The more astronomers learn about interstellar comet 3I/ATLAS, the colder its birthplace appears to have been.

New observations made with the William Herschel Telescope (WHT) on La Palma in the Canary Islands have revealed unusually large quantities of nitrogen in the comet’s gasseous plasma tail. The result suggests that 3I/ATLAS formed at temperatures below about –240°C, far from the star around which it was born.

The finding adds an independent line of evidence to earlier studies of 3I/ATLAS, which have also pointed towards formation in an extremely cold environment beyond our Solar System.

‘This object gives us a rare chance to study material that formed somewhere completely different to our own Solar System,’ says study leader Lea Ferellec of Northumbria University.

‘Finding that it’s so rich in nitrogen tells us it likely formed in extremely cold conditions, far from its home star.’

Ferellec and her colleagues Cyrielle Opitom and Colin Snodgrass used the new WEAVE spectrograph on the 4.2-metre WHT to study gases streaming away from 3I/ATLAS as the comet moved away from the Sun.

As sunlight heats a comet, gases released from its nucleus can become electrically charged, or ionised. These ions are then swept away by the solar wind to form a plasma tail. By spreading the tail’s light into a spectrum, astronomers can identify the different ions within it.

WEAVE simultaneously detected five ions in the tail of 3I/ATLAS, an unusual achievement even for comets belonging to our own Solar System and a first for an interstellar object. Crucially, the team was able to measure the abundance of ionised molecular nitrogen, N₂⁺, relative to ionised carbon monoxide, CO⁺.

The amount of nitrogen preserved in a comet is particularly sensitive to the temperature at which its ices originally formed. The unusually high ratio found in 3I/ATLAS points to temperatures below about 33 kelvin (–240°C), placing its formation far out in the frozen reaches of its original planetary system.

The researchers were also able to trace how the different ions changed with distance along the comet’s tail, the first time this level of detail has been achieved for an interstellar object.

3I/ATLAS was discovered in July 2025 and is only the third confirmed interstellar object to pass through our Solar System, following 1I/‘Oumuamua in 2017 and comet 2I/Borisov in 2019. Because such objects formed around other stars before being expelled into interstellar space, their chemistry provides astronomers with a rare opportunity to compare the raw materials of other planetary systems with our own.

‘Every one of these objects we study helps us understand a little more about how planets form around other stars,’ said Ferellec.

The research is published in Monthly Notices of the Royal Astronomical Society.

Roman lifted off aboard a SpaceX Falcon Heavy rocket from Launch Complex 39A at NASA’s Kennedy Space Center in Florida at 07:26 local time (12:26 BST) on 30 August. Roman separated from the rocket’s upper stage at 12:58 BST, successfully completing the launch and beginning its journey into deep space.

The launch came around nine months ahead of NASA’s original schedule, an unusual achievement for a major space observatory. Roman is now beginning its journey towards the second Sun–Earth Lagrange point, L2, about 1.5 million kilometres from Earth, where it will operate in the same region of space as the James Webb Space Telescope.

Despite the early hour in Florida, the mood during NASA’s launch coverage was celebratory. ‘This is a mission absolutely worth getting up for,’ said NASA Administrator Jared Isaacman.

Roman carries a 2.4-metre primary mirror, the same diameter as Hubble’s, but its Wide Field Instrument gives it a radically different view of the Universe. Its 300-megapixel infrared camera can image a field of view around 200 times larger than Hubble’s infrared instrument while retaining comparable sharpness.

Roman has been designed to survey enormous areas, allowing astronomers to study whole populations of galaxies, stars and planets. Among its biggest goals is investigating dark energy, the mysterious phenomenon thought to be driving the accelerating expansion of the Universe. By mapping billions of galaxies across cosmic time, Roman will trace how the Universe has expanded and how its large-scale structure has grown under the influence of dark matter.

Closer to home, Roman will conduct a census of planets throughout the Milky Way using gravitational microlensing. This occurs when the gravity of a foreground star bends and magnifies the light from a more distant star. A planet accompanying the foreground star can produce a distinctive additional signal in that magnification.

NASA estimates that Roman’s surveys could uncover around 100,000 exoplanets, including worlds in orbits that are difficult to detect using other techniques.

Roman also carries the Coronagraph Instrument, a technology demonstration designed to block the overwhelming glare of a star so that much fainter planets and discs of material around it can be seen directly. The technologies it demonstrates could eventually contribute to future space telescopes capable of directly studying Earth-like planets.

Roman has had a long journey to the launch pad. The mission grew out of the Wide Field Infrared Survey Telescope, or WFIRST, concept and makes use of a 2.4-metre telescope assembly donated to NASA by the US National Reconnaissance Office in 2012. It was renamed in 2020 in honour of Nancy Grace Roman, NASA’s first chief astronomer and one of the driving forces behind the Hubble Space Telescope.

Roman will now spend approximately three months travelling to L2 and undergoing deployments, activation, calibration and testing before beginning science operations. Its primary mission is planned to last five years, with sufficient propellant potentially allowing another five.

Its first science images are expected in early 2027.

‘I am more thrilled than I can possibly explain,’ said Dr Dominic Benford, programme scientist for the Nancy Grace Roman Space Telescope, during the NASA live stream in the run-up to the launch.

Despite the early hour, Benford’s unusual tie knot was no bleary-eyed mistake. He has previously told The Space Madness Podcast that there are ‘thousands of ways to tie a necktie’.

Read our in-depth feature about the extraordinary science that Roman will be conducting in our September issue.

The James Webb Space Telescope has already found distant galaxies that seem uncomfortably large for the young Universe they are seen in. Now astronomers have discovered evidence that such galaxies may contain even more mass in stars than previously estimated, deepening the mystery.

The problem comes from estimating a galaxy’s population of small, faint stars such as red dwarfs. These contribute relatively little to a galaxy’s light, but if there are enough of them they can account for a substantial amount of its mass.

Because the smallest stars are too faint to see individually at enormous distances, their numbers have to be inferred. Until now, astronomers did this by assuming that stars were born in roughly the same proportions as they are in the Milky Way. This distribution of stellar birth masses is known as the initial mass function, or IMF.

Chloe Cheng of Leiden University in the Netherlands and her colleagues put this assumption to the test. They used JWST to obtain exceptionally deep spectra of nine massive galaxies seen as they were about seven billion years ago, combining them with earlier observations from the European Southern Observatory’s Very Large Telescope in Chile.

Low-mass stars leave subtle fingerprints in a galaxy’s spectrum, absorbing particular wavelengths of light. By measuring these telltale features, the team could estimate how many faint dwarf stars were hiding among the much brighter stars.

They found that several galaxies contained substantially more low-mass stars than expected. Astronomers describe such a population as having a ‘bottom-heavy’ IMF. Instead of following the stellar recipe familiar from the Milky Way, these galaxies appear to have formed disproportionately large numbers of small stars.

‘If a galaxy were a city, the brightest stars would be the skyscrapers that immediately catch your eye from afar,’ says Cheng. ‘Our models demonstrate that a far more numerous population of low-mass stars is concealed by those rare, bright stars, like houses hidden between skyscrapers.’

Two of the oldest galaxies that Cheng studied appear to have formed very early and are likely descendants of the remarkably massive galaxies JWST has discovered within the first billion or so years after the Big Bang. Those early galaxies are already difficult for astronomers to explain because there does not seem to have been enough time for them to grow so large. If they too contain an unexpectedly large population of faint stars, their estimated stellar masses could be three to four times greater, deepening the conundrum of how the young Universe built such enormous galaxies so quickly.

‘This result shows that much more mass than previously thought is hidden in low-mass stars, says Mariska Kriek of Leiden Observatory, who led the research. Because low-mass stars commonly host planets, the result ‘could even indicate that more planets formed in the early universe than we had previously assumed,’ she says.

However, the connection to JWST’s earliest galaxies remains an inference. Cheng’s team has studied their possible descendants, not the early galaxies themselves. Future observations will attempt the much harder task of measuring stellar populations closer to the epoch when those first galaxies actually formed. If the same abundance of faint stars is found there, some of the Universe’s earliest galaxies may turn out to be even more extraordinary than they already appear.

Read more here.

On the evening of 12 August 2026, the Moon will pass between Earth and the Sun, producing a striking solar eclipse. The Moon’s dark umbral shadow will cross eastern Greenland and the western tip of Iceland before travelling over Spain and ending at sunset near the Balearic Islands.

Across the UK, the event will be visible as a deep partial eclipse. The Moon will cover around 90 per cent of the Sun at maximum, rising to about 95 per cent in the far southwest, leaving a thin crescent hanging low in the western sky. Although observers in Britain will not see totality, the eclipse should create an atmospheric transformation as daylight fades and the landscape often takes on a cooler, silvery appearance.

When to watch

Exact timings will vary with location, but across much of central Britain:

• First contact: shortly after 18:10 BST.
• Maximum eclipse: a little after 19:00 BST.
• Last contact: shortly after 20:00 BST.

Because the Sun will be close to the western horizon, choosing a location is especially important. Buildings, trees and distant hills may obstruct the view, particularly near maximum eclipse. Visit your planned observing site beforehand, ideally at around the same time of evening, and check that you have a clear sightline towards the west.

The eclipse begins when the Moon appears to take its first small bite from the Sun. As the event progresses, the bright disc will narrow into an increasingly delicate crescent. The changing quality of the light may be just as memorable as the eclipse itself.

Protect your eyes

Even when 90 per cent of the Sun is covered, the remaining crescent is still dangerously bright. Never look directly at the Sun without ISO 12312-2 certified solar eclipse glasses or a proper solar filter. The same rule applies to cameras, binoculars and telescopes: each must be fitted with an appropriate solar filter before being pointed at the Sun.

No filter? No problem. Use a kitchen colander!

If you do not have suitable equipment, you can observe the eclipse indirectly. Hold a kitchen colander between yourself and the Sun and look at the ground beneath it: the gaps will project multiple tiny images of the eclipsed Sun. Gaps between leaves can produce the same effect, scattering little crescent Suns across a wall, path or sheet of card.

These projection methods are simple, safe and sociable. If clouds obscure the event – or if you cannot find a safe observing location – watching a reputable live stream is a better choice than taking risks with the Sun.

Photographing the eclipse

The simplest approach is often the most rewarding. A smartphone can record the changing light and the reaction of the people around you, especially when used for a wide view rather than a heavily zoomed-in image. Mounting the phone on a tripod and recording video a few minutes before maximum eclipse can capture the gradual fall of daylight and the atmosphere of the occasion.

For DSLR or mirrorless cameras, a wide-angle time-lapse is a low-stress option. Include both the Sun and the surrounding landscape, use manual focus, shoot in RAW and begin taking frames about once a second as the eclipse approaches maximum. A tripod will keep the composition steady while you step back to experience the event.

Close-up photography is considerably more demanding. For observers travelling into the path of totality, long focal lengths, careful focusing, tracking and multiple exposures are needed to record features such as the corona and prominences. Solar filters must remain in place during the partial phases and be removed only when the Sun is completely covered – something that will occur only for observers within the path of totality. The filter must be replaced immediately as totality ends.

For observers in the UK, where the eclipse remains partial, the filter should never be removed. Unless you already have experience with high-magnification eclipse photography, a wide-angle time-lapse or unattended video will provide a better balance between recording the event and actually enjoying it.

Let us know how you get on! Email images to gallery2026@astronomynow.com or share your experience via yourspace@astronomynow.com

Find out more in the current issue of Astronomy Now – take out a digital subscription for instant access!

Humans have been deliberately crashing spacecraft into the Moon for more than 65 years, while nature has been targeting our natural satellite for billions. What makes today’s collision significant is the changing role of the Moon itself. In the near future, astronauts and landers, bases and even observatories will begin to occupy the lunar surface. That means uncontrolled lunar impacts will increasingly become a matter of safety, traffic management and scientific protection.

The discarded Falcon 9 upper stage that slammed into the Moon near Einstein crater today began its journey earlier this year, carrying Firefly Aerospace’s Blue Ghost lunar lander. Travelling at around 2.4 kilometres per second, the 13.8-metre-long stage was expected to excavate a crater a few tens of metres across. This is tiny by lunar standards, but the crater should later be identifiable by NASA’s Lunar Reconnaissance Orbiter.

Although such an impact may feel extraordinary, it belongs to a long tradition of human exploration.

The first spacecraft ever to reach another world, the Soviet Union’s Luna 2, did so by crashing into the Moon in September 1959. NASA’s Ranger probes followed the same philosophy during the early 1960s, transmitting ever more detailed images until their final, inevitable impacts. At a time when lunar soft landings had not yet been mastered, impacts were the only practical way to obtain close-up photographs of the surface.

Beyond pictures, scientists soon realised that impacts could become experiments in their own right. During the Apollo programme, NASA crashed several Saturn V upper stages into the lunar surface so that seismometers left behind by the astronauts could record the vibrations, allowing researchers to probe the Moon’s interior. With an impact mass of roughly 13–14 tonnes, these upper stages were about three times the mass of today’s Falcon 9 stage.

More recently, NASA’s LCROSS mission deliberately fired a spent Centaur rocket stage into the permanently shadowed Cabeus crater near the lunar south pole. The accompanying spacecraft flew through the debris plume, confirming that water ice and other volatile materials were present in the excavated material.

Other orbital missions subsequently disposed of in carefully planned crashes into the Moon include ESA’s SMART-1 spacecraft, NASA’s twin GRAIL orbiters and the LADEE mission. Nor is today’s accidental Falcon 9 impact unprecedented. In 2022, an old Chinese rocket stage struck the Moon’s far side. In both cases, the impending impact had been known for months.

Yet this catalogue of human impacts tells only part of the story. The Moon is continually bombarded by nature itself. The craters visible through even the simplest backyard telescopes were excavated by natural impactors over billions of years. Smaller impacts continue constantly today.

Without a substantial atmosphere to burn up incoming objects, even relatively small rocks strike the surface at cosmic speeds, producing brief flashes that are routinely monitored by astronomers. In recent months, the Artemis astronauts circling the Moon also reported seeing several probable impact flashes on the lunar night side.

Other, more dramatic sightings date back centuries. In 1178, the monk Gervase of Canterbury recorded an account of flames apparently erupting from the Moon’s crescent. For many years it was suggested that this marked the formation of Giordano Bruno crater. Modern studies, however, show that explanation is almost certainly incorrect, and what the witnesses saw remains uncertain.

So, if natural and artificial impacts are so common, why has this week’s Falcon 9 collision attracted so much attention?

Beyond the inevitable interest attracted by anything associated with SpaceX, the answer is that the Moon itself is changing.

For most of the Space Age, the lunar surface was effectively empty. A new crater simply joined billions of old ones on the barren surface. Today, however, the Moon is poised to become an operational environment.

Multiple nations are planning sustained exploration around the south pole. Commercial landers could soon routinely ferry scientific equipment and other cargo to the surface. Future observatories may seek out the radio silence of the lunar far side or the natural cold of permanently shadowed craters.

Future collisions could disturb scientifically valuable sites, throw abrasive dust across nearby instruments or complicate the management of an increasingly busy lunar environment. They could also pose a danger to astronauts and their bases.

As Astronomy Now explored in this month’s feature on lunar astronomy, protecting future observatories may eventually require designated disposal zones, traffic management and internationally agreed scientific preserves.

In that sense, today’s Falcon 9 impact highlights an important shift in humanity’s relationship with the Moon. We have always crashed things into our nearest neighbour. Now, however, we can no longer do so without considering what lies beneath or nearby.

Read more about lunar space debris and its potential impact on astronomy in the August issue of Astronomy Now. Instant access available via the Astronomy Now archive app subscription or one-off digital issue purchase.

One of the biggest mysteries in modern astronomy is how the Universe managed to grow enormous black holes so quickly.

Less than a billion years after the Big Bang, the Universe already contained quasars powered by supermassive black holes consuming vast amounts of gas. Many of those black holes contain hundreds of millions or even billions of times the mass of the Sun. Astronomers are still trying to understand how they reached such enormous sizes in such a short cosmic time.

One difficulty in investigating these objects is that, beyond their sheer distance, there have simply been too few of them to build up any kind of overall picture. After decades of searching, only nine quasars were known from the Universe’s first 770 million years. With such a meagre handful, it is hard to know whether you are studying general characteristics or individual quirks.

Now ESA’s Euclid space telescope has changed that picture dramatically. In its first 18 months of observations, Euclid has identified 31 quasars dating from between 600 and 800 million years after the Big Bang. Astronomers describe such distances using redshift, a measure of how much the expansion of the Universe has stretched an object’s light, with higher values corresponding to more distant objects seen further back in time. Follow-up observations with some of the world’s largest telescopes have confirmed the candidates as quasars, more than doubling the number known beyond redshift seven and revealing the two most distant quasars yet found.

While it is the record-breaking aspect of these discoveries that is capturing the headlines, the real story is that astronomers finally have enough objects to begin studying the earliest quasars as a population rather than as isolated curiosities.

‘With only a few quasars known beyond redshift seven, we simply cannot answer these questions,’ says Daming Yang of Leiden Observatory in the Netherlands, first author of the paper describing the work. ‘Finding more of them at such distances – and pushing to even greater distances – is the only way forward.’

Euclid was designed primarily to investigate dark matter and dark energy by mapping the large-scale structure of the Universe. But its combination of a wide field of view and sensitive near-infrared imaging is also proving remarkably effective at uncovering some of the most distant objects ever seen.

As the Universe expands, light from remote quasars is stretched to longer wavelengths before reaching Earth. By the time light from the earliest quasars arrives, much of it has shifted into the infrared, making these objects difficult to detect with traditional optical surveys. Euclid was built to observe these wavelengths across enormous areas of sky, allowing it to uncover many more candidates than previous searches.

The team first used Euclid’s visible and infrared images to identify promising candidates. Machine-learning techniques and data from other surveys helped refine the sample before astronomers turned to large ground-based observatories, including the W. M. Keck Observatory in Hawaii, the Magellan telescopes in Chile and the Large Binocular Telescope in Arizona, to confirm them spectroscopically.

Those spectra, produced by splitting an object’s light into its individual wavelengths, revealed the so-called ‘Lyman-alpha break’, a sharp drop in brightness caused by neutral hydrogen in the young Universe absorbing light at specific wavelengths. The position of this feature allows astronomers to estimate each quasar’s redshift and hence how far back in cosmic history it is being seen.

The two most distant quasars lie at redshifts of 7.77 and 7.69, meaning astronomers see them as they were only around 670 million years after the Big Bang.

The enlarged sample opens a new route to investigating how the first supermassive black holes formed and grew so quickly because a quasar marks the period during which a galaxy’s central black hole is actively consuming matter. Each new quasar therefore offers a view of a black hole actively growing in the young Universe.

By comparing the quasars’ brightness, accretion properties and host galaxies across a meaningful population, researchers can begin to investigate which characteristics are common and which belong only to exceptional objects.

The new discoveries are especially valuable because many are less luminous than the handful of quasars previously known at comparable distances. Those earlier objects may therefore have represented only the brightest and most extreme examples. Euclid is beginning to reveal a broader population, giving astronomers a better chance of tracing how black holes and their host galaxies developed together during the first billion years.

The same quasars can also show how these growing black holes and their host galaxies affected the Universe around them. They existed during the epoch known as reionisation.

After the first atoms formed, most of the hydrogen between galaxies was neutral. As the first stars, galaxies and accreting black holes appeared, their energetic radiation gradually stripped electrons from that hydrogen. By studying how much neutral hydrogen remained along different lines of sight, astronomers can trace when and how this transformation unfolded.

Quasars are among the best tools for performing this investigation. Their intense light acts like a distant searchlight, shining through the hydrogen between galaxies before reaching Earth. The intervening gas leaves subtle absorption signatures in a quasar’s spectrum, allowing astronomers to probe conditions across vast stretches of the young Universe. With only a handful of such quasars, those sightlines have been rare. With dozens now available, researchers can begin building a much more complete picture of how reionisation unfolded.

The discoveries also strengthen Euclid’s role as a general-purpose observatory for studying the distant Universe. Although the mission’s principal goal remains understanding dark matter and dark energy, it is already demonstrating that its survey of more than one-third of the sky will provide an unparalleled resource for many other areas of astrophysics.

And this is only the beginning. The current discoveries come from just the first part of Euclid’s six-year survey. The team expects the completed mission to uncover hundreds more quasars from the first billion years of cosmic history, perhaps even pushing beyond a redshift of eight.

‘We have a real sample at such high redshift for the first time, and we can finally start answering the questions that were unanswerable before,’ says Yang.

By turning rare curiosities into a population, Euclid promises to give astronomers a way to investigate both how the first giant black holes grew and how their radiation changed the Universe around them.

To read about how astronomers are rethinking their ideas about dark matter, check out our July 2026 issue.

Astronomers have caught a young galaxy system apparently blowing away the gas it needs to keep making stars, offering a natural explanation for one of the surprises thrown up by the NASA/ESA/CSA James Webb Space Telescope: the large number of ‘dead’ galaxies in the early Universe.

The system, known as CRISTAL-02, is seen as it was just 1.1 billion years after the Big Bang. It is not a calm, settled galaxy, but a collection of star-forming clumps caught in the final stages of a cosmic collision. That collision appears to have funnelled gas into dense regions, triggering a furious burst of star formation. Now, the same process may be helping to shut the galaxy down for good.

The discovery, made using JWST and the Atacama Large Millimeter/submillimeter Array (ALMA), reveals a huge plume of cold gas extending around 7,000 light-years from CRISTAL-02. The gas is moving away from the galaxy in a powerful wind, driven not by an obvious active black hole but by the energy released when short-lived massive stars explode as supernovae.

“Dense regions of the universe are like very active cities,” says lead author Dr Rebecca Davies, of Swinburne University of Technology in Australia. “Galaxies collide and undergo frenzied bursts of star-formation. But when the biggest stars burn out, they explode as supernovae, launching powerful winds that blast away the very gas galaxies need to keep forming stars.”

The result is a possible ‘galaxy-killing wind’. Galaxies are often described as dead, or quiescent, when they have stopped forming significant numbers of new stars. Their existing stars may continue to shine for billions of years, but the galaxy’s growth has effectively ended because the cold gas reservoir from which new stars form has been removed, heated or used up.

JWST has already found unexpectedly large numbers of massive dead galaxies in the early Universe, when the cosmos was only one or two billion years old. This has posed a problem for galaxy evolution models, because such galaxies must have grown rapidly and then shut down almost immediately. Some proposed explanations have invoked more exotic early-Universe physics. For example, one idea is that dark energy, the mysterious force associated with the accelerating expansion of the Universe today, may have been stronger or behaved differently in the young cosmos, allowing galaxies to grow and die faster than expected.

The new study points to a simpler possibility: violent galaxy mergers may have triggered intense starbursts that then powered winds strong enough to sweep away the galaxies’ own fuel.

CRISTAL-02 is forming stars at a rate of around 260 solar masses per year, roughly three times faster than expected for a galaxy of similar mass at the same epoch. However, the outflow is removing gas at about 520 solar masses per year, twice the star-formation rate. If that continues, and if fresh cold gas is not drawn in from the galaxy’s surroundings, CRISTAL-02 could exhaust or eject its molecular gas reservoir on a timescale of tens of millions of years.

“The galaxy has a powerful wind that is ejecting material twice as fast as the galaxy forms stars,” says Davies. “If this rapid blowout continues, the galaxy could be dead in less than 50 million years.”

The evidence comes from combining two different views of the gas. ALMA detected the cold material, while JWST’s Near Infrared Spectrograph observed warmer ionised gas. Together, these observations reveal a wind made of gas in different physical states. Both appear to be moving out from the galaxy in a roughly two-coned shape, like material being blasted above and below a galactic disc, similar to winds seen in nearby galaxies undergoing intense bursts of star formation.

The researchers estimate that the outflow contains about 1.5 billion solar masses of cold gas. The projected outflow velocity is around 640 kilometres per second, comparable to the galaxy’s estimated escape velocity, meaning that some of the material may leave the system altogether rather than falling back later.

The team finds no evidence that a currently active supermassive black hole is powering the wind. However, the researchers note that they cannot entirely rule out an earlier burst of black-hole activity that has since faded.

If CRISTAL-02 is typical, the mechanism could be widespread. The study notes that almost half of massive galaxies at this epoch are undergoing major mergers. Such collisions can drive gas inward, ignite intense star formation and then launch powerful winds that suppress or even halt further star formation.

“Almost half of early massive galaxies are interacting with other nearby galaxies, suggesting this isn’t a quirk but a widespread cosmic phenomenon,” says Davies. “CRISTAL-02 offers a natural solution to the mystery of why these massive galaxies live fast and die young.”

Read more: Multiphase images of a powerful supernova-driven wind in the early Universe

ESA’s Rosalind Franklin rover could touch down in the remains of a vast ancient water system on Mars, after new orbital mapping showed that clay-rich deposits at its landing site extend far beyond previous estimates.

The rover is due to land at Oxia Planum, a low-lying region near the boundary between Mars’s southern highlands and northern lowlands, where clay minerals preserve evidence of a time when liquid water was active on the Red Planet. The new study suggests that these clays are not just a local feature, but part of a much larger sequence that stretches towards Mawrth Vallis, around 300 kilometres away.

That gives the landing site a much wider significance. The clay deposits may extend roughly 600 kilometres across and rise by more than a kilometre in elevation. One possible explanation is that they were shaped by an extensive body of water several kilometres deep around four billion years ago. If so, ESA says its shorelines would rank among the highest ever proposed for ancient Mars.

Another possibility is that the deposits were formed when huge volumes of water flooded across broad plains from ancient groundwater reservoirs. Either way, the result points to a large-scale watery environment rather than a small, isolated patch of altered rock.

“Because the area is so large, we are not talking about a localised occurrence, but rather a regional or global process that would have required immense amounts of water,” says Jorge Vago, ExoMars project scientist. “We are targeting the oldest deposits in the sequence, which makes the potential implications for the geology and early climate of Mars very relevant for the Rosalind Franklin mission in its search for life.”

Clay minerals are among the most important targets in the search for ancient life on Mars because they form in the presence of liquid water and can preserve chemical clues to the environment in which they were deposited. Oxia Planum was selected as Rosalind Franklin’s landing site because of its ancient, clay-bearing rocks.

This new analysis was led by Inés Torres Auré, of the University of Lyon, France, and is published in the journal Icarus. The team used mineral data from OMEGA on ESA’s Mars Express orbiter and CRISM on NASA’s Mars Reconnaissance Orbiter to compare the rock layers between Oxia Planum and Mawrth Vallis. Their results show that both sites contain similar mineral layers, suggesting that they are linked within the same broader geological story.

“We now have a new timeline: Oxia Planum’s clays formed first, about four billion years ago, predating those at Mawrth Vallis,” says Torres Auré. “By landing at Oxia Planum, we’ll uncover a large-scale process that shaped ancient clays across Mars.”

The study also identifies a palaeosurface, an ancient ground surface that was exposed long enough to be cratered before later being buried by younger deposits. Its presence suggests a pause in sedimentation, followed by a change in water chemistry and mineralogy across both Oxia Planum and Mawrth Vallis.

“We have identified a pause in deposition, which is quite puzzling because it implies a period of minimal surface activity (except for meteorite bombardment), followed by a shift in water chemistry and mineralogy in both Oxia Planum and Mawrth Vallis,” says Torres Auré.

Rosalind Franklin is designed to test these orbital interpretations from the surface. The rover carries cameras, spectrometers, ground-penetrating radar and an onboard laboratory, as well as a drill capable of collecting samples from up to two metres below the martian surface. That depth is important because any possible organic material near the surface is exposed to radiation and oxidising chemistry that can destroy delicate biological signatures over time.

“We will use the instruments on board to ground truth the discoveries made from orbit, learn about the ancient environment in which they formed, and if they preserve any evidence of martian life,” says Elliot Sefton-Nash, ExoMars deputy project scientist. “Warmth and nutrients on an early martian seabed could have provided habitats for early life.”

Although Rosalind Franklin was delayed from its intended launch by the collapse of cooperation with Russia, the extra time has allowed more detailed preparations to take place. As a result, its scientific target now looks even more compelling. Rather than simply sampling one promising clay outcrop, Rosalind Franklin may be able to investigate a surviving fragment of a much larger water-rich chapter in Mars’s early history.

Its findings could have direct implications for Mars’s climate, its habitability, and where future missions should look for the planet’s most carefully preserved traces of ancient life.

Clay continuity between Oxia Planum and Mawrth Vallis by Inés Torres Auré et al. is published in Icarus, 2 June 2026.

Read more about the search for life in the Universe in our May 2026 issue.

The Moon may preserve a record of the raw ingredients that helped life begin on Earth. New analysis of lunar samples returned by China’s Chang’e missions has revealed a diverse suite of organic compounds embedded within the soil. They offer a rare glimpse of the early Solar System’s chemistry that has long since been erased from our planet.

The findings come from material collected by Chang’e-5 and Chang’e-6, which brought back samples from the Moon’s surface in 2020 and 2024 respectively. Using high-resolution analytical techniques, researchers identified nitrogen-bearing organic matter occurring in several distinct forms, including particle-like fragments, thin coatings and inclusions within mineral grains.

These features are typically only a few micrometres across or smaller. Chemically, the material is dominated by carbon, nitrogen and oxygen, and is largely amorphous rather than crystalline. In some cases, the team identified amide functional groups, which represent a more complex level of chemical organisation. These findings indicate that the lunar organic matter has undergone some chemical reworking, rather than remaining in a primitive, unaltered state.

To be clear, these compounds are not signs of life. Instead, they are simple carbon-based molecules, widely regarded as the chemical precursors to biology. Yet, their presence on the Moon is significant because it provides a relatively unaltered record of the processes that distributed and transformed organic material in the early Solar System.

According to the research team, the most likely origin of the material is from colliding asteroids and comets that were rich in organic compounds. The cratered face of the Moon tells us that these have bombarded the lunar surface for billions of years. As they struck, they delivered carbon-bearing material that became mixed into the regolith. Unlike Earth, where geological activity and weathering recycle and erase ancient records, the Moon has remained largely unchanged, even though the researchers found that some alteration had clearly taken place.

Isotopic measurements reinforce this picture of active processing on the lunar surface. Isotopes are atoms of the same element that have different masses because they contain different numbers of neutrons. Researchers found that the hydrogen, carbon and nitrogen isotopic ratios are systematically lighter than those typically found in carbonaceous meteorites, implying that the material has been modified after its initial delivery.

The researchers interpret this as evidence for repeated cycles of impact-driven heating, evaporation and re-condensation. In this scenario, incoming asteroids and comets deliver organic material, which is then partially broken down and vaporised by other impacts before re-condensing onto surface mineral grains, forming new nitrogen- and oxygen-bearing compounds.

Further evidence of surface processing comes from signatures of ‘solar wind implantation’, the embedding of charged particles from the Sun into the outer layers of lunar grains. It is identified here for the first time in lunar organics. Variations in hydrogen isotopes and hydrogen-to-carbon ratios near grain surfaces point to prolonged irradiation by charged particles from the Sun. This ‘fingerprint’ of solar wind interaction also helps rule out terrestrial contamination as the source of the material.

The team describe the Moon as acting like a ‘time capsule’, storing evidence of how organic matter has evolved under space conditions. By studying these materials in detail, scientists can begin to reconstruct how the building blocks of life were delivered across the Solar System and how they were altered before ever reaching a planet like Earth.

The results also highlight the growing importance of sample-return missions. Laboratory analysis of pristine material allows researchers to probe chemical structures at a level of detail that remote observations or even in-situ experimentation cannot match. With further samples expected from future lunar missions, the Moon is likely to play an increasingly important role in understanding the chemical pathways that may ultimately have led to life on Earth.

The study was led by a research team from the Institute of Geology and Geophysics of the Chinese Academy of Sciences (IGGCAS), in collaboration with researchers from institutions including the University of New Mexico and Changsha University of Science and Technology. Their findings were published in Science Advances on 8 April and can be read in full here.

Astronomers may not need to see the same dark matter signal everywhere in the Universe to confirm its existence. A new theoretical study suggests that dark matter could consist of more than one type of particle, potentially resolving a long-standing observational puzzle.

Dark matter itself is inferred because the visible contents of the Universe (stars, gas and dust) cannot account for the gravitational effects that are observed. Galaxies rotate too quickly to be held together by their luminous matter alone, galaxy clusters would disperse without additional unseen mass, and patterns in the cosmic microwave background require far more matter than we can detect directly. These all point to a substantial component of invisible matter that interacts gravitationally but does not emit, absorb or reflect light, hence the name ‘dark matter’.

The work, published in the Journal of Cosmology and Astroparticle Physics, revisits one of the most debated hints of dark matter: an excess of gamma rays observed at the centre of the Milky Way by NASA’s Fermi Gamma-ray Space Telescope.  

This emission has been interpreted by some researchers as a possible signal of dark matter particles annihilating each other. However, the same signal has not been convincingly detected in smaller, dark matter–rich systems such as dwarf galaxies. This discrepancy has cast doubt on the interpretation.

“If certain theories of dark matter are true, we should see it in every galaxy,” said Gordan Krnjaic, one of the study’s authors.  

Dwarf galaxies are considered prime targets in the search for dark matter. They contain large amounts of the unseen material but relatively few stars, meaning there is little astrophysical ‘background noise’ to obscure potential signals. In conventional models, if dark matter annihilation produces gamma rays in the Milky Way, similar emissions should also be detectable in these quieter environments.

The absence of such a signal has therefore been a significant challenge. Either the Milky Way’s gamma-ray excess is not caused by dark matter (perhaps instead arising from a population of unresolved pulsars) or the underlying theory is incomplete.

The new study offers a third possibility.

Instead of assuming dark matter is made of a single particle species, the researchers propose that it may consist of two distinct types of particle. Crucially, these particles would only annihilate when they encounter each other — not when they meet identical counterparts.

“What we are trying to point out is that you could have a different kind of environmental dependence,” said Krnjaic. “Dark matter could straightforwardly be two different particles, and the two different particles need to find each other in order to annihilate.”

In this scenario, the strength of any gamma-ray signal depends not only on the overall amount of dark matter present, but also on the relative abundance of the two particle types. If both components are present in similar proportions, as might be the case in the Milky Way, annihilations could occur frequently enough to produce a detectable signal.

By contrast, if one component dominates in dwarf galaxies, encounters between the two species would be rare, suppressing the gamma-ray emission even in regions rich in dark matter.

This ‘two-state’ model therefore allows for a gamma-ray excess in the Milky Way while remaining consistent with the lack of similar detections in dwarf galaxies. It represents a more flexible alternative to standard scenarios, in which the annihilation rate is either constant or strongly dependent on particle velocity.

The idea does not yet resolve the mystery, but it reframes how astronomers interpret both detections and non-detections. In particular, it suggests that the absence of a signal in certain environments may not be decisive evidence against a dark matter origin.

Future observations will be key. More sensitive measurements of dwarf galaxies with the Fermi telescope, or its successors, could reveal faint gamma-ray emissions or confirm their absence with greater confidence. Either outcome would place tighter constraints on the proposed model.

For now, the study highlights how much remains unknown about dark matter, which is thought to make up around 85 per cent of the Universe’s matter but has never been directly detected.

Rather than a single, simple particle, it may prove to be a more complex mixture that reveals itself only under the right cosmic conditions. Or astronomers are chasing illusions and the real reason for the cosmic discrepancies is that we do not fully understand gravity.

Read the original paper here.