "Our results suggest that the dust is sufficiently abundant and concentrated enough to potentially kick-off planet formation. This is an important insight that will initiate further observations and theory."

Ultimately, this new technique and its power to study infant planetary systems could also aid our understanding of how our own planetary system took shape around 4.6 billion years ago.

"What excites me most is the timing. With ALMA delivering increasingly detailed disk images, and future facilities on the horizon, there has never been a better moment to develop these methods," team member Farzana Meru of the Department of Physics at the University of Warwick said. "Combining our dust-based diagnostics with gas pressure observations will open up a powerful new window onto the hidden planets shaping these disks and the diverse planetary systems they will go on to form."

The team's research was published on Thursday (May 28) in The Astrophysical Journal.

We have learned a lot about the planets in our own backyard, and for a long time we assumed the rest of the galaxy looked roughly the same. A rocky planet meant a clear-cut structure: a dense metallic core, a silicate mantle, and a thin atmosphere on top. That picture works fine for Earth.

But according to a new paper submitted to the Astrophysical Journal, it might not work for most of the rocky planets in the universe. By far the most common type of planet we have found around other stars is about a class of worlds called sub-Neptunes: planets larger than Earth but smaller than Neptune. Their close cousins, the super-Earths, are slightly smaller and likely lost most of their hydrogen long ago. The textbook story has these planets forming in essentially the same way Earth did, just with different amounts of leftover gas piled on top. Iron sinks to the middle, silicate rock floats above it, hydrogen sits on top of that.

But here is the wrinkle. At the pressures and temperatures inside a sub-Neptune, hydrogen, silicate, and iron don’t actually behave like they do near the surface of Earth. Above about 4,000 degrees Kelvin, hydrogen and molten silicate become fully miscible. They stop being oil and water. They become one fluid. The authors behind a new study submitted to the Astrophysical Journal and currently available on arXiv worked out what that means for the structure of these planets, and the answer is surprising.

If a planet accretes less than about one percent of its mass in hydrogen, it follows the familiar script and forms a discrete metallic core just like Earth. But if it picks up more hydrogen than that, the whole inside of the planet becomes a single, mixed, churning fluid of iron, silicate, and hydrogen. No core. No mantle. Just a homogeneous blend all the way down to within a few thousand kilometers of the center.

That is a significant departure from how we usually draw these worlds in cross-section. The internal structure determines how a planet cools, how it holds onto its atmosphere, and how its radius evolves over time. The authors find that this miscibility framework can reproduce a number of features we already see in the exoplanet population that the old layered-cake models struggled to explain.

One of those features is the radius gap, the curious deficit of planets right between super-Earth and sub-Neptune sizes that the James Webb Space Telescope and Kepler Space Telescope have mapped out.

Another is the way planet radii depend on orbital period. Both fall out naturally if you assume that young sub-Neptunes store a substantial fraction of their hydrogen inside this miscible interior, then slowly release it into the outer envelope as the planet cools and the miscibility region shrinks. The hydrogen literally bubbles out of the rock over hundreds of millions of years.

There is a testable consequence here, and that is what makes this paper more than a thought experiment. If hydrogen is gradually exsolving from the interior into the atmosphere, then young sub-Neptunes should contract more slowly than standard models predict.

They should look slightly puffier than they should be for their age. We are now starting to find sub-Neptunes around very young stars (cosmic toddlers, only tens of millions of years old) where this signature could actually be measured. JWST and the next generation of transit surveys are going to put numbers on it.

The caveats are real. The model rests on theoretical extrapolations of how hydrogen, silicate, and iron behave at conditions we can’t yet reproduce in a laboratory, although high-pressure experiments are starting to catch up. The internal heat budgets of these planets are still uncertain, and small errors in those parameters propagate into the predictions. And the inverse modeling approach the authors use (start with the observed planet population, work backward to the physics that produced it) is necessarily statistical rather than deterministic.

Still, the basic claim is bold and clean. The most common type of planet in the galaxy may not look anything like Earth on the inside. The familiar concept of a planetary core, that small dense metallic heart we take for granted, may be the exception rather than the rule out there. Earth might be the weird one.

NASA's exoplanet-hunting spacecraft TESS, or Transiting Exoplanet Survey Satellite, has released its most complete view of the sky over Earth — the map reveals the location of 6,000 potential worlds beyond the solar system.

The mix of possible and confirmed extra-solar planets, or exoplanets, were identified by the mission prior to Sept. 2025. That's the month that marked the conclusion of TESS's second mission extension. (The exoplanet-hunting spacecraft launched from Space Launch Complex 40 at Cape Canaveral in April 2018.)

"Over the last eight years, TESS has become a fire hose of exoplanet science," Rebekah Hounsell, a TESS associate project scientist at NASA’s Goddard Space Flight Center in Greenbelt, Maryland, said in a statement. "It's helped us find planets of all different sizes, from tiny Mercury-like ones to those larger than Jupiter. Some of them are even in the habitable zone, where liquid water might be possible on the surface, an important factor in our search for life beyond Earth."

TESS searches for exoplanets using the tiny dips in brightness they cause as they cross, or "transit," the face of their parent star and block starlight. The total area of sky the mission searches is broken down into sectors, containing tens of thousands of stars. TESS uses its four cameras to observe each sector for around a month, looking for minuscule brightness dips before moving on.

The new TESS all-sky mosaic is made up of 96 sectors seen between April 2018 and Sept. 2025. The blue dots represent around 700 confirmed exoplanets, including exotic objects like planets being destroyed by their own host stars to worlds ravaged by global volcanoes. The orange dots represent candidate exoplanets detected by TESS that are yet to be confirmed.

And these extraordinary discoveries continue with discoveries not yet worked into this new mosaic. Just this year, TESS discovered a planetary system unlike any seen before, consisting of a super-Earth and a companion planet that possesses a highly elliptical and tilted orbit. Also this year, TESS discovered evidence of two planets smashing together, leaving a cloud of debris in front of their parent star; studying that cataclysmic collision could help us investigate a possible smash-up between Earth and a planetary body billions of years ago. It is such a smash-up that scientists believe may have birthed the moon.

"The more we dig into the large TESS dataset, especially using automated algorithms, the more surprises we find," Allison Youngblood, the TESS project scientist at NASA Goddard, said. "In addition to planets, TESS has helped us study rivers of young stars, observe dynamic galactic behavior, and monitor asteroids near Earth.

"As TESS fills in more of the night sky, there's no knowing what it might see next."

A remote hot Jupiter exoplanet has foregone the typical solitary life that worlds of its kind normally lead, in favor of companionship with another planet — and now, astronomers think they know why.

Hot Jupiters are gas giants that orbit exceedingly close to their star. However, they don't form that close, but are rather assembled much farther out before migrating inward. When they make that trip, they usually kick out any other planets in their way — but the hot Jupiter TOI-1130c seems to have latched onto a smaller planet as a traveling companion. The two seem to have migrated towards their star together.

The TOI-1130 system is located 190 light-years away and was found by Chelsea Huang of the University of South Queensland, who spotted the system in 2020 when sifting through data from NASA's Transiting Exoplanet Survey Satellite (TESS) while at the Massachusetts Institute of Technology (MIT).

"This was a one-of-a-kind system," said Huang in a statement. "Hot Jupiters are 'lonely', meaning that they don't have companion planets inside their orbits. They are so massive and their gravity so strong, that whatever is inside their orbit just gets scattered away. But somehow, with this hot Jupiter, an inner companion has survived, and that raises questions about how such a system could form."

Now an international team of astronomers led by MIT's Saugata Barat and including Huang think they have found the answer by bringing the James Webb Space Telescope (JWST) to bear on the hot Jupiter's companion, which is a mini-Neptune type world three-and-a-half times the diameter of Earth and catalogued as TOI-1130b. By observing the system when the mini-Neptune was transiting its star, they were able to search for where the planet's atmosphere was absorbing the star's light. The wavelengths of light being absorbed told them that the planet sports a "heavy" atmosphere full of water vapor, carbon dioxide, sulfur dioxide and signs of methane. In this context, "heavy" means heavier than hydrogen and helium, elements which would be expected to dominate the atmosphere if the mini-Neptune had formed close to its star.

Instead, the mini-Neptune and the hot Jupiter must have formed beyond the snow line — sometimes called the "frost line" — which is the distance in the protoplanetary disk that bequeathed the planets where temperatures were cold enough for water to be ice rather than liquid or vapor.

"This is the first time we've observed the atmosphere of a planet that is inside the orbit of a hot Jupiter," said Barat. "This measurement tells us this mini-Neptune indeed formed beyond the 'frost line'."

The mini-Neptune survived rather than get bundled out of the way by the marauding hot Jupiter because the two metaphorically held hands while migrating in together, before finally settling into their current orbits where they are anchored by a gravitational resonance between them.

In their current orbits, TOI-1130b orbits its star every four days at a distance of 4.2 million miles (6.8 million kilometers or 0.0453 astronomical units, AU) and with a temperature of 1,025 degrees Fahrenheit (550 degrees Celsius). Meanwhile, TOI-1130c orbits every eight days at a distance of 6.8 million miles (10.9 million km or 0.0731 AU), which is close enough to reach a temperature of 930 degrees F (500 degrees C). In other words, the planets are in a 2:1 resonance in which the mini-Neptune orbits twice for every one orbit of the hot Jupiter.

However, the gravitational ties between the two planets also posed a challenge for Barat's team to observe them with the JWST.

Because the two worlds tug on each other gravitationally, pulling each other around or holding each other back at different points in their orbits, it leads to transit timing variations, or TTVs — discrepancies in when they are expected to transit their star. With time on the JWST highly sought after, Barat's team would only get one chance to observe the planets and if they miscalculated and observed at the wrong time, they would miss them.

"It was a challenging prediction and we had to be spot on," said Barat.

To accomplish this, Judith Korth of Lund University in Sweden developed a model based on past observations of the system with which to predict when each planet would be transiting. The model worked a treat, with JWST's observations not only explaining the TOI-1130 system, but possibly all mini-Neptunes that are found close to their star.

"This system represents one of the rarest architectures that astronomers have ever found," summarized Barat. "The observations of TOI-1130b provide the first hint that such mini-Neptunes that form beyond the water/ice lines are indeed present in nature."

The findings were published on May 5 in The Astrophysical Journal Letters.

Planets may form more easily around pairs of stars than around single stars like the sun, according to new research.

Binary star systems, in which two stars orbit each other, are common throughout the Milky Way — and, in fact, even our sun may not have always been alone. For decades, astronomers believed such multi-star systems were hostile environments for planet formation, with competing gravitational forces stirring up surrounding material and preventing planets from taking shape.

The new study, however, suggests that while the inner regions of these systems are indeed too chaotic for planets to form, their outer reaches may actually produce planets more efficiently than single-star systems do.

"Close to a binary star it's simply too violent for planets to form," study lead author Matthew Teasdale of the University of Lancashire said in a statement. "But move farther out and the disk becomes an ideal environment for planet formation."

Using computer simulations, Teasdale and his team modeled the swirling disks of gas and dust that surround young binary stars — the birthplaces of planets — called protoplanetary disks. These simulations revealed that regions close to the two stars form a "forbidden zone," where intense gravitational forces create a turbulent environment too unstable for planets to emerge.

But beyond this boundary, the disk can become unstable enough to break apart under its own gravity, a process known as gravitational instability that can rapidly produce multiple young planets, particularly large gas giants similar to Jupiter, the study reports.

"What we're finding is that they can actually be extremely productive," Dimitris Stamatellos, an astrophysics professor at the University of Lancashire in the U.K. and a co-author of the new paper, said in the statement. "Once you get past the danger zone, planets can form quickly and in large numbers."

At the same time, the gravitational complexity of these systems can eject some worlds entirely, sending them drifting through interstellar space as so-called rogue planets, according to the new study.

The results suggest that real-life versions of the iconic twin-sun world Tatooine "may be far less rare than we once imagined," the statement read.

Astronomers have already discovered more than 50 planets that orbit two stars, known as circumbinary planets, including several on wide orbits far from their host stars. The findings could help explain how these worlds can form and survive despite the competing gravitational forces at play.

The findings also open new avenues for observation, the researchers say, with powerful instruments such as ALMA (short for Atacama Large Millimeter/submillimeter Array), the James Webb Space Telescope, and the upcoming Extremely Large Telescope that could help astronomers spot these planet-forming disks, and perhaps even witness them fragmenting to form new worlds.

This research is described in a paper published April 27 in the journal Monthly Notices of the Royal Astronomical Society.

Using NASA's exoplanet-hunting spacecraft TESS (Transiting Exoplanet Survey Satellite) and Antarctic Search for Transiting ExoPlanets (ASTEP) on the Antarctic Plateau, astronomers have discovered a rare and uniquely weird planetary system.

The extrasolar planets, or exoplanets, that swirl around the star TOI-201 have orbits that are changing so rapidly that astronomers can see the changes in real time. The behavior of the system, located around 370 light-years from Earth, is something scientists have never seen before.

TOI-201 is 1.3 times the mass of the sun and also has a diameter of 1.3 times the size of our home star. The exoplanets that orbit the star include a rocky super-Earth with six times the mass of our planet that has a year lasting just 5.8 Earth-days. Its planetary siblings are a gas giant with half the mass of Jupiter, completing an orbit every 53 days, designated TOI-201b, and another gas giant that has 16 times the mass of Jupiter that completes an orbit every 2,883 days (about 7.9 years).

"Most planetary systems appear as 'peas in a pod,' meaning the planets have a similar range of parameters and share a similar orbital plane," team member Amaury Triaud, from the University of Birmingham in the U.K., said in a statement. "This is not the case in the TOI-201 system, which contains three orbiting objects very distinct from one another, and which interact gravitationally."

The team's results were published on April 15 in the journal Science.

This planetary system is going through changes

Changes to planetary systems and shifting orbits aren't unique to TOI-201, but these transformations usually occur on timescales of millions and even billions of years.

TOI-201 is different because of the highly flattened or elliptical and tilted orbit of the outer planet, which gravitationally pulls on the inner worlds. This causes shifts in the orientation of the inner planets' orbits, and changes to the timing of their "transits," the times in which a planet directly crosses the face of its parent star. The situation is so extreme that in around 200 years, the planets won't line up in front of their star at all.

"In the solar system, almost all planets are coplanar, but here, this is not the case and each planet is different," Tristan Guillot, an astronomer at the Observatoire de la Côte d’Azur, said. "This points to some active orbital reorganisation within the system, providing us a glimpse of what happens shortly after planet formation."

Guillot is a lead researcher in the ASTEP project, an observatory at Antarctica's Concordia Station, which sits atop a 2-mile (3.2 kilometer) deep glacier in one of the world's most isolated environments and takes advantage of the long polar nights to observe other planetary systems.

"The goal was to characterize the TOI-201 planetary system to understand not just what planets are there, but how they interact with each other dynamically," research team leader Ismael Mireles, a PhD candidate at the University of New Mexico, said. "This helps scientists understand how planetary systems like our own solar system form and evolve over time."

TESS spotted a rare transit by the outer planet as telescopes across the globe saw the gravity of this object tugging on TOI-201. Astronomers then noticed delays in the transit of TOI-201b.

"Usually, planets are like metronomes with each transit in front of the star happening exactly one orbital period after another. However, we were following TOI-201b, and suddenly the planet started transiting about half an hour late," Triaud said. "This sudden jump was very surprising, and we reported our observations. Other astronomers around the globe noticed intriguing signals too, and by working together, the team could start to understand this system.

"This discovery was enabled by having a telescope in Antarctica. Whilst the logistics involved are difficult, its unique situation and its access to optimal astronomical conditions are key to studying exoplanetary systems with long orbital periods such as TOI-201."

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.

GREENBELT, Md. — On Tuesday (April 21) here at NASA's Goddard Space Flight Center, I watched as scientists stood proudly around a metal contraption with towering orange solar panels and a sparkling silver base. Gleaming right before me in a sterile white clean room stood the Nancy Grace Roman Space Telescope — at last, complete.

"I very much hope, and in fact, expect, that the most exciting science from Roman is going to be the things that we didn't expect, that we couldn't predict, but that will set the new deep questions for future missions to address," Julie McEnery, senior project scientist of Roman said during a press conference on Tuesday.

Named for NASA's first chief of astronomy and the first woman to hold an executive position at the agency, this space telescope should turn out to be yet another valuable tool in our species' hunt to understand the true nature of the universe. It'll stand among the ranks of our other powerful robotic eyes on the sky — famed instruments like the James Webb Space Telescope (JWST), SPHEREx, the Euclid Space Telescope and even the aged but always impressive Hubble. Except, as is the case with each of those landmark observatories, this new one has its own specialty. We'll get into some of those specs soon.

Above all, now projected to launch in September 2026 — eight months ahead of schedule, and under budget — the Nancy Grace Roman Space Telescope (or "Roman" for short) has the potential to show us pockets of the cosmos we've yet to touch.

According to NASA, Roman's primary mirror measures about 7.9 feet (2.4 meters) wide, which is similar to Hubble's. However, Roman has the ability to take images that capture a patch of the sky at least 100 times larger than Hubble can.

"Its surveying capabilities are over 1,000 times faster than Hubble, and can chart 200 times more sky in a single image," NASA administrator Jared Isaacman said during the conference. "What would take Hubble 2,000 years to process, Roman can do in a year — the images it captures will be so large there is not a screen in existence large enough to show them."

To put that into context, over its approximately 35 years of service so far, Hubble has gathered about 400 terabytes of data; once fully operational at its workstation in space, Roman should be able to create 500 terabytes of data per year.

As for what this data could hold, well, the possibilities are pretty endless. That's typically the gold standard for a telescope; as scientists like to say, we're always hoping to answer questions we never even thought to ask.

Cosmic and panoramic

Roman is specifically calibrated to capture images of the universe in visible and near-infrared light. Different telescopes view the universe in different light wavelengths. The JWST, for instance, specializes in infrared observations, while Hubble's powers allow it to see some infrared but mostly visible and ultraviolet light.

Diversifying in this way is important, because you can think of a patch of sky as having various layers. As an example, many extremely distant objects can be seen only in infrared light — which consists of super-long wavelengths that aren't visible to the human eye — so you need an infrared telescope to decode that layer. But there are also visible-light objects in the same patch of sky that need to be studied in greater detail, for which you need a telescope that behaves like an ultrapowerful human eye. And so on.

A few things set Roman apart, including that quick data-processing speed we discussed earlier.

Compared to the JWST, Roman's images — taken with its aptly named Wide Field Instrument (WFI) — will be 50 times wider but more shallow, because Roman doesn't need to access the deep universe the way the JWST does. As we discussed, it can't see infrared like the JWST can and therefore would be wasted in looking too far back.

More specifically, WFI is composed of a 300-megapixel visible-to-near-infrared imaging camera and slitless spectrometer (a special tool that allows scientists to capture light dispersion of objects in a field of view). But there is something uniquely special about that shallow, panoramic view.

It means scientists don't have to be as picky about which patch of sky they're looking at. They can just survey and hope to find a cool lead to zoom in on. This offers Roman the ability to catch events that transpire very quickly, such as fast radio bursts, and increases the chances that scientists can witness remarkable supernovas, colliding neutron stars and other easy-to-miss phenomena right as they happen.

"So we're going to see thousands of supernovae, and some of these are going to be further away than any supernovae we've ever seen before," Dominic Benford, program scientist for the Nancy Grace Roman Telescope told Space.com. "We'll trace the history of the universe through exploding stars."

There is also the hope that Roman helps us unravel one of the greatest mysteries of our universe — the details of its dark side.

The dark and faint universe

Despite years upon years of searching for an answer, scientists still don't know what exactly dark matter and dark energy are. All we know so far for sure is that our universe's normal matter does not appear to be enough to prevent galaxies from falling apart like horses on a merry-go-round that isn't nailed together properly, and that the universe is also accelerating in its continuous expansion far faster than seems normal. The former is explained by a substance called "dark matter" picking up where normal matter leaves off, and the latter is explained by "dark energy" driving that expansion.

These two substances collectively constitute 95% of the universe yet have never been detected with certainty. It's absolutely bizarre, if I may say.

Of course, with that kind of track record, it can't be known for sure whether Roman will suddenly reveal what the dark universe actually is — but if all goes to plan, we can expect it to bring us quite a bit closer.

Thanks to that lovely wide field of view, Roman will be able to rapidly image tons of galaxies to generate detailed, 3D vistas of the cosmos. It will therefore be able to show us things like the dynamics of different galaxies and track the universe's expansion — the two main ways we investigate dark matter and dark energy.

"We'll also study how the universe itself has expanded over time. And these are the keys to unlocking the fundamental nature of dark matter, dark energy, the fabric of the universe itself," McEnery said.

And that's not to mention what the Roman's other special instrument suite can do for science. For example, it has a coronagraph, a tool that can block the glare of distant suns and help the mission directly image exoplanets. In fact, NASA says this telescope's coronagraph can detect planets 100 million times fainter than their stars. That capability is about 100 to 1,000 times better than existing space-based coronagraphs, the agency explains in an overview.

"The Roman Coronagraph will be capable of directly imaging reflected starlight from a planet akin to Jupiter in size, temperature, and distance from its parent star," that overview states.

Road to launch

Now that Roman is complete, the next phase of its journey can soon commence. That'll include being shipped to the launch site, NASA's Kennedy Space Center in Florida, and undergoing any necessary launch-related testing.

A hefty amount of prelaunch testing has already been conducted on Roman so far, including the poor observatory being blasted with extreme sounds, being shaken up to an extreme degree, being exposed to extreme heat and extreme cold — and way more (all just as extreme). Sounds rough, but the point is to make sure Roman will be able to handle the rigors of launch and the most extreme environment we know of: space.

"Most of the stuff that's left are the final checkouts, and the final wrap-ups," Jeremy S. Perkins, Observatory Integration and Test Scientist for Roman, told Space.com "There is lots of blanket close-outs and making sure that we've put all the sensors on and taken off the ones that were there for testing."

As for launch procedures, once all aspects of testing are squared away, NASA has chosen a SpaceX Falcon Heavy rocket to carry this treasure to space. There have been 11 Falcon Heavy launches to date, with a 100% success rate for the 230-foot-tall (70-meter-tall) vehicle.

Once in space, after separating from that rocket, Roman will head to a stable point about a million miles away from Earth called Lagrange Point 2, or L2. This is a popular spot for our space explorers to end up because it allows them to remain shielded from the sun's heat while still orbiting in such a way that mission control can communicate with them easily.

Hopefully the JWST, Euclid and the rest of the L2 crew welcome Roman with open arms (solar panels?).

Correction 4/21: Julie McEnery's name has been updated to reflect the correct spelling.

Using the James Webb Space Telescope (JWST), astronomers have investigated an alien planet that could help define the line dividing planets and stars.

The curious exoplanet is 29 Cygni b, a gas giant with around 15 times the mass of Jupiter that lies 133 light-years away from Earth.

Most planets are thought to form via a "bottom-up" process that sees tiny clumps of rock and ice coming together to gradually grow a world. However, bottom-up processes struggle to account for the formation of planets with as much mass as 29 Cygni b.

Such giants are thought to form instead via a top-down process — the direct collapse of dense patches of gas and dust in the protoplanetary disks that swirl around infant stars. That's the same way that stars themselves form, from dense patches in much larger clouds of interstellar gas and dust.

Now, JWST has collected multiple lines of evidence that suggest there is a way that huge planets such as 29 Cygni b could form via bottom-up processes, just like their more diminutive counterparts.

29 Cygni b sits on the dividing line of formation processes. Though its large mass suggests a top-down process, its wide orbit — an average distance from its star of 1.5 billion miles (2.4 billion kilometers), similar to that of Uranus in our own solar system — hints at a bottom-up formation mechanism.

The team directly imaged 29 Cygni b using JWST's Near-Infrared Camera (NIRCam), as part of a program that will image four exoplanets, all of which orbit their stars within around 9.3 billion miles (15 billion km) and have masses between one and 15 times that of Jupiter. The planets are all also relatively young and are still hot from their formation, with temperatures ranging from 990 to 1,830 degrees Fahrenheit (530 to 1,000 degrees Celsius), meaning they should all have similar atmospheric chemistry, too.

The researchers hunted for light being absorbed by carbon dioxide and carbon monoxide, which allowed them to measure the proportions of elements heavier than helium, which astronomers call "metals," in 29 Cygni b's atmosphere.

This revealed that, not only is the exoplanet around 150 times richer in metals than Earth, but it is also much more metal-rich than its parent star. This indicates that, as it was forming, the gas giant gathered a wealth of metal-enriched clumps of material from its natal protoplanetary disk.

The team also determined that the orientation of 29 Cygni b's orbit is aligned with the rotation of its parent star, which indicates it did indeed form within a protoplanetary disk.

As the program continues to investigate similar planets, it will discover if other such worlds also greedily grabbed metal-rich matter during their formation. This could finally help scientists understand how the most massive planets in the Milky Way were born, be it like stars or like smaller planets.

The team's research was published on Tuesday (April 14) in the Astrophysical Journal Letters.

In the new film "Project Hail Mary", humanity sends an interstellar ship to another star system — Tau Ceti — in a last-ditch effort to save Earth from an alien threat. As it turns out, the key to rescuing our planet is a microbe that evolved on a world orbiting this star.

But how likely is it that the Tau Ceti system actually harbors alien organisms? And out of the thousands of planets discovered in other solar systems, how do researchers determine where to look for life?

A new study published in the Monthly Notices of the Royal Astronomical Society aims to help answer those questions. The paper's authors homed in on the 45 known exoplanets most likely to host life. And they highlighted which techniques astronomers can use to find more.

Astronomers usually find exoplanets using the “transit method”, where they measure how much a star dims when a planet passes in front of it. The larger the planet, the greater the dimming. The other major way to look for exoplanets is by measuring their host stars' "wobble." Planets exert a gravitational pull on their stars, like a dog straining on a leash, explains Lisa Kaltenegger, an astrophysicist at Cornell University and lead author of the new study. The closer the planet and the smaller the star, the more noticeable the wobble.

Scientists have discovered more than 6,000 exoplanets to date, but the majority of them are probably sterile worlds. Most are what are known as "hot Jupiters" — essentially massive, gaseous planets orbiting extremely close to their star.

The fact that we’ve found so many doesn’t necessarily mean that hot Jupiters are more common than other types of planets; it could be that they're just easier to spot. But scientists agree that these worlds make poor prospects in the search for life. The new paper proposes that researchers are more likely to find potentially habitable worlds by looking for smaller, cooler stars, around which rocky planets are easier to see.

To be considered a candidate for life, a planet needs to meet two criteria: it must have a rocky surface, and it must fall within the so-called “habitable zone” — the orbital distance at which liquid water can exist.

Unfortunately, since the book version of Project Hail Mary was published in 2021, scientists have determined that Tau Ceti probably doesn’t have planets in its habitable zone after all. That’s good news for humanity, Kaltenegger jokes, because it means the sun-munching astrophage couldn’t have evolved there.

But if we were to build an interstellar ship to look for life, where should we send it? According to Kaltenegger’s team, there are a couple of prime candidates. The first is the TRAPPIST-1 system. Discovered in 1999, this small red star has no fewer than seven rocky planets in its habitable zone. It is currently an area of interest for the James Webb Space Telescope.

A lesser-known star spotlighted in the study is called TOI-715. This red dwarf is orbited by a “super-Earth” three times the mass of our own planet called TOI-715 b, which sits comfortably in its habitable zone. However, this system is 139 light-years away, making it a bit far even for a future interstellar ship.

Much closer is Proxima Centauri. At just 4.25 light-years from us, it’s just a cosmic stone’s throw away. This system also hosts an Earth-like planet in its habitable zone.

In addition to the 45 planets in the habitable zone, Kaltenegger and her colleagues identified 24 more in the margins of habitability. "We call them 'planets on the edge,'" she says. “They’re the most interesting ones.” These worlds may not circle their stars at a distance that allows for liquid water, but that doesn’t necessarily mean they’re devoid of life. In "Project Hail Mary", we meet the friendly alien Rocky, who comes from a planet that is (ordinarily) devoid of liquid water. Like Rocky's home world, some of these planets may be home to life that has figured out how to get by without H2O.

For Kaltenegger, the search for life beyond Earth necessitates out-of-the-box thinking. We should focus our resources on the places most likely to host life, but if we keep our search too narrow, we risk missing out on potentially incredible discoveries. Take a page out of Project Hail Mary's playbook, she says: "Creativity and imagination, I think, are just pillars of science."

Astronomers have narrowed the search for extraterrestrial life from thousands of distant worlds down to just a few dozen promising candidate planets, offering a clearer roadmap for one of science's biggest questions: Are we alone?

In a new study, a team of researchers led by Lisa Kaltenegger of the Carl Sagan Institute at Cornell University identified 45 rocky exoplanets that sit within their stars' habitable zones, where temperatures could allow liquid water to exist on their surfaces. Out of more than 6,000 known exoplanets, these worlds represent some of the most compelling places to search for alien life.

The team used data from the European Space Agency's now-retired Gaia mission and the NASA Exoplanet Archive to refine estimates of how much stellar energy each planet receives — one of the key factors determining whether a world might be too hot, too cold or just right for life as we know it.

But rather than simply asking which planets might host life, the team set out to answer a deeper question: What are the limits of habitability? To do that, they deliberately included worlds that push the boundaries in their catalog.

"We know Earth is habitable, while Venus and Mars are not. We can use our solar system as a reference to search for exoplanets that receive stellar energy between what Venus and Mars get," study co-author Abigail Bohl said in a statement.

"Observing these planets can help us understand when habitability is lost, how much energy is too much and which planets remain habitable — or maybe never were," Bohl added.

The team also considered planets with elliptical orbits; further research here might determine how much such "orbital eccentricity" a planet can have before it loses its habitability.

Crucially, this new exoplanet catalog is not meant to be an exhaustive list of potentially habitable worlds. Instead, it serves as a strategy for future research. The team highlighted which planets are best suited for different observation techniques, helping guide powerful instruments like the James Webb Space Telescope and other observatories to probe for biosignatures, or potential signs of life.

"While it's hard to say what makes something more likely to have life, identifying where to look is the first key step — so the goal of our project was to say, 'Here are the best targets for observation'," said co-author Gillis Lowry, who is now a graduate student at San Francisco State University.

Among the most compelling targets is the TRAPPIST-1 system, about 40 light-years away, which hosts multiple potentially habitable Earth-size rocky planets. Interestingly, these worlds may be tidally locked to their star, with permanent day and night sides. Still, Trappist-1 e is considered one of the leading candidates to host liquid water.

Another standout is LHS 1140 b, a denser, larger world considered a "super-Earth" about 48 light-years away. With a mass more than five times that of Earth and slightly higher overall density, it could be a water-rich ocean world.

Closer to home, Proxima Centauri b, orbiting our nearest stellar neighbor just 4.25 light-years away, remains tantalizing to astronomers, despite concerns about intense stellar flares that could strip away its atmosphere.

With next-generation observatories coming online, future observations of these 45 worlds may bring scientists closer than ever to determining whether life exists beyond Earth.

A study on the research was published in the Monthly Notices of the Royal Astronomical Society on March 19.

Astronomers have discovered over 100 new worlds beyond the solar system hiding in data collected by NASA's exoplanet-hunting spacecraft TESS (Transiting Exoplanet Survey Satellite), and it's thanks to artificial intelligence. The technique also identified a further 2,000 or so candidate extrasolar planets, or exoplanets, around half of which were hitherto undetected.

Considering that there are around 6,000 exoplanets currently in NASA's exoplanet catalog, confirming those candidate worlds would represent a major boost in our hunt for planets around other stars. The innovative new AI program behind this discovery is called RAVEN, and was developed by researchers at the University of Warwick in the U.K.

TESS spots exoplanets by recording the tiny dips in starlight they cause when they pass in front of the face of the parent star, a passage called a "transit." RAVEN studied TESS observations of over 2.2 million stars collected during the NASA spacecraft's first four years, hunting for planets so close to their home stars that they complete an orbit in just 16 Earth days. The AI pipeline could therefore help to confirm how common these tight-orbit planets are and the kind of systems in which they are most often found.

"This represents one of the best characterized samples of close-in planets and will help us identify the most promising systems for future study," team leader Marina Lafarga Magro of the University of Warwick said in a statement.

RAVEN's eagle eye is scanning the Neptunian desert

Since the first exoplanets were discovered in the mid-1990s, the exoplanet catalog has burgeoned to over 6,000 confirmed entries, but thousands of candidates identified by exoplanet-hunting space missions like TESS, Kepler and CHEOPS (Characterizing Exoplanet Satellite) remain unconfirmed.

That is because scientists need to determine whether small dips in starlight are actually caused by transiting exoplanets or if they have another, non-planetary cause. This means making these confirmations more rapidly and confidently is a major challenge that astronomers are eager to ease.

"The challenge lies in identifying if the dimming is indeed caused by a planet in orbit around the star or by something else, like eclipsing binary stars, which is what RAVEN tries to answer," RAVEN head developer Andreas Hadjigeorghiou of the University of Warwick said in the statement. "Its strength stems from our carefully created dataset of hundreds of thousands of realistically simulated planets and other astrophysical events that can masquerade as planets."

Hadjigeorghiou developer explained that the team trained machine learning models to identify patterns in the data that can tell astronomers the type of event that has been detected, something that AI models excel at. RAVEN is designed to handle the whole exoplanet-detection process in one go — from detecting the signal to vetting it with machine learning and then statistically validating it. That means that it has an additional edge over other contemporary tools that only focus on specific parts of this process, Hadjigeorghiou said.

"RAVEN allows us to analyze enormous datasets consistently and objectively," senior team member and University of Warwick researcher David Armstrong said in the statement. "Because the pipeline is well-tested and carefully validated, this is not just a list of potential planets — it is also reliable enough to use as a sample to map the prevalence of distinct types of planets around sun-like stars."

Within the candidate close-in planets, researchers could then determine the types of planets and their populations in detail. This revealed that around 10% of stars like the sun host a close-in planet, validating findings made by TESS's exoplanet-hunting predecessor Kepler.

RAVEN was also able to help researchers determine just how rare close-in Neptune-size worlds are, finding that they occur around just 0.08% of sun-like stars. This absence of these worlds close to their parent star is referred to as the "Neptunian desert" by astronomers.

"For the first time, we can put a precise number on just how empty this 'desert' is," leader of the Neptunian desert study team, Kaiming Cui of the University of Warwick said in the statement. "These measurements show that TESS can now match, and in some cases surpass, Kepler for studying planetary populations."

The RAVEN results demonstrate the power of AI to search through vast swathes of astronomical data to spot subtle effects.

The team's research was published across three papers in the journal Monthly Notices of the Royal Astronomical Society and is also available on the paper repository site arXiv.

Astronomers have observed two planets forming around a distant infant star, thus discovering a planetary system that offers us a look at the appearance of the solar system over 4 billion years ago.

The infant star in question is named WISPIT 2, and it's located around 437 light-years away with an estimated age of around 5.4 million years old. If that makes this star sound anything but an infant, consider that our middle-aged star, the sun, is 4.6 billion years old.

WISPIT 2 is surrounded by a donut-shaped cloud of gas and dust called a protoplanetary disk in which scientists have now detected two planets, designated WISPIT 2b and WISPIT 2c. And excitingly, there are structural hints with WISPIT 2's protoplanetary disk of more forming protoplanets. "WISPIT 2 is the best look into our own past that we have to date," discovery team leader Chloe Lawlor of the University of Galway, Ireland, said in a statement. "These structures suggest that more planets are currently forming, which we will eventually detect."

WISPIT 2 is only the second system in which astronomers have successfully detected two forming planets. The other system, PDS 70, lacks the extended disk and the distinct gaps and bands seen around WISPIT 2. That means that this system offers an unparalleled look at how planetary systems like our own solar system are formed.

"WISPIT 2 gives us a critical laboratory not just to observe the formation of a single planet but an entire planetary system," team member Christian Ginski of the University of Galway said in the statement.

The discovery history of WISPIT 2

WISPIT 2b was the first infant planet discovered around this infant star, detected last year and determined to have a mass around five times that of Jupiter and orbiting its parent star at a distance equivalent to 60 times the distance between Earth and the sun.

Following this discovery, astronomers found hints of an additional object closer to WISPIT 2, confirming this to be a planet using the Very Large Telescope (VLT) and the VLT Interferometer (VLTI). The newly found planet, WISPIT 2c, orbits its parent star at around 15 times the distance between Earth and the sun, meaning it's about four times closer to its star than WISPIT 2b is.

The researchers then captured an image of this forming planet using the VLT's Spectro-Polarimetric High-Contrast Exoplanet Research (SPHERE) instrument, further confirming it is a planet with another VLT instrument, GRAVITY+.

"Critically, our study made use of the recent upgrade to GRAVITY+ without which we would not have been able to get such a clear detection of the planet so close to its star," team member Guillaume Bourdarot of the Max Planck Institute for Extraterrestrial Physics in Germany said in the statement.

Both WISPIT 2b and WISPIT 2c are carving grooves in the protoplanetary disk around their parent star. This is happening because, as they orbit the star, their gravitational influences collect material from the disk to facilitate their growth.

At least one more planet is indicated in the system by a less-pronounced gap —further out from the system's central star than WISPIT 2b sits. The team hopes this third planet will be visible with the Extremely Large Telescope (ELT), currently under construction in the Atacama Desert region of northern Chile.

"We suspect there may be a third planet carving out this gap, potentially of Saturn's mass, owing to the gap's being much narrower and shallower," Lawlor said.

The team's research was published on Tuesday (March 24) in The Astrophysical Journal Letters.

A world, cold and alone, drifting through the inky blackness between star systems. Sounds pretty desolate, right? We're talking about free-floating planets, those cosmic wanderers that don't bother with orbiting a sun, just cruising solo through the void.

Astronomers reckon there could be a whole bunch of these vagabond rogue planets out there, maybe as many as 21 for every star in our Milky Way galaxy. That's a truly staggering number, a cosmic fleet sailing in eternal night. For a long time, we figured these lonely giants were just that: lonely. Definitely not the kind of place you'd pack a swimsuit. But what if they're not so lonely after all?

Now, picture a moon, an exomoon if you will, clinging to one of these rogue planets. No star for warmth, just the cold embrace of interstellar space. How could anything possibly stay warm enough for, say, liquid water, which we think is pretty important for life? Well, here's where things get interesting.

When a planet gets booted from its star system, its exomoons can get a bit … strange. Their orbits get stretched and squeezed, and all that gravitational tug-of-war generates something we call tidal heating. It's like kneading dough, but with entire celestial bodies, warming them from the inside out. So, while there's no sun, there's a built-in furnace.

But figuring out how to keep those exomoons cozy and warm was a real head-scratcher. Early models, bless their hearts, tried to cook up scenarios where thick, carbon dioxide-rich atmospheres could trap enough heat from that tidal flexing to keep water sloshing around, according to a new paper appearing in the preprint journal arXiv.

The idea was that CO2 would act like a big, insulating blanket. The problem? Carbon dioxide is a bit finicky. Under the immense pressures needed to trap enough heat, it tends to condense, turning from a gas into a liquid or even a solid, leading to what we call atmospheric collapse. Not exactly conducive to a long-term liquid water party. It was a clever idea, but it just didn't hold water. Literally.

Here's the delightful twist: It turns out hydrogen, that most abundant and unassuming element, might be the unsung hero. Instead of relying on temperamental CO2, a new breed of models shows that exomoons with thick, hydrogen-dominated atmospheres can be surprisingly good at holding onto heat.

It's all thanks to a process called collision-induced absorption, or CIA. Essentially, when hydrogen molecules get squished together in a dense atmosphere, they briefly team up to absorb infrared radiation, effectively trapping heat. This ingenious mechanism can keep surface temperatures just right for liquid water, potentially for truly mind-boggling stretches of time — we're talking up to 4.3 billion years.

So, how did astronomers cook up this new recipe for habitability? They didn't just pull it out of a hat. They used some seriously sophisticated tools, combining a radiative transfer code called HELIOS to model how heat moves through the atmosphere with an equilibrium condensation chemistry code named GGchem to figure out the precise chemical makeup of these bizarre worlds. It's a grand challenge tackled with clever computational solutions, painting a picture of these extreme exomoons where tidal heating and those thick, hydrogen-rich atmospheres conspire to create billions of years of potentially habitable surface conditions.

Now, before you go packing your bags for a hydrogen moon vacation, it’s important to remember that science is a journey, not a destination. This self-consistent atmospheric model, while brilliant, is still built on a few approximations and assumptions. For instance, the HELIOS code, while powerful, assumes a constant gravitational pull, which might get a little wonky for super-thick atmospheres on moons with low gravity.

And the models are currently only looking at "dry" atmospheres, not considering how water vapor itself might influence the temperature profile, or how condensation might affect things. Also, GGchem calculates chemistry for each atmospheric layer in isolation, without thinking about how atoms and molecules might move between those layers.

And hey, just because a world can have liquid water doesn't automatically mean it's teeming with life. We're still learning the intricate dance of habitability.

But here's the exciting bit: this is just the beginning of understanding these rogue worlds. Future research will undoubtedly dive deeper, exploring other atmospheric compositions beyond just hydrogen, and pushing the models further by adding in more complex atmospheric physics, like clouds and more nuanced ways to handle water vapor.

This new understanding of exomoons around free-floating planets throws open a massive, unexpected cosmic real estate market for life. Who knew the loneliest places in the universe might actually be some of the coziest, just waiting for us to figure out their secrets?

An exoplanet so light that it would float on water, were there an ocean large enough, is continuing to frustrate astronomers by concealing its closest secrets with a layer of haze thicker than any ever seen on a planet before.

The haze is so thick that not even the vision of the James Webb Space Telescope (JWST) can penetrate it, leaving the mystery of how this ultra-low density world and its sibling planets all formed unsolved for now.

"These ultra-low density planets are rare and they defy conventional understanding of how gas giants form," said Jessica Libby-Roberts of the University of Tampa in Florida in a statement. "And if explaining how one formed wasn't difficult enough, this system has three!"

Kepler-51d is a member of a four-planet system orbiting a young Sun-like star 2,615 light years away. They were discovered by NASA's Kepler Space Telescope, which observed the planets transiting their star. From the amount of the star's light blocked during the transits, astronomers deduced the size of the worlds, and from transit timing variations — the way each planet's gravity pulls and pushes on the other planets, varying exactly when they are seen to transit — their masses were measured. Planets 51b, c and d have 7.1, 9 and 9.7 times the radius of Earth, respectively, making them about the same size as Saturn.

However, planets b, c and d have masses only 3.7, 5.6 and 5.6 times greater than Earth's, respectively. Saturn, on the other hand, has a mass 95 times more than Earth. So, these worlds are a similar size to Saturn, but much (much) less massive. (The fourth planet in the system, e, was only discovered in 2024 and its mass and radius are yet to be measured to any degree of accuracy.)

It is remarkable that the densities of planets 51b, c and d have more in common with cotton candy (or candy floss as we call it in the U.K.!) than with the planets we are more familiar with.

As such, Kepler-51d and its fellow ultra-low density worlds are completely alien to the planets in our own solar system. Take the gas giants Jupiter or Saturn, for example, which have large, dense and well-defined cores that on their own are ten times more massive than Earth. These cores formed first and then their gravitational pull attracted masses of gas from the planet-forming disk that encircled the Sun 4.5 billion years ago.

In contrast, the ultra-low density worlds of Kepler-51 "have tiny cores and huge atmospheres giving them a density akin to cotton candy," said Libby-Roberts. It is not clear how these small cores could have accreted relatively large amounts of gas.

So in search of answers, when Libby-Roberts was at Penn State University she led a team in 2020 to observe the Kepler-51 system spectroscopically using the Hubble Space Telescope's Wide-Field Camera 3. The purpose was to look for signs of the chemical composition of the atmosphere around the planets, which could provide clues as to how far from their star these worlds formed, and how they subsequently came to be so tenuous. Given their low density, they are undoubtedly rich in hydrogen and helium, the two lightest and most common elements in the universe, but the various trace gases present in their atmosphere could tell us more about their origin.

Yet Hubble found no sign of any chemistry, leading Libby-Roberts and her colleagues to suspect that there could be a featureless haze swamping the atmosphere of the planets.

Now, Libby-Roberts has returned to the Kepler-51 system, using the JWST's Near Infrared Spectrometer (NIRSpec) to try and probe harder into the atmosphere of Kepler-51d in the hope of detecting its chemical composition.

They aimed to accomplish this via transit spectroscopy. When Kepler-51d transits its star, some of its star's light filters through the planet's atmosphere. Any molecules present can absorb certain wavelengths of the star's light, which should show up in the star's spectrum as absorption lines.

"A star's light is filtered through the atmosphere of the planet before it reaches our telescopes," said Libby-Roberts. "If we look across a range of wavelengths, across a spectrum, we get a sort of fingerprint of the planet's atmosphere that reveals its composition."

Yet the spectrum still showed no signs of the chemistry of 51d's atmosphere, meaning that the haze that is present must be the thickest ever encountered on an exoplanet if even NIRSpec, operating at longer wavelengths than Hubble, cannot see through it.

"It seems very similar to the haze we see on Saturn's largest moon Titan, which has hydrocarbons like methane, but at a much larger scale," said co-researcher Suvrath Mahadevan at Penn State. "Kepler-51d seems to have a huge amount of haze, almost the radius of Earth."

There are currently no planet-formation models that can explain how such low density worlds can form, particularly so close to their star — if 51b, c and d were transported to our solar system they would all be packed into a region well inside the orbit of Venus.

"It's possible that [51d] formed further away and moved inward, but we are still left with a ton of questions about how this planet — and the other planets in this system — formed," said Libby-Roberts. "What is it about this system that created these three really oddball planets, a combination of extremes that we haven't seen anywhere else?"

It is possible that we are seeing these planets in a transitory phase. The system is half a billion years old, so young compared to our 4.5-billion-year-old solar system. Being young, the Kepler-51 star is still quite active and its stellar wind will be stripping away the outer gases of the ultra-low density planets. Perhaps if we came back in a billion years' time, much of each planets' gas will have been whittled away leaving behind a small core.

Some answers could still be forthcoming. A separate team is performing NIRSpec observations of Kepler-51b to try and find evidence of the composition of its atmosphere. They might instead find that it is also covered in haze, but if they are successful, then the clues those observations provide might also apply to 51c and d.

Then measurements of Kepler-51d are reported in the 16 March issue of The Astronomical Journal.

Astronomers have used the James Webb Space Telescope (JWST) to investigate a new type of planet. This molten lava world beyond the solar system likely smells like rotten eggs, and suggests that there is a much wider diversity of worlds beyond our solar system than previously recognized.

The extra-solar planet, or exoplanet, is designated L 98-59 d, and it orbits a small red star located about 35 light-years away. Data from the JWST and an array of Earth-based telescopes suggest that this exoplanet, which is around 1.6 times the size of the Earth, is extremely low-density. Its atmosphere is packed with hydrogen sulfide, a compound known for its distinct rotten egg stench.

Under normal circumstances, L 98-59 d would either be classified as a rocky gas dwarf, with an atmosphere rich in hydrogen, or as a water-rich "hycean" ocean world. However, this exoplanet fits into neither category, justifying the creation of a new category of exoplanets replete with heavy sulfur molecules.

"This discovery suggests that the categories astronomers currently use to describe small planets may be too simple. While this molten planet is unlikely to support life, it reflects the wide diversity of the worlds which exist beyond the solar system," team leader Harrison Nicholls of the University of Oxford in the UK said in a statement. "We may then ask: what other types of planets are waiting to be uncovered?"

Oceans of magma

Nicholls and colleagues were able to use advanced computer simulations to retell the nearly 5 billion-year history of L 98-59 d. They then compared these models to actual telescope data to reconstruct what must be happening deep below the surface of this exoplanet.

They determined that L 98-59 d likely has a mantle of molten silicate, similar to the lava found on Earth, and an ocean of magma that spans the whole planet. This vast global magma ocean allows the exoplanet to lock away huge amounts of sulphur over vast periods of time. Sulfur-rich gases have then been released into the atmosphere of L 98-59 d over billions of years. This includes the sulfur dioxide and other sulfur-based molecules the JWST spotted in the planet's upper atmosphere.

The magma reservoir may have also helped L 98-59 d hold on to its hydrogen and sulphur-rich atmosphere, preventing it from being lost to space as a result of bombardment of X-rays from its parent star.

Over billions of years, molecules have been exchanged between the planet's atmosphere and its interior, shaping it into the first world in a new class of gas-rich sulphurous planets sustaining long-lived magma oceans.

The team's simulations show that L 98-59 d was likely born with vast amounts of volatile material and may have once been a much larger sub-Neptune planet. The world likely shrank and cooled over billions of years, losing some, but not all, of its atmosphere.

"What's exciting is that we can use computer models to uncover the hidden interior of a planet we will never visit," team member Raymond Pierrehumbert of the University of Oxford said. "Although astronomers can only measure a planet’s size, mass, and atmospheric composition from afar, this research shows that it is possible to reconstruct the deep past of these alien worlds - and discover types of planets with no equivalent in our own solar system."

The team's results were published on Monday (March 16) in the journal Nature Astronomy.

Astronomers have collected evidence of a violent collision between two planets in a distant star system. The first clues of this cataclysmic event came when a rather boring star began behaving very oddly. The collision seems to resemble the event in our history in which a planetary body slammed into Earth and created the moon.

The star in question is Gaia20ehk, an ordinarily stable main-sequence star like the sun located around 11,000 light-years away with a steady and predictable light output. Until 2016, that is, when something very strange started to happen."

The star's light output was nice and flat, but starting in 2016, it had these three dips in brightness. And then, right around 2021, it went completely bonkers," team leader and University of Washington researcher Anastasios Tzanidakis said in a statement. "I can't emphasize enough that stars like our sun don't do that. So when we saw this one, we were like 'Hello, what's going on here?'"

Tzanidakis and colleagues discovered that the flickering of Gaia20ehk wasn't intrinsic to the star itself, but was the result of copious amounts of rock and dust passing in front of it as it orbited the star.

The source of this debris? The collision of two planets that orbited Gaia20ehk.

"It's incredible that various telescopes caught this impact in real time," Tzanidakis explained. "There are only a few other planetary collisions of any kind on record, and none that bear so many similarities to the impact that created the Earth and moon. If we can observe more moments like this elsewhere in the galaxy, it will teach us lots about the formation of our world."

The right type of planetary smash-up

Planets form from collisions and mergers between increasingly large chunks of material called planetesimals around young stars. During the chaos that represents the infancy of planetary systems, such impacts are common. However, over the course of 100s of millions of years, these turbulent conditions settle, resulting in a stable solar system like ours.

Though planetary collisions are probably quite common, seeing them in distant planetary systems is no mean feat, requiring a lot of patience and a huge amount of good fortune. The colliding planets also have to orbit their star directly between it and our view for debris from a collision to cause dimming events, which can take many years to unfold.

"Andy's unique work leverages decades of data to find things that are happening slowly — astronomy stories that play out over the course of a decade," team member James Davenport, a University of Washington scientist, said. "Not many researchers are looking for phenomena in this way, which means that all kinds of discoveries are potentially up for grabs."

As such, spotting such an event is extraordinary to say the least. In fact, seeing such events is so rare that when Tzanidakis and team first saw the fluctuation in brightness of Gaia20ehk, they couldn't account for the short dimming periods, followed by chaotic fluctuations. It was something never seen before.

The researchers could only clear up this mystery when they investigated Gaia20ehk with different telescopes using infrared light.

"The infrared light curve was the complete opposite of the visible light," Tzanidakis said. "As the visible light began to flicker and dim, the infrared light spiked. Which could mean that the material blocking the star is hot — so hot that it's glowing in the infrared." Two planets slamming together could generate this heat, and the right type of collision could create enough material to cause dips in brightness.

"That could be caused by the two planets spiraling closer and closer to each other," Tzanidakis explained. "At first, they had a series of grazing impacts, which wouldn't produce a lot of infrared energy. Then, they had their big catastrophic collision, and the infrared really ramped up."

There are some clues that this collision resembles the impact our planet experienced around 4.5 billion years ago that created the debris that would coalesce and form the moon. In fact, this obscuring dust cloud orbits the star Gaia20ehk at a distance of around 93 million miles, which is around the distance between the Earth-moon system and the sun. Thus, there is a possibility that when this matter around Gaia20ehk cools, it could form an exomoon and a planet-moon system similar to ours.

But this could take a few million years to occur. While astronomers may not get the opportunity to study this process to its conclusion, the hunt is on for other similar collisions. This could help to reveal just how common the events that created the moon are. And because Earth's primary natural satellite is considered to have been integral to the development of life on Earth, discovering the frequency of such events may shine a light on the possibility of life elsewhere in the Milky Way.

"How rare is the event that created the Earth and the moon? That question is fundamental to astrobiology," Davenport said. "It seems like the moon is one of the magical ingredients that make the Earth a good place for life. It can help shield Earth from some asteroids, it produces ocean tides and weather that allow chemistry and biology to mix globally, and it may even play a role in driving tectonic plate activity.

"Right now, we don't know how common these dynamics are. But if we catch more of these collisions, we'll start to figure it out."

The team's research was published on Wednesday (March 11) in The Astrophysical Journal Letters.

The world's first commercial space telescope has released its first measurements as it begins its journey to help track nearby stars that might host habitable exoplanets.

The suitcase-sized satellite, called Mauve, launched atop a SpaceX Falcon 9 rocket last November and is the first in a planned fleet of small commercial spacecraft designed to provide observing time to astronomers around the world.

While Earth observation and telecommunications have for years been dominated by commercial providers, astronomy has so far been fully in the hands of government-funded agencies and institutions. But the outfit behind Mauve — the London-based company Blue Skies Space, a spin-out from University College London — realized that a new, customer-driven approach might provide a faster route to fill gaps in the scientific understanding of the universe.

On Feb. 9, after months of instrument checks, Mauve pointed at a star known as eta Ursa Majoris, capturing a five-second observation in the visible and ultraviolet portions of the light spectrum. Located some 104 light-years from Earth, eta Ursa Majoris is one of the brightest stars in the constellation Great Bear (Ursa Major). Much hotter than our sun, the star is especially bright in ultraviolet light, which is Mauve's specialty.

"We wanted to look at a stable star, which behaves in a constant way over time and for which there has already been high-quality spectra collected from other instruments in the past," Blue Skies Space CEO Marcell Tessenyi told Space.com.

Ultraviolet emissions can be measured by the Hubble Space Telescope, but that iconic observatory also covers other areas and is in very high demand. The last dedicated mission to observe stellar ultraviolet light was the International Ultraviolet Explorer, which ran out of fuel in 1996. The Blue Skies team realized that, with advances in satellite technology, a small, privately funded space telescope can provide an opportunity to obtain such measurements.

Ultraviolet light offers the best opportunity to observe stellar flares, flashes of high-energy radiation from the magnetically dense regions known as sunspots. Flares flush the environment around the star with streams of energetic particles, which may affect the habitability of planets in the star's vicinity.

Solar flares produced by the sun can cause radio blackouts and geomagnetic storms on Earth, which interfere with radio communications and affect satellites in orbit. But the sun is a relatively quiet star, and Earth's magnetic field is strong enough to protect our planet against those outbursts. Mars, on the other hand, lacks a global magnetic field and therefore has its thin atmosphere constantly eroded by space weather.

By monitoring the activity of nearby stars, Mauve will help scientists better home in on those that might host exoplanets that could potentially harbor life. The mission is expected to begin delivering scientific data in the next few weeks, Tessenyi said.

"We are now doing the same set of measurements with all kinds of different stars to work out the behavior of the instrument," said Tessenyi. "As soon as this phase is closed, we are officially starting the science operations."

Research institutions from all over the world have already subscribed to the mission, including teams from the U.S., Japan and multiple European countries.

Cash flow from Mauve's operations will help Blue Skies Space complete the development of its next mission, called Twinkle, a 220-pound (100-kilogram) satellite designed to directly observe nearby exoplanets and measure the compositions of their atmospheres.

Tessenyi said the company is currently in discussions with its scientific customers to see what other areas of study they would like to see covered with dedicated commercial missions. The company is also currently working with the Italian Space Agency to develop the concept for a satellite constellation to measure radio waves emitted by cosmic sources from the orbit of the moon.

"It's a fascinating opportunity that we have here because, obviously, the space sector has evolved a lot over the last decade, whether it is regular cost-effective launch opportunities or the commoditization of lower-cost platforms for low Earth orbit satellites," Tessenyi said. "There are plenty of opportunities for many satellites to do space science."

Still, he thinks that commercial astronomy will always remain in the shadow of large government-funded space missions that push technology to new limits and open completely new vistas.

"The space agencies are doing an incredible job with pushing the technology, developing these incredibly clever and complex facilities like James Webb and others, which are really progressing knowledge and technological capabilities," Tessenyi said. "We, on the other hand, are operating more in the domain of reusing existing components, benefitting from historic investments from the agencies into technologies, and reusing them in novel ways to try to increment the provision of data."

The Mauve satellite was developed and built in three years, an extremely fast timeline compared to the frequently decades-long development timelines of government-funded space missions. The observatory, built by a group of companies from Hungary, the Netherlands, Italy and Latvia, is expected to remain in Earth orbit for at least three years.

It's one of the most instantly recognizable scenes in cinematic history: Luke Skywalker gazes at a double sunset to the haunting melody of a mournful French horn. And while "Star Wars" may take place in a galaxy far, far away, planets orbiting binary stars actually do exist in the Milky Way. Yet mysteriously, there are not as many as scientists expect — and new research might explain why.

Of the thousands of single-star systems in our galaxy, around 10% are known to have planets. Scientists thus expected about 10% of the 3,000 known binary star systems in our galaxy to have them, too. But of the more than 6,000 confirmed exoplanets in the Milky Way, just 14 confirmed planets have been found around pairs of stars.

Researchers from the University of California, Berkeley, and the American University of Beirut suggest the culprit might be Albert Einstein's theory of general relativity.

In most binary star systems, two stars orbit each other in elliptical paths. A planet caught in that dance feels gravitational forces from both stars, causing its orbital orientation to slowly rotate in a process known as precession. Meanwhile, the binary stars' own orbits also precess due the rules of general relativity. As time progresses, tidal forces between the stars can draw them closer, accelerating their precession and causing an orbiting planet's precession to slow.

When the precession rates align, the planet's orbit becomes highly stretched. According to lead author Mohammad Farhat of the University of California, Berkeley, this resonance can destabilize the planet's path. "Either the planet swings too close to the stars and is torn apart, or its orbit is so perturbed that it's ejected from the system," he said in a statement.

The team's models suggest that in tight binaries — those with orbital periods of a week or less — such disruptions are common. These systems also happen to be the ones most likely to be monitored by missions like NASA's Kepler and TESS, which detect planets by watching for starlight dimming as a planet passes in front of them. That could partly explain the surprisingly low number of circumbinary planets in observational data.

Ultimately, there might be hundreds or thousands of Tatooines in the Milky Way — we just aren't sure how to look for them yet.

The team's findings were published in The Astrophysical Journal Letters on December 8, 2025.

Scientists investigating the puzzling, long-lasting, and extreme dimming of a distant star have narrowed the suspects down to either a so-called "failed star" brown dwarf or a truly massive super-Jupiter exoplanet.

The dramatic fading of this star, located around 3,200 light-years away in the Monoceros constellation, was first spotted at the end of 2024. The dimming came as a surprise, as the star, designated ASASSN-24fw and measuring around twice the size of the sun, had previously been known to be stable. The stellar dimming was one of the longest ever observed, lasting for around 200 days. It was also extreme, with the brightness of ASASSN-24fw reduced by 97%. Such extreme and long-duration dimming events are incredibly rare.

Astronomers deduced that this dimming was caused by the saucer-like rings extending out from 15.8 million miles (26 million kilometers), or about half the distance between the sun and its closest planet, Mercury. The big question is, what is this ring system looped around? The leading suspects have now emerged as a brown dwarf or a massive extrasolar planet, or exoplanet, many times the size of Jupiter, the solar system's largest planet.

"Various models made by our group show that the most likely explanation for the dimming is a brown dwarf – an object heavier than a planet but lighter than a star – surrounded by a vast and dense ring system. It is orbiting the star at a farther distance with the ring," team leader Sarang Shah, of the Inter-University Centre for Astronomy and Astrophysics (IUCAA), India, said in a statement. "Long-lasting dimming events like this are exceptionally uncommon as they require very perfect line-ups. The dimming began gradually because the outer parts of the rings are thin, and only became obvious when the denser regions passed in front of the star."

Small failed star or giant planet?

Brown dwarfs get the unfortunate nickname "failed stars" because, like stars, they form from collapsing clouds of gas and dust, but fail to gather enough material from what remains of that natal cloud to pile on the mass needed to trigger the fusion of hydrogen to helium in their cores. That is the process that defines what a main-sequence star is.

The dividing line between brown dwarfs and massive gas giant planets is a blurred one in terms of mass. The lower limit of brown dwarf mass is considered to be around 13 times the mass of Jupiter, with the upper limit dividing the heaviest brown dwarfs and the lightest stars being around 80 Jupiter masses, or around 0.08 times the mass of the sun. Currently, a ringed brown dwarf is the prime suspect for the ASASSN-24fw dimming event.

However, because the team can't yet pin down the mass of the dimming body beyond determining it to be greater than three times the mass of Jupiter, they still can't rule out the possibility that the culprit is a super-Jupiter exoplanet.

What is more certain is the fact that ASASSN-24fw itself is closely circled by gas and dust fragments, which seem to be the remains of previous planetary collisions. This is something that is common around young stars that have turbulent and violent environments, but is uncommon for stars as old as ASASSN-24fw, estimated to be around 1 billion years old.

"Large ring systems are expected around massive objects, but they are very difficult to observe directly to determine their characteristics," team member Jonathan Marshall, an independent post-doctoral researcher affiliated with Academia Sinica, Taiwan, said. "This rare event allows us to study such a complex system in remarkable detail. In fact, while studying this dimming, we also serendipitously discovered that ASASSN-24fw also has a red dwarf star in its vicinity."

The team now intends to measure the temperature, age, and chemical composition of ASASSN-24fw as well as determine the evolutionary stage it is in. Gathering further data about this star from the Very Large Telescope (VLT) in the Atacama Desert region of northern Chile and the James Webb Space Telescope (JWST) should help to better reveal how planetary systems like this one evolve.

Astronomers will have to wait a little longer to get another look at the extreme dimming of ASASSN-24fw, however. The team expects the mysterious object to once again impact the brightness of the star in between 42 and 43 years.

The team's results were published on Thursday (Feb. 12) in Monthly Notices of the Royal Astronomical Society.

Astronomers have discovered a planetary system that appears to flip one of astronomy's most reliable rules on its head; it orbits a small, faint red star known as LHS 1903.

LHS 1903 is a cool M-dwarf star, smaller and far less luminous than our sun. Using a combination of space- and ground-based telescopes, scientists identified four planets circling the star. The three innermost planets initially seemed to follow a familiar pattern seen across the Milky Way, with the closest planet being rocky and the next two being gas giants.

However, when researchers took a closer look at a fourth, more distant planet using the European Space Agency's (ESA) Characterizing Exoplanet Satellite (CHEOPS), they found something surprising. Despite orbiting farther from the star than the gas giants, the outermost planet appears to be small and dense — likely rocky, similar in composition to Venus. That makes the system's architecture rocky–gaseous–gaseous–rocky, a highly unusual arrangement that is rarely observed in planetary systems, according to the study.

"This strange disorder makes it a unique inside-out system," study lead author Thomas Wilson, physics professor from the University of Warwick, said in a statement. "Rocky planets don't usually form far away from their home star, on the outside of the gaseous worlds."

In most systems, including our own solar system, rocky planets are found close to the star, while gas giants form farther out. Traditional models suggest intense stellar radiation near a star strips away light gases, leaving behind dense, rocky cores. Farther out, cooler temperatures allow planets to accumulate and retain thick atmospheres of hydrogen and helium, forming gas giants.

The newly characterized outer planet around LHS 1903 appears to defy that expectation.

After considering whether the planets might have swapped positions or whether the outer rocky planet lost its atmosphere in a collision, the team ruled out those explanations. Instead, they found evidence that the four worlds may have formed sequentially in a process known as inside-out planet formation, according to the statement.

In this scenario, planets form one by one, starting close to the star. Each newly formed planet sweeps up surrounding dust and gas, evolving in a different environment and potentially leaving the outer regions depleted of the material needed to form gas giants. By the time the fourth planet formed, the system may have already run out of gas, leaving behind a small, rocky world.

"By the time this final outer planet formed, the system may have already run out of gas, which is considered vital for planet formation," Wilson said in the statement. "Yet here is a small, rocky world, defying expectations. It seems that we have found first evidence for a planet that formed in a gas-depleted environment."

The discovery suggests that planetary systems may evolve in more diverse ways than previously thought. As astronomers continue studying stars like LHS 1903, they may uncover more systems that challenge long-standing ideas about how planets form and where different types of worlds belong.

Their findings were published in the journal Science.

Life on Earth may exist thanks to an incredible stroke of luck — a chemical sweet spot that most planets miss during their formation but ours managed to hit.

A new study shows that Earth formed under an unusually precise set of chemical conditions that allowed it to retain two elements essential for life as we know it: phosphorus and nitrogen. Without a perfect balance of these elements, a rocky planet could appear habitable on the surface yet be fundamentally incapable of supporting biology, according to the study.

"During the formation of a planet's core, there needs to be exactly the right amount of oxygen present so that phosphorus and nitrogen can remain on the surface of the planet," study lead author Craig Walton, of ETH Zurich in Switzerland, said in a statement.

Earth seems to have hit this delicate chemical sweet spot during its formation nearly 4.6 billion years ago, and the new findings could change how scientists search for alien life, the researchers said.

When young planets form, they are often partially or fully molten. As heavy metals sink inward to form a core, lighter materials remain closer to the surface. During this chaotic stage, known as core formation, the amount of oxygen present plays a decisive role in determining where other elements end up — and whether they remain accessible for future life.

The study suggests that oxygen levels must fall within a surprisingly narrow range for both phosphorus and nitrogen to stay in a planet's mantle and crust. Too little oxygen, and phosphorus bonds with iron and is dragged into the core, depriving the surface of a key ingredient for DNA, cell membranes and energy transfer. Too much oxygen, and nitrogen is more easily lost to space. Either way, the chemistry needed for life never fully comes together.

Using models of planetary formation and geochemical behavior, the researchers found that Earth sits squarely inside this narrow range of medium-level oxygen, which they called the chemical Goldilocks zone. Ultimately, our planet retained enough phosphorus and nitrogen to later fuel biology — a result that may be far from common among rocky worlds.

"Our models clearly show that the Earth is precisely within this range," Walton said in the statement. "If we had had just a little more or a little less oxygen during core formation, there would not have been enough phosphorus or nitrogen for the development of life."

Conversely, the researchers also modeled the formation of other planets such as Mars, where oxygen levels were outside this chemical Goldilocks zone. On Mars, for example, the models show more phosphorus in the mantle than on Earth, but less nitrogen, creating challenging conditions for life as we know it, according to the statement.

The findings challenge the traditional focus on the habitable zone, the region around a star where liquid water can exist. While water is critical, the study suggests it may be only part of the story. A planet could orbit at the right distance from its star and still lack the internal chemical inventory required for life to ever emerge.

Crucially, the oxygen conditions that shape this process are linked to the chemical makeup of the host star itself. Because planets form from the same material as their stars, stellar chemistry can hint at whether a system is even capable of producing life-friendly planets in the first place.

If the researchers are right, Earth may be less a cosmic norm and more a fortunate exception — a planet that hit a rare chemical jackpot early on. Using Earth as a benchmark could help scientists zero in on exoplanets that are the most likely to have the perfect balance of elements essential for life.

"This makes searching for life on other planets a lot more specific," Walton said. "We should look for solar systems with stars that resemble our own sun."

Their findings were published Feb. 9 in the journal Nature Astronomy.

A possible rocky exoplanet referred to as a 'cold Earth' that could orbit on the outer edge of the habitable zone has been found around a star 146 light-years away.

Known as HD 137010b, the exoplanet is considered at this stage to be a candidate world, meaning that its existence has yet to be confirmed. The star is a K-type dwarf, meaning it is a little smaller, dimmer and cooler than our sun, and HD 137010b would receive just 29% of the heat and light that Earth does from our sun. Based on our best estimates of the size of its star, the planet likely has a diameter just 1.06 times that of Earth, and orbits once every 355 days, although there's a huge amount of uncertainty in that estimation. This imprecision means that exactly what conditions are like on the planet's surface remain open to debate.

Based on its orbital period of 355 days, HD 137010b is right on the very edge of its star's habitable zone. The planet's surface is likely frozen, unless it has a much thicker atmosphere than Earth does. If it has no atmosphere at all, then its average surface temperature would be –90 degrees Fahrenheit (–68 degrees Celsius) which is marginally colder than Mars (where the average temperature is –85 degrees Fahrenheit(–65 degrees Celsius).

A team of astronomers led by Alexander Venner at the Max Planck Institute for Astronomy in Germany came across this 'maybe' planet while sifting through archive data from the Kepler Space Telescope's K2 mission, which ended in 2018.

Venner's team only found one transit of HD 137010b (one instance of it passing in front of its host star) that lasted ten hours, but were able to rule out the usual false positives, such as stellar activity causing the star to dim, by using new and historical images, as well as observations by other observatories. Usually it takes a minimum of two or three transits to confirm a planet's discovery.

Because HD 137010b transits a relatively bright star in our sky, there's hope that instruments such as the James Webb Space Telescope will be able to search for an atmosphere around the planet. Most of the stars observed by Kepler were fainter than magnitude 13 in our sky, so HD 137010b's star is an outlier at magnitude 10, bringing it in range of even 6-inch (150mm) amateur telescopes. For professional observatories, magnitude 10 is easy.

Why do we need a bright star to learn more about HD 137010b? Because astronomers can detect the atmosphere of an exoplanet based on the light that passes through it at two different points in the planet's orbit.

One point occurs when it is transiting, during which the star's light is filtered through the planet's atmosphere and is absorbed at wavelengths corresponding to atmospheric molecules. The second point is when the planet is hidden behind the star, so the light of just the star can be subtracted from the light of the star and planet together, leaving just the light from the planet. Either way, this requires a bright star to produce a signal large enough to be convincing.

The problem is that with an orbital period of somewhere around 355 days, transits of HD 137010b don't come along very often, and without knowing the orbital period precisely, astronomers don't know when to look for the next transit. However, if NASA's TESS (Transiting Exoplanet Survey Satellite) or the European Space Agency's CHEOPS (Characterising ExOPlanets Survey) don't observe a transit, then ESA's forthcoming PLATO (PLAnetary Transits and Oscillations) mission, which is scheduled for launch in December 2026, stands a very good chance of detecting HD 137010b.

And what could PLATO find? There's actually a host of possibilities for HD 137010b and we shouldn't write it off as a frozen Earth just yet. If its atmosphere contains substantially more carbon dioxide than ours, then the surface may yet be warm and wet.

Venner's team gives HD 137010b a 40% chance of orbiting within the so-called 'conservative' habitable zone. Think of this as the pessimistic, narrower option, where the greenhouse effect curtails the zone's inner edge and the loss of carbon dioxide from a planetary atmosphere marks its outer edge.

On the other hand, there's a 51% chance that HD 137010b is in the 'optimistic' habitable zone, a wider band where planetary rotation limits the greenhouse effect on the inner edge and geothermal activity can keep a planet warm on the outer edge. But there's also a 50/50 chance that HD 137010b isn't in the habitable zone at all.

So for now, HD 137010b remains a 'maybe' planet, but maybe we won't have to wait too long to find out exactly what kind of planet it really is.

The discovery of HD 137010b was described in a paper published on Jan. 27 in The Astrophysical Journal Letters.

Scientists argue that limiting the search for life strictly to a star’s traditional habitable zone is too restrictive. That is in light of new climate models, and observations that suggest that liquid water—and therefore potentially life-supporting conditions—can exist well beyond these classical boundaries.

The habitable zone is defined as the region around a star where a planet could maintain liquid water on its surface without turning to ice or gas.

The fact that this water is neither too hot nor too cool has also led to the habitable zone being nicknamed the Goldilocks zone. In our solar system, this zone begins at around the orbit of Venus, the second planet from the sun, past the orbit of Earth, and out to roughly the orbit of Mars.

“[However,] this concept is rooted in the principle that liquid water is necessary for biochemical processes essential to life,” writes a team of researchers in a paper published on Jan. 12 in the Astrophysical Journal. “Although other factors, such as chemical energy sources, elemental diversity, and long-term environmental stability, are also important.”

Using an analytical climate model, the scientists have shown that tidally locked planets—which always show the same face to their star—can maintain liquid water on their permanent night side, even when orbiting much closer to their star than the traditional inner edge of the habitable zone.

“Initially, this configuration raised concerns about extreme temperature gradients and atmospheric collapse on the dark side,” the team writes. “However, 3D climate models have demonstrated that given a sufficient atmospheric pressure, or the presence of an ocean, efficient heat redistribution between the day and night sides can stabilize temperatures and maintain habitable conditions.”

This suggests that for tidally locked planets, common around small M-class and K-class stars, the inner edge of the habitable zone may actually lie closer to the star than in the case of rapidly rotating planets. This extended habitable zone could help explain recent observations made by the James Webb Space Telescope (JWST) of water vapor and other volatile gases in the atmospheres of warm super-Earths closely orbiting their M dwarf stars.

“Signs of water vapor and volatiles have been detected in JWST transmission spectra of small exoplanets,” they write. “Some of these exoplanets are closer to their M dwarf hosts than the inner [habitable zone] boundary […] Water detection on such planets is intriguing, since one would doubt the survival of atmosphere and water under such harsh conditions.”

These findings suggest that such planets can retain significant amounts of water despite lying outside the classical habitable zones—and this doesn’t apply to planets orbiting their stars too closely. The team argues that the habitable zone should be extended in both directions. Even on cold planets far from their stars, liquid water can exist beneath thick ice layers, as subglacial lakes or through internal heating. Similar environments on Earth, such as Antarctica’s subglacial lakes, support microbial life, demonstrating that surface liquid water is not the only possible habitat.

Through a reassessment of habitable zone models and boundary calculations, this study expands the range of worlds considered potentially habitable, revealing new targets in the search for life.

When the Undertones sang about "Teenage Kicks," they could well have been inadvertently referring to the chaotic and violent "teenage" periods of planetary systems that are shaped by collisions between bodies of various sizes, such as the impact upon Earth by a massive body that created the moon.

Now, using the world's largest radio telescope project, the Atacama Large Millimeter/submillimeter Array (ALMA), astronomers have captured snapshots representing the chaotic "teenage years" of planets forming around infant stars.

The breakthrough, made as part of the Resolve exoKuiper belt Substructures (ARKS) survey being conducted by ALMA, could not only help scientists better understand the processes that drive the evolution of planetary systems, but it could also help us better understand a turbulent period of our own solar system's history that has, until now, been shrouded in mystery.

"We've often seen the 'baby pictures' of planets forming, but until now, the ‘teenage years’ have been a missing link," team co-leader Meredith Hughes of Wesleyan University, Connecticut, said in a statement. "This project gives us a new lens for interpreting the craters on the moon, the dynamics of the Kuiper Belt, and the growth of planets big and small. It’s like adding the missing pages to the Solar System's family album."

Teenage kicks

Hughes and colleagues used the 66 radio telescopes located in the Atacama desert region of northern Chile that make up ALMA to observe 24 disks of dusty debris around infant stars, the detritus that remains after planets have formed.

"Debris discs represent the collision-dominated phase of the planet formation process," ARKS team member Thomas Henning of the Max Planck Institute for Astronomy (MPIA) said. "With ALMA, we are able to characterise the disc structures pointing to the presence of planets. In parallel, with direct imaging and radial velocity studies, we are searching for young planets in these systems."

Evidence of this period of the solar system's history can be seen in the icy ring of comets beyond the orbit of Neptune known as the Kuiper Belt. These objects were created through massive collisions and planetary migrations that occurred around the sun billions of years ago, around the same time as Earth's moon was forming.

Planet baby pictures are fairly easy to obtain because the gas-rich disks in which they form, protoplanetary disks, are bright. Debris disks like the 24 seen by ALMA are thousands of times fainter, which is why they have proved so elusive for many years.

ALMA collected the radio wavelength emissions from dust particles and other molecules in these disks to build a picture of their complex structures, revealing multiple rings, wide and smooth outer halos, and unexpected arcs and clumps.

"We're seeing real diversity – not just simple rings, but multi-ringed belts, halos, and strong asymmetries, revealing a dynamic and violent chapter in planetary histories," ARKS team member and University of Exeter researcher Sebastián Marino said.

The key to this level of detail is the fact that with its 66 antennas, ALMA and its radio interferometry technique provide a wider view than any single telescope. This has confirmed that the teenage phase of planetary systems is a time of great upheaval.

"These discs record a period when planetary orbits were being scrambled and huge impacts, like the one that forged Earth's moon, were shaping young solar systems," team member Luca Matrà, of Trinity College Dublin, Ireland, added.

The team's research was published on Tuesday (Jan. 20) in the journal Astronomy & Astrophysics.

"Super-Earth" exoplanets may have an in-built way to protect themselves from harmful radiation, giving any potential life on such worlds a better chance of surviving, according to recent research.

Super-Earths, worlds larger than Earth but smaller than Neptune, are among the most commonly detected types of extrasolar planets, or exoplanets, in the Milky Way. Because many have been found within their stars' habitable zones — regions where liquid water could exist and, thus, potentially support life — scientists have increasingly focused on whether these planets can sustain life-friendly conditions over billions of years.

The new study suggests that many super-Earths may be able to generate powerful magnetic fields from molten rock not in their cores, like Earth does, but in a layer sandwiched between the core and mantle.

"A strong magnetic field is very important for life on a planet," study lead Miki Nakajima, an associate professor in the department of Earth and environmental sciences at the University of Rochester in New York, said in a statement. "Super-earths can produce dynamos in their core and/or magma, which can increase their planetary habitability."

The findings, published Jan. 15 in the journal Nature Astronomy, help resolve a long-standing puzzle about how super-Earths might maintain magnetic fields despite interiors whose structures differ from Earth's, the researchers say.

"This paper suggests that, like in many other things, exoplanets might not necessarily follow the solar system paradigm concerning magnetic field generation," Luca Maltagliati, a senior editor at Nature Astronomy, who was not involved with the new study, wrote in a brief piece summarizing the findings. "Planets with masses 3-6 times that of Earth might have their main magnetic field engine not in the core like the Earth but in a layer between the core and mantle."

Long-lived magnetic shields are considered essential for habitability because they help prevent planetary atmospheres from being stripped away by stellar winds and protect surfaces from harmful cosmic and stellar radiation.

Without such protection, even planets located in otherwise favorable habitable zones may struggle to maintain the conditions needed for life, meaning such magma-driven magnetic fields could play a crucial role in making super-Earths habitable across the galaxy.

Earth's magnetic field, which has operated for more than 3 billion years, is generated by the movement of liquid iron in the outer core surrounding a solid inner core. That inner core is critical because it releases heat and lighter elements that keep the molten outer core moving, allowing our planet to sustain its magnetic field.

But larger rocky worlds such as super-Earths are thought to have cores that are either fully solid or fully liquid, which typically limit the operation of a conventional, Earth-like core dynamo.

Nakajima and her team point to an alternative mechanism known as a basal magma ocean (BMO), a layer of molten rock that forms between the core and the mantle. Such layers are thought to arise during planet formation, according to the new study, when repeated large impacts generate global magma oceans that partially crystallize and concentrate iron-rich melt at depth.

The idea of a BMO-driven dynamo was first proposed as a way to explain how Earth may have generated a magnetic field early in its history, before its inner core had formed. Such a layer would have formed following the moon-forming impact, but it likely solidified after roughly 1 billion years, the new study notes.

Super-Earths, by contrast, are larger and experience much higher internal pressures, conditions that could allow basal magma oceans to persist for far longer and sustain magnetic fields over billions of years, the researchers say.

To test whether these deep magma layers could generate magnetic fields, Nakajima and her team conducted shock experiments that compressed rock-forming materials to the extreme pressures expected inside planets several times more massive than Earth. The researchers then combined the lab results with planetary models to determine how massive a super-Earth must be to generate a magnetic field.

They found that under such crushing pressures, iron-rich magma becomes metallic and electrically conductive, suggesting that super-Earths roughly three to six times Earth's mass could maintain BMO-driven magnetic fields for several billion years, longer, and potentially stronger than magnetic fields generated by Earth-like metallic cores alone.

In some cases, the resulting magnetic field at the planet's surface could rival or even exceed Earth's, according to the statement.

"Although detecting the magnetic fields of exoplanets remains challenging," the researchers wrote in the briefing, "it might be possible to observe such strong BMO-driven dynamos in future observations."

A gas giant planet beyond the solar that wobbles as it circles its star, hinting to astronomers that it is orbited by its own moon. To make this suspected discovery even more remarkable, if this moon exists it would be absolutely massive, comparable to around half the mass of Jupiter. That would make it thousands of times more massive than any moon orbiting a solar system plane  — so massive it could make astronomers reconsider what constitutes a moon.

The extra-solar planet, or "exoplanet," suspected to host this tremendous exomoon is HD 206893 B, a gas giant with 28 times the mass of Jupiter, which orbits a young star located around 133 light-years from Earth. The team behind this research detected signs of the potential exomoon while investigating HD 206893 B with the GRAVITY instrument at the Very Large Telescope (VLT) located in the Atacama desert region of northern Chile.

"What we found is that HD 206893 B doesn't just follow a smooth orbit around its star. On top of that motion, it shows a small but measurable back-and-forth 'wobble'. The wobble has a period of about nine months and a size comparable to the Earth–moon distance," team leader and University of Cambridge astronomer Quentin Kral told Space.com. "This kind of signal is exactly what you would expect if the object were being tugged by an unseen companion, such as a large moon, making this system a particularly intriguing candidate for hosting an exomoon."

The GRAVITY instrument allowed the team to use a technique called astrometry, which precisely measures the positions of stars and other astronomical bodies over time. This allows astronomers to detect tiny aberrations in motion that are the result of a gravitational "tug" from an unseen body.

"This technique has previously been used to measure the long, slow orbits of massive exoplanets and brown dwarfs, where observations spaced years apart are sufficient," Kral said. "In our study, we pushed this approach much further by monitoring the object over much shorter timescales, from days to months. What we found is that HD 206893 B doesn't just follow a smooth orbit around its star. On top of that motion, it shows a small but measurable back-and-forth 'wobble.'"

The result of this investigation was the inference of a companion body orbiting HD 206893 B around once every nine months at a distance of around one-fifth the distance between Earth and the sun. The orbit of this potential exomoon is tilted at around 60 degrees relative to the orbital plane of its parent planet, potentially indicating some type of interaction has disturbed this system at some point in its history.

Of course, what would be really extraordinary about this exomoon, if confirmed, is its absolutely tremendous mass, around 40% of Jupiter's mass, or around nine times the mass of the ice giant Neptune! That is so big it could call into question the definition of the word "moon."

"In our solar system, the most massive moon is Ganymede, which is still extremely small compared to what we are inferring here. Ganymede is thousands of times less massive than Neptune, so there is an enormous gap in mass between the largest moons we know and this potential exomoon candidate," Kral said.

"This naturally raises the question of whether such an object should even be called a moon. At these masses, the distinction between a massive moon and a very low-mass companion becomes blurred. However, there is currently no official definition of an exomoon, and in practice, astronomers generally refer to any object orbiting a planet or substellar companion as a moon."

Though astronomers believe that several exomoons have been detected in the past, all of these possible detections have been controversial. Thus, the team is hoping that the exomoon of HD 206893 B can be the first to be officially confirmed.

"Exomoons are difficult to detect because they produce signals that are extremely small compared to those of planets, and those signals depend very strongly on both the observing technique and the system's geometry," Kral explained.

The most successful method of exoplanet detection thus far has been the transit method, which measures the dip in light caused as a planet crosses, or "transits", the face of its parent star.

However, this technique hasn't been nearly as successful at detecting exomoons.

"The transit method — which has been the most successful technique for finding exoplanets — can, in principle, detect moons comparable in size to Jupiter's largest moons. However, it is most sensitive to planets orbiting very close to their stars, and theoretical studies suggest that such close-in planets are unlikely to retain large moons over long periods of time," Kral said.

"Astrometry, the technique we use, is sensitive to longer-period moons orbiting planets or substellar companions far from their stars. This makes it particularly promising for detecting exomoons in regions where they are expected to be stable — at least for the most massive moons, which are likely to be the first ones we can find."

In addition to hopefully confirming the presence of this exomoon, Kral and colleagues think this research and the technique they used lay down a future roadmap for exomoon discovery in other planetary systems.

"It's important to keep in mind that we are likely only seeing the tip of the iceberg," Kral concluded. "Just as the first exoplanets discovered were the most massive ones orbiting very close to their stars — simply because they were the easiest to detect — the first exomoons we identify are expected to be the most massive and extreme examples.

"As observational techniques improve, our definitions and understanding of what constitutes a moon will almost certainly evolve."

The team's research is available as a pre-peer-reviewed paper on the repository site arXiv, and accepted for publication in Astronomy & Astrophysics

The secret behind the formation of super-Earth and sub-Neptune exoplanets has been revealed, thanks to a study of four young planets that are evaporating.

Some 350 light-years away, the V1298 Tau system features an infant sun-like star, just 23 million years old, orbited by four planets on compact orbits close to their star, and all of which are seen to transit. Discovered in 2019 by astronomers Erik Petigura of the University of California, Los Angeles and Trevor David of the Flatiron Institute in New York, using data from the Kepler space telescope's K2 mission, the four planets are huge, with radii between five and 10 times that of Earth.

Now, a team of astronomers led by John Livingston from the Astrobiology Center in Tokyo and including Petigura and David, have used "transit timing variations" to measure the mass of each of the four planets. This has allowed the researchers to determine that the planets are very low density and that the atmosphere of each world is photoevaporating into space. This, says Livingston's team, is the key to the formation of super-Earths and sub-Neptunes.

Super-Earths are rocky planets larger and more massive than our own planet. Sub-Neptunes are partially gaseous worlds smaller than Neptune. Together, the two types of planet are the most common classes of world discovered by exoplanet hunters so far. (Planets smaller than Earth may indeed be more common, but they are harder to detect, so we haven't found as many.) What's curious is that our solar system contains neither a super-Earth nor a sub-Neptune, and astronomers don't know why our solar system lacks one of these common planets, or how such worlds form.

This is why the observations of V1298 Tau are such a big step forward. When a planet transits, or passes in front of, its host star, it blocks some of the star's light. The amount of light it blocks tells us the planet's radius. The frequency with which we see that planet transit then tells us its orbital period. The four planets have orbital periods of 8.2, 12.4, 24.1 and 48.7 Earth days, respectively. This is a very compact system — all four planets could easily fit inside the orbit of our solar system's innermost planet, Mercury.

Because the planets are all fairly close, their gravity tugs on each other, sometimes pulling a planet along its orbit a little faster, and sometimes causing it to go a little slower, depending on the respective planets' relative locations. This results in the planets sometimes being a little late or a little early for their scheduled transit. These transit timing variations, or TTVs, can tell researchers the mass of the planets: The greater the variation in the timing of a transit, the more massive the mass of the planet pulling on the transiting world.

With the radii and the masses of the planets known, Livingston's team could then calculate the densities of the planets, and found them to be extremely light.

"The unusually large radii of the young planets led to the hypothesis that they have very low densities, but this had never been measured," said Trevor David in a statement. "By weighing these planets for the first time, we have provided the first observational proof. They are indeed exceptionally puffy, which gives us a crucial, long-awaited benchmark for theories of planet evolution."

Indeed, the planets are some of the least dense known. They all formed with an extended atmosphere, like Neptune, but because they are so close to their star, extreme ultraviolet light and X-rays are heating their atmospheres. This causes the atmosphere of each world to expand and become bloated — so bloated, in fact, that the planets only have a loose grip on their atmosphere. Consequently, the atmosphere on each world is inevitably being stripped into space by the stellar wind of radiation. This process is known as photoevaporation. Livingston's team even looked for the spectral features of these outflows from the planets, but their signal is overpowered by the strong stellar winds.

The photoevaporation will continue for another 100 million years, by which time the planets will have been whittled down. The measurements suggest that all four worlds have a similar-size rocky core. The inner two worlds appear on course to lose their atmospheres altogether and become rocky super-Earths. The outer two planets are currently twice as massive, as their greater distance from their star offers them a little protection, but they too are on track to either lose their atmospheres entirely, or to keep some of it and evolve into mini-Neptunes.

The compact nature of their orbits suggests that this is how peas-in-a-pod systems, such as the worlds of TRAPPIST-1, form — planets of similar size and mass all on regularly spaced, circular orbits.

"What's so exciting is that we're seeing a preview of what will become a very normal planetary system," said Livingston. "The four planets we studied will likely contract into super-Earths and sub-Neptunes — the most common types of planets in our galaxy, but we've never had such a clear picture of them in their formative years."

The findings were reported on Jan. 7 in the journal Nature.

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

We live in a very exciting time: answers to some of the oldest questions humanity has conceived are within our grasp. One of these is whether Earth is the only place that harbors life.

In the last 30 years, the question of whether the sun is unique in hosting a planetary system has been resoundingly answered: we now know of thousands of exoplanets orbiting other stars.

But can we use telescopes to detect whether any of these distant worlds also harbor life? A promising method is to analyze the gases present in the atmospheres of these planets.

We now know of more than 6,000 exoplanets. With so many now catalogued, there are a number of ways to narrow down which worlds are the most promising for biology. Using the planet's distance from its host star, for example, astronomers can work out its likely temperature.

Earth is the only planet in the solar system with liquid water oceans on its surface, so mild temperatures are a possible requirement for a habitable planet. Whether a planet has the correct temperature for liquid water is strongly influenced by the presence and nature of the planet's atmosphere.

Astonishingly, we can identify molecules present in the atmospheres of exoplanets. Quantum mechanics causes each atmospheric chemical to have its own distinct barcode-like pattern, which it leaves on the light passing through it. By collecting starlight that has been filtered through an exoplanet's atmosphere, telescopes can see the barcodes of the molecules making up that atmosphere.

To take advantage of this, the planet needs to transit – pass in front of – the star from our point of view. This means it only works for a small fraction of known exoplanets.

The strength of the signal depends on the abundance of the molecule in the atmosphere: stronger for the most abundant molecules and gradually weaker as the abundance decreases. This means it is generally easiest to detect the dominant molecules, though this is not always true. Some of the barcodes are intrinsically strong, while others are weak.

For example, Earth's atmosphere is dominated by diatomic nitrogen (N₂), but this molecule has a feeble barcode compared to the much less abundant diatomic oxygen (O₂), ozone (O₃), carbon dioxide (CO₂) and water (H₂O).

Detecting molecules

The James Webb Space Telescope (JWST) is a large space telescope which collects light at infrared wavelengths. It has been used to probe the atmospheres of a variety of exoplanets.

The detection of molecular imprints in the atmosphere of an exoplanet is not completely straightforward. Different teams of workers can derive different results as a consequence of making slightly different choices in the way they handle the same data. But despite these difficulties, reproducible and robust detections of molecules have been made. Simple molecules with strong barcodes such as methane, carbon dioxide and water have been detected.

Planets larger than Earth but smaller than Neptune – so called sub-Neptunes – are the most common type of known exoplanet. It was for one of these planets, K2-18b, that a bold claim of a detection of a biosignature was made in 2025. The analysis detected dimethyl sulphide, with a claimed less-than-once-chance-in-1,000 that this detection was spurious.

On Earth, dimethyl sulphide is produced by phytoplankton in the oceans, but is rapidly broken down in seawater illuminated by sunlight. As K2-18b may be a planet completely covered by a water ocean, the detection of dimethyl sulphide in its atmosphere could imply an ongoing supply of it from microbial marine life there.

Re-examination of the K2-18b dimethyl sulphide detection by other researchers casts doubt on this claim. Most significant was the 2025 demonstration by Arizona State University's Luis Welbanks and colleagues that the choice of molecular barcodes to include in the analysis radically affected the results.

They found that numerous alternatives, not explored in the original paper, provided equally good or better fits to the measured data.

For Earth-sized planets which are presumably rocky, it is quite challenging to detect an atmosphere at all with JWST. However, the future is promising, as a number of planned missions will allow us to learn a lot more about planets which may be similar to the Earth.

Upcoming missions

With a planned launch in 2026, the European Space Agency's Plato telescope will identify planets far more similar to Earth and suitable for transmission spectroscopy than those we currently know of.

NASA's Nancy Grace Roman space telescope, which is set to launch in 2029, will pioneer coronagraphic techniques that allow starlight to be cancelled out so the very much dimmer planets orbiting nearby stars can be studied directly.

The European Space Agency's Ariel telescope, with a planned launch in 2029, is a dedicated transmission spectroscopy mission, designed to have the capabilities to determine the compositions of exoplanet atmospheres.

NASA's Habitable Worlds Observatory (HWO) is currently in the planning stages. This mission will use a coronagraph to study around 25 Earth-like planets, looking for a variety of hallmarks of habitability.

HWO will have broad wavelength coverage from the ultraviolet out to the near-infrared. If a twin of the Earth were orbiting one of HWO's nearby target stars, the telescope would collect the starlight reflected from the planet. This reflected starlight would include the barcode signatures of diatomic oxygen (O₂) and other gases characteristic of our planet’s atmosphere. It would also reveal a signature of starlight being absorbed by photosynthesising plants: the so-called "vegetation red edge".

Earth's surface is divided into land and oceans, which reflect light differently. HWO would be able to reconstruct a low-resolution map of the surface from the changes in the reflected light as continents and oceans rotate in and out of view.

So the future looks very promising. With the spacecraft set to launch in coming years, we might close in on the question of whether Earth is unique in hosting life.