If you were approaching the edge of a spiral galaxy, arriving from afar through the cosmos, it might look something like this.

What is it?

In this new snapshot by the Hubble Space Telescope's Advanced Camera for Surveys (ACS), we can see the edge of the spiral galaxy NGC 1827. Found about 37 million light-years from Earth, this galaxy sparkles in this side-on view.

Not all spiral galaxies are the same. This galaxy is what is known as an "intermediate" spiral, which means that its structure sits somewhere between that of a barred and unbarred spiral galaxy. Barred galaxies have a distinctive central, bar-shaped structure, while the unbarred variety lacks this bar and can look more like circular spirals.

NGC 1827's spiral shape isn't clear from the side, however. From this perspective, we see its twinkling edge, speckled with stars and woven together with brown ribbons of dust.

Why is it incredible?

Beneath the beauty of this spiral edge lies an expansive, cosmic landscape. Bright blue stars dot the spiral's side, with one particularly luminous star taking the spotlight with four diffraction spikes — created by light bending through the inner workings of Hubble's camera — emanating from its center.

This image was captured as part of a larger Hubble survey that's exploring 260 satellite galaxies, which are galaxies gravitationally bound to larger hosts. Hubble is specifically looking to survey satellite galaxies that lie near host galaxies similar to our own Milky Way.

So far, Hubble has spotted 111 such satellites and will continue to observe, hunting for the rest.

By studying satellite galaxies like this one, which also happens to be an especially low-mass galaxy, researchers could better understand the complicated dynamics both within the galaxies themselves and between them and their host galaxies.

On Oct. 13, 1773, a French astronomer named Charles Messier discovered the "Whirlpool Galaxy," also known as Messier 51, or M51.

Charles Messier was scanning the sky for objects that could confuse comet hunters when he catalogued the galaxy as M51. However, Messier wasn't able to see the spiral structure, and he didn't identify it as a galaxy.

Seventy-two years later, another astronomer named William Parsons saw the whirlpool shape, but he thought it was a spiral nebula. Eventually, Edwin Hubble found out that M51 and other features like it were actually galaxies.

Why it mattered

The Whirlpool Galaxy is located about 31 million light-years from Earth and just might be the textbook case of a spiral galaxy. But in 1773, it was just one of 51 (at the time of its discovery) of "comet-like 'objects to avoid'" in the night sky.

The Whirlpool Galaxy's designation as M51 marks it as the 51st non-comet object catalogued by Messier, who was the chief astronomer of the Marine Observatory in Paris dedicated to studying comets. According to a NASA account, Messier stumbled across his first non-comet object, M1 (also known as the Crab Nebula), while studying a comet in 1758. The objects looked like fuzzy blobs like comets, but didn't move like a comet. By 1773, at the time he first spotted M51, he had catalogued over four dozen such objects to help prevent astronomers from mistaking them for comets.

The Whirlpool Galaxy appears as a dazzling spiral in images by the Hubble Space Telescope, and has a magnitude of 8.4 on the brightness scale used by astronomers. That means it can be observed through a small telescope ("most easily during May," NASA says) in the constellation Venatici (the Hunting Dogs) in the northern sky, just below the handle of the Big Dipper star pattern.

Scientists suspsect the Whirpool Galaxy gets is striking spiral shape from a close interaction with its neighbor galaxy NGC 5195, which may have passed through M51's main disk about 500 million years ago, scientists with NASA's Spitzer Space Telescope have said.

"This gravitational tug of war may also have triggered an increased level of star formation in M51," they added in a statement. "The companion galaxy's pull would be inducing extra starbirth by compressing gas, jump-starting the process by which stars form."

Want more space history? Check out our full On This Day In Space Story archive and watch our On This Day In Space videos on YouTube.

Astronomers have discovered the most distant Fast Radio Burst (FRB) ever detected. Not only could this help untangle the mystery of what causes these powerful but brief explosions of radio waves, but because FRBs are incredible celestial messengers, it could also reveal details of 11 billion years of cosmic evolution.

This FRB, designated FRB 20240304B, was first observed by astronomers using the MeerKAT radio telescope in South Africa. Then, using the James Webb Space Telescope (JWST), astronomers tracked it back to its home galaxy, located around 11 billion light-years away. This revealed that FRB 20240304B has been travelling to Earth since the universe was just 3 billion years old or so.

That doesn't just make this FRB 20240304B the most distant and earliest FRB ever detected; it more than doubles the distance of the previous record holder!

"This is an extraordinary glimpse into the distant universe," team co-leader Manisha Caleb from the Sydney Institute for Astronomy said in a statement sent to Space.com. "We have caught a fast radio burst from a time when the universe was only about three billion years old, and we have used that brief flash of radio light to learn about the matter it has travelled through over billions of years."

The team's research was published on Thursday (Oct. 8) in the journal Science.

A record breaking cosmic messenger

Fast Radio Bursts are mysterious blasts of radio waves that usually flare just once, and in the mere milliseconds they last, emit many times more energy than the sun can radiate in a year.

As these powerful millisecond-long blasts of radio waves travel billions of light-years to reach Earth, they pass through gas and dust in galaxies and through the "cosmic fog" lying between these galaxies, the so-called intergalactic medium. By measuring how much the signal slows down, scientists can effectively weigh this fog of gas to map the distribution of matter in galaxies.

That makes them crucial tools for understanding how galaxies use gas and dust to form stars and grow. Thus, FRBs are a metaphorical cosmic 'fossil record' blasting through space at light speed with the energy of a multitude of stars.

With that in mind, it is little wonder that as a record-breaking example of a fast radio burst, FRB 20240304B has already shocked astronomers. It did this by delivering a surprise about its home galaxy.

"The galaxy hosting this burst is surprisingly small, metal-poor and undergoing a very active episode of star formation," team member Laura Driessen, of the University of Sydney, said. "That gives us an important clue about the environments in which FRBs are born and shows that these brief radio flashes can tell us not only about the distant universe, but also about how galaxies and their stellar populations evolve."

One of the leading suspects in the creation of FRBs are magnetars, a type of neutron star created when a massive star collapses and dies in a supernova explosion. Unlike "standard" neutron stars, magnetars have fearsomely strong magnetic fields  — the strongest magnetic fields in the known universe, in fact.

There are different theories about how magnetars are born: one involving existing older neutron stars colliding and merging, the other involving environments with burgeoning star formation.

The galaxy from which FRB 20240304B originates seems to support that latter formation route, as it is young in the midst of "starburst," a period of extreme star formation.

Scientists will work on the mystery of the FRB/magnetar connection. In the meantime, this newly detected and tracked blast of radio waves definitely has expanded the boundaries of the cosmos that can be probed with FRBs.

"In principle, sufficiently powerful bursts could be detectable from the very early universe," team member Kavya Shaji said.

That means that FRBs are emerging as a promising way to study the first stars and galaxies in the universe. This is even more exciting considering that this research validates teaming the JWST with radio telescopes to detect and track FRBs back to their points of origin.

"Our results further show the amazing capability of the JWST, where we can push boundaries beyond what was previously possible," team member Themiya Nanayakkara of the University of Sydney said.

What might look like a "photo negative" of this swirling galaxy is actually the same view in another wavelength.

What is it?

As you can see in this dual image, two different observatories looked at the same galaxy and ended up with totally opposite results.

M83, or Messier 83, is a spiral galaxy found 15 million light-years away. A popular target for observation, the galaxy has a picture perfect swirl. But depending on how you look, it can completely transform.

In the galactic view on the left, we can see the galaxy as it looks in submillimeter wavelengths, which is found between far-infrared and microwave wavelengths. This orange and black view, which evokes Halloween vibes, was captured by ALMA (the Atacama Large Millimeter/submillimeter Array) in Chile.

To the left of this spooky view, we can see M83 in visible light. This sparkling purple, pink, blue and gray look comes from observations with the Wide Field Imager at the European Space Observatory's La Silla Observatory, also in Chile.

Why is it incredible?

The universe is not always as it seems. While we might learn remarkable truths about a galaxy by looking at it in visible light, an infrared or submillimeter view could reveal details we never would have seen otherwise.

By exploring the universe with different observatories, different wavelengths and different points of view, we can glean more information than we ever could otherwise. This diversity is essential to our growing understanding of the cosmos.

This is why, when new space telescopes like NASA's Nancy Grace Roman Space Telescope launch, they aren't intended to replace other, older telescopes, but rather add to a collective and varied power.

With these two views of M83, we can see the incredible structures of gas and dust that make up the galaxy's signature spiral in visible light, but we can also see the cold molecular gas only visible in submillimeter wavelengths.

MEGATRON is a good guy!?! Well, at least to cosmologists who are using this simulation to transform (sorry, couldn't resist) our understanding of the universe's first stars. Of course, in this case Megatron isn't the diabolical leader of the Decepticons who killed Optimus Prime in the Transformers franchise, but the most detailed simulation to date of the early universe.

Beginning in 2023 and set to run until 2030, MEGATRON uses James Webb Space Telescope (JWST) data to combine cutting-edge cosmological simulations with sophisticated models of radiation, chemistry, and galaxy formation. This allows researchers to investigate how the first galaxies and the first stars, known as Population III (POP III) stars, lit the shadows of the cosmic dark ages.

This is an important quest; POP III stars were primarily composed of hydrogen and helium, the lightest elements, and all that was available in the universe's infancy. However, during their lives, POP III stars forged heavier elements, which astronomers call metals. Upon their supernova deaths, POP III stars distributed elements like nitrogen, carbon, and oxygen to become the building blocks of the next generation of stars, their planets, and eventually life itself, be it here on Earth or anywhere else it exists in the cosmos.

"The elements that make our world and life possible – carbon, oxygen, iron and many others – were forged by stars. To understand where those elements came from, we need to understand how the first stars formed and enriched their surroundings," Martin Rey from the Department of Physics at the University of Bath said in a statement. "MEGATRON allows us to test these ideas directly by comparing detailed simulations with observations from JWST and the chemical fingerprints preserved in ancient stars."

This new research represents the first major finding from MEGATRON. So what did it find?

MEGATRON saves the day!?!

The first MEGATRON results demonstrate the importance of the interplay between starlight, gas, and newly forged elements in connecting astronomical data of galaxies in the early universe provided by the JWST and chemical fingerprints found within ancient stars in our galaxy, the Milky Way.

"The JWST gives us a direct glimpse of the infant cosmos, while stellar archaeology allows us to study the relics of those earliest times in our own galactic neighborhood," Rey explained. "MEGATRON provides a physical bridge between the two."

This unification could reconstruct the properties of POP III stars, in turn revealing how they enriched their surroundings with metals.

MEGATRON did this by simulating the evolution of a young galaxy that had the potential to grow into a system similar in mass to the Milky Way, beginning with pristine unspoiled hydrogen and helium gas. The simulation tracked the motion of gas, the passage of starlight, and the change in chemical concentrations, thus revealing how stars shape the gas in and around galaxies over billions of years.

The findings imply that some cosmological models may underestimate just how important the radiation emitted by stars and the chemical changes in gas around galaxies are to cosmic evolution.

With high-resolution reconstructions of these factors, MEGATRON recreated structures in the gas that fail to manifest in simpler models. This could improve predictions for current and future astronomical observations.

The team will now continue to use MEGATRON to forge even stronger links between astronomical observations and theory. This will become even more vital as the JWST continues to transform our understanding of the earliest galaxies and as large-scale astronomical surveys provide increasingly detailed information about ancient stars in our cosmic backyard.

"MEGATRON provides a common physical framework for interpreting two of astronomy's most exciting new datasets: JWST's view of the earliest galaxies and the stellar fossil record," Rey concluded. "Together, these complementary observations allow us to test competing models of the first stars in ways that weren't previously possible."

The team's research was published across four papers in the Open Journal of Astrophysics, with more to come.

Scientists have discovered how jets launched by supermassive black holes can determine how their host galaxies "die." The research answers the long-standing question of why galaxies don't have more stars.

After all, large galaxies, including the Milky Way, are surrounded by huge cocoons of gas and dust called the circumgalactic medium, and that material serves as the raw building blocks for stars. During intense star-forming phases, this gas moves into galaxies and fuels this process, but eventually something stops this material from cooling, clumping, and birthing stars, or from moving into galaxies at all, effectively "killing" them.

This research suggests that when feeding supermassive black holes blast jets of plasma from around them, this reaches far beyond the center of galaxies where these cosmic titans reside and beyond their outer limits, thus disrupting the gas around galaxies. This has a major effect on how galaxies form stars and thus how they grow and evolve.

"This is a pathbreaking result that solves the long-standing mystery of how black holes influence galaxies, their stars, and life as we know it," team co-leader Sanchayeeta Borthakur of Arizona State University said in a statement. "This work opens a new direction to explore further the intricacies of the connection between the supermassive black holes trillions of miles from where we are to how we came to be here."

Black holes maybe small (relatively) but they pack a punch

Ok, supermassive black holes can't exactly be called "small," packing a mass millions or billions of times that of the sun into a width about that of the solar system. But compared to galaxies, which can host 100 billion similarly sized star systems, even these cosmic titans are relatively small in stature.

Even though feeding black holes can pour vast amounts of energy back into their cosmic environments via jets and radiation, the effect they have is still somewhat perplexing.

"The surprising question is: How can something so small energetically impact something so enormous?", team co-leader Namrata Roy of the Raman Research Institute said.

Roy and Borthakur focused their investigation on feeding or active black holes, using observations of hundreds of galaxies with active jets, collected by the Dark Energy Spectroscopic Instrument (DESI) survey and radio jet measurements from the LOFAR Two-meter Sky Survey (LoTSS). They found points at which ionized gas glows brightly along their jets. This represents the plasma hitting and passing through clumps of surrounding gas, energizing it.

This indicates that black hole jets don't influence gas around galaxies in a uniform manner, but at preferred points. The greatest impact was seen close to the outer edges of galaxies, where plasma jets first hit the circumgalactic medium, and at the outer edge of the circumgalactic medium itself. That latter region is where the jets release the most energy.

The team's findings reveal clear fingerprints of the impact black hole jets have in disrupting potential star-forming material even right out to the circumgalactic medium. That's key in understanding how star formation is cut off and how galaxies are killed.

"What excites me most is the scale of the connection," Roy said. "A black hole is incredibly small compared to a galaxy, but its impact can reach hundreds of thousands of light-years, far into the galaxy’s outer reaches. The jet carries the energy outward, and the gas lights up along its path."

The findings also offer a new way for scientists to test the impact of black hole jets on galaxies.

The team's research was published in the Astrophysical Journal Letters.

Most people never forget their first home, carrying their memories with them as they travel. New research suggests that this adage may be true for wandering black holes too. That's because it seems that rogue black holes that break away from their cosmic homes may carry with them the histories of the galaxies they may eventually escape.

These rogue black holes can be displaced when their home galaxies collide and merge. This begins journeys of billions of years that carry these black holes far from the point at which they formed. This process can be even more pronounced in smaller galaxies in which the gravitational influence is weaker, and the black holes are less likely to be strongly bound to the galactic center.

Scientists have known that the activity of supermassive black holes at the heart of galaxies strongly influences the evolution of their host galaxies, but these findings indicate that though rogue black holes may be less influential, they may be important witnesses to the processes that shape galaxies.

"Our results show that considering wandering black holes, in addition to centered black holes, is essential for understanding the origins and dynamics of massive black holes and the histories of their host galaxies," team leader Emma Jane Weller of Yale University said in a statement.

Evidence of 'heavy seeds' in the early universe

There is currently some debate regarding how black holes first started growing in the infant cosmos. Some scientists suggest that the first massive stars died and collapsed to create smaller black holes or "light seeds." Others theorize that black hole growth gets a head start when dense patches in vast clouds of gas and dust directly collapse to create much more massive black holes, or so-called "heavy seeds."

If wandering black holes carry with them a record of their birth, then they could help settle the light seed vs. heavy seed debate.

"What is exciting about our findings is that black holes seem to remember more than the circumstances of their birth," team member Priyamvada Natarajan of Yale said. "Their present-day locations carry the imprint of everything that has happened to their host galaxies. By separating black holes at galactic centers from those that are wandering, we can begin to disentangle these two histories."

To do this, the team turned to a cosmological simulation called ASTRID, which is capable of tracing roughly 13.5 billion years of cosmic history, modeling the interplay between dark matter scaffolding, gas dynamics, and star formation right back to just 300 million years after the Big Bang.

Using ASTRID, the team modelled galaxies with masses between 10 million and 1 billion times that of the sun tracking their evolution over around 12.6 billion years. ASTRID has a strength that was important to this particular investigation. It doesn't pin black holes down to the heart of their galaxies; instead, it allows them the leeway to roam.

The team confirmed that black holes were more likely to wander in low-mass galaxies, also finding that such galaxies seem to retain information about their initial seed population even after billions of years of growth and collisions and mergers with other galaxies. They also found that low-mass galaxies with a central black hole stopped forming stars before those with wandering black holes.

"Some of the universe's most revealing black holes may be the ones that have wandered away. Black holes are remarkable cosmic archivists," Natarajan said. "Their abundance tells us something about how they were born, while their locations preserve a record of how their galaxies were assembled."

By teaming this approach with X-ray, radio, optical, and infrared astronomical observations, scientists could get closer than ever before to understanding the origins of black holes.

"Each of these methods can probe different parts of the population," Weller concluded. "By combining observations with the results from simulations, we may be able to identify the imprints of black hole formation and galaxy evolution."

The team's research was published on Sept. 7 in The Astrophysical Journal Letters.

Using the James Webb Space Telescope, astronomers have discovered that just 500 million years after the Big Bang, galaxies were already pumping heavy elements into their surroundings. That means the early universe wasn't as pure and unspoiled as previously believed, potentially impacting our theories of cosmic evolution.

Soon after the universe began, it was filled with the lightest element, hydrogen, and a little helium. As such, the first stars formed from these elements — but as these stars aged, they forged heavier elements, which astronomers collectively call "metals." These metals were dispersed when these first, or POP III, stars exploded at the end of their lives. This meant the next generations of stars, POP II and POP I, stars were progressively more metal-enriched.

This we all knew, but new James Webb Space Telescope (JWST) research suggests the process occurred earlier than previously thought. What this means is the gas surrounding galaxies was richer in metals like oxygen and carbon when the universe was just 3% of its current age.

"If you start out with pure vanilla ice cream but start mixing in sprinkles soon after, it won't be long until you can no longer find any pristine, plain, vanilla ice cream," team leader Yongda Zhu of the University of Arizona said in a statement. "We observed that heavy elements escaped from galaxies very, very early in cosmic time.

"Not only were the galaxies producing these elements, but they were also dispersing them, possibly seeding other galaxies."

Back to the beginning

To better understand the composition of the early cosmos, Zhu and colleagues used the JWST data to observe three galaxies that are seen as they were around 13.3 billion years ago. This corresponds with an important point in the evolution of the universe called the Epoch of Reionization.

At this time, the light from the first stars was stripping electrons from the hydrogen gas between them, a process called ionization. This allowed light to travel more easily through the cosmos, ending the so-called cosmic dark ages.

"We used the galaxies themselves as background light sources," said Zhu. "As light from the galaxies traveled toward Earth, it passed through surrounding gas, and we were able to look at the light's absorption patterns to detect specific elements."

That's possible because elements absorb and emit light at characteristic wavelengths, meaning when starlight passes through interstellar clouds, the elements within those clouds leave distinct fingerprints in that light.

The observations revealed gas containing oxygen, carbon, silicon and other metals flowing from these early galaxies into intergalactic space.

The chemical fingerprints of this gas more closely resembled those of modern galaxies than was expected. That means early galaxies were already pumping metals into the cosmos.

"Think of these elements, which originated from the galaxies' stars, as food dye dropped into a cup of water," said Zhu. "The color begins to spread through the water, and, in a similar fashion, these heavy elements from early galaxies began to escape into space and 'enrich' their surroundings."

The discovery could explain why astronomers have thus far struggled to find POP III stars. They have been looking for signs of starlight illuminating pristine hydrogen gas, but this gas was gone much earlier than they knew.

The team's research was published on Thursday (Sept. 24) in the journal Nature Astronomy.

Astronomers have studied nine local galaxies to discover how shock waves from the galaxies' central supermassive black holes sculpt star formation.

The team of researchers studied galaxies with active galactic nuclei (AGNs) at their hearts. These are bright and turbulent regions powered by central engine supermassive black holes with masses of millions or even billions of times that of the sun that are feeding on copious amounts of gas and dust. As energy flows out of these regions and strikes surrounding gas clouds, called the interstellar medium, it generates powerful and fast-moving "shocks."

These shocks are also known as "AGN feedback," and they pump vast amounts of energy into their surroundings, shunting around gas and dust that is the raw material for star formation. While this feedback has often been attributed with ending star formation in galaxies, scientists have long suspected that this process can also drive star formation and therefore the growth and evolution of galaxies. This new research maps out how that happens.

"We're seeing that black holes are not just consuming material at the centers of galaxies, but they're actively reshaping their surroundings," team member Lisa Kewley of the Center for Astrophysics | Harvard & Smithsonian said in a statement. "This work helps us understand a complex feedback cycle that plays an important role in galaxy evolution."

Supermassive black holes as stellar sculptors

All large galaxies are thought to have supermassive black holes residing at their cores. But not all of these black holes are active. For instance, Sagittarius A* (Sgr A*), at the heart of the Milky Way, is relatively dormant. Its feeding habits are the equivalent of a human being eating one grain of rice every million years.

Other supermassive black holes are surrounded by large amounts of gas and dust and swirling flattened clouds called "accretion disks" that feed them. The immense gravitational influence of these black holes generates incredible amounts of friction in the accretion disk, causing the objects to glow brightly as AGNs.

These AGN emissions are bolstered by the fact that supermassive black holes are notoriously messy eaters, channeling matter they don't eat toward their poles. From there, this matter is blasted out as powerful "burps" consisting of twin jets of plasma that can stretch out for thousands of light-years. This means supermassive black holes and AGNs have a considerable influence on their surroundings.

The team used the Very Large Telescope (VLT) and its Multi Unit Spectroscopic Explorer (MUSE) to study AGNs in which supermassive black holes are actively accreting matter.

"Once we resolved them, we could see that they not only accrete things, but they also eject things," Peixin Zhu of the Center for Astrophysics said in the statement. "The injection and accretion are linked with each other."

The team performed a 3-dimensional analysis to identify three different aspects of AGNs and their surroundings: the radiation flowing from the AGN, the excitation of the surrounding interstellar medium by shocks, and star formation.

They found that arcs and rings of star formation tended to appear at distances between 2,600 and 20,000 light-years from the centers of galaxies. The researchers also observed cones of radiation extending out from the accretion disks of AGNs, where fast shocks both rippled through central regions and traveled perpendicular to the radiation cones.

This shock behavior is consistent with models of interactions between AGN jets and the interstellar medium. The team thinks that in galaxies with less powerful jets, black hole winds also contribute to shock generation.

"The most interesting phenomenon about shocks is that they always go perpendicular to where the black hole's injected outflows go," Peixin said. "It is very common, and we see it consistently appearing across the whole nine galaxies."

The research demonstrates that actively feeding black holes are engaged in a complex cycle of accretion and outflow that drives their interaction with their host galaxies.

By separating the different aspects of this process, the scientists behind these findings have provided a clearer picture than ever before of this cycle and how it influences star formation.

The team's research was published on Monday (Sept. 14) in The Astrophysical Journal.

Dwarf galaxies: Are there not enough or are there too many? The new discovery of 50 "ghost" galaxies located up to 100 million light-years away from us may solve this puzzle.

For decades, astronomers studying the surroundings of the Milky Way have determined there are too few dwarf satellite galaxies orbiting our own galaxy when compared to predictions made by the standard model of cosmology. This problem of "missing satellite galaxies" became even more complicated recently when studies of the local universe revealed some galaxies may be surrounded by too many galactic satellites. In addition to this, scientists are also still puzzled about how dwarf galaxies are distributed around the larger galaxies they orbit.

To answer these questions, a team of astronomers searched further afield, looking for faint satellite galaxies around three galaxies. The first was NGC 5068, a spiral galaxy located 17 million light-years away, the second was NGC 5084, a lenticular galaxy 80 million light-years away, and the last was NGC 5087, an elliptical galaxy 100 million light-years away. The researchers discovered almost 50 faint dwarf galaxies orbiting these distant galaxies.

"Studying these islands of nearly invisible stars is not just astronomical stamp collecting," team leader Crescenzo Tortora, a researcher at the Italian National Institute for Astrophysics (INAF), said in a statement. "It is the only way we have to solve some of the major puzzles of the cosmological model and finally understand how mysterious dark matter shapes and molds the entire universe."

Smashing new dwarf galaxies

The team obtained the deepest images to date of the three galaxies' surroundings using the Very Large Telescope (VLT) as part of its VST (VLT Survey Telescope) SMASH survey. Rather than use an algorithm to identify possible dwarf galaxies, Tortora, also the VST SMASH survey principal investigator, and his colleagues conducted a meticulous visual inspection of VLT images to ensure no potential dwarf galaxies were missed.

This involved masking light from foreground stars and other astronomical bodies to allow the faint ghostly galaxies to shine through. This led to the observation of 47 dwarf galaxies, of which only four had previously been discovered.

The team then identified the nature of the candidate dwarf galaxies by comparing their colors and structures to observations of other dwarf galaxies. The ghost galaxies took various shapes — there were dwarf spheroidals, dwarf ellipticals and dwarf irregulars. Some demonstrated internal structures that suggested they're dwarf spirals. And all of these candidate dwarf galaxies were found to have a mass between one million and one billion times the mass of the sun.

"Thanks to the deep VST observations, we were able not only to 'see' some extremely faint galaxies better, but also to characterize their light profiles with a high signal-to-noise ratio. By gathering more light, we better mapped their outer regions," team member and INAF researcher Rossella Ragusa said.

"An example of this is the comparison we conducted with one of the dwarf galaxies in the sample — which had previously been discovered using less-deep data — whereby we determined its dimensions and the shape of its light profile, particularly in the galaxy's outermost, fainter regions, with greater precision and accuracy," Ragusa added.

Confirming the newly observed objects are definitely dwarf galaxies will require further observations. Thankfully, however, the region studied in the VST-SMASH survey falls within the field of view of the Euclid space telescope. Euclid's first images have already led to the discovery of a wealth of dwarf galaxies, with more likely to come in future data releases.

"We look forward to studying these same fields with Euclid's eyes, so we can confirm or update our findings," Tortora said.

The team's research was published on Friday (Sept. 11) in the journal Astronomy & Astrophysics.

NASA's Chandra X-ray Observatory has found a brand new type of an otherwise familiar object – compact binary systems that steal gas from other stars, but which do so while emitting very low-energy X-rays but copious amounts of ultraviolet.

Chandra spotted 84 suspicious object emitting very low-energy X-rays in six galaxies – four evolved ellipticals and two spirals, namely our near-neighbor the Andromeda Galaxy (M31) and the Pinwheel Galaxy (M101).

"We've never encountered a group of objects that act like this," said Mustafa Muhibullah of the University of Alabama in a statement.

Compact objects, in the form of black holes, neutron stars and white dwarfs, are the remains of stars that have died. Their small size and powerful gravity means that they're adept at getting close to orbiting companion stars and ripping the stars' outer layers of gas away. The gas swirls around the compact object, falling onto its surface, and this accretionary process usually produces torrents of high-energy X-rays because the stolen gas becomes superheated by the compact object's gravitational vice-like grip.

Because of their weak X-rays, Muhibullah's team refer to them as 'hypersoft X-ray sources'. Since low-energy X-rays and ultraviolet light are next to each other on the electromagnetic spectrum, Muhibullah and his team suspect that the low-energy X-rays are spillover from objects emitting prodigious amounts of ultraviolet. Moreover, they think that these objects are lower-level compact binaries.

They're hard to find though, because the interstellar medium of hydrogen and helium gas between the stars absorbs ultraviolet light. This could be why we have yet to find any hypersoft X-ray sources in our own galaxy, because we have to look through the interstellar medium through the plane of the Milky Way.

Consequently, there could be a large population of hypersoft X-ray sources that remain undiscovered and they could have an important effect on the universe around them.

"These clandestine X-ray sources are actually among the most energetic objects in galaxies, and they could be solving two cosmic mysteries at once," said Muhibullah.

The interstellar medium is filled with ionized gas where atoms have been shorn of electrons. Hot, massive stars do output a lot of high-energy ultraviolet light, but there are not enough of these stars to account for all the ionization. If hypersoft X-ray sources are dumping torrents of ultraviolet into space, they could explain the ionization instead. For stars to form, gas has to be cold and not ionized, so hypersoft X-ray sources could be gently regulating star formation within galaxies.

The second mystery is the puzzle over how exactly type Ia supernova explosions detonate. We know that they are fueled by white dwarfs accreting matter from a close companion star and, once the accumulated matter raises the white dwarf's mass beyond 1.44 times the mass of our sun – known as the Chandrasekhar limit – it explodes, but the details of what on the white dwarf actually ignites and how are fuzzy.

Studying a new breed of compact binary might finally reveal the answers and offer more clues about when white dwarfs become ready to explode.

"If we could find a way to spot these type Ia supernova explosions before they go off, that would be really important," said Jimmy Irwin of the University of Alabama, who is a member of Muhibullah's team. "Right now, we study them after they've exploded and astronomers have struggled to understand what is actually ignited."

Since type Ia supernova explosions are used as markers on the cosmic distance ladder, used for measuring the strength of dark energy and the expansion of the Universe, the benefits from understanding them better are clear to see in our efforts to understand how the Universe is evolving.

The findings were published on Sept. 9 in Nature Astronomy.

It is nearly impossible to fathom the entirety of a single galaxy — these realms can span hundreds of thousands of light-years, and sometimes are even millions of light-years across. So imagine the grandeur of now one but two galaxies tangled together, in the process of merging into one. That's what you're seeing in today's featured image.

What is it?

The merging galaxies shown above were discovered by a group of students using the Gemini North Telescope, located on the Maunakea volcano in Hawaii — a very popular and often controversial location for ground-based telescopes. The students hailed from two local institutions, Waiākea High School and the Volcano School of Arts and Sciences, and had access to the telescope with the Project Hōkūlani internship.

They named their discovery Nā 'Uhane Māhoe Huki Pū i ke Ola, which translates to "The Twin Spirits Pulling Together Creating Life."

"'Uhane (spirit) was an important theme for our group. Our experiences throughout the week — 'oli (stargazing), visiting the summit and learning about the awesome scientific discoveries made possible by Maunakea — ignited our own spirits as we prepare for life after high school," Samantha Silva-Sampaio, one of the students, said in a statement.

The students also explain how the rest of the name fits in with their time at Gemini North. "Huki Pū," they say, has to do with the physical aspect of the two galaxies being pulled together, just like communities coming together to enable the discovery as a whole. And "i ke Ola" is meant to show that life can be created from interacting galaxies because this process gives rise to star birth, and hopefully we'll find a star besides the sun one day that hosts life on a world around it.

Why is it incredible?

The galaxy merger depicted in the image is formally known as NGC 7253 and is located around 200 million light-years from Earth in the constellation Pegasus. This region is also known as the Hawaiian constellation Ka Lupe o Kawelo.

What's especially spectacular about the image we see above is how sharply defined both galaxies appear during their gravitational interaction. It is also a treat to be able to live in a time when we can view an event happening so utterly far away with this much detail.

Galaxy mergers aren't a new thing, though. They occur all across the universe, and indeed even the Milky Way and our neighboring galaxy Andromeda are expected to collide (or maybe not?) at some point in the future. But not to fear — though it may not seem it from this image, within every galaxy is, well, a lot of space. So much so that it'd be surprising for anything in the colliding galaxies to actually smash together.

What does happen, however, is enchanting. All the interstellar gas and dust from both galaxies join together and lead to a spike in star formation. This means a ton of beautiful sparkles should decorate the final product of NGC 7253.

"'Uhane in this image reminds us that astronomy is not just science or spirit; it's both at the same time," Manu Silva-Sampaio, another one of the student discoverers, said in the statement.

Astronomers have used the MeerKAT radio telescope to detect hydrogen gas billions of light-years away from us — from a period when the cosmos was billions of years younger than its current age of 13.8 billion years.

The research may provide astronomers with a new way of mapping the large-scale structure of the universe. The technique would rely on charting out where hydrogen, the universe's lightest and most abundant element, is located across the cosmos. It's known as hydrogen intensity mapping.

Neutral hydrogen emits a faint radio signal that astronomers call the 21-centimeter line. As the cosmos expands under the influence of dark energy, the wavelength of this radio signal is stretched, or "redshifted." The extremity of the redshift allows astronomers to determine how long a particular signal has been travelling to us and thus what period of the universe the hydrogen that emitted it existed in.

Using the 21-centimeter line, hydrogen intensity mapping allows astronomers to trace radio emissions from hitherto unseen galaxies and build a 3D picture of the largest structures in the universe. Up until this point, however, this technique has relied on combining radio wave detection with observations from galactic surveys operating with visible light, or electromagnetic radiation our eyes have evolved to see.

This new research defies that trend, building a hydrogen intensity map using radio waves detected by the MeerKAT radio telescope, made up of 64 antennas in the Meerkat National Park in the Northern Cape of South Africa.

"This is a very exciting milestone," team leader Sourabh Paul said in a statement. "Hydrogen intensity mapping has long been seen as a promising way to map the universe efficiently, but the signal is extremely faint and difficult to isolate from foreground emission, human-made radio-frequency interference, and instrumental effects.

"Detecting it directly with MeerKAT shows that this technique is becoming a practical tool for cosmology."

Mapping with MeerKAT

The team behind this research analyzed around 96 hours of MeerKAT observations, finding signals from hydrogen dating back 4 billion to 5 billion years. This hydrogen spans distances of many million light-years, similar to the distance between the Milky Way and our neighbor galaxy, Andromeda.

The achievement represents a step forward in the usefulness of hydrogen mapping.

"Neutral hydrogen is one of the key ingredients for understanding how galaxies form and evolve," team member Zhaoting Chen of the University of Edinburgh said in the statement. "With intensity mapping, we do not need to detect every individual galaxy. Instead, we can measure the collective signal from hydrogen across large cosmic volumes, giving us a new way to study both galaxy evolution and the underlying matter distribution of the universe."

Future cosmological surveys could greatly benefit from the advancement of hydrogen mapping. This will be a major factor when the Square Kilometre Array Observatory (SKAO), currently under construction in the Murchison region of Western Australia and the Karoo region of South Africa.

"MeerKAT continues to open new windows for cosmology," team member Laura Wolz of the University of Manchester in the U.K. said in the statement. "The fact that this signal can be extracted from observations that were not originally designed for hydrogen intensity mapping is very encouraging. It shows the enormous scientific value of MeerKAT data and points the way to future observations with SKAO."

The team will now focus on collecting further observations with MeerKAT that cover larger areas of the sky over longer periods of time. This should provide astronomers with even more detailed hydrogen maps that could, in time, help understand how the largest structures in the cosmos took shape over the course of billions of years.

"This was a challenging data analysis process, requiring a detailed understanding of the many sources of contamination that can affect such a faint measurement," team member Mario G. Santos of the University of the Western Cape, Australia, said in the statement. "It is particularly remarkable that the data used in this study were taken in 2018, when MeerKAT had only just started science operations.

"There is now a rich trove of MeerKAT data waiting to be explored with this method."

The team's research was published in the July edition of The Astrophysical Journal Letters.

Scientists are closer than ever before to confirming that a galaxy known as "Cloud 9" is the first "starless" or "failed" galaxy ever discovered by humanity.

A starless galaxy is one with virtually no stars despite possessing a wealth of gas and dust that would normally serve as the building blocks of stars. The dominant element of a starless galaxy would be dark matter, the mysterious "stuff" that remains effectively invisible because it doesn't interact with light.

Located 14 million light-years away near the spiral galaxy Messier 94 (M94), Cloud 9 is currently the best candidate for a starless galaxy humanity has discovered to date. It contains a vast cloud of hydrogen gas with an estimated mass of 1 million times that of the sun, and dark matter with around 5 million solar masses. Yet, the Hubble Space Telescope discovered in January this year that Cloud 9 emits virtually no starlight.

"But the most striking aspect of our research was the absolute emptiness of the image at the location of Cloud 9. When you look at an image reaching those depths and see nothing where a structure containing a million solar masses of gas should be, it is genuinely remarkable," team leader Ignacio Trujillo of the Instituto de Astrofísica de Canarias, Spain, told Space.com.

"Most objects in the universe leave some trace of light. Cloud 9 does not. That silence is, in its own way, the most compelling result we could have obtained."

On the hunt for a failed galaxy

Trujillo explained that despite having enough raw material to build a small galaxy, Cloud 9 seems to have never formed any significant stellar population.

"That combination — gas but no stars, sitting in a relatively normal environment — makes it one of the most compelling candidates for what theorists call a 'dark' or starless galaxy," Trujillo added. "The concept has been theoretically predicted for decades, but observationally confirmed cases remain elusive.

"The difficulty is obvious: if there are no stars, there is no visible light to detect, and the only way to find such objects is through their gas emission — typically neutral hydrogen observed at radio wavelengths — combined with extremely deep optical imaging to rule out the presence of even a faint stellar component."

Trujillo and colleagues set about investigating Cloud 9 using the HiPERCAM camera on the Gran Telescopio Canarias, the world's largest optical telescope. This led to them obtaining the deepest images ever taken of the Cloud 9 region, approximately ten times deeper than any previous optical imaging of this object. "Honestly, the depth we achieved with HiPERCAM in just 2.36 hours of integration was striking," Trujillo said. What they saw left no questions about the nature of this galaxy.

"The result was clear: we detected absolutely no stellar emission within the region corresponding to the location of Cloud 9," Trujillo said. "Assuming an old, metal-poor stellar population — which would be the hardest kind to detect — we can set an upper limit on the total stellar mass of just 16,000 solar masses.

"Cloud-9 appears to be, within the limits of our observations, genuinely starless."

Why do some galaxies 'fail?'

Though starless galaxies are on the verge of escaping the realms of the purely theoretical thanks to this investigation of Cloud 9, how they form is still something of a puzzle.

However, scientists do have a pretty solid idea of how a galaxy could take shape without birthing stars.

"The leading theoretical explanation involves the ultraviolet background radiation that permeates the universe," Trujillo said. "After the epoch of reionization, this radiation field heats the gas in low-mass dark matter halos to temperatures high enough that the gas cannot cool efficiently and collapse to form stars."

The researcher added that simulations of this period of the cosmos predict that dark matter halos below a certain mass threshold, around 5 billion solar masses, should remain essentially starless.

"Cloud 9 has a halo mass consistent with this regime. In this picture, starless galaxies are not exotic anomalies but a natural and abundant prediction of standard cosmological models," Trujillo explained. "The challenge has simply been finding them."

As impressive as these results are, the jury is still out on Cloud 9 as a starless galaxy. Further investigation will be needed before scientists can firmly declare they have discovered the first starless galaxy.

"On the stellar side, deeper space-based imaging would be particularly valuable because resolving individual stars avoids many of the problems associated with diffuse-light measurements," Trujillo concluded.

"Hubble has already provided extremely strong evidence, and future facilities such as the James Webb Space Telescope (JWST) could potentially push the search further, although the optimal filters and stellar tracers would need to be carefully chosen."

The team's research is available on the paper repository site arXiv.

A trio of NASA space telescopes teamed up to capture a gorgeous new look at the glowing spiral galaxy NGC 4258 and its two anomalous extra arms.

What is it?

This image shows NGC 4258, also known as Messier 106, a spiral galaxy located some 24 million light-years away in the constellation Canes Venatici, the "Hunting Dogs." It is a fairly bright galaxy and can be viewed in the spring sky in the Northern Hemisphere with most telescopes.

Messier 106 is noteworthy for having two "anomalous" extra arms, the long curved regions of bright gases, dust and young stars that are characteristic of all spiral galaxies. But while most spiral galaxies have only a pair of arms, Messier 106 has two pairs. According to NASA, the extra set is composed of hot gases that are churned away from the galactic center by the supermassive black hole at the heart of NGC 4258.

Why is it incredible?

This image shows off the incredible teamwork that NASA's flagship orbital observatories can pull off. It combines X-ray observations from NASA's Chandra X-ray observatory (seen here in royal blue), optical light gathered by the Hubble Space Telescope (red, yellow and pale blue), and infrared light seen by the James Webb Space Telescope (bright orange).

By combining multiple types of light into one image, NASA is able to reveal the complete picture of what this energetic galaxy is made of.

The image also shows the incredible power of the black holes found at the centers of galaxies. "M106 helps show how supermassive black holes can create structural features that mimic star-bearing spiral arms, influencing a galaxy's evolution," NASA wrote in a statement accompanying the image.

This image was part of a NASA release of 16 new "galactic gems" captured by Chandra and other observatories.

The Milky Way has something of a torrid and violent history, given that our galaxy has fueled its own growth by cannibalistically devouring smaller galaxies. Now, astronomers have discovered evidence of our galaxy's earliest bout of cannibalism in the form of "scarring" at the heart of the Milky Way left behind by a galactic morsel it devoured around 12 billion years ago.

Working as part of the ARMA (Cluster Ages to Reconstruct the Milky Way Assembly) project, the team behind this discovery used dense conglomerations of ancient stars called globular clusters to find traces of a merger that occurred around 1.8 billion years earlier than the previously earliest known event of this type.

Prior to this, the history of the Milky Way colliding and merging with both smaller and larger galaxies had only been reconstructed up to around 10 billion years ago, around 3.8 billion years after the Big Bang. The earliest bout of cosmic cannibalism involved the collision with and consumption of the dwarf galaxy Gaia-Enceladus about 10 billion years ago. That means the earliest history of the Milky Way was, until now, shrouded in mystery.

"This work tells us what happened to the Milky Way in its infancy," team member Chiara Zerbinati of the Department of Physics and Astronomy at the University of Bologna, Italy, said in a statement. "It sheds light on a particularly significant event that influenced the entire subsequent evolution of the galaxy. If one of humanity's great questions is 'where do we come from?', we offer at least a piece of the answer."

A helping hand from Hubble

The key development in the quest to delve further back into the history of the Milky Way was delivered by the Hubble Space Telescope.

"We started with the ambition of reconstructing the assembly history of the Milky Way, that is, all the galactic merger events that led to its current appearance," team leader Davide Massari of the Italian Institute for Astrophysics (INAF) said. "We used globular clusters as tracers: especially in the inner regions of the galaxy, where extinction is highest, they are the only objects for which we can obtain excellent measurements of both orbital motion and age."

Astronomers developed a technique using Hubble data that allowed them to discover the ages of globular clusters with a far greater precision than had ever been possible before. This revealed that the globular clusters at the heart of our galaxy can be categorized in three distinct ways based upon their age and their metallicity, a measure of elements heavier than hydrogen and helium, which astronomers refer to as metals.

One group of globular clusters could be linked directly to the Gaia-Enceladus merger; one belonged to the original Milky Way; but there also existed a third group distinct enough from the other two groups that it must have come from some hitherto undiscovered merger event.

The team was able to deduce some things about this doomed galaxy from this third group of globular clusters. They found the unfortunate galaxy had around the same mass as Gaia-Enceladus, about 500 million times the mass of the sun. For comparison, the Milky Way today has a mass of around 1.5 trillion solar masses.

The researchers also found that most of the matter from this devoured dwarf galaxy was dumped into the Milky Way within 20,000 light-years of our galaxy's heart. They also gave a name to this violent, yet formative cosmic event.

"The final name, Low-energy-Kraken-Heracles (LKH), is an acronym that pays homage to the three papers that first hypothesized the existence of this ancient galactic encounter," Massari concluded.

The team's research was published on Monday, August 17, in the journal Nature Astronomy.

Imagine looking at a vast city on Earth from a great distance, knowing nothing about that city; you may assume that its only buildings are the largest, most visible skyscrapers. But, get closer or look with a far more powerful tool, and you would begin to discover smaller buildings between mountainous skyscrapers.

Now, the James Webb Space Telescope has discovered that this looks like that is a fitting analogy for early galaxies.

Astronomers are finding that in between the brightest stars, the 'tallest skyscrapers' in the above analogy, there are much fainter stars analogous to smaller buildings. That means early galaxies may actually have a lot more mass packed into them than we believed.

The team behind this research reached this conclusion by using the James Webb Space Telescope (JWST) to study nine early galaxies that have passed through their period of intense star formation. They combined this data with observations from the Very Large Telescope (VLT) here on Earth to measure the population of small and faint stars in these galaxies for the first time. What they found was that the proportion of small stars in these galaxies is much greater than is found in modern galaxies like the Milky Way. This comes as something of a surprise to scientists who have assumed these populations would be similar.

"This means that the galaxy as a whole is much more massive than previous estimates suggested," team member Chloe Cheng of Leiden University, Netherlands, said in a statement.

The first 'cosmic cities' weren't dominated by skyscrapers, it just looks that way

Astronomers study galaxies and calculate their stellar population rates using the total light, or spectrum, coming from these cosmic metropolises. The problem is, the more massive a star is, the brighter it is. Thus, the overall spectrum of a galaxy is dominated by the most massive stars, while smaller stars are drowned out.

The sensitivity of the JWST has allowed astronomers to finally give these smaller stars a chance to shine and stand out, like spotting an incredible piece of architecture in a vast metropolis of glass and steel.

"Until recently, this type of measurement was simply not possible," team member Martje Slob of Leiden University said. "We needed not only a telescope that collects sufficient light, but also spectra of exceptional quality and new analysis techniques to reliably distinguish the subtle features of small stars."

The team's discovery has implications for our understanding of young galaxies in the early universe. This is because scientists had always assumed the stars of different masses were born in the same proportion across cosmic history. Now that seemingly isn't the case.

That is especially true if more early galaxies are like one particularly striking example examined in this study. This galaxy, which formed less than 1.5 billion years after the Big Bang, contains up to four times the mass previously estimated thanks to its huge population of smaller stars.

Thus, our models of galaxy formation may need some serious revision in the near future.

"This result shows that much more mass than previously thought is hidden in small stars," team leader Mariska Kriek of Leiden University said. "That has implications for all kinds of fields within astronomy. Because many planets orbit small stars, it could even mean that more planets formed in the early universe than we previously assumed."

The team now intends to apply this method to more of the universe's earliest galaxies, hoping to stretch their investigation back to the universe's first stars.

The team's research was published on Wednesday (August 18) in the journal Nature Astronomy.

Sometimes, incredibly powerful space telescopes work together to accomplish amazing things. Recently, observations made by both the James Webb Space Telescope and Hubble were combined in a composite image that shows the incredible nature of the "Black Eye Galaxy," more formally known as Messier 64.

What is it?

The Black Eye Galaxy is a strange spiral galaxy located 17 million light-years from Earth, in the constellation Coma Berenices, a name that means "Berenice's Hair" in Latin.

Discovered in 1779, the Black Eye Galaxy is fairly isolated from other galaxies and is known for its hypnotizing "stare." This look is created by the galaxy's internal, swirling motion. However, unlike many other spiral galaxies, the gas in the outer reaches of this one rotates in the opposite direction to the gas and stars closer to its center, creating an especially unusual motion.

To capture this incredible composite view of the galaxy, astronomers combined near and mid-infrared wavelength observations made by JWST and ultraviolet, visible and near-infrared observations made by Hubble.

Why is it incredible?

As we look forward to observations from NASA's upcoming flagship space observer, the Nancy Grace Roman Space Telescope, this collaborative effort shows how such powerful instruments don't replace one another; rather, they bring different capabilities to the table and can complement each other.

And, while this new image is the result of a team effort of cutting edge-technology, the Black Eye Galaxy is also a favorite target for backyard astronomers because it can often be spotted in small telescopes.

The Hubble Space Telescope has discovered evidence that our galaxy experienced a significant collision and merger with a dwarf galaxy 11.8 billion years ago.

Mergers between galaxies are one of the main ways in which galaxies can grow. However, while we can witness mergers taking place in other galaxies, figuring out our Milky Way galaxy's history requires painstaking detective work. Even now, the story is only partly known.

"Our home is the Milky Way galaxy, but we do not know how our house was built," Davide Massari of the Astrophysics and Space Science Observatory of Bologna in Italy said in a statement. Massari is lead author of a paper describing the discovery of an ancient galactic merger. "In this paper we discover where the first significant batch of bricks came from: a dwarf galaxy that we call LKH."

LKH stands for Low-energy–Kraken–Heracles, which is an obtuse reference to three earlier research papers that tangled with the idea of mergers early in our galaxy's history.

In recent years, one other significant merger has come to light, which is a collision with a galaxy referred to as the Gaia–Sausage–Enceladus (GSE) galaxy about 10 billion years ago. The GSE had its own family of globular star clusters that became integrated with the Milky Way's own globular clusters during the collision.

Now, Massari's team have discovered a third population of globular clusters that do not seem to be native to the Milky Way, nor to have belonged to the GSE galaxy. Instead, they seem to have arrived 11.8 billion years ago, which is before the GSE merger.

"Thanks to the high resolution and depth of Hubble imaging, we could measure the age and the metal content of these clusters with unprecedented precision," said astronomer Chiara Zerbinati of the University of Bologna, who is a co-author on the paper. Metals are astronomer-speak for elements heavier than the hydrogen and helium that formed in the Big Bang, so they include the likes of oxygen and carbon as well as iron and aluminum.

"Coupled with measurements from [the European Space Agency mission] Gaia, this made it possible to distinguish a population of globular clusters that are different from the others," said Zerbinati. "These are the clusters that were born in LKH and they tell us when that galaxy was devoured by ours, and how massive it was."

Based on the number and mass of imported globular clusters, the team calculated that LKH had a total mass of 500 million times the mass of our sun. This is only slightly more massive than the Sagittarius Dwarf galaxy (approximately 400 million solar masses), which the Milky Way is currently cannibalizing and an order of magnitude less massive than the Small Magellanic Cloud. However, 11.8 billion years ago, which is just two billion years after the Big Bang, our Milky Way galaxy was much smaller and LKH would have contributed a sizable chunk of mass, in terms of stars, gas and dark matter, to the Milky Way.

The discovery of the merger adds an important new event to the Milky Way's history, one that would have undoubtedly influenced the evolution of our galaxy. For example, the collision could have spurred a fresh burst of star formation, helping the Milky Way to grow, while the chemistry of the stars from LKH will have impacted the Milky Way's overall chemical evolution as those stars died and passed their remains into the interstellar medium to be reborn in new stars.

"Some past studies have argued that the earliest phases of our galaxy's evolution were defined by stars born only in our galaxy," said Massari. "Here, we have shown that stars born in external galaxies also need to be considered."

The discovery of the merger with LKH was reported on Aug. 17 in the journal Nature Astronomy.

Thanks to the Hubble Space Telescope, astronomers have shed light on a recent chapter in the history of our Milky Way's neighboring galaxy, Andromeda.

Using Hubble Space Telescope observations of Andromeda's stars, a research team showed that the spiral galaxy's rate of making new stars has dramatically slowed down in the last 40 million years. And they've found more evidence that one of Andromeda's own neighbors — a smaller galaxy called M32 — may be to blame.

"We can't explicitly say that we are seeing a decrease in star formation because of M32. But it's right there, and it's definitely the most likely suspect," said Tobin Wainer, a graduate student at the University of Washington and one of the astronomers, in a statement.

Astronomers like Wainer knew from prior research that Andromeda saw a burst of star formation about 2 billion years ago (possibly as a result of a collision with an unknown galaxy). They also knew that star formation had slowed down since then. What they did not know was how quickly that deceleration had been. If they could find out, they could fill in some of the gaps in Andromeda's history.

At 2.5 million light-years' distance, Andromeda is near enough to Earth that Hubble can measure its stars. In the past several years, Hubble has conducted two surveys of Andromeda. While Hubble can only make out stars in Andromeda that are brighter than our sun, these two surveys still gave Wainer and colleagues a compendium of 200 million stars, covering two-thirds of Andromeda's disk.

Wainer and colleagues parceled out this vast space into a grid of squares, 300 light-years to a side. They reconstructed the history of each square by examining the colors of its stars.

A square with many bright blue stars, for example, probably saw a lot of star formation recently, since blue stars tend to be younger. On the other hand, if a square only contains smaller, redder stars, we know those stars are longer-lived and older, and that square probably hasn't seen a lot of newborn stars.

The astronomers mapped out a story of slowing star formation. Around 500 million years ago, on average, Andromeda turned the equivalent of our sun's mass in gas and dust into newborn stars each year. As millions of years passed, that rate declined. About 40 million years ago, it was about one-half the sun's mass each year. Then, it tilted into a dramatic deceleration. Today, it stands at about one-fifth the sun's mass each year.

Curiously, they found that Andromeda's starmaking slowdown is especially pronounced on one particular side of the galaxy, starting about 60 million years ago. Astronomers know this side of Andromeda is closest to another galaxy: M32.

Astronomers have eyed M32 with suspicion for some time now. M32 is only located about 16,000 light-years from Andromeda (Andromeda is formally called M31) and it looks like the rump core of a spiral galaxy that lost its arms. It's possible that this is actually the aftermath of a collision between M32 and its larger neighbor. It's possible, though not confirmed, that Andromeda's slowing bears the fingerprints of this collision.

We may not need to wait long for more answers. Just as Hubble can see Andromeda's stars, so too will the Nancy Grace Roman Space Telescope, set to launch in late August. In the coming years, Roman will be able to measure even more of Andromeda than Hubble has.

The Milky Way's spiral disk may have flipped over by 90 degrees, in turn altering the solar system's orbit around the center of the galaxy.

Spiral galaxies such as the Milky Way have two main, visible, structural components: a disk that encapsulates most of its stars, gas and the central black hole, and a more diffuse halo of older stars that encapsulates the disk.

However, the Milky Way's stellar halo has always been a bit of an oddity. The European Space Agency's Gaia mission measured the motion of the halo's stars to find they rotate slowly compared to other material within the spiral disk. Now, supercomputer models led by Kirill Batrakov of the University of Durham have found what triggers this: galactic mergers and spiral disks becoming flipped over.

In their simulations, Batrakov and colleagues tracked the evolution of 25 Milky-Way-like galaxies across billions of years. They found that those which had slowly spinning haloes also experienced head-on mergers with other galaxies and had their disk flipped at some point.

"We already know that the Milky Way had a massive head-on collision in the past with a galaxy known as Gaia-Sausage-Enceladus," Batrakov said in a statement. "So, we think that the Milky Way disk likely flipped in the past."

Gaia-Sausage-Enceladus was a dwarf galaxy with more than 10 billion times the mass of our sun that slammed into the Milky Way between 8 billion and 11 billion years ago. The evidence for this collision was also found in Gaia's measurements of the motions of stars. The colliding galaxy's strange name comes in part because as it was ripped to pieces by the Milky Way's gravity, its stars were channeled onto highly elongated, sausage-shaped streams that our galaxy incorporated into its halo.

This collision was the last major impact that our Milky Way galaxy experienced, but maybe not the last major event that it experienced. At some point, the Milky Way's disk seems to have also flipped, but what caused this is uncertain. Also of note: The simulations showed that galaxies whose disks flipped hadn't always experienced a merger.

"We think that there might possibly be different mechanisms driving the disk flips," Batrakov told Space.com. "At this point, we are not sure which scenario applies to the Milky Way specifically and a further investigation is needed on the precise mechanics of disk flips."

These two mechanisms — the merger and the flip — would both contribute to the slower spinning halo. The head-on merger sees lots of stars from the Gaia-Sausage-Enceladus galaxy get thrown into the halo but on trajectories strongly misaligned with the disk. So, relative to the disk, they collectively rotate more slowly.

The disk flip leads to a similar situation. In the simulations, the flip is measured with respect to the space around the galaxy, but as the orientation of the disk changes relative to the halo, the halo doesn't immediately reorient with it and takes its time to synchronize its rotation with the disk. Hence, this misalignment results in the halo having less coherent rotation relative to the new orientation of the disk.

If the disk flip occurred during the solar system's lifetime, then it could have impacted our own orbit around the galactic center.

"A disk flip means that most of the Milky Way's stars once moved on very different trajectories than they do today, possibly even our sun, meaning our 'stable' spot in the galaxy might not have been so stable for the solar system's whole lifetime," said Batrakov.

Much of what we understand about other galaxies comes from our knowledge of the Milky Way and its story.

"Finding that its disk flipped adds a new chapter to that story, one we must account for when placing the Milky Way in a broader context of other galaxies," said Batrakov, who recognizes just how incredible it is that we can infer this story through careful observations billions of years after the fact.

"What excites me most is that this complex history can be reconstructed just from present-day observations," he said.

Batrakov presented his work at the Royal Astronomical Society's National Astronomy Meeting, being held at the University of Birmingham between July 20 and July 24.

For the first time, astronomers have reconstructed the magnetic field of an entire cluster of galaxies, from its central nucleus to its outer limits.

The record-breaking achievement is the product of the deepest-ever observations of the galaxy cluster Abell 2255, located around a billion light-years away — and those observations are thanks to the European radio telescope LOFAR (Low Frequency Array).

Abell 2255 has long been known for its complexity in radio waves. Its vast, diffuse radio emissions are created by particles called electrons racing at near-light, or relativistic, speeds and interacting with magnetic fields of galaxies in the cluster. Thus, using Abell 2255 as a cosmic laboratory to study the universe in radio waves could lead scientists to a better understanding of how magnetic fields come about and evolve. These observations could also help paint a picture of the dynamics of hot gas in galaxy clusters. This could reveal how the largest structures in the universe are constructed.

As part of the LOFAR Galaxy Cluster Ultra-Deep Field project, this team used 224 hours of radio image collection to discover that the distribution of large-scale magnetic fields throughout Abell 2255 (which itself stretches out for several million light-years) are not randomly distributed. Instead, these magnetic fields seem to be organized by the motion of gas that occurred during the formation of this galactic cluster.

"Obtaining very sensitive images of galaxy clusters at radio wavelengths is crucial to understanding how electrons are accelerated to relativistic speeds and magnetic fields are amplified on large cosmic scales," team leader Andrea Botteon, of the Italian National Institute for Astrophysics (INAF), said in a statement. "The complexity of these studies is due to the elusiveness of the radio signal from electrons moving in very weak magnetic fields. We believe that the mechanism that 'turns on' these gigantic radio emissions is linked to the formation process of galaxy clusters."

Botteon added that for this research he and his colleagues combined the deepest radio observations ever made with an innovative data analysis technique that allowed them to reconstruct the shape of a galaxy cluster's magnetic field for the first time.

"The coherence of the magnetic field lines observed in some regions of the cluster suggests that the morphology of the field is intimately linked to the dynamics of the gas in which it resides, where it can be 'stretched' or 'compressed' by the motions associated with the formation of the cluster itself," Botteon said.

This analysis revealed that, in some regions, the magnetic fields follow very specific directions, stretching radially along extended radio emissions. In contrast to this, in regions dominated by shock waves, magnetic fields are orientated at tangents. This suggests magnetic fields in Abell 2255 are carved out by the same dynamics that allow clusters to accrete gas and grow.

This serves as the first observational evidence that the same mechanisms that allow galaxies to grow and cluster, creating the largest structures in the universe, also shape their magnetic fields.

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

Infant stars or "protostars" celebrate their independence with cosmic fireworks in a stunning new image from the James Webb Space Telescope (JWST).

NASA released this image to celebrate the 250th anniversary of the birth of the U.S. It is a fitting tribute as the protostars break away from the molecular cloud in which they formed to become fully fledged stars in their own right.

Protostars are born when patches in vast molecular clouds cool and form clumps, collapsing under their gravity. Protostars continue to gather material from these prenatal clouds until they have enough mass to trigger the nuclear fusion of hydrogen into helium in their cores, the process that defines what a main-sequence star is.

What is it?

The protostars sit in a region known as FS Tau, located around 450 light-years away, which has become a popular target for astronomers aiming to study the evolution of low-mass stars.

Why is it incredible?

Though previously well studied, it has taken the incredible infrared observing power of the JWST to peer through the thick clouds of star-forming gas and dust in FS Tau and visualize the protostars of this region in great detail.

One of the aims of this research is to investigate the impact that radiation and outflows of material from low-mass stars have on their environment. The outflows occur as protostars gather matter from their surroundings, occasionally blasting out some of this matter.

The JWST image of FS Tau reveals gaps between the outflows that support the theory that protostars gather or "accrete" matter in discrete episodes, between which they lie dormant.

The effect of protostar outflows on their environment can be seen in the JWST image via the prominent blue ridges. These represent gas that has been shunted by outflows, creating dense regions of matter that reflect light from proximate protostars.

The result is cosmic fireworks that put even the most impressive July 4 celebrations to shame. But at least we get hot dogs.

NASA's Chandra X-ray Observatory has released four stunning images of cosmic wonders, depicted in red, white and blue to coincide with the United States' 250th anniversary on July 4.

The four images reveal superheated gas in a distant galaxy cluster, the swirling spiral galaxy known as Messier 94, a glowing nebula found in our own Milky Way galaxy, and the Cassiopeia A supernova remnant, respectively.

Along with the colorful cosmic images, the Chandra team produced sonifications in which the data collected by the powerful X-ray telescope was translated into sound. In this case, the sonifications turn these images into celestial music, mapping X-ray data into different audio frequencies and musical instrument sounds.

Galaxy cluster ZwCl 0024+1652

In this image, the galaxy cluster ZwCl 0024+1652 comes alive in vibrant blues and reds. The red in the image is produced from X-ray data collected by Chandra, revealing vast amounts of superheated gas surrounding these galaxies, found some 4 billion light-years from Earth in the Pisces constellation.

This image combines X-ray data from Chandra along with optical data from the Hubble Space Telescope, depicted here in blue. The Hubble data reveals the presence of dark matter, according to a statement from NASA.

Because dark matter does not interact with light, astronomers can't image it directly; its presence can be detected through the gravitational influence it has on surrounding matter that does interact with light.

Messier 94

Chandra also peered deep into the 'eye' of the spiral galaxy Messier 94 (M94, or NGC 4736), sometimes colloquially referred to as the Cat's Eye Galaxy. This galaxy is found some 16 million light-years away in the constellation Canes Venatici, the "Hunting Dogs."

In this swirling image, X-ray data collected in space by Chandra was combined with visible light photography taken by telescopes here on Earth. The images show the distinctive inner region of Messier 94, known as a starburst ring, in which new stars are being born.

M94 is also notable for its curious lack of dark matter, according to NASA. "Astronomers do not know why it lacks the normal amount of dark matter, but the galaxy has been the subject of extensive study as a result," the agency wrote in a statement.

Nebula NGC 3603

This image combines X-ray data from Chandra with optical, infrared, and ultraviolet light from NASA's Hubble Space Telescope to reveal the twinkling cluster of gases and thousands of stars known as NGC 3603.

This nebula, found in our own Milky Way galaxy, is a vast region of gas and dust surrounding a dense concentration of massive stars. NGC 3603 is located 20,000 light-years away from our solar system in the Carina constellation, a Southern Hemisphere constellation named after the Latin word for a ship's keel.

NGC 3603 contains some of the most massive stars in the known universe, according to NASA. "These huge stars live fast and die young, burning through their hydrogen fuel quickly and ultimately ending their lives in supernova explosions," the agency pointed out in a prior statement about the nebula.

Cassiopeia A

When some stars die, they explode in massive events known as supernovas. The light from one of the most well-known examples of a supernova reached Earth in the 17th century, appearing as a bright point of light in the Cassiopeia constellation. But because this exploded star is located some 11,000 light-years away from Earth, it means that the supernova actually occurred over 10,000 years ago, according to NASA.

Today, the leftover gases from that supernova are known as Cassiopeia A. Astronomers believe the star that produced the supernova was somewhere in the neighborhood of 15 to 25 times more massive than the sun.

In the image below, Chandra's X-ray data was combined with infrared light gathered by the James Webb Space Telescope to help visualize the luminous shell of gas in reds, whites and blues.

Using the James Webb Space Telescope, astronomers have spotted a massive and densely packed galaxy cluster at "cosmic noon." The fact that this cluster is so highly evolved could change theories of cosmic evolution, as it seems to exist before such structures were thought to be possible.

Designated XLSSC 122 and first seen in 2014, the cluster immediately stood out to the team in James Webb Space Telescope (JWST) data because, being so large and concentrated, it resembled the galactic clusters found much closer to our own galaxy. However, this cluster is seen as it was around 10.4 billion years, just around 3.4 billion years after the Big Bang, a time when such structures were theorized to have only just begun to assemble.

Even more excitingly, XLSSC 122 is acting as a gravitational lens and is aligned with even more distant galaxies, amplifying their light and making them easier to study.

"When we got those first images back from JWST, we said, 'wow, look at this, there's strong lensing coming from this cluster!' XLSSC 122 has now set the record for the most distant galaxy cluster displaying strong lensing, which is a valuable tool for astronomers," team leader Kyle Finner of the California Institute of Technology said in a statement.

What is gravitational lensing and why is it so useful?

Gravitational lensing was first predicted by Albert Einstein in his 1915 theory of gravity, known as general relativity. General relativity says that objects with mass cause the fabric of space and time to warp. Think of this as being akin to placing a bowling ball on a stretched rubber sheet. Gravity arises from this curvature.

The greater the mass of the object, the more extreme the curvature and thus the greater the gravitational influence of that object.

But there is another consequence. Light normally travels in a straight line, but spacetime is the track that it follows. If spacetime is curved, then the path of light is also curved. The closer that light travels to an object of great mass, the more its path swerves.

That means when an object of great mass, in this case XLSSC 122, comes between Earth and a more distant light source, light from that background source arrives at our telescopes at different times based on the path it took around the intermediate object. This amplifies light from the background source and has been used by the JWST team to great effect in the study of ancient galaxies.

When the Hubble Space Telescope previously studied XLSSC 122, it wasn't able to capture images that showed it was a strong gravitational lens; it took the tremendous observing power of the JWST to determine this.

The strong lensing of this early galaxy cluster could also help unravel the mystery of dark matter. Effectively invisible because it doesn't interact with light, dark matter does interact with gravity. Plus, because it outweighs the "ordinary matter" that makes up stars, planets, moons, and gas clouds in galaxies by a ratio of five to one, dark matter makes the largest contribution to the lensing effect of galaxies and galactic clusters like XLSSC 122.

This means that gravitational lensing can be used to study the distribution of otherwise invisible dark matter in galaxy clusters, which is a vital element of galactic evolution, as it is thought that galaxies and galaxy clusters gather along vast filaments of dark matter. The hunt is now on for more lensing clusters like XLSSC 122, and if they are found so early in the universe's history, a major revision of cosmology may be on the cards.

"Strong lensing is a way to measure the dark matter without actually seeing the dark matter. It gives us a sensitive probe of our cosmological models,” said Finner. "It's still early in the JWST era, and if we can start to get data on tens or hundreds of these types of objects at this stage in the universe, then we can really start putting our cosmological models to the test."

The team's results were presented on June 17, 2026, at the 248th meeting of the American Astronomical Society. The research is available as a paper published in The Astrophysical Journal Letters.

A bizarre radio galaxy discovered by a citizen scientist has left astronomers puzzled, revealing a never-before-seen "bow-and-arrow" structure that could offer rare insight into how galaxies are reshaped by colossal shock waves as they plunge through galaxy clusters.

Named RAD-BAARG (short for Radio Bow-And-Arrow Radio Galaxy), the object spans nearly 1.8 million light-years across, making it almost 18 times wider than the Milky Way. Its unusual structure was first identified by a citizen scientist participating in the RAD@home Astronomy Collaboratory, which allows volunteers to review telescope data and flag unusual features that might otherwise be missed.

Astronomers say they haven't seen anything like it. "The structure of this source is unlike that of any radio galaxy I have seen in the last 25 years," the University of Mumbai's Ananda Hota said in a statement published by the Royal Astronomical Society. The statement adds that astronomers believe the structure may be "one of the clearest known radio signatures of a giant bow shock generated by a galaxy falling supersonically into a cluster environment."

Following its discovery, researchers studied the object using observations from the LOFAR (Low Frequency Array) Two-meter Sky Survey (LoTSS), one of the deepest low-frequency radio surveys ever conducted and particularly well suited to detecting faint, diffuse radio emissions.

Unlike typical radio galaxies, which produce two relatively symmetrical jets of charged particles powered by supermassive black holes, RAD-BAARG has a dramatically lopsided appearance. One jet feeds a wedge-shaped region that curves backward into an enormous arc, while the other twists into an S-shaped structure before fading into a long tail. Together, the features resemble a bow with an arrow drawn across it, according to the statement.

The radio-emitting plasma from RAD-BAARG appears to illuminate an otherwise extremely faint, extended feature. At these low radio frequencies, aged and diffuse electron populations become more visible, allowing astronomers to trace structures that are otherwise invisible at optical or higher radio frequencies, making surveys like LoTSS especially powerful for identifying and confirming such diffuse emission.

Researchers believe the extreme asymmetry may be linked to the galaxy's motion through a dense galaxy cluster. As it falls toward the cluster's center, it likely moves at supersonic speeds through the hot, diffuse gas that fills the space between galaxies. This motion is thought to generate a bow shock that compresses magnetic fields and charged particles, reshaping the radio-emitting plasma into large-scale structures.

The team also found that RAD-BAARG resides in a complex "multi-halo" environment containing several overlapping reservoirs of hot gas, making it an especially valuable system for studying how galaxy clusters influence radio galaxies.

"LOFAR allows us to see this faint, low-surface-brightness emission in remarkable detail," Pratik Dabhade, co-lead author of the study from the National Center for Nuclear Research in Poland, said in the statement.

"With LoTSS DR3 and the future Square Kilometre Array Observatory (SKAO), we may find many more systems where radio galaxies reveal otherwise invisible interactions between jets, galaxies, and their environments."

If confirmed, RAD-BAARG could become a key example of how extreme cluster environments reshape radio galaxies, providing new insight into how supermassive black hole jets interact with their surrounding environments.

The findings were published June 22 in the journal Monthly Notices of the Royal Astronomical Society: Letters.

An intense demolition derby of at least six galaxies smashing into one another has been found lurking in the early universe by the James Webb Space Telescope. This merger is also expected to fuel the growth of a supermassive black hole and trigger the formation of what will eventually become one of the most massive galaxies in the cosmos.

"What makes this special is that we can follow both the build-up of a giant galaxy and the growth of the black hole at its center," Huub Röttgering, an astronomer at the Netherlands' Leiden Observatory, said in a statement.

The discovery came after a tip-off from radio astronomers who had noticed emissions that seemed to be coming from an undiscovered active black hole. When the James Webb Space Telescope (JWST) looked closer, it found a surprise.

"We didn't find a single galaxy, but an entire complex of at least six galaxies," said Aayush Saxena of the University of Oxford.

These six galaxies sit at a redshift of 4.0, which equates to a time about 12 billion years ago, just 1.8 billion years after the Big Bang.

Through the vision of the JWST's Near-Infrared Camera the six galaxies appear fuzzy, reminiscent of a faraway version of Stephan's Quintet, which is a collection of five galaxies, four of which form a compact group that are on course to merge to become a giant elliptical galaxy.

Similarly, the six galaxies spotted by the JWST, and collectively termed TGSSJ1530+1049, will undergo a series of rapid mergers to become what is known as a 'brightest cluster galaxy,' which is an enormous elliptical galaxy of the kind found at the center of galaxy clusters.

"We call structures like this protoclusters: the precursors of the vast collections of galaxies we see today," said Leiden's Roderik Overzier. "These are places where matter came together very early on. We think we are seeing a rare moment when several massive galaxies still exist separately, but are already in the process of forming one much larger galaxy."

Already a supermassive black hole has formed at the heart of this galactic maelstrom, and radio observations with the European VLBI (very long Baseline Interferometer) Network and the U.K.'s e-MERLIN (enhanced Multi-Element Remotely Linked Interferometer Network) at a resolution on the scale of a 100 milliarcseconds have identified radio lobes and hotspots typical of an active black hole's jet interacting with the gas surrounding it.

"Using a network of connected radio telescopes, we were able to produce a very sharp image of TGSSJ1530+1049," said Krisztina Gabányi of Eötvös Loránd University in Budapest, Hungary. "The radio emission is produced as material falls into the black hole, while some of it is expelled again at high speed."

The jet doesn't seem to extend as far as all the galaxies in TGSSJ1530+1049 yet, implying that the black hole is still fairly young.

The six galaxies of TGSSJ1530+1049 span a volume only a few tens of thousands of light-years across, which is smaller than our Milky Way galaxy — and yet, they pack in a humungous amount of stars, equivalent to hundreds of billions of solar masses and a star-formation rate somewhere between 70–163 solar masses per year. That's a frenetic pace compared to the Milky Way, which produces much less than ten solar masses per year.

TGSSJ1530+1049 is one of the densest collections of heavyweight galaxies found in the early universe so far, and is giving exciting clues as to how the most massive galaxies, clusters and black holes in the universe formed.

The JWST observations are reported in The Open Journal of Astrophysics, while the radio measurements are described in a paper in Astronomy & Astrophysics.

In 2025, the European Space Agency dark universe detective spacecraft Euclid turned its attention to the heart of the Milky Way for just 26 hours. In just over one day, Euclid was able to create the largest and most detailed photo of this region of our galaxy ever made.

The image, packed with 60 million stars, could help scientists hunt for extrasolar planets, exoplanets, in this region known as the galactic bulge.

Euclid is designed to study dark energy, the mysterious force that drives the accelerating expansion of the universe, by studying distant galaxies. That means the space telescope is powerful enough to distinguish individual stars in the central bulge of the Milky Way. Other telescopes fail to do this because they are too blinded by the densely packed stars in this region.

Euclid was requested to monitor the central bulge of the Milky Way to assist astronomers in the hunt for exoplanets because this is the perfect region for so-called "microlensing" events to occur.

"To catch microlensing, you need to observe parts of the sky that are crowded with stars, such as close to the center of our galaxy," team leader Jean-Philippe Beaulieu of the Institut d'Astrophysique de Paris in France said in a statement.

Microlensing is a weak form of gravitational lensing that occurs when objects with mass cause the very fabric of space to warp. When light from a background source passes through this warping of space, its path is curved. This can be used to study the background source; for example, scientists have used it to great effect with the James Webb Space Telescope (JWST) to study some of the most distant and early galaxies. However, the curvature of light from background sources can also be used to detect faint objects like planets.

Spotting planets using microlensing requires one star to pass in front of another and act as a gravitational lens. The presence of a planet causes a tiny perturbation in the lensing of light from the background star. It's a small effect, but one that has been used very effectively in the detection of exoplanets.

"During the last twenty years, almost 300 exoplanets have been discovered using this technique, all with ground-based telescopes and all towards the center of our galaxy," Beaulieu said. "This image from Euclid includes 51 known planetary systems – and it will assist in studying many more that will be found."

Despite Euclid's study of the central bulge pointing the way forward in observing new microlensing events, there are no such events in the data from the ESA spacecraft. That is because detecting such events takes around 20 days.

Instead, it will be up to telescopes like the forthcoming Nancy Grace Roman Space Telescope to observe this region for longer periods and compare with this day's worth of Euclid data to find microlensing events.

"In 24 hours, Euclid has already captured the stars involved in all the future microlensing events that the Roman space telescope will detect, but before the stars and planets involved have aligned," team member Natalia Rektsini of the Institut d'Astrophysique de Paris said.

"This means that anyone who detects a microlensing event in the same region, for example, with Roman, will be able from now on to use Euclid data as a time reference in the past and see how the stars looked before they overlapped. Since Euclid can clearly separate individual stars, one can then measure how fast they move over time and use that information to confirm the existence of a planet and determine its mass. This would not be possible with data from one point in time."

One reason this is so exciting to exoplanet hunters is that other techniques used to spot these distant worlds tend to excel at detecting hot and massive planets close to their host stars.

Microlensing, however, can be used to detect more diminutive planets much farther from their host stars and with chillier temperatures. That means it could be used to detect ice giants like Uranus and Neptune in wide orbits around central bulge stars.

"This result shows what a relatively small, dedicated team can achieve within a large international mission," says Valeria Pettorino, Euclid Project Scientist at ESA.

"That's why this Euclid data will be a time reference for past and future missions and enable studies of exoplanets and their masses. This data can also be used for other scientific applications, from brown dwarfs and binary stars to stellar motions and dust across our galaxy."

A bright, dense cluster of hot, massive stars in a galaxy that existed 1.4 billion years after the big bang has been found helping to end the early universe's foggy days during which neutral hydrogen gas was draped across the cosmos, obscuring ultraviolet light from luminous objects.

The cluster was found emitting ultraviolet light in a small but quickly growing galaxy by the Hubble Space Telescope. The presence of this ultraviolet light, and the star-forming history of the cluster producing it, suggests that bursts of star formation contributed to waves of ionizing radiation that gradually cleared out the opaque neutral hydrogen.

In the aftermath of the big bang, the universe was filled with neutral hydrogen gas that is opaque at short wavelengths of light, such as ultraviolet. However, this ultraviolet light was the neutral hydrogen's worst enemy, gradually ionizing the gas across the universe. Once ionized, hydrogen gas cannot absorb ultraviolet light — and so, the cosmos became transparent at those wavelengths.

Because of this, the first billion or so years are called the Epoch of Reionization. It is referred to as "reionization" rather than ionization because, technically, the gas had already been ionized once before during the first 379,000 years after the Big Bang.

While investigating what brought about this epoch, astronomers had identified two chief suspects that could have produced sufficient amounts of ultraviolet light to ionize the neutral hydrogen. One is active supermassive black holes and the other is the first generations of hot, massive stars. The problem is, given that neutral hydrogen is adept at absorbing the ultraviolet light, astronomers have had difficulty tracing that ultraviolet back to its source and identifying which of the two suspects are the main culprit.

In 2023 the James Webb Space Telescope (JWST) made a major breakthrough, finding a galaxy that existed just 900 million years after the Big Bang that was producing enough energy to ionize the neutral gas surrounding it.

Now the Hubble Space Telescope has gone further, detecting ultraviolet light from a galaxy called MXDFz4.4. This ultraviolet light should only be visible if the surrounding gas had already been ionized.

"Observing a galaxy like this was thought to be impossible," said Ilias Goovaerts of the Space Telescope Science Institute (STScI) in Baltimore, who led the discovery, in a statement. "Researchers expected the 'fog' of neutral hydrogen that filled the early universe would be too thick and obscure our view of its ionizing light. Hubble not only spotted that light, but it also helped reveal incredible details about the galaxy's characteristics."

MXDFz4.4 was first identified in the MUSE eXtremely Deep Field (MXDF), with MUSE being the Multi Unit Spectroscopic Explorer on the European Southern Observatory's Very Large Telescope in Chile. The "z4.4" part of its name tells us that the galaxy exists at a redshift of 4.4, meaning that it existed 12.37 billion years ago. As the universe has expanded in the time since then, the ultraviolet light has been redshifted into visible wavelengths that were detected by Hubble.

"Astronomers have found many galaxies that existed at this point in the history of the universe, but we haven't detected ionizing photons from any of them, making MXDFz4.4 one of a kind," said Marc Rafelski, who is the Hubble Deputy Mission Head at STScI.

MXDFz4.4 is 100 times smaller than our Milky Way galaxy but is forming stars ten times faster than our galaxy is. Many of those stars are being born in the tight, luminous cluster producing the ionizing ultraviolet.

The cluster contains "A lot of young, hot, massive stars in a small space [that] do a better job of blasting through opaque gas," said Goovaerts.

Furthermore, by comparing Hubble's observations of MXDFz.4.4 with those of the JWST, which probed for cooler, older stars in the galaxy, Goovaerts and Rafelski's team discovered that the stars in the cluster had formed in bursts, each burst producing fresh quantities of ionizing ultraviolet radiation that helped to clear out more and more of the neutral gas over time. We now see the galaxy about 250 million years after it finished reionizing the surrounding gas. These hot, massive stars in the cluster end their lives after a few million years as supernova explosions, the blast waves and radiation from which can create bubbles in the gas light years across, creating further pathways for ultraviolet light to escape and be detected by Hubble.

The observations seem to nail down the theory that clusters of hot, massive, luminous stars in young galaxies in the early universe played a dominant role in ionizing the universe's neutral gas.

"Hubble's observations of MXDFz4.4 let us test our hypotheses much closer to the Era of Reionization than ever before," said Rafelski. "Finding more galaxies, especially at slightly later cosmic times where larger samples are within reach, would let us refine these measurements and figure out what cleared our view as that era was ending."

The results were published on June 23 in The Astrophysical Journal.

Using the James Webb Space Telescope (JWST) and the Atacama Large Millimeter/submillimeter Array (ALMA), astronomers may have uncovered new clues about a longstanding mystery in galaxy evolution: why so many massive galaxies in the early universe appear to have died far sooner than expected.

Galaxies are often considered "alive" when they are actively forming stars and "dead" when star formation has largely ceased. In today's universe, dead galaxies are common. But astronomers have been surprised to find large numbers of them in the early universe, when galaxies were expected to be rapidly growing and churning out stars.

Using ALMA and JWST observations of a distant galaxy, researchers have detected a "galaxy-killing" wind — an enormous, high-speed outflow of gas — that is powerful enough to strip a galaxy of the raw material needed to make new stars. The discovery could help explain the puzzling population of massive "dead" galaxies found throughout the young cosmos, according to a statement from the Royal Astronomical Society.

"Dense regions of the universe are like very active cities," Rebecca Davies, lead author of the study from Swinburne University of Technology in Melbourne, said in the statement. "Galaxies collide and undergo frenzied bursts of star formation. But when the biggest stars burn out, they explode as supernovas, launching powerful winds that blast away the very gas galaxies need to keep forming stars."

Davies and colleagues observed a galaxy called CRISTAL-02 as it appeared just one billion years after the Big Bang, catching it in the midst of a rapid growth spurt.

The observations revealed that CRISTAL-02 is forming stars at roughly twice the rate of similar galaxies from the same era. At the same time, JWST and ALMA detected a vast plume of cold gas extending far from the galaxy — a telltale sign that material is being blown out into intergalactic space, according to the statement.

"The galaxy has a powerful wind that is ejecting material twice as fast as the galaxy forms stars," Davies added. "If this rapid blowout continues, the galaxy could be dead in less than 50 million years, explaining the origin of the mysterious massive dead galaxies in the early universe."

The discovery is particularly intriguing because CRISTAL-02 is not a single galaxy. Instead, it consists of multiple galaxies in the final stages of a merger. During these cosmic collisions, gas is funneled toward galactic centers, triggering intense bursts of star formation, later followed by supernova explosions that drive powerful winds that prevent any new stars from being born.

What's more, observations suggest that nearly half of massive galaxies in the early universe were interacting with nearby companions, indicating that mergers and their galaxy-killing winds may have been widespread. In turn, many of the universe's earliest giant galaxies may have effectively destroyed their own ability to form stars — helping explain why so many of these galaxies seem to have lived fast and died young.

"If many early galaxies collide and experience rapid growth, then it may not be surprising that we see so many dead galaxies in the early universe," Davies said in the statement. "CRISTAL-02 offers a natural solution to the mystery of why these massive galaxies live fast and die young."

The study was published June 10 in the journal Monthly Notices of the Royal Astronomical Society: Letters.

Galaxies don't grow forever. At some point, even the most prolific star-forming galaxies start to slow down, then stall, then settle into a long quiet retirement. Astronomers have known about this transition for a long time, but we haven't had a clean physical explanation for why it happens, and why it happens at the particular mass scale that it does.

A new paper led by Preetish Mishra of the Korea Institute for Advanced Study, along with an international team of scientists, makes a clear and testable proposal: that the slowdown in galaxy growth is caused by the birth of a stable cloud of hot gas surrounding the galaxy, and that cloud forms at a very specific mass: roughly 10^12.5 solar masses. Above that threshold, galaxies stop being efficient stellar factories, no matter how much raw material they have on hand.

The question is: what flips the switch?

To get to that calculation, the team used the Horizon Run 5 simulation, one of the largest cosmological simulations ever created. It takes a chunk of virtual universe roughly a gigaparsec across, models the full physics of gas, gravity, star formation, supernovas, and supermassive black holes from shortly after the Big Bang to the present day, and lets researchers track individual galaxies through their entire histories. Mishra and colleagues picked out roughly 20,000 of the most massive central galaxies and watched what happened to them over cosmic time.

The key quantity they tracked is the stellar-to-total mass ratio. It's a measure of how much of a galaxy’s entire mass budget (stars, gas, dark matter, black holes, everything) actually ends up locked into stars. Think of it as a galaxy's star-formation efficiency report.

The team found that this ratio peaks sharply in galaxies with total masses between about 10^12.4 and 10^12.7 solar masses. Below that range, galaxies are turning gas into stars roughly as fast as the gas comes in. Above it, they slow down by more than a factor of three. That peak is the critical mass.

Mishra's theory as to why galaxies stop growing is the formation of a hot gas halo that has reached gravitational equilibrium. As a galaxy grows, the gas falling into it gets shock-heated. Up to a certain mass, that gas cools quickly enough to keep raining down and feeding new star formation.

Past the critical mass, the halo gets dense and hot enough to hold itself up against gravity for billions of years. The gas can no longer cool fast enough to fall in and the galaxy is suddenly cut off from its fuel supply. It keeps gobbling up dark matter and dragging in satellite galaxies, but the cool gas that actually makes stars stops arriving.

The paper also rules out a competing explanation. One natural guess is that galaxies above the critical mass simply lose more of their normal matter to outflows from supernovas and active galactic nuclei. The team checked this directly by computing how much of each galaxy's baryon budget actually stayed bound to the system. The variation turned out to be no more than 30 percent. That isn't nothing, but it can't account for the factor-of-three drop in star formation efficiency. The decisive change is on the inflow side, not the outflow side.

A few caveats are worth flagging. Horizon Run 5 is a simulation, not a telescope, and its results depend on the sub-grid physics used to model star formation, supernovas, and black hole feedback. The authors did sensitivity tests and the basic result holds up, but the precise numerical value of the critical mass scale could shift as those prescriptions improve.

The analysis also restricts itself to galaxies above 10^10.8 solar masses to make sure each one has enough simulation particles to be reliably resolved. Smaller galaxies are a story for another simulation.

What makes this work satisfying is that it pins a famous observational pattern to a single, specific physical mechanism. Not just that galaxies above a certain mass quench, but that they quench because their hot gas halos become self-supporting. That is the kind of statement that can be checked against future surveys of galaxy clusters and the warm-hot intergalactic medium, the gas and dust between galaxies.

We will know whether they got the right answer once those surveys roll in.

The Small Magellanic Cloud seems to be coming undone at the gravitational hands of its sibling galaxy, the Large Magellanic Cloud, which has been found to be unwrapping its little brother's stars.

The Small and Large Magellanic Clouds (SMC and LMC for short) are two dwarf irregular galaxies passing close to the Milky Way. The LMC is about 163,000 light years away from us, while the SMC is further away at about 200,000 light-years from us. Both are subject to disruption from the Milky Way's gravity, which triggers bursts of star formation within them and rips away a stream of gas from both, called the Magellanic Stream.

However, new results from the Visible and Infrared Survey Telescope for Astronomy (VISTA) at the European Southern Observatory's Paranal mountaintop site in Chile have shown the Milky Way isn't the only galaxy affecting the SMC. It turns out that the diminutive galaxy's bigger brother, the LMC, is also a disruptive influence.

As part of VISTA's Survey of the Magellanic Clouds (VMC), the four-meter aperture telescope has spent the past 11 years carefully mapping the motions of millions of individual stars in the Magellanic Clouds. VISTA's near-infrared vision sees through some dust in the Magellanic Clouds, giving it a clearer view of the stars.

"When I saw the results for the first time, I was amazed by the quality of the measured stellar motions," said Florian Niederhofer of Germany's Leibniz Institute for Astrophysics Potsdam (AIP) in a statement. "By combining observations that have been taken over a time baseline of more than a decade, we were able to map the internal kinematics of the Small Magellanic Cloud with a level of detail that is outstanding for observations from the ground."

Niederhofer's team published the results from the LMC in 2022, revealing how stars moved through the dwarf galaxy's off-center bar feature, which is similar to a galactic bar often found in the center of large spiral galaxies including the Milky Way. There were no major shocks there, but the results of the SMC measurements have caught everyone by surprise.

Previous measurements implied that the motion of stars in the SMC were indicative of the rotation of the dwarf galaxy, but according to these new results, that was a misinterpretation. Instead, stars are moving en masse outwards from the core of the SMC, in directions generally aligned along an axis pointing from (as seen from Earth) southeast to northwest. Extend that line, and it points all the way back to the LMC. This is exactly what we would expect if gravitational tidal forces from the LMC were tugging on the part of the SMC closest to it, stretching the SMC.

The average velocity of these stars is 10.6 miles (17 kilometers) per second, and over the course of a few hundred million years these stars could travel several thousand light-years. This gives an indication of how much the SMC has been distorted perhaps over billions of years. In the past its structure must have been more compact and defined, as opposed to its amorphous shape today.

"The results reveal large-scale tidal expansion throughout the SMC and challenge long-standing assumptions that the Small Magellanic Cloud behaves like a rotating disk," said the AIP's Sreepriya Vijayasree, who is the lead author of the research paper describing the findings. "The study shows that the internal motions of stars in the Small Magellanic Cloud are dominated not by orderly rotation, but by gravitational disturbances caused by repeated encounters with the LMC over billions of years."

The motions of the stars are like a time machine, a legacy of past events that have become imprinted on how the stars travel through space. Another case in point is that VISTA has also detected that older red giant stars in the SMC all seem to have their own bulk motion northward. These red giants are stars that were born around two billion years ago, and their motion is the result of some other gravitational interaction dating back to that time. Given that astronomers believe the Magellanic Clouds to be passing close to our galaxy for the first time, this mysterious interaction two billion years ago may not have even taken place near the Milky Way.

As for the future, the Magellanic Clouds are slowing as they interact with the Milky Way's halo, and recent simulations have shown that then Magellanic Clouds are destined to merge with the Milky Way in billions of years' time. Until then, the two dwarf galaxy siblings will stick together, even if the big brother does continue to pick on the little one.

The findings were published in Astronomy & Astrophysics.

Astrophotographer ing. Cornelis Van Zuilen has shared a staggeringly detailed image of the galaxies known as the "Leo Triplet", after spending 60 hours capturing the light of the cosmic heavyweights from his balcony in the Netherlands.

The Leo Triplet is made up of the spiral galaxies M65, M66 and NGC 3628, which are located about 30 million light-years from Earth in the constellation Leo. The group lies close to the bright star Chertan, which forms part of the hind leg of the great lion represented in the stellar formation, according to NASA.

"At the end of 2024, I bought my Askar 103APO telescope, giving me enough focal length to seriously focus on galaxies and begin my long-term project of photographing the entire Messier Catalogue," Van Zuilen told Space.com in an email. "After finishing my first image of the Leo Triplet in 2025, I really wanted to see the gigantic tidal tail of NGC 3628 and decided to return with a much more ambitious goal."

For 2026, Van Zuilen aimed to create a detailed composite shot of the galactic trio created from at least 60 hours of light data. "Beginning on April 6, I photographed the Leo Triplet over 18 clear nights, collecting 85 hours of data, of which exactly 60 hours and 3 minutes met my quality standards," continued Van Zuilen.

Having met his target, Van Zuilen set to work combining and editing the data using the astronomy software PixInsight. The end result was a striking galactic portrait that revealed the intricate spiral structures of M65 and M66, along with the edge-on profile of NGC 3628, which is also colloquially known as the "Hamburger Galaxy" by dint of its distinctive dust lane.

Van Zuilen's image also reveals a 300,000-light-year-long "tidal tail" of stars and galactic material stretching away from NGC 3628. This structure is thought to have formed during a gravitational interaction with a galactic neighbor, according to the National Science Foundation's Noir Lab.

"Using a PixInsight galaxy identification script, no fewer than 548 catalogued galaxies were identified within the image, highlighting the incredible depth achieved through 60 hours of integration time from my balcony here in Heiloo, a village in the Netherlands," concluded Van Zuilen. "I hope you like this final image as much as I do!"

You may also like: Expert advice for new stargazers: How to begin your amateur astronomy journey.

Interested in capturing your own images of the night sky? Then be sure to read our beginner's guide to photographing the Milky Way, along with our picks of the best cameras and lenses for astrophotography.

Editor's Note: If you would like to share your astrophotography with Space.com's readers, then please send your photo(s), comments, and your name and location to spacephotos@space.com.

Our home galaxy didn't pop into existence all at once. The Milky Way was formed gradually, as smaller galaxies, or dwarf galaxies, were subsumed into our own galaxy over billions of years.

It turns out that the stars leftover from these dwarf galaxies still share characteristics, and scientists are getting better at identifying them. By studying their similarities, scientists use these stars to determine their galaxies of origin. A team of astronomers say that they have identified a sample of these 20 stars that — due to their similar features — may have grown up together in a dwarf galaxy which the researchers have dubbed "Loki."

"We might have detected one of the various small systems that contributed to form our Milky Way," astronomer Federico Sestito, a postdoctoral fellow at University of Hertfordshire and study coauthor, told Space.com via email.

The study, published in the Monthly Notices of the Royal Astronomical Society, builds on previous work from Sestitio. He had already identified the stars that they ended up surveying for the new study. But now, Sestitio and the team have new features that they can use to identify stars' original galaxies.

"This work can be thought of as a sort of follow-up of previous works," Sestitio said. "In the past, we had to look at these old stars with peculiar motion; however, we lacked chemical information, which is now available with this work."

Growing up together

Helium and hydrogen were main ingredients for the early stars that were formed in our universe. Once formed, the stars fused these two elements together, which created heavier elements that made later generations of stars. This process happened again and again over many generations.

Those early stars are considered "metal-poor." Because they formed so early, the stars only have traces of the heavier elements, like iron. Being metal-poor is one of the identifiers the scientists used to figure out which stars formed in the same dwarf galaxy.

"We think these old and metal-poor stars were formed in one small galaxy that was ingested by the forming Milky Way," Sestitio says.

But it's not just that these 20 stars are metal-poor; scientists have identified many stars in our galaxy that share this feature. The stars' elemental makeup isn't sufficient for determining the galaxy. To narrow it down, the team considered other features like location and orbit.

"[The stars] orbital motion is peculiar as they are confined close to the Milky Way disc, which is usually populated by younger and metal-rich stars," Sestitio says.

The Milky Way disc is the circular flowing whirlpool-like structure, where most of our galaxy's stars, including our own sun, are located. The 20 stars' unique positioning was another indication that they might all be related.

"This was possible thanks to precise orbital motion and chemical information of metal-poor and old stars," Sestitio says.

While the orbital motion of these stars has been previously identified and studied, the chemical information is new, and it gave the researchers a much stronger indication for the stars' shared galaxy of origin.

Chemically unique

The features that the team needed to study were diverse, so they used a patchwork of methods.

"I think my favorite part of this research is having put together various techniques and methodologies to better understand the origin of these stars," Sestitio said.

The astronomers used high-resolution spectroscopy, orbital motion, and even theoretical simulations to interpret the stars' chemical and orbital characteristics.

"We are providing a complete picture, as much as we can, of the properties of these stars," Sestitio said.

The team compared the chemical properties in the stars to those of stars in the galactic halo, dwarf galaxies, as well as simulated populations. They found that the chemical signatures from the 20 stars indicated enrichment from high-energy supernovas, hypernovas, fast-rotating massive stars, and neutron star mergers.

However, they found no indication of white dwarf explosions. The researchers say that this means the origin of stars was likely "short-lived, energetic dwarf galaxy."

Hidden galaxies

Sestitio has been working on identifying these old galaxies, because understanding more about them helps us learn more about the Milky Way as a whole.

"The most metal-poor stars in our galaxy, which are also among the oldest stars, are extremely important celestial objects," Sestitio said. "They can open a window on the early processes related to the formation of the Milky Way (and galaxies in general), the origin of the elements, and the properties of the very first stars."

There could be many more of these 'Loki' galaxies hidden around the Milky Way. While it's fairly easy to find small galaxies that are disrupted and accreted in the Milky Way's periphery, Sestitio says, finding them in our galaxy's disc is a much harder task.

The disc is crowded with younger stars that are comparably metal-rich. So, surveying and picking out the right stars in the disc takes time. But Sestitio is looking forward to discovering new insights into the Milky Way's formation.

"While this work might be limited in the number of observed stars, the future is looking great," he says. "We will have multi-object spectroscopic facilities that will obtain chemical information for thousands of stars.

"At that point, we will be able to better understand the properties of many building blocks that formed our galaxy."

For decades, astronomers have described the galaxy cluster Abell 2029, a vast city of galaxies in the Virgo constellation, as "the most relaxed clusters in the universe." But beneath that placid exterior, scientists have now found, the cluster is still reverberating from an ancient cosmic collision.

New observations from the Chandra X-ray Observatory suggest giant "sloshing" motions in the cluster's gas — triggered by a merger roughly 4 billion years ago — may help heat the cluster alongside energy released by the supermassive black hole at its center. That could help explain why the gas in galaxy clusters does not cool as quickly as expected, the researchers say. But of note, Chandra's new data also revealed massive substructures still visible today, including gigantic spirals, shock fronts and waves of superheated gas rippling through the cluster, according to a statement released last week by Chandra X-ray Observatory.

"Overall, our results suggest that A2029 is still settling from past interactions," a team of researchers led by astrophysicist Courtney Watson of Boston University write in the new paper, "showing that even the initially most relaxed-looking clusters can be hiding a rich history of dynamical activity."

Hosting more than a thousand galaxies, Abell 2029 is among the largest known galaxy clusters, which are sprawling collections of galaxies bound together by gravity and immersed in enormous clouds of heated gas. At its center sits IC 1101, a colossal elliptical galaxy estimated to span nearly 6 million light-years across, making it one of the largest galaxies ever discovered.

Astronomers have since the 1990s regarded Abell 2029 as unusually tranquil. Most recently, two studies published in 2025 using the XRISM observatory, which studies the universe in X-ray light, found extremely low levels of turbulence in the superheated gas filling the space between galaxies, suggesting the cluster had not experienced a recent major disruptive interaction such as a merger.

But a third XRISM study, also published in 2025, hinted that all was not entirely calm.

Researchers at that point had detected cooler pockets of gas embedded within the hotter cluster atmosphere — possible leftovers, they said, from ancient "sloshing" motions triggered by a long-ago collision.

The new Chandra X-ray Observatory observations add fresh evidence to that more turbulent history, revealing that — like ripples lingering long after a stone strikes water — the scars etched into Abell 2029's superheated gas continue to tell the story of a violent cosmic encounter billions of years ago.

Using 21 new X-ray observations collected in 2022 and 2023, along with archival data gathered earlier, Watson and her colleagues traced enormous structures hidden within the cluster's hot gas, including one of the longest continuous "sloshing spirals" ever observed, the study reports. The spiral stretches nearly 2 million light-years from the cluster's center.

The observations also revealed a concave "bay"-like depression south of the cluster core, a broad "splash" of cooler gas extending southeastward, and evidence of a possible shock wave propagating through the cluster outskirts, according to the paper.

To uncover the array of hidden substructures, the team used image-processing techniques that removed the cluster's otherwise smooth and symmetrical X-ray glow. Computer simulations that then traced the cluster's history suggest the structures likely formed after a smaller galaxy cluster plunged through Abell 2029 billions of years ago, the study notes.

That collision would have displaced the hot gas, causing it to oscillate and swirl through the cluster's gravitational field, "similar to how wine moves in a wine glass," the statement read.

The study suggests those giant sloshing motions may help regulate how the cluster cools over time by redistributing heat through the intracluster gas, alongside energy injected by the active supermassive black hole at the center of IC 1101, which is one of the most massive known to date.

That matters because the gas inside galaxy clusters constantly radiates energy away in X-rays and should gradually cool over time, and scientists suspect energy released by supermassive black holes, known as AGN feedback, helps reheat that gas and prevent runaway cooling.

But the new findings suggest black hole activity alone may not fully explain what is happening in Abell 2029, and that the large-scale sloshing caused by the ancient merger may also play an important role in stirring and heating the gas, the new study notes.

Meanwhile, the splash feature of cooler gas may trace a wake of material left behind after the smaller cluster made a second pass through Abell 2029, the study suggests. Simulations indicate the smaller cluster initially swept through the larger one, dragging gas sideways and generating the enormous spiral. Gravity from the larger cluster would have then slowed the smaller object and pulled it back for another encounter, producing shock fronts and additional disturbances in the gas.

The bay structure may represent overlapping gas flows where the outer edge of the spiral intersects with material stripped from the smaller cluster during the collision, according to the study.

Alternatively, the study notes, the bay feature could be associated with the edge of a giant "ghost bubble" — an ancient cavity carved into the gas by activity from the supermassive black hole at the center of IC 1101.

Although Watson and her colleagues found no clear evidence of previously undiscovered radio bubbles in the cluster gas, they note that projection effects could make such structures difficult to detect if they are partially aligned along our line of sight.

This research is described in a paper published December 2025 in The Astrophysical Journal.

Using the James Webb Space Telescope, astronomers have mapped the "cosmic web" of galaxies — the largest structure in the universe — with unprecedented detail.

This is the largest James Webb Space Telescope (JWST) survey conducted to date, and is known as COSMOS-Web. It traces a network of galaxies back to when the universe was about 1 billion years old.

The cosmic web is the term scientists use to describe a skeleton-like framework of filaments and sheets of dark matter and gas along which galaxies gathered and evolved over time, which is punctuated by nearly empty voids. Thus, the cosmic web forms the architecture of the universe — it's a singular, intricate, far-reaching structure that traps galaxies and galactic clusters like flies strung along the sticky silk web of a greedy spider.

The results obtained by the COSMOS-Web team further demonstrate the power of the JWST to refine and redefine our view of the universe since the $10 billion space telescope began beaming data back to Earth in the summer of 2022.

"JWST has completely changed our view of the universe, and COSMOS-Web was designed from the start to give us the wide, deep view we need to see the cosmic web," leader of this research, Hossein Hatamnia of the University of California, Riverside (UCR), said in a statement. "For the first time, we can study the evolution of galaxies in cluster and filamentary structures across cosmic time, all the way from when the universe was a billion years old up to the nearby universe."

By the "nearby universe," Hatamnia means up to a distance of around 1 billion light-years. The solar system is estimated to be around 2 light-years wide, giving you an idea of just how far astronomers consider our cosmic backyard to extend. COSMOS-Web extends this by another 13 or so billion light-years.

That kind of depth of view is the only way astronomers can get a true picture of the cosmic web.

The large-scale structure delivered by COSMOS-Web provides a wealth of information greater than that provided by earlier maps of the same region of sky captured by the Hubble Space Telescope. Team member and UCR scientist Bahram Mobasher explained that comparing Hubble and JWST shows that many cosmic structures had been "smoothed over" in data from the JWST's space telescope predecessor.

"The jump in depth and resolution is truly significant, and we can now see the cosmic web at a time when the universe was only a few hundred million years old, an era that was essentially out of reach before JWST," Mobasher said. "What used to look like a single structure now resolves into many, and details that were smoothed away before are now clearly visible."

The impressive leap in detail provided by the JWST and COSMOS-Web is the result of the unification of two of this powerful new space telescope's key strengths.

"The telescope detects many more faint galaxies in the same patch of sky, and the distances to those galaxies are measured far more precisely," Hatamnia said. "Each galaxy can therefore be placed into the correct slice of cosmic time, sharpening the map's resolution."

The team's research was published on May 6 in The Astrophysical Journal.

Astronomers have captured an extraordinary new look at the hidden birthplaces of star clusters, uncovering fresh clues about how galaxies evolve — and how young planets may be shaped by their stellar environments.

Using observations from the James Webb Space Telescope (JWST) and the Hubble Space Telescope, astronomers studied nearly 9,000 young star clusters across four nearby galaxies: Messier 51, Messier 83, NGC 628 and NGC 4449. The newly released images reveal glowing clouds of gas and dust where thousands of stars are actively forming, while also highlighting the JWST's growing ability to uncover hidden galactic structure. Brilliant knots of newborn stars, dark rivers of dust and glowing cavities carved by stellar winds combine to create a vivid portrait of galaxies in constant motion.

While the JWST's infrared vision allowed scientists to peer through thick cosmic dust, Hubble traced older, fully exposed clusters in visible light. Together, the observations allow researchers to study star clusters from their earliest, dust-shrouded stages to fully emerged stellar groups, according to a statement from NASA.

"This work brings together researchers simulating star formation and those working with observations, as well as groups researching planet formation," Alex Pedrini, lead author of the study from Stockholm University and the Oskar Klein Centre in Sweden, said in the statement. "Using Webb, we can look into the cradles of star clusters and connect planet formation to the cycle of star formation and stellar feedback."

By developing simulations that account for stellar dynamics in emerging star clusters, researchers discovered the universe's largest star clusters break free from their birth clouds much faster than expected, dramatically altering their surroundings in the process. The team found that the most massive clusters cleared away their natal gas clouds in about five million years, while smaller clusters took up to eight million years to emerge — a relatively small difference that could influence how star formation unfolds within galaxies over time.

"Simulations of star formation and stellar feedback have struggled to reproduce how star clusters form and emerge from their natal clouds," said Angela Adamo, co-author of the study and Principal Investigator of the FEAST (Feedback in Emerging Extragalactic Star Clusters) program, which collected the observations used in the research as part of a broader effort to investigate how newly formed stars shape the galaxies around them. "These results give us important new constraints on that process."

Once freed from their birth material, these giant clusters unleash intense ultraviolet radiation and stellar winds that heat and disperse nearby gas — a process known as stellar feedback. Because cold gas is the raw material needed to form new stars, stellar feedback can effectively regulate future star formation inside galaxies.

The findings could also reshape scientists' understanding of planet formation. Young planetary systems developing around stars inside these clusters may become exposed to harsh ultraviolet radiation earlier than expected. That radiation can erode the disks of gas and dust surrounding newborn stars, potentially limiting how large planets are able to grow, according to the statement.

Their findings were published May 6 in the journal Nature Astronomy.

An enormous supercluster made up from over 20 individual galaxy clusters hiding behind our dusty Milky Way is even larger than astronomers had thought, affecting the motion through space of all the galaxies and galaxy clusters in our corner of the cosmos.

The Vela Supercluster was discovered in 2016 thanks to a team led by Renée C. Kraan-Korteweg of the University of Cape Town in South Africa. Some 870 million light-years away, it lurks close to the plane of the Milky Way. Extragalactic astronomers refer to a region behind our Milky Way as the 'Zone of Avoidance' because dust between our galaxy's stars blots out, or deeply reddens, light from more distant galaxies behind it.

Given that this Zone of Avoidance takes up about 20% of the entire sky from our vantage point on Earth, that's a lot of celestial real estate inaccessible to us.

Fortunately, astronomers have their ways and means of bypassing the Zone of Avoidance, and now, Kraan-Korteweg and her team have done just that to discover the true scale of the vast Vela Supercluster.

Gravity from huge superclusters tugs on the motions of galaxies across the universe, drawing them closer. We see these subtle galaxy motions as 'cosmic flows', like tides and eddies that carry galaxies this way and that.

However, while we knew the Vela Supercluster was exceptionally massive when it was discovered, it didn't seem massive enough to account for all the cosmic flows seen by astronomers.

The CosmicFlows catalogue, organized by astronomers in France and Hawaii, is a record of measurements of the 'peculiar' motions of galaxies, or rather, their motions that deviate from that expected by the continuous expansion of space. Once gravitational interactions with nearby galaxies have been accounted for, any excess peculiar motion is therefore the result of 'cosmic flows' — the gravitational attraction across hundreds of millions or even billions of light-years towards large centers of mass.

There are many cosmic flows across the universe as streams of galaxies head in one direction or another. The 'Great Attractor,"–– the romantic name given to one large supercluster also hidden by the Zone of Avoidance and connected to the Laniakea supercluster of which the Milky Way is a tiny part — is just one source of cosmic flow. The Shapley Supercluster, located 650 million light-years away, is another.

Now, Kraan-Korteweg and her astronomers, in a study led by Amber Hollinger of the Lyon 1 Claude Bernard University in France, have discovered the origin of the excess cosmic flow: the Vela Supercluster is larger than was thought.

By using 65,518 galaxy distance measurements from the latest CosmicFlows catalogue, coupled with 8,283 new galaxy redshifts close to the plane of our galaxy, Kraan-Korteweg's team were able to identify other galaxies and galaxy clusters that apparently are part of the Vela Supercluster. The extra data came from observations with SALT, the Southern African Large Optical Telescope, and the MeerKAT radio telescope array in South Africa. In particular, MeerKAT was able to detect galaxies in the Zone of Avoidance because radio waves from their hydrogen gas can pass through our Milky Way's dust lanes relatively unhindered.

They found that the Vela Supercluster is comparable in mass to the Shapley Supercluster, and contains 33,800 trillion solar masses worth of material spread across a volume approximately 300 million light-years wide. It is so huge and massive that its gravitational influence over galaxies in the universe exceeds even that of the Great Attractor. It is made from two walls of galaxy clusters, each with a dense, massive core, moving towards one another under gravity.

"This discovery helps complete our map of the nearby Universe," said the research team in a statement. "For the first time we can clearly see one of the major gravitational players hidden behind our own galaxy."

Kraan-Korteweg's team have nicknamed the Vela Supercluster "Vela-Banzi," which means 'revealing widely' in the isiXhosa language of South Africa.

The findings are described in a paper on the arXiv pre-print paper repository.

In its infancy, the universe had a bit of an identity crisis.

For the first few hundred million years, the vast cosmic gas between galaxies was primarily a chilly, dense affair. But then, it seemed to wake up, deciding to get all warm and fuzzy.

This strange shift in the cosmos’ early disposition is a crucial clue to how the very first galaxies burst into being, shaping everything we see today. The early universe, a mere whisper after the Big Bang, just a few hundred million years old — that's when the first stars and galaxies were starting to flicker on, like fairy lights across a cosmic dark.

The fuel for all this grand production: gigantic clouds of gas, mostly hydrogen. Astronomers have always suspected these baby galaxies were busy, but new glimpses from the James Webb Space Telescope are showing them to be even brighter and larger than our wildest dreams. They're like finding teenagers sitting in a kindergarten class, way ahead of their expected development.

This cosmic precociousness means our existing models of how galaxies form might need a serious tune-up. We thought we had a pretty good handle on how gas falls into dark matter halos, cools down, and then ignites into stars. But the JWST data suggests a much more aggressive, faster-paced star-making frenzy in those early days. The question becomes: How did these young galaxies manage such a booming business so quickly?

To untangle this mystery, Umberto Maio from the INAF-Italian National Institute of Astrophysics and the Institute for Fundamental Physics of the Universe, working with Céline Péroux at the European Southern Observatory, decided to dive into the virtual cosmos. They created incredibly detailed computer simulations, a sort of cosmic time machine called ColdSIM, to rewind the clock and watch how gas behaved in the first billion years after the Big Bang. Their goal was to make predictions about the early universe’s baryon budget — that's the accounting sheet for all the "normal" matter, the stuff stars and planets are made of, and where it ended up.

What they found was a universe in flux. Before a pivotal moment called the epoch of reionization — when the universe finally became transparent to ultraviolet light — the gas was indeed mostly cold. It was the perfect, dense environment for star formation. But as star formation really picked up, and that intense ultraviolet light started zipping around, things changed. The simulations showed that the gas quickly shifted, becoming dominated by a warm, less dense phase. It’s like the universe went from a quiet, cool morning to a bustling, sun-drenched afternoon, with all that energy from new stars and radiation heating things up.

This wasn't just a minor temperature change. It fundamentally altered the rhythm of galaxy evolution. The team's clever simulations traced the journey of various types of gas, carefully avoiding the usual shortcuts in models that can often lead to fuzzy answers. They found some eye-opening things about how these infant galaxies put themselves together.

For starters, the stellar return fraction was surprisingly low. This is the amount of material that stars eject back into the surrounding gas when they die, essentially recycling fuel for the next generation of stars. In the early universe, it seems, stars were less efficient at this recycling. Lower quantities of old stellar material returned to the gas, meaning that new stars largely formed from fresh, pristine gas constantly falling in from the cosmic web. It's a bit like a construction site that keeps getting new materials delivered rather than reusing much from demolished buildings.

But even with less recycling, these galaxies were burning through their gas at an astonishing rate. Maio and Péroux discovered that the depletion times — the time it would take for a galaxy to convert all its gas into stars at its current rate — were incredibly short. Much shorter than we see in galaxies today. This means that early galaxies were true star-forming machines, gobbling up gas and spitting out stars with a furious intensity. It paints a picture of baby galaxies throwing one heck of a tantrum, furiously making stars with every available bit of gas.

So, why does any of this matter? Because it rewrites a part of our cosmic origin story. Our initial predictions for these early galaxies, based on observations of later, more mature galaxies, simply weren't capturing this dynamic, rapidly evolving picture. It turns out that you can't just take what you know about middle-aged galaxies and apply it to their energetic youth. The physical processes, from gas dynamics to stellar feedback, are just too different when the universe itself is so young and compact.

Of course, this cosmic detective story is far from over. Numerical simulations are powerful, but they’re always battling with the sheer complexity of the universe. Modeling everything from the intricate, multi-phase structure of gas to the powerful winds blown out by massive stars and black holes is a huge challenge. There are still big uncertainties, like the exact initial mass function of stars (how many big stars versus small stars are born) and the precise amount of "metals" needed to kickstart cooling. Our models still have plenty of room to grow.

But the good news is, we’re armed with ever more powerful tools. The James Webb Space Telescope is out there, giving us sharper and sharper images of these distant, ancient galaxies. And coming down the pipeline are next-generation radio telescopes, like the Square Kilometer Array (SKA), which will let us peer even deeper into the cold gas reservoirs of these early galaxies. These new eyes on the sky will give us the crucial real-world data needed to test these new theoretical predictions, helping us refine our models and paint an even clearer picture of the universe's chaotic, yet beautiful, beginnings.

The journey to understand how the universe built itself, one galaxy at a time, is still unfolding before us.

Here at Space.com, we love the night sky, rocket launches and sci-fi just as much as you do. Each month (from here on out) we want to celebrate that love by bringing you a collection of eclectic staff photos that show you a little of what we've been up to.

Expect launch photos, snaps of historic hardware destined for space, images of the night sky and, from time to time, photographic evidence of our entertainment editor Ian Stokes infiltrating Amazon's London office to sneak a peek at their May the 4th Star Wars offering … allegedly.

Don't forget! We love nothing more than seeing your discussions in the comments section under each article and, of course, featuring and enjoying your astrophotography, which you can share with us and the readers at spacephotos@space.com!

Photos from Space (.com)

We'll kick off with our spaceflight writer Josh Dinner, who took a road trip down to NASA's Kennedy Space Center in Florida to report first hand on the historic launch of the Artemis 2 mission to the far side of the moon!

"Witnessing SLS launch from the press site was more than just seeing the rocket liftoff  —  it was feeling it," Dinner told Space.com. "The shake and crackle of the solid boosters and legacy shuttle tech ripping through the sky is truly one to behold, and shooting Artemis 2 was an absolute experience. Whenever I photograph a launch, I always shoot at least a little underexposed. Accounting for the flame is important, especially when it comes to those blindingly bright solids."

"From farther away, you don't want to set your shutter too fast, but for my launchpad cameras, up close, that's where I'll plan for minimum exposure time. It makes your RAW images dark everywhere else, but that's all easily brought out in minor edits. I love getting to see the details of the flames as they explode from the rocket's engines.

"And with Artemis 2 I got extra lucky with some small water droplets that didn't quite dry off the lens as my cameras braved a rain storm the night before liftoff. They created some nice flares I think really add some uniqueness."

Managing editor Brett Tingley, meanwhile, set his sights further afield to photograph a stunning spiral galaxy shining 11.6 million light-years from Earth in the constellation Ursa Major.

"On March 28, 2026, I hiked out to a dark area in the Appalachian mountains to capture some deep sky objects," explained Tingley. "Bode's Nebula (Messier 81) was positioned perfectly overhead during the evening hours, allowing for a perfect long-exposure shot. Despite its name, Messier 81 is actually a galaxy - one of the brightest in the night sky."

"This was taken with a Celestron Origin Mk II using a nebula filter, enabling me to capture its spiral shape in great detail. It's incredible to be able to set up a smart telescope and watch images like this one develop in real time, putting deep space objects out in the cosmos right at our fingertips"

Space.com astronomy editor Monisha Ravisetti was lucky enough to spend a little time with the Nancy Grace Roman Space Telescope at NASA's Goddard Space Flight Center in Maryland earlier this month, ahead of its planned September 2026 launch.

"As a space journalist, it's tremendously routine for me to write about space telescopes," said Ravisetti. "I've pored over vast cosmic landscapes imaged by the tried and true Hubble Space Telescope, but what sticks out is this instrument launched before I was born. More times than I can count, I've tried to make sense of ancient black holes or glowing nebulas that sit millions of light-years away from me, but often, I owe these sights to the James Webb Space Telescope.

"Indeed, I've only seen the JWST in photos. My iPhone lock screen used to be a Euclid image, but again, I've never seen Euclid itself. These physical observatories have therefore remained in my imagination just like the universe they observe — places I'll never be able to explore."

"The Nancy Grace Roman Space Telescope is the first observatory headed beyond Earth that I got to see in person. It was a surprising experience. Did it look as grand as you'd expect something so pivotal to look? Not really, honestly. It was relatively compact, industrial and most importantly, comprehensible. It appeared as a piece of real, mechanical equipment.

"But while I looked on, I started to realize why it seemed profound to be this telescope's witness. It's surreal to remember a very reasonable object will eventually show us corners of our universe we haven't yet reasoned with. It's surreal to remember that these telescopes really aren't just intangible items in my imagination, and neither are those cosmic places I'll never explore."

Skywatching editor Daisy Dobrijevic captured a gorgeous view of the Triangulum Galaxy, using a smart telescope that cut through the light-polluted city sky to reveal fantastic detail on the deep sky object.

"I captured this view of the Triangulum Galaxy (M33) from my garden in Nottingham, U.K., using the Vaonis Vespera Pro," said Dobrijevic. "Despite working under Bortle 6 skies, I built up 3 hours of total exposure time across multiple nights, taking advantage of the Vespera Pro's multi-night observing mode — an invaluable feature when clouds inevitably roll in."

"I was genuinely surprised by just how much detail I could pull out in such a short amount of time, especially given the light pollution!"

Space.com editor-in-chief joined Dinner in Florida to witness the launch of Artemis 2 first hand, before heading out to Houston to report on the astronaut's progress as they broke the record for the most distant crewed spaceflight in human history, ahead of their safe return to Earth.

"I have waited my entire life to see astronauts launch to the moon," recalled Malik. "It was worth it. For just about my entire career, NASA has been trying to send astronauts back to the moon. First, it was Project Constellation and a goal of 2020. Then, maybe it was 2024. Then Constellation was cancelled and I instead watched dozens of space shuttle and rocket launches stay in low-Earth orbit. Even Artemis 1 in 2024, I missed. It was scrubbed several times (I saw them all) and when it finally did fly, I couldn't be there."

"But a month ago, Artemis 2 was something else. I've seen the largest rocket on Earth — SpaceX's Starship — launch (and explode) and that was loud. But watching four astronauts launch on NASA's most powerful rocket since the Saturn V hits different. First, it was SO LOUD. Much louder than the Starship launch because we were just 3 miles away (about 2 miles closer). You felt it in your bones and it drowned out all sound. But also because there were PEOPLE on this one. Four astronauts that I have spoken with personally at one time or another. Then they went to the moon.

And for the first time in my 49 years, more than half of that as a space reporter, I feel like a new space age is finally beginning, one in which astronauts finally reach the moon to stay, then Mars, and then who knows where else? (I vote for Titan and Venus, but that's just me.)"

Our senior producer/video wizard Steve Spaleta chose to reminisce over a collection of legendary aircraft — and the creation of a legendary photo.

"After covering the unveiling of Virgin Galactic’s Spaceship Unity at the Mojave Air and Space Port in February 2016, Dave Brody (Space.com’s former exec. producer) and I visited the Joe Davies Heritage Airpark in Palmdale. The photo here shows a retired Shuttle Carrier Aircraft, a Boeing 747-100SR—one of only two ever used to ferry space shuttles.

"The outdoor aerospace museum, free to the public, also features a Lockheed JetStar used by NASA, along with several military aircraft, including a B-52 Stratofortress. Dave Brody snapped the image and joked, “add a Rick or an Alembic, and that’s an album cover.”

Harry Bennett, our e-commerce staff writer and overall photography enthusiast snapped a stunning view of Vega shining in the constellation Lyra.

"Vega shines a beautiful white-blue with four prominent diffraction spikes, giving it an angelic presence amongst a vast star field, " said Bennett. "It is the fifth brightest star in the night sky and the second brightest in the northern hemisphere. I took this shot using the enhanced vision mode on the Unistellar Odyssey Pro, which stacks four-second exposures continuously until you stop it."

"I have a soft spot for it because it is the first smart telescope I ever used and it gave me the ability to capture mind-blowing images of night sky objects even from a city center. It is fully automatic and can orient itself, find a target and start imaging all from a few presses on your smartphone. People can be swept up in smart telescopes’ ability to capture amazing detail on deep-sky objects like galaxies but forget that imaging individual stars can really make you feel magical."

Entertainment editor Ian Stokes went off campus to take a look at Amazon's office in London in disguise as a scout trooper. At least we think it's Ian?

"I channelled my inner Bothan and managed to infiltrate the Amazon office in London and while they didn’t have the droids I was looking for, they did have a bunch of Star Wars merch on display ahead of the May the Fourth festivities. They had a bunch of cool lightsabers, figurines, and helmets for staff and visitors to check out, including the snazzy scout trooper helmet that I’m sporting here.

"Sadly I was escorted from the premises when I tried to add myself to the cast list for the new Stargate show they’re working on."

Editor's Note: If you would like to share your photography with Space.com's staff and readers, then please send your photo(s), comments, and your name and location to spacephotos@space.com.

The Sombrero galaxy looks like a work of science fiction in a stunning new image showcasing its hat-shaped appearance in stunning detail.

What is it?

Messier 104, nicknamed the Sombrero galaxy, is a spiral galaxy located about 28 million light-years from Earth.

At an apparent magnitude of +8, it's too dim to see with the naked eye. However, binoculars or a small telescope will reveal its distinctive, wide, sombrero shape, making it a favorite target for skywatchers.

If you're looking for Messier 104 in the night sky, you can find it in the constellation Virgo.

This image of the far-off galaxy was captured using the Department of Energy-fabricated Dark Energy Camera (DECam), mounted on the U.S. National Science Foundation Victor M. Blanco 4-meter Telescope at Cerro Tololo Inter-American Observatory. The observatory is part of the National Science Foundations' NOIRLab (formally the National Optical-Infrared Astronomy Research Laboratory), the U.S. center for ground-based nighttime optical astronomy.

Why is it incredible?

It's no secret how the Sombrero galaxy got its nickname. With a very distinctive, wide and flat shape and it really does look like a cosmic sombrero.

The name itself has no scientific meaning — it's simply a reflection of a very human habit of finding familiar shapes in the unfamiliar.

The Sombrero galaxy holds nearly 2,000 globular star clusters, nearly 10 times more than the number in our own Milky Way. But in looking at this galaxy like a big, cosmic hat, it becomes somehow more relatable. Humans have been doing this with galaxies, stars, constellations, and even cloud shapes for as long as we have existed, and it brings the cosmos close.

A new citizen science project invites the public to scan never-before-seen images from the Euclid Space Telescope in search of galaxies bending spacetime.

Led by the European Space Agency (ESA), the initiative, called Space Warps, uses data from Euclid to crowdsource the search for rare cosmic distortions known as gravitational lenses. These occur when massive foreground objects such as galaxies or galaxy clusters warp spacetime, bending and magnifying the light from more distant background objects. As Euclid continues its survey, sending around 100 GB of data to Earth each day, citizen scientists are being asked to help identify strong gravitational lenses in the dataset, according to a statement from the space agency.

"We can't wait to see what we will find within this unprecedented dataset," Aprajita Verma, Space Warps' co-founder and project lead at the University of Oxford, UK, said in the statement. "Join us on Space Warps to take part in this exciting search!"

Gravitational lensing can produce striking visual signatures: stretched arcs of light, duplicated galaxy images or near-perfect rings known as Einstein rings. Beyond their visual appeal, these "space warps" are powerful scientific tools. By magnifying extremely distant galaxies, gravitational lenses allow astronomers to study objects that would otherwise be too faint to detect, while also offering clues about the distribution of dark matter throughout the universe.

Finding these lenses, however, is far from straightforward. Even with modern machine learning tools, the subtle distortions can be difficult to reliably identify in large imaging surveys. Citizen scientists, by contrast, are often adept at picking out unusual patterns that algorithms miss.

Through the Space Warps project, hosted on the Zooniverse platform, participants are shown real Euclid images and asked to flag potential lensing features. Roughly 300,000 AI-selected images — refined using results from the initial Euclid citizen science strong lens search — will be shown, representing the top candidates drawn from 72 million galaxies in the mission's first data release.

No scientific background is required to participate. Volunteers are guided through examples, along with an explanation of what gravitational lenses are and how to recognize them before classifying data from the mission's growing archive. Participants also get an early look at images not yet released publicly, ahead of Euclid Data Release 1.

Over 2,500 volunteers have already joined Space Warps to identify rare strong lenses. Participants are asked to place a marker on features that suggest there is gravitational lensing in an image. A marker can simply be added to an image by clicking on the lens feature — or easily deleted — and users can then move on to the next image by clicking done.

The Zooniverse platform makes it easy to comb through the images, allowing users to pan/zoom each image, or change to a flip-book view of the different colored images. The platform also has a built-in Field Guide to help distinguish real signals from imposters, as well as training images and real-time feedback to help sharpen classifications.

The scale of the task reflects Euclid's ambition. Since its launch in 2023, the mission has begun mapping the large-scale structure of the universe in unprecedented detail, capturing vast numbers of galaxies across a wide swath of the sky. Its high-resolution, wide-field imaging makes it especially well suited for spotting strong gravitational lenses, which are rare but scientifically valuable.

Researchers estimate that citizen scientists could help identify more than 10,000 new lens candidates over the course of the project — a major expansion of the current catalog. Those discoveries would help improve measurements of how matter, both visible and invisible, is distributed across cosmic scales.

The effort builds on earlier successes in citizen science, where volunteers working through the Zooniverse have already contributed to the discovery of hundreds of gravitational lens candidates. In fact, in March 2025, 500 galaxy-galaxy strong lenses were found nestled in just the first 0.04% of Euclid data, most of them previously unknown. Those classifications not only add to scientific databases but also help refine the artificial intelligence systems increasingly used to process astronomical data, according to the statement.

As Euclid continues to survey the cosmos, Space Warps highlights a growing reality in modern astronomy: the biggest datasets in history are increasingly being explored not just by scientists and supercomputers, but by anyone with an internet connection and a willingness to help uncover the universe's hidden distortions.

Registration on the Zooniverse platform is required to participate in the research and save possible classifications for further investigation. By exploring and interacting with Euclid images, volunteers have a unique chance to contribute directly to discoveries that could reshape our understanding of the universe.

The Small Magellanic Cloud (SMC) looks spectacular in a new snapshot. But something about it might really surprise you.

It looks like this detailed image of a far-off galaxy was captured an advanced space telescope, or a huge ground-based scope. However, it was actually snapped with a camera sporting a telephoto lens from right here on Earth.

What is it?

The SMC is a dwarf galaxy that holds hundreds of millions of stars. The galaxy is near our very own Milky Way; in fact, it's one of our closest neighbors. Still, it is nearly 200,000 light-years away.

Despite that distance, the SMC can be seen with the naked eye from the Southern Hemisphere.

This unique visibility may have played a role in this spectacular image, which was captured by Petr Horálek, a NOIRLab Audiovisual Ambassador, using a camera and a wide-aperture telephoto lens on the mountain Cerro Pachón in Chile. This image capture took four hours under the dark skies above the mountain.

Why is it incredible?

In looking at this photo, you might assume it was captured by a space telescope like Hubble. It's a detailed and striking view of this far-off galaxy.

But Horálek captured this image with just a camera and telephoto lens. NOIRLab's ambassador program is a joint venture with the Vera C. Rubin Observatory, and ambassadors share science with the public and their local communities.

This image is beautiful, but it also represents an exciting achievement in astrophotography.

Our universe is full of mysteries, but few are as perplexing as the dark, tiny galaxies that hover around larger ones like the Milky Way.

Small, dim, and almost invisible, dwarf spheroidal galaxies are packed to the brim with something we can't see: dark matter. They're like cosmic icebergs, with most of their mass hidden from plain sight, making them some of the most exotic objects in the universe.

But these deceptively simple structures hide a deep secret. For years, astronomers have scratched their heads over a thorny problem, often called the "cusp-core problem." Our best theories for dark matter, based on the cold dark matter model, predict that the density of this invisible stuff should get incredibly steep, forming a "cusp" at the very center of these galaxies. Like a mountain peak, sharp and pointy, where dark matter congregates.

Yet, when we peer at the actual movements of stars inside many of these dwarf galaxies, what we often see is something flatter, more like a gentle hill – a "core." It’s a bit like finding a perfectly smooth, inviting plateau where you expected a jagged, impassable summit. This persistent mismatch has fueled a serious debate, leaving us wondering if our understanding of dark matter, or perhaps galaxy formation itself, is fundamentally off.

This mystery has challenged the standard picture of how galaxies form and evolve. But astronomers are clever, and they keep digging. Consider this: these galaxies aren't just born with their final shape, but instead evolve into it, following a cosmic blueprint. This is the idea at the heart of new research from Jorge Peñarrubia and Ethan O. Nadler, affiliated with the Institute for Astronomy at the University of Edinburgh and the Department of Astronomy & Astrophysics at the University of California, San Diego. They propose that dwarf spheroidal galaxies are always moving toward a specific, stable configuration, a cosmic resting place they call a "dynamical attractor." It's like every tiny galaxy has a pre-determined final form, and no matter its starting conditions, it's destined to build itself into that design.

How does a galaxy find its way to this precise blueprint? It's not a gentle drift toward equilibrium. Stars inside these dwarf galaxies get a constant, chaotic cosmic kick in the pants. They don't just orbit smoothly around the galaxy's center, like planets around a star. Instead, they’re constantly jostled by what Peñarrubia and Nadler describe as "stochastic force fluctuations." Think of it like a pinball machine. The stars are the pinballs, and instead of perfectly smooth walls, they're continually bumping into invisible, unpredictable bumpers, always gaining a little bit of energy.

What are these invisible bumpers? They are "dark subhaloes" — clumps of dark matter embedded within the galaxy's larger, smoother dark matter halo. Yes, even within the mysterious dark matter, there are smaller, lumpier bits. Causing trouble. These dark subhaloes exert unpredictable gravitational forces, giving energy to the stars and pushing their orbits outward. The stars gain energy, their orbits expand, and the entire stellar system starts to puff up and spread out. This process, in which stellar orbits expand and gain energy, is a kind of internal "heating" for the galaxy, driving its evolution. This internal heating is a powerful force, but it’s not the only game in town.

The universe is a busy, often violent place, and dwarf spheroidal galaxies often find themselves caught in the gravitational pull of much bigger galaxies, like our own Milky Way. When a large galaxy tugs on a smaller one, it can rip away its outer layers — a process called tidal stripping. This external stripping accelerates the heating and expansion of the dwarf galaxy, nudging it toward that dynamical attractor even faster. But even dwarf galaxies that are floating alone in the cosmic void, isolated from the gravitational harassment of their larger neighbors, still evolve toward this attractor through their own internal heating. It just takes them a bit longer. For example, a dwarf galaxy in isolation might need as long as 14 billion years — essentially the age of the universe — to fully reach its stable form.

So, how do Peñarrubia and Nadler know this isn't just some clever mathematical conjecture? They didn't just concoct a theory out of thin air. These researchers built entire tiny universes, running elaborate "N-body experiments" — fancy computer simulations that track the motions of zillions of stellar particles and dark subhaloes over billions of years. They even placed some of their model dwarf galaxies on eccentric orbits around a simulated Milky Way, just to see how the relentless tug of tides would affect things. Their experiments showed that a dwarf spheroidal galaxy has to shed more than 99% of its initial dark matter before it starts losing a significant number of its stars, thanks to how the stars and dark matter separate over time.

And they didn't stop there. They also applied what they call the "Heating Argument" to real-world data from the dwarf galaxies orbiting our Milky Way. What they found was fascinating: these galaxies follow specific "tidal tracks" that match what you'd expect from their model. Their stellar orbits, on average, expand to a point where the speed at which the stars are jiggling around — what astronomers call the velocity dispersion — is about half the peak speed that dark matter could make them go within the halo. This holds true for different theoretical dark matter distributions, whether they’re "cuspy" like a sharp peak or "cored" like a gentle plateau. For a common stellar distribution model, the ratio could be 0.54, or for another, 0.48. It’s a remarkable consistency, suggesting a universal behavior.

This all means that the incredible diversity we see in dwarf spheroidal galaxies today — their different sizes and internal motions — isn't necessarily a snapshot of how they were born, like distinct species. Instead, it’s a dynamic story of evolution, a journey driven by both internal gravitational jostling from dark subhaloes and external tidal forces from larger neighbors. They're all marching toward a common, stable state, a kind of cosmic destiny. The structural diversity we observe is largely an evolutionary outcome, not just a random scattering of initial conditions. This reframes our understanding of their very structure and persistence.

Of course, science is never truly settled. We still have many puzzles to crack. Attempts to figure out the exact dark matter distribution inside these galaxies are notoriously tricky, partly because of what's called the "mass-anisotropy degeneracy." It’s difficult to tell if stars are moving in perfectly random directions or if there's a preferred direction, which makes calculating the dark matter's gravitational pull a real headache. Plus, we often can't tell the full 3D orientation of these dim galaxies along our line of sight, adding another layer of uncertainty to their total halo masses and density profiles. So, while we have a brilliant new framework, the precise total masses and density profiles of individual dwarf spheroidal galaxies remain elusive. This model, for instance, simplifies by not fully accounting for how dark subhaloes affect the smooth overall dark matter potential.

Still, this work gives us a powerful new lens through which to view these tiny, dark-matter-dominated worlds. It highlights how the subtle, ongoing interactions within and around a galaxy can completely reshape its destiny. The universe, it seems, has a way of guiding even its smallest inhabitants toward predictable, stable forms, offering a tantalizing glimpse into the grand, unfolding story of cosmic evolution. What other hidden attractors are out there, waiting for us to discover? We've got a lot more to learn about how these cosmic dance partners choreograph their lives, and the detective work continues, one tiny, dark galaxy at a time.

Ever dreamt of being present during the birth of the first galaxies? Perhaps being able to fast-forward through billions of years of cosmic evolution to watch those galaxies grow and shape the universe we know today? Of course, that sadly isn't possible. But thanks to a revolutionary new and unique audiovisual simulation of "virtual universes," scientists have developed the best picture of cosmic evolution to date, and you too can see and hear it!

The COLIBRE virtual universes use the standard model of cosmology to model the dynamics of cold galactic dust and gas, which form the building blocks of stars, from the first billion years after the Big Bang to the present day. With more computing power than previously available to other cosmic simulations, COLIBRE developed a synthetic universe that closely resembles observations the James Webb Space Telescope (JWST) has been making of the early cosmos. As such, the research offers validation of the standard model of cosmology, also known as the Lambda Cold Dark Matter (LCDM) model.

And fascinatingly, this synthetic universe is so convincing that even some astronomers are doing double-takes.

"It is exhilarating to see 'galaxies' come out of our computer that look indistinguishable from the real thing and share many of the properties that astronomers measure in real data, such as their number, luminosities, colors and sizes," COLIBRE team member Carlos Frenk said in a statement. "I like to tease my observer colleagues by asking, 'Which galaxy catalogue do you think these images came from?' What is most remarkable is that we are able to produce this synthetic universe purely by solving the relevant equations of physics in the expanding universe."

The simulation runs on the COSMA8 supercomputer at Durham University, and has overcome a challenge that others have found insurmountable: the modeling of cold gas. But difficulty with such modeling was a problem because stars form when cold gas and dust collapse under their own gravity — to accurately simulate stars, you need to be able to accurately simulate cold gas movements. COLIBRE was also able to simulate small dust grains and their impact in helping form hydrogen molecules and blocking ultraviolet light that would prevent gas from cooling and birthing stars.

"Much of the gas inside real galaxies is cold and dusty, but most previous large simulations had to ignore this," COLIBRE leader Joop Schaye, of Leiden University in the Netherlands, said in the statement. "With COLIBRE, we finally bring these essential components into the picture."

Yet, as good as the synthetic universes are, there is still one cosmic puzzle the JWST has unveiled that they can't answer. Those are the so-called "little red dots" this instrument has been seeing in abundance during one period of cosmic time.

That could be because these enigmatic objects – which appear in vast numbers 600 million years after the Big Bang but disappear after the universe is around 1.5 billion years old — are heavy black hole seeds.

Though most of the simulations were completed in 2025, some are still running, and the data they have already delivered will take years to analyze.

"We're excited not just about the science, but also about creating new ways to explore it," James Trayford, of the University of Portsmouth, U.K., who led the development of COLIBRE's dust model and the sonification of its visualizations, said in the statement. "These tools could provide new insights, make our field more accessible, and help us build intuition for how galaxies grow and evolve."

The COLIBRE research was published on Monday (April 13) in the journal Monthly Notices of the Royal Astronomical Society.

The April new moon has arrived bringing several nights of spectacular dark skies perfect for observing the planets of the solar system, majestic constellations and the galaxies that lie beyond.

April's new moon occurs at 7:52 a.m. EDT (1152 GMT) on April 17, when the moon is positioned between the sun and Earth, rendering it lost from sight in the daytime sky, with the entirety of its near side bathed in shadow.

The moonless nights surrounding this phase are the perfect time to indulge in skywatching and night sky photography, as subtle constellations and deep sky objects often lost behind a veil of moonlight glisten in the twilight realm.

Visible planets

Look to the west shortly after sunset on April 17 to find Venus appearing as a bright evening star 15 degrees from the horizon, with the blue-white stars of the Pleiades open star cluster glowing 10 degrees above — roughly the width of your clenched fist held at arm's length.

The ice giant Uranus can be found a little under 5 degrees to the lower left of the star cluster. It'll be too dim to spot with the naked eye — without exceptionally dark skies and perfect vision — but a pair of binoculars or a small telescope will allow you to spot its disk as a tiny greenish dot, according to telescope manufacturer Celestron.

Jupiter, meanwhile, will shine high overhead, below Castor and Pollux — the brightest stars of the constellation Gemini. Turn a 6-inch telescope on Jupiter and you may notice a line of bright dots extending outward from the gas giant's colorful disk. Those are the Galilean moons Io, Ganymede, Europa and Callisto!

Head out an hour before sunrise on April 18 and find yourself a clear view to the eastern horizon for a chance to catch a planetary triangle rising in the glow of the coming dawn.

Mars will sit higher in the sky,with Saturn below and Mercury off to the right. Neptune will also be present to the upper right of Mercury, though the distant ice giant will be far too dim to spot with the naked eye.

Stars and constellations

The dark nights surrounding the new moon are a perfect time to explore some of the subtler constellations that glisten in the northern hemisphere sky.

First, locate the sickle-like formation of stars representing the head and chest of the great lion represented in the constellation Leo, which can be found high above the southern horizon in April with the bright star Regulus at its base.

Next, look to the lower right of Regulus to find a circlet of stars representing the head of the great serpent in the constellation Hydra, along with a string of stars that wind down and to the east towards the horizon, which mark its tail. Hydra is the largest constellation in the night sky, though it's often overlooked due to its lack of bright stars.

Perched along Hydra's back are the compact constellations Corvus (the crow) and Crater (the cup). To their east is the blue-white light of Spica — the brightest star in the constellation Virgo.

For a spot of deep sky viewing, why not head out to a dark sky location and sweep your telescope over the patch of sky where Leo, Virgo and the constellation Coma Berenices meet?

First, find Denebola, the star that marks the tail of the lion in Leo, and Vindemiatrix using a handy stargazing app. Roughly halfway between the two is Markarian's Chain — a spectacular string of galaxies whose ancient light can be spied with the aid of a modest telescope.

Read more: Galaxy season: Spring brings deep space wonder to the northern hemisphere night sky.

You could also capture spectacular images of the stars with the help of our beginner's guide to photographing the night sky. Be sure to check out our picks of the best telescopes and binoculars for exploring the night sky, along with our roundups of the top cameras and lenses for astrophotography available in 2026.

Editor's Note: If you would like to share your night sky photography with Space.com's readers, then please send your photo(s) along with your name, location and comments to spacephotos@space.com.

The Hubble Space Telescope has spotted a spiral galaxy swirling through the darkness of space, emanating an otherworldly glow through its cosmic, branching arms.

What is it?

A new image captured by the Hubble Space Telescope shows the barred spiral galaxy IC 486 in all its glory.

This galaxy is located about 380 million light-years from Earth, just to the left of the constellation Gemini.

IC 486 is a barred spiral galaxy, which means that it is a spiral galaxy — or a galaxy with a spiraling disk with "arms" that extend from its center — with a central bar-shaped structure composed of stars. These bars are seen in about two thirds of all spiral galaxies we've observed.

Why is it incredible?

The incredible nature of this image speaks for itself. The soft, gossamer glow of the spiral galaxy seems straight out of science fiction, but it is even more amazing to know that it is a real image of a real, massive galaxy far out in the cosmos.

But beyond its beauty, this image holds a multitude of scientific wonders. Highlighted at the center of the galaxy by a bright white glow, for instance, is IC 486's active galactic nucleus (AGN), the center of the galaxy and an active supermassive black hole.

Astronomers have discovered a rare "Einstein Cross" gravitational lens, revealing a young galaxy with shockingly mature stars.

The galaxy in question is J1453g, an elliptical galaxy that is the first gravitational lens at a large cosmic distance for which astronomers have been able to precisely "weigh." J1453g lenses the light from a more distant quasar, a region of space dominated by a ravenously feeding supermassive black hole, magnifying it and causing it to appear multiple times in the same image in the shape of a cross.

The galaxy is seen as it was around 8 billion years ago, when the universe was less than 6 billion years old. However, though it is a "primordial galaxy" in its early stages of development, J1453g is surprisingly similar to the Milky Way, our "mature" home galaxy. What this shows us is that the growth and evolution of galaxies could be much more complex than previously theorized.

"The discovery of this exceptional object has allowed us to accurately study the nature of the stars at the center of an elliptical galaxy in a remote era of the universe, when the galaxy was still young," team leader Quirino D'Amato, a researcher at the Italian National Institute for Astrophysics (INAF), said in a statement. "The fact that their composition is very similar to what we see today in the Milky Way, in a completely different environment and era, is surprising.

"This tells us that we are still far from fully understanding the processes of galaxy formation and evolution, and represents an important point for the development of future models."

What is gravitational lensing?

This research wouldn't have been possible with a quirk of the cosmos first posited by Albert Einstein in his 1915 magnum opus theory of gravity, general relativity.

General relativity suggests objects with mass give rise to a curvature in the very fabric of space and time, united as a four-dimensional entity called "spacetime." The bigger the mass of an object, the greater the curvature it generates, and we experience these warps in spacetime as gravity. Thus, the greater mass an object has, the greater its gravitational influence.

And when light passes through warps in spacetime, something fascinating happens. The usually straight path of light gets curved along the warp, with the degree of curvature dictated by how close to the object of mass the light passes.

That means when an object of great mass comes between Earth and a more distant object, light from that background object can arrive at our telescopes at different times. These intervening bodies can cause background objects to be magnified, or "gravitationally lensed." Indeed, this phenomenon is used to great effect by the James Webb Space Telescope (JWST) to see ancient and distant galaxies.

Every so often, the difference in arrival time can cause a background object to appear multiple times in the same image, too. These multiple manifestations of the same background body can take circular arrangements, or Einstein Rings, and can also appear as rarer Einstein Crosses.

In the case of this Einstein Cross, the gravitational lens is the galaxy J1453g in near-perfect alignment with Earth and a distant quasar, the active region at the heart of the galaxy, which is powered by a feeding supermassive black hole.

Gravitational lensing isn't just useful for seeing objects ordinarily way beyond our view; the lensing effect can tell scientists a great deal about the body doing the lensing as well. In this case, the team was able to use the cross-shaped manifestations of this quasar to determine the mass distribution of the stars J1453g to an unprecedented level of precision. That revealed something that defies what current models suggest.

Scientists usually expect the central bulges of elliptical galaxies to form rapidly and thus be dominated by low-mass stars. However, it appears that J1453g has a configuration like that of the Milky Way, which is a barred spiral galaxy, meaning some elliptical galaxies may form more slowly with higher mass stars at their hearts. Another possibility is that J1453g was transformed in its early history by a violent incident, such as a collision and merger with another galaxy.

As such, the team's results not only represent one of the most robust measurements of star birth in the adolescence of the universe, but also represent a new window on the formation and evolution of massive cosmic structures. Indeed, the research suggests a more dynamic and complex history for galaxies than was previously thought possible.

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

NASA's X-ray spacecraft XRISM, which stands for X-ray Imaging and Spectroscopy Mission, has clocked how fast winds are ripping from a distant galaxy bursting with star formation.

It would appear these winds travel at an incredible 2 million miles per hour (3.21 million kilometers per hour).

The superheated gas from this galaxy, Messier 82 (M82), flows from a region of intense stellar activity at the galaxy's heart. M82 is located around 12 million light-years away from us in the northern constellation Ursa Major and classified as a "starburst galaxy" because it is forming stars 10 times as rapidly as the Milky Way does.

"The classic model of starburst galaxies like M82 suggests that shock waves from star formation and supernovas near the center heat gas, kick-starting a powerful wind," team member Erin Boettcher, of the University of Maryland, College Park, and NASA’s Goddard Space Flight Center in Greenbelt, Maryland, said in a statement. "Prior to XRISM, though, we didn't have the ability to measure the velocities needed to test that hypothesis. Now we see the gas moving even faster than some models predict, more than enough to drive the wind all the way to the edge of the galaxy."

Boettcher measured the speed of these galactic winds using the XRISM (pronounced "crism") spacecraft's Resolve instrument.

Cigar galaxy has smoking hot winds

Also known as the Cigar Galaxy, M82 is known for its cool winds composed of vast amounts of gas and dust that stretch out for around 40,000 light-years. These winds have been observed with a wealth of space telescopes, including the Hubble Space Telescope, the James Webb Space Telescope (JWST), Chandra and Spitzer.

The aim of this team's investigation was to connect these massive outflows of matter with stellar activity in M82. This includes discovering the effect of high-speed particles called cosmic rays on the winds of the galaxy. This is important because researchers suggest the same phenomenon that blows these winds also launches cosmic rays and believe they may be the main source of pressure pushing the outflows.

XRISM measured the 2-million-mph speed of these winds by observing X-ray radiation being emitted by superheated iron at the heart of M82. This also revealed a temperature of 45 million degrees Fahrenheit (25 million degrees Celsius) at M82's galactic center, with this heat generating pressure that pushes the winds outward, from high pressure to low pressure, just like the movement of winds through Earth's atmosphere.

These winds aren't just extraordinary for their speeds and initial temperatures, but also for the amount of material they shunt. The team found the center of M82 expels the equivalent of seven suns each year. That poses something of a puzzle for astronomers.

"If the wind blows steadily at the speed we've measured, then we think it can power the larger, cooler wind by driving out four solar masses of gas a year. But XRISM tells us much more gas is moving outward," XRISM Member Edmund Hodges-Kluck said in the statement. "Where do the three extra solar masses go? Do they escape out of the galaxy as hot gas some other way? We don't know."

XRISM will continue to observe M82, potentially helping scientists solve this puzzle while simultaneously building better models of starburst galaxies.

"Some of our early models of starburst galaxies were developed in the 1980s, and we're finally able to test them in ways that weren’t possible before XRISM," team member Skylar Grayson of Arizona State University, said in the statement. "It provides opportunities to figure out why the model might not be capturing everything that’s going on in the real universe."

The team's findings were published on Wednesday (March 25) in the journal Nature.

Astronomers have spotted the most distant and brightest "space laser," or megamaser, ever seen, and it's blasting out from a collision between galaxies that occurred when the universe was just half its current age.

This galaxy system, designated HATLAS J142935.3–002836, is emanating light that needed to travel for about 8 billion years before it reached the MeerKAT radio telescope in South Africa. The laser is specifically a hydroxyl megamaser, meaning it is similar to a laser but is seen in microwave or radio wave radiation rather than in visible light. The prefix "hydroxyl" refers to the fact that this space laser was created when hydroxyl molecules, each composed of one oxygen and one hydrogen atom, smashed into one another within the gas-dense, colliding galaxies.

Even with its impressive brightness, HATLAS J142935.3–002836 wouldn't have been visible if it weren't for the influence of gravity on the fabric of space, aka the concept of gravitational lensing. This phenomenon was first predicted by Albert Einstein in his magnum opus theory of how gravity works, general relativity, back in 1915, and is still a key tool for astronomers exploring the universe.

Gravitational lensing describes what happens when light from a distant source, our megamaser in this case, passes by warps in spacetime caused by an object of great mass, like a cluster of galaxies. The closer that light passes to the warping object, or gravitational lens, the more strongly its otherwise straight path gets curved. As a result, light from the same object can arrive at our telescopes at different times, and this magnifies the background object.

"We discovered a very distant hydroxyl megamaser using the MeerKAT radio telescope. The signal comes from a galaxy at high redshift and is strongly magnified by gravitational lensing," discovery team leader Thato Manamela of the University of Pretoria told Space.com. "This magnification makes the emission easier to detect and allows us to study a system that would otherwise be too faint to observe."

Manamela added that megamasers are rare based on studies conducted in the near universe, usually found in bright infrared galaxies that contain huge amounts of gas and dust. These environments are often the result of two or more galaxies colliding and merging to birth a new "daughter" galaxy. Mergers like this trigger bouts of intense star formation, as well as creating the physical conditions that allow the hydroxyl molecules to amplify radio emission.

"This megamaser is unusual because it is located at a very large distance. That means we are observing it from a much earlier time in the universe," Manamela continued. "The signal is also gravitationally lensed, which boosts the brightness and provides a natural magnifying effect. This combination makes it one of the most distant and powerful hydroxyl megamasers known."

The fact that a megamaser is erupting from this galaxy collision indicates the presence of dense molecular gas and intense activity.

"By studying the emission lines, we can learn about the gas kinematics, the physical conditions in the galaxy, and the processes driving star formation," Manamela said. "Megamasers can also act as indicators of dual active galactic nuclei or pairs of supermassive black holes, systems that are expected to produce gravitational waves."

"This will help us understand how common megamasers were in the early universe and how they relate to galaxy evolution and star formation," Manamela concluded.

The team's research has been accepted for publication in the Monthly Notices of the Royal Astronomical Society Letters and is available as a preprint on the paper repository server arXiv.