Is there life on Mars … in clay? Scientists think that the minerals in clay could be the key to finding signs of ancient life on the Red Planet.

The European Space Agency is still working toward launching its ExoMars Rosalind Franklin rover to Mars to search for signs of life. And, according to a statement from the space agency, the rover is now aiming to land at Oxia Planum, a depression on the Martian surface where it's thought that water was once plentiful. There, scientists think that they might find major clues in the hunt for life in the basin's clay, according to a new paper.

"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. Warmth and nutrients on an early martian seabed could have provided habitats for early life," ExoMars deputy project scientist Elliot Sefton-Nash added in the statement.

Scientists have spent years searching for signs that life once existed on Mars. It's thought that water on Mars evaporated around three billion years ago, but before then the planet likely had a more substantial atmosphere and water flowing in rivers and into lakes all across its surface. Because of the planet's history, many scientists think that it's most likely that at some point in the ancient past, the planet must have supported life. While this has yet to be confirmed, last year scientists found what is currently thought of as the strongest possible biosignature, or physical evidence of life, on Mars.

In a new study, researchers have found extensive clay deposits at Rosalind Franklin's proposed landing site. They found this clay to reach roughly 186 miles (300 kilometers) outward from Oxia Planum, stretching as far as a Martian valley called Mawrth Vallis. To spot the clay, they first studied the planet from orbit.

Researchers used the OMEGA instrument on ESA's Mars Express orbiter and NASA's Mars Reconnaissance Orbiter to explore the minerals and rock layers on Mars between Oxia Planum and Mawrth Vallid, finding mineral layers at both sites as well as markers showing changes in water chemistry over time. These observations add to other studies pointing to water on ancient Mars.

With ESA's upcoming rover, some scientists think that the clues to life on Mars could be hiding in this clay in the Oxia Planum region.

"By landing at Oxia Planum, we’ll uncover a large-scale process that shaped ancient clays across Mars," lead author Inés Torres Auré of the University of Lyon in France said in the statement.

Scientists think that it's possible that the area of Oxia Planum could have once been home to a body of water as big as an ocean or the region could possibly have experienced incredible flooding some four billion years ago, according to the statement.

"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. 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," ExoMars project scientist Jorge Vago explained in the statement.

While we have never confirmed life off-Earth and it could be different from the life we know, as far as life on Earth is concerned, water is a necessary ingredient.

ESA's Rosalind Franklin rover is projected to launch to the Red Planet in 2028. The rover will be part of ESA's ExoMars program alongside the agency's Trace Gas Orbiter which is already traveling around Mars. Rosalind Franklin will have a drill, allowing it to explore below the planet's surface as the pair work together from orbit and on the Martian surface to hunt for signs of ancient life.

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

At long last, SpaceX has a Mars launch firmly on the books.

Company founder and CEO Elon Musk has had the Red Planet in his sights for decades. Indeed, the world's richest man has repeatedly said that he established SpaceX in 2002 primarily to help humanity settle the fourth rock from the sun.

But the company hasn't launched a Mars mission to date, or even inked a customer for one — until now.

On Thursday (April 16), NASA announced that it has selected SpaceX's Falcon Heavy rocket to launch Europe's first-ever Mars rover, a life-hunting robot called Rosalind Franklin. If all goes to plan, the liftoff will take place in late 2028 from NASA's Kennedy Space Center in Florida.

Things have certainly not gone to plan for Rosalind Franklin to this point, however. The rover is part of Europe's ExoMars exploration program, which was established about 15 years ago with NASA as a key partner.

ExoMars consists of two missions: Rosalind Franklin and the Trace Gas Orbiter (TGO), which was designed to sniff out methane and other interesting compounds from high above Mars. Each was supposed to launch atop its own United Launch Alliance Atlas V rocket — TGO in 2016 and Rosalind Franklin in 2018. (It was just known as the ExoMars rover at the time; Rosalind Franklin wasn't named until 2019.)

But NASA dropped out of the ExoMars program in 2012 due to budget issues, leaving the European Space Agency scrambling. ESA eventually found a new partner in Russia, which successfully launched TGO in 2016 on a Proton rocket and built a landing platform and some science instruments for Rosalind Franklin.

The rover's launch was then delayed by multiple issues, including parachute concerns and supply-chain problems caused by the COVID-19 pandemic. ESA powered through, readying Rosalind Franklin for a planned September 2022 Proton liftoff — but then Russia threw a wrench into the works. It invaded Ukraine in February of that year, spurring Europe to sever most of its space partnerships with Russia, including those concerning ExoMars.

So, ESA needed help once again, and this time it turned to its original partner: NASA. The two space agencies signed a deal in 2024 laying out NASA's contributions to the Rosalind Franklin mission. The American agency would procure a commercial launch vehicle for the rover and provide part of the propulsion system that would help it land softly on Mars, as well as heaters to keep Rosalind Franklin's electronics and scientific instruments warm during the bitterly cold Red Planet nights.

NASA would also provide "specialized electronics and a state-of-the-art mass spectrometer for the Mars organic molecule analyzer science instrument, which will search for the building blocks of life in samples collected at the rover’s landing site, Mars’ Oxia Planum," agency officials wrote in Thursday's announcement.

In that announcement, NASA revealed that it has approved initiation of the Rosalind Franklin partnership's "implementation" phase, putting the mission on solid footing for its planned 2028 launch. The agency also told us what rocket would be doing the lifting — SpaceX's Falcon Heavy.

The launcher consists of three modified, strapped-together Falcon 9 first stages; an upper stage, with the payload attached, sits atop the central booster. All three first stages are designed to be reusable.

The Falcon Heavy debuted in February 2018 and has 11 launches under its belt to date, all of them successful. The rocket hasn't flown since October 2024, when it sent NASA's Europa Clipper probe toward Jupiter's famed ocean moon Europa.

While the Rosalind Franklin mission marks SpaceX's first Mars contract, the company is also working to get to the Red Planet on its own dime using its Starship megarocket.

SpaceX envisions Starship — the biggest and most powerful rocket ever built — helping humanity establish bases on the moon and Mars. The rocket has flown 11 suborbital test flights to date, the last two of them fully successful, but has yet to reach orbit or demonstrate off-Earth refueling — a capability it must master for deep-space missions.

SpaceX plans to launch a small fleet of uncrewed Starships to Mars when the vehicle is ready, Musk has said. But it's unclear when that will be. Red Planet launch windows come around just once every 26 months, and the next one is fast approaching: It opens this October.

So, Starship's Mars dreams may have to wait until 2028, just like those of Rosalind Franklin.

The first astronauts to set foot on Mars should hunt for signs of past or present Red Planet life.

That's the overarching conclusion of an in-depth report about human Mars exploration from the U.S. National Academies of Sciences, Engineering and Medicine that came out today (Dec. 9).

"The detection of life on Mars is a persistent top priority for explorers of many disciplines, and it is the top science objective in this report," states the 240-page document, which is called "A Science Strategy for the Human Exploration of Mars."

The National Academies prepared the report for NASA, which wants to send astronauts to the Red Planet as soon as the mid-2030s. The document offers recommendations for how the agency can maximize the science gains of its planned crewed Mars campaign.

Those recommendations are extensive and detailed. For example, the report lays out 11 science objectives that such a campaign should pursue, with the search for signs of life (as well as indications of "indigenous prebiotic chemistry" and a broad assessment of habitability) at the top of the list.

The other 10 objectives, listed in order of descending priority, are:

• Characterize Mars' water and carbon dioxide cycles
• Map Martian geology in detail
• Determine how the Martian environment affects the physical and psychological health of astronaut explorers
• Figure out what starts and drives Martian dust storms
• Determine the availability and accessibility of Martian resources that could "support permanent habitation"
• Discover if exposure to the Martian environment affects DNA and reproduction
• Learn about the population dynamics of microbes on Mars, and if microbial species from Earth could adversely affect astronauts' health and performance on the Red Planet
• Determine how Martian dust affects astronauts and their hardware
• Learn how the Martian environment affects a transplanted ecosystem of Earth microbes, plants and animals
• Gain a better understanding of the Martian radiation environment and how it may affect crewmembers and their missions

"A Science Strategy for the Human Exploration of Mars" also proposes four possible three-mission campaigns, the top-ranked of which could achieve all 11 of the above objectives.

That campaign would send all three missions to "a low- to mid-latitude site with near-surface glacier ice and diverse geology," the report states. "The search for prebiotic chemistry and life would focus on near-surface niche environments, such as geologically recent transiently habitable zones, and/or ice, including layered ice."

Another possible campaign would target the deep subsurface, establishing a powerful drilling operation that could get 1.2 to 3 miles (2 to 5 kilometers) beneath the red dirt, where pockets of liquid water are thought to exist.

Both of those proposed campaigns would feature an initial 30-sol crewed surface mission, an uncrewed cargo delivery flight and then a 300-sol astronaut mission on the surface. (One sol, or Martian day, is slightly longer than an Earth day — about 24 hours and 40 minutes.) So would a third proposed campaign, though a fourth would launch three crewed 30-sol missions to three different sites on the Red Planet.

There is some commonality across all the proposed campaigns. For example, according to the report, no matter how NASA's crewed Mars plans take shape, the agency should aim to build a science lab on the Red Planet's surface, haul Mars samples home from every astronaut mission and set up a recurring "Mars Human-Agent Teaming Summit" to maximize and coordinate the efforts of robotic missions, astronauts and artificial intelligence.

In addition, the report notes, a concerted search for Mars life will be constrained by current "planetary protection" guidelines, which aim to minimize the chances that our exploration efforts contaminate other worlds with Earth microbes or bring alien life to our shores.

Therefore, the document states, "NASA should continue to collaborate on the evolution of planetary protection guidelines, with the goal of enabling human explorers to perform research in regions that could possibly support, or even harbor, life."

Possible giant "karstic" caves that formed when slightly acidic water dissolved bedrock have been identified on Mars and hailed as one of the best locations on the Red Planet to search for preserved biosignatures.

"With the expected technological advances in the coming decades, if missions are specifically designed for these targets, we believe that in situ exploration of Martian karstic caves is an achievable goal," said Chunyu Ding, of the Institute for Advanced Study at Shenzhen University in China, in an interview with Space.com.

The caves, in the Hebrus Valles region between the extinct volcano Elysium Mons and Utopia Planitia in Mars' northern mid-latitudes, are revealed by eight skylights, which are holes in the ceiling of the caves that are visible on the surface as pits ranging from tens to over 100 meters across. The skylights are distinguishable from craters because they don't possess raised walls or splashes of ejecta around them. It is thought that the skylights form when the surface partially collapses into the empty cave below it.

Caves and skylights have been found on Mars before, but as lava tubes formed in volcanic regions. Hebrus Valles, on the other hand, is not a volcanic region; it displays ancient river channels and copious hydrated minerals and sediments deposited by bodies of liquid water on the surface long ago.

These features were identified by scientists led by Ding and his Shenzen colleague Ravi Sharma. Their team used archive data from a variety of Mars missions, including mineralogical maps based on observations by the Thermal Emission Spectrometer on NASA's now-defunct Mars Global Surveyor, hydrogen detections (as a proxy for water) from the Gamma-Ray Spectrometer on the agency's Mars Odyssey, and models of the Martian terrain built around data from the HiRISE camera on NASA's Mars Reconnaissance Orbiter.

They determined that the skylights and their surroundings are consistent with what's termed "karstic" caves. Karstic refers to the dissolution of carbonate- and sulfate-bearing bedrock. While we find karstic caves in many locations on Earth, this is the first time that they have been identified on Mars.

The observations show that the Hebrus Valles region is rich in carbonate rock such as limestone and sulfate rock such as gypsum. Over 3.5 billion years ago, when Mars was warmer and wetter, these carbonate and sulfate sediments were laid down by large pools of liquid water, such as lakes and seas. When Mars grew cold, the surface water went away, much of it forming sub-surface ice and frozen brines.

Indeed, the Gamma-Ray Spectrometer data from Mars Odyssey points to water ice possibly still existing there in some quantity. At some point, local heating events, perhaps from distant volcanoes, impacts or long-term orbital variations, would have melted the subsurface ice and brines, and the liquid water would have run through cracks and fractures in the ground, dissolving the rock and turning those cracks into large caves.

Not all regions of Mars meet the requirements to form karstic caves, since for one thing carbonate and sulfate rocks are not omnipresent. Nor do all locations, particularly lower-latitude areas, host subsurface ice and frozen brines or have been geologically stable for long enough to allow the caves to form and their rocky ceiling to collapse and form the skylights.

"Our results suggest that Hebrus Valles is unlikely to be a completely isolated case, but these caves also will not be everywhere on Mars," said Ding. "They are likely concentrated in a limited set of regions that satisfy the necessary depositional and hydrological conditions. It is quite reasonable to expect more karstic caves to be discovered in other, similar environments in the future."

Indeed, more than just the eight caves may be present in Hebrus Valles; there could be others that have not yet experienced a ceiling collapse and revealed themselves. Of those known so far, the skylights appear to be several tens to over 100 meters across, and underground the cavities could be several times larger still, and tens of meters deep.

Karstic caves are the perfect location to preserve ancient biosignatures. The watery and stable microclimate within the caves long ago could have hosted microbial colonies, and today the caves are protected from the extreme conditions on Mars' surface, such as wildly different diurnal temperatures, dust storms and solar ultraviolet and cosmic-ray radiation. Hence future life-seeking missions may seek to explore them.

However, the surrounding rock will limit the transmission of radio signals from inside the caves to orbiting spacecraft, making exploration of the caves more difficult, but not impossible, said Ding.

"From an engineering standpoint, directly entering these caves is a major challenge," he said. "However, our geomorphological analysis suggests that not all candidate caves are simple vertical shafts. In our paper, we use the term 'accessible potential karstic caves.'"

Most of the skylights are characterized by steep walls descending down into the darkness of the caves, but among the eight Hebrus Valles caves there is evidence for slopes made by rocky debris in multiple, step-like formations that might allow a staged descent.

This could be accomplished by multiple robotic explorers forming a communications chain down into the caves, ranging from wheeled rovers that carefully navigate down each step, to climbing robots lowered by winches or aerial rotorcraft that can fly in and out of the skylights.

The cave's rocky shielding might not only lend itself to preserving biosignatures, but could also offer protection to future Mars astronauts, shielding them and their outposts from the hazards of radiation and dust storms on the surface. If so, it could be that humanity's future on Mars is to be found underground.

The conclusions of Ding's team were published on Oct. 30 in The Astrophysical Journal Letters.

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

NASA's search for evidence of past life on Mars just produced an exciting update. On Sept. 10, 2025, a team of scientists published a paper detailing the Perseverance rover's investigation of a distinctive rock outcrop called Bright Angel on the edge of Mars' Jezero Crater. This outcrop is notable for its light-toned rocks with striking mineral nodules and multicolored, leopard print-like splotches.

By combining data from five scientific instruments, the team determined that these nodules formed through processes that could have involved microorganisms. While this finding is not direct evidence of life, it's a compelling discovery that planetary scientists hope to look into more closely.

To appreciate how discoveries like this one come about, it's helpful to understand how scientists engage with rover data — that is, how planetary scientists like me use robots like Perseverance on Mars as extensions of our own senses.

Experiencing Mars through data

When you strap on a virtual reality headset, you suddenly lose your orientation to the immediate surroundings, and your awareness is transported by light and sound to a fabricated environment. For Mars scientists working on rover mission teams, something very similar occurs when rovers send back their daily downlinks of data.

Several developers, including MarsVR, Planetary Visor and Access Mars, have actually worked to build virtual Mars environments for viewing with a virtual reality headset. However, much of Mars scientists' daily work instead involves analyzing numerical data visualized in graphs and plots. These datasets, produced by state-of-the-art sensors on Mars rovers, extend far beyond human vision and hearing.

Developing an intuition for interpreting these complex datasets takes years, if not entire careers. It is through this "mind-data connection" that scientists build mental models of Martian landscapes – models they then communicate to the world through scientific publications.

The robots' tool kit: Sensors and instruments

Five primary instruments on Perseverance, aided by machine learning algorithms, helped describe the unusual rock formations at a site called Beaver Falls and the past they record.

Robotic hands: Mounted on the rover's robotic arm are tools for blowing dust aside and abrading rock surfaces. These ensure the rover analyzes clean samples.

Cameras: Perseverance hosts 19 cameras for navigation, self-inspection and science. Five science-focused cameras played a key role in this study. These cameras captured details unseeable by human eyes, including magnified mineral textures and light in infrared wavelengths. Their images revealed that Bright Angel is a mudstone, a type of sedimentary rock formed from fine sediments deposited in water.

Spectrometers: Instruments such as SuperCam and SHERLOC – scanning habitable environments with Raman and luminescence for organics and chemicals – analyze how rocks reflect or emit light across a range of wavelengths. Think of this as taking hundreds of flash photographs of the same tiny spot, all in different "colors." These datasets, called spectra, revealed signs of water integrated into mineral structures in the rock and traces of organic molecules: the basic building blocks of life.

Subsurface radar: RIMFAX, the radar imager for Mars subsurface experiment, uses radio waves to peer beneath Mars' surface and map rock layers. At Beaver Falls, this showed the rocks were layered over other ancient terrains, likely due to the activity of a flowing river. Areas with persistently present water are better habitats for microbes than dry or intermittently wet locations.

X-ray chemistry: PIXL, the planetary instrument for X-ray lithochemistry, bombards rock surfaces with X-rays and observes how the rock glows or reflects them. This technique can tell researchers which elements and minerals the rock contains at a fine scale. PIXL revealed that the leopard-like spots found at Beaver Falls differed chemically from the surrounding rock. The spots resembled patterns on Earth formed by chemical reactions that are mediated by microbes underwater.

Together, these instruments produce a multifaceted picture of the Martian environment. Some datasets require significant processing, and refined machine learning algorithms help the mission teams turn that information into a more intuitive description of the Jezero Crater’s setting, past and present.

The challenge of uncertainty

Despite Perseverance's remarkable tools and processing software, uncertainty remains in the results. Science, especially when conducted remotely on another planet, is rarely black and white. In this case, the chemical signatures and mineral formations at Beaver Falls are suggestive – but not conclusive – of past life on Mars.

There actually are tools, such as mass spectrometers, that can show definitively whether a rock sample contains evidence of biological activity. However, these instruments are currently too fragile, heavy and power-intensive for Mars missions.

Fortunately, Perseverance has collected and sealed rock core samples from Beaver Falls and other promising sites in Jezero Crater with the goal of sending them back to Earth. If the current Mars sample return plan can retrieve these samples, laboratories on Earth can scrutinize them far more thoroughly than the rover was able to.

Investing in our robotic senses

This discovery is a testament to decades of NASA's sustained investment in Mars exploration and the work of engineering teams that developed these instruments. Yet these investments face an uncertain future.

The White House's budget office recently proposed cutting 47% of NASA’s science funding. Such reductions could curtail ongoing missions, including Perseverance's continued operations, which are targeted for a 23% cut, and jeopardize future plans such as the Mars sample return campaign, among many other missions.

Perseverance represents more than a machine. It is a proxy extending humanity’s senses across millions of miles to an alien world. These robotic explorers and the NASA science programs behind them are a key part of the United States' collective quest to answer profound questions about the universe and life beyond Earth.

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

Only a little over a week after scientists announced NASA's Perseverance rover may have detected a potential biosignature in a Martian rock named Sapphire Canyon, a new study suggests similar habitable conditions were widespread across Jezero Crater — the site of that major discovery — broadening the stage for the search for ancient life on Mars.

In the study, scientists identified 24 minerals that chart Jezero's changing environment, highlighting both the volcanic origins of rocks in the crater and a long history of their interaction with water. Although the research does not analyze the Sapphire Canyon sample directly, it shows the crater as a whole experienced multiple episodes of water activity, each with conditions that could have supported life (as we know it).

"There were several times in Mars' history when these particular volcanic rocks interacted with liquid water," study lead author Eleanor Moreland of Rice University in Texas said in a statement, "and therefore more than one time when this location hosted environments potentially suitable for life."

The study draws on three years of data collected by Perseverance, which has been exploring Jezero since landing on Mars in 2021. Using the rover's X-ray instrument (PIXL) and a newly developed algorithm called MIST, researchers were able to identify the minerals and assemble a so-called "mineralogical archive" of the crater, according to the statement.

Minerals are natural storytellers, forming under specific combinations of temperature, chemistry and pH. At Jezero, they reveal three stages of water-rock interaction, each with different implications for habitability, the new study notes. To ensure accuracy, the team ran their identifications through thousands of statistical simulations — a process likened to how meteorologists model hurricane tracks — to account for instrument error and assign confidence levels to each match, according to the statement.

The oldest rocks on the crater floor bore signs of hot, acidic fluids, recorded in minerals such as greenalite, hisingerite and ferroaluminoceladonite. These conditions would have been least favorable for life, scientists say, as high temperatures and low pH are known to damage biological structures.

"These hot, acidic conditions would be the most challenging for life," study co-author Kirsten Siebach, who is an assistant professor of Earth, environmental and planetary sciences at Rice University, said in the statement. "But on Earth, life can persist even in extreme environments like the acidic pools of water at Yellowstone, so it doesn't rule out habitability."

Later episodes of water activity left behind minerals such as minnesotaite and clinoptilolite, which formed in cooler, more neutral waters that would have been friendlier to microbes, the study reports.

Finally, researchers found widespread deposits of sepiolite, a mineral that forms in low-temperature, alkaline waters considered highly hospitable from an Earth perspective. Its presence across all regions Perseverance has explored suggests a broad episode of habitable conditions, scientists say.

"These minerals tell us that Jezero experienced a shift from harsher, hot, acidic fluids to more neutral and alkaline ones over time — conditions we think of as increasingly supportive of life," Moreland said in the statement.

Alongside these alteration minerals, the team also confirmed the presence of volcanic building blocks such as pyroxene, feldspar and olivine, reinforcing the prevailing view that Jezero's floor was formed by ancient lava flows later transformed by water.

The new findings also add context to last year's headlines, when Perseverance's work at Cheyava Falls — where Sapphire Canyon was sampled — revealed intriguing signs of conditions often linked to microbial life. At the time, scientists described it as the strongest evidence yet that Mars may once have hosted primitive organisms, though they stressed that nonbiological explanations, such as certain mineral reactions from heating, could not be ruled out.

Follow-up analyses have since found no evidence the rock was heated, but researchers caution that only laboratory studies on Earth can settle the biological-versus-nonbiological debate.

"We're pretty close to the limits of what the rover can do on the surface," Katie Stack Morgan, Perseverance Project Scientist at NASA's Jet Propulsion Laboratory in Pasadena, California, said during a press conference last week on Sept. 10. "That was by design. The payload of the Perseverance rover was selected with a Mars sample return effort in mind; the idea was for our payload to get us just up to the potential biosignature designation and have the rest of the story told by instruments here on Earth."

Each tube cached on Mars could hold a crucial piece of the puzzle — and perhaps, the first direct evidence of life beyond Earth. But the path to bringing them home continues to remain uncertain. After years of cost overruns, NASA announced in January that it would study cheaper alternatives for its proposed Mars Sample Return (MSR) program, which would aim to deliver samples by 2035. The agency's 2026 budget proposal, however, calls for canceling the program.

"We believe there is a better way to do this, a faster way to get these samples back," Sean Duffy, NASA's acting administrator, said during the press conference last week, , though he offered no details on cost, timing, or technical approach.

Meanwhile, China is pushing ahead with its own Mars sample-return mission. The Tianwen-3 mission aims to collect at least 500 grams of Martian rock and soil as early as 2028 and return them to Earth by 2031 — potentially beating NASA to the milestone. If successful, China would secure the first Mars samples and perform a dramatic leap in planetary science leadership.

In addition to revealing Mars' mineral story, the new MIST algorithm developed by the study authors could prove critical in deciding which rocks to return to Earth, the new study notes. By identifying minerals and assigning confidence levels to each detection, it helps mission scientists prioritize the most valuable samples. Such a catalog, tied to specific sampling sites, would be vital when selecting which sealed cores to bring back under the MSR program.

"The results reported here can be crucial when down-selecting which samples, if not all, are returned to Earth," the researchers wrote in the study.

The study was published on Sept. 11 in the Journal of Geophysical Research.

A pair of new studies presented at the Joint Meeting of the Europlanet Science Congress and the Division for Planetary Science (EPSC-DPS) suggest the European Space Agency's (ESA) upcoming Mars rover mission, Rosalind Franklin, may have better odds of detecting ancient organic material than previously realized. It all comes down to natural processes that occurred at the rover's landing site: the clay-rich Oxia Planum.

One of the studies, led by Dr. Aleksandra Sokołowska of Brown University and Imperial College London, has identified 258 rockfalls around the Oxia Planum region using high-resolution imagery from NASA's Mars Reconnaissance Orbiter (MRO)

The rockfalls may expose material from beneath the Martian surface. Additionally, tracks carved by falling rocks or sliding debris could bring subsurface dirt into more accessible positions for rover samples.

"The discovery of rockfalls in Oxia Planum opens up the exciting possibility for the rover to increase the diversity of its samples with material that would otherwise be inaccessible," Sokołowska said in a statement.

Because the rocks were previously embedded in geological features, such as crater walls and cliff faces, some of their recently revealed surfaces might have been shielded from harsh radiation. That protection could increase the odds that organic molecules still exist intact here.

The second study, led by Ananya Srivastava of the University of Western Ontario, highlights layered clay deposits at Oxia Planum — clays are well noted for their ability to preserve organic materials.

Spectral and compositional data from MRO and ESA's Mars Express mission show alternating orange and blue layers in the clay in various thicknesses, suggesting the clays were transported from other areas of Mars via rivers and flood events.

"The clays could record a far wider range of ancient Martian climatic conditions than previously believed if they came in multiple pulses from various source regions," said Srivastava. "This diversity of environments improves the prospect that organic molecules were preserved under favourable conditions, strengthening the chances of uncovering the most thrilling discovery — clues for life beyond Earth."

The Rosalind Franklin rover, named after the pioneering British chemist whose photographic research was critical in revealing the double helix structure of DNA, is well-equipped to search for organic compounds at Oxia Planum. It houses a drill capable of reaching a depth of more than six feet (two meters) — deeper than any previous drill attempts on Mars.

Currently, the Rosalind Franklin rover — part of ESA's ExoMars program — is scheduled to launch in 2028 after facing years of setbacks. In the early 2000s, NASA agreed to provide ESA with crucial technologies for the rover, but the partnership ended in 2012 after former President Barack Obama cut funding for the mission.

Russia's Roscosmos filled the gap, and the rover was set to launch in 2022. Then came Russia's invasion of Ukraine, which ended Roscosmos' involvement in the project and pushed the launch date back.

NASA returned to the mission in 2024, but the partnership still faces an uncertain future. Proposed budget cuts under the Trump administration may see NASA pull out of the mission yet again. Hopefully, studies like the ones presented at EPSC-DPS will emphasize the importance of the Rosalind Franklin rover — and urge policymakers to keep NASA's participation intact.

While most people searching for signs of alien life these days might have their eyes on the exoplanet K2-18b, one team of researchers is keeping their sights a little closer to home.

Texas A&M researcher Michael Tice and a team of international scientists have revealed new clues about Mars' potential to have supported life, thanks to data collected by NASA's Perseverance rover.

Since 2021, Perseverance has been exploring Mars' Jezero Crater, using its mobile laboratory to support the work of scientists around the world. Tice and his team, in particular, have been using Perseverance to analyze Martian rocks. Their goal is to study the planet's volcanic and hydrological history, looking for indicators that Mars might have once been habitable.

Through their research, the team has discovered two types of mineral-rich volcanic rocks: a dark rock with iron, magnesium, pyroxene and plagioclase feldspar, as well as a light-toned trachyandesite with plagioclase crystals and potassium.

Simulating the formation of the rocks' minerals through thermodynamic modeling, the researchers determined that Mars has a very complex volcanic history — one that might have been able to provide the key compounds needed for life.

"The processes we see here — fractional crystallization and crustal assimilation — happen in active volcanic systems on Earth," Tice said in a statement. "It suggests that this part of Mars may have had prolonged volcanic activity, which in turn could have provided a sustained source for different compounds used by life."

As advanced as Perseverance is, its toolkit is still limited compared to what we have here on Earth, so there's only so much we can learn about samples from afar. As such, Tice looks forward to NASA's planned Mars Sample Return mission to conduct further research on the volcanic rock.

"We’ve carefully selected these rocks because they contain clues to Mars’ past environments," Tice said. "When we get them back to Earth and can analyze them with laboratory instruments, we’ll be able to ask much more detailed questions about their history and potential biological signatures."

The team's research was published in the journal Science Advances on Jan. 24, 2025.

A lone researcher may have figured out how Mars was able to support rivers and seas even after the planet had begun to grow cold and its atmosphere thin, and it's all thanks to a cycle of water and carbon dioxide.

We know from geological and mineralogical evidence that, around four billion years ago, Mars was warm and wet enough to have extensive liquid water on its surface, from rivers and lakes to a vast northern sea. This period covers two geological eras: the Noachian, which ran from 4.1 to 3.7 billion years ago, and the Hesperian, which endured from 3.7 to about 3 billion years ago. The Noachian is characterized by warmer conditions, but by its latter stages Mars should have been starting to grow cold as it steadily lost its atmosphere to space. Yet there is still evidence of river channels and seas dating back to the late Noachian and into the Hesperian era. Planetary scientists have been mystified as to how Mars could still be wet at this time, and one theory is that the Red Planet experienced an unexplained period of global warming.

Now, though, researcher Peter Buhler of the Planetary Science Institute in Arizona may have solved the problem, thanks to his modeling of the role of carbon dioxide ice settling onto the south polar cap.

The model "describes the origins of major landscape features on Mars — like the biggest lake, the biggest valleys and the biggest esker system — in a self-consistent way," Buhler said in a statement. "And it's only relying on a process that we see today, which is just carbon dioxide collapsing from the atmosphere."

Related: Water on Mars: Exploration & evidence

Eskers are long, gravelly ridges left by running water, and their presence near Mars' south pole is a big clue about how events played out on the Red Planet.

Usually, Buhler spends his time modeling the carbon-dioxide cycle on Mars today. During Martian winter, a layer of carbon-dioxide ice settles out on top of the polar caps of water ice. While it is just a thin layer on the north polar cap, the south polar cap has much more, with a permanent layer of carbon dioxide ice 26 feet (8 meters) thick, with more added in winter. This additional carbon dioxide is normally locked away in the Martian dirt, but during what passes as Martian summer it can sublimate into the atmosphere and be transported to the winter pole.

Buhler wanted to see what effect this process had 3.6 billion years ago, during the early Hesperian when the atmosphere — despite beginning to leak out into space after Mars' magnetic field that had warded off the solar wind shut down — was still much thicker than it is today. He found that a layer of carbon dioxide ice 650 meters (0.4 miles) thick would settle onto Mars' south polar cap each winter.

The carbon dioxide did two things. It first acted as an insulator, preventing heat leaking out of the planet's interior from escaping at the south pole. It also added weight and pressure onto the ice cap. Combined, these effects led to temperatures and pressures at the base of the ice cap that allowed the ice there to melt and form a pool of water. Eventually, over many winters, water ice and carbon dioxide ice continued freezing out onto the ice cap while, below, the liquid water built up to such an amount that it began seeping out at the sides of the ice cap.

Once exposed to the cold air, according to the new modeling work, the liquid water would freeze as permafrost. This isn't the end of the story, though. Liquid water would keep on forming behind the ice, looking for ways to escape.

"The only way left for the water to go is through the interface between the ice sheet and the rock underneath it," said Buhler. "That's why on Earth you see rivers come out from underneath glaciers instead of just draining into the ground."

The rivers would still freeze as they popped up above ground, but the volume of water was such that it would keep burrowing under this ice, which eventually formed a frozen ceiling over the rivers many dozens of meters (hundreds of feet) thick. The rivers themselves were only a meter or so deep, but they were long, running for thousands of kilometers away from the south pole.

This is where the eskers come in. They are the remains of these long subglacial rivers, and many have been found extending radially away from the southern polar region.

Even today, we can see the remains of four large river channels flowing into Argyre Planitia, which is a huge impact basin 1,700 kilometers (1,100 miles) wide and 5.2 kilometers (3.2 miles) deep. Over millions of years, the sub-glacial rivers filled Argyre with water to form an ocean as large as the Mediterranean. And, over those millions of years, the meltwater kept on coming, causing Argyre to episodically overflow and flood Mars' northern plains.

Related: Ocean's worth of water may be buried within Mars — but can we get to it?

"This is the first model that produces enough water to overtop Argyre," said Buhler. "It's also likely that the meltwater, once downstream, sublimated back into the atmosphere before being returned to the south polar cap, perpetuating a pole-to-equator hydrologic cycle that may have played an important role in Mars' enigmatic pulse of late-stage hydrologic activity."

Eventually, Mars grew too cold for even this meltwater process to take place. There was recently a claim of a subsurface lake still existing beneath the south polar ice cap on Mars today, but significant doubt has been cast on this idea.

What's neat about Buhler's model is that it doesn't need to enact any unexplained warming to account for the evidence for water that we see — it's literally the same carbon dioxide cycle that we see on Mars today. Unfortunately, Mars has grown so cold, with so little carbon dioxide available, that the days of widespread liquid water on the Red Planet have been over for billions of years.

Buhler's research was published on Nov. 1 in the Journal of Geophysical Research: Planets.

Salt water could be running down some slopes of Mars every spring, researchers suggest.

Such a finding would suggest new directions to search for any life that still existed on the Red Planet.

Clusters of dark, narrow lines that periodically emerge and lengthen on slopes in the warmer regions suggest briny water on Mars might still be flowing in a few rare places on the planet's surface.

"This is water today, not in the past," study co-author Alfred McEwen, a planetary scientist at the University of Arizona, told SPACE.com. [Photos: The Search for Water on Mars]

A great deal of evidence on the Martian surface suggests the planet was wet and perhaps capable of supporting life in the past. Although frozen water has been detected near the surface in many middle-to-high latitudes, there has been no definitive evidence that liquid water still runs across its surface.

"Water today on Mars was suggested previously, but it's not clear if those claims withstood follow-up studies," McEwen added. "That may prove true with this case as well, but for now, this is the best candidate for water today on Mars."

Strange lines on Mars

The scientists discovered the strange lines after a University of Arizona student used a computer algorithm on pictures of the Martian surface taken by the High Resolution Imaging Science Experiment (HiRise) on the Mars Reconnaissance Orbiter. The algorithm was capable of identifying subtle changes on Mars over time. The images covered a variety of latitudes and span across approximately three Martian years.

The student, Lujendra Ojha, said in a statement: "I was baffled when I first saw those features in the images after I had run them through my algorithm. We soon realized they were different from slope streaks that had been observed before. These are highly seasonal, and we observed some of them had grown by more than 200 meters [650 feet] in a matter of just two Earth months." [FAQ: What the Possibility of Water on Mars Means]

These finger-like streaks extend down some slopes during the warmest months of the Martian year. They fade in winter, then re-emerge in the spring.

"What's most interesting to me is that it took so long to discover these details from images that were seen or acquired long ago but not examined in detail long ago," McEwen said. "It makes me wonder how many other things we're missing." 

These features, called "recurring slope lineae," reach down steep slopes such as the rims of impact craters, usually on sides facing the equator. While they can be hundreds of feet long, they are only about 1.6 to 16 feet (0.5 to 5 meters) wide, much narrower than gullies seen in the past on Martian slopes.

The scientists detail their findings in the Aug. 5 issue of the journal Science.

Is saltwater flowing on Martian slopes?

The best explanation the researchers have produced so far for these features is that they are made by salty water, which would be capable of staying liquid at colder temperatures than pure water. [Video: Did Mars Make Life, And Lose It?]

A flow started by briny water could rearrange grains or change surface roughness in a way that darkens its appearance. "The flows are not dark because of being wet," McEwen said.

How these streaks brighten again when temperatures drop is harder to explain. "It's a mystery now, but I think it's a solvable mystery with further observations and experiments," he said.

As to what the source of this water might be, "that is the $10,000 question," McEwen said. "It probably has to come from vapor, either from the atmosphere or from subsurface ground ice, or it's coming from brines in the crust that are stable over geological time. But it's all speculation right now — we wish we knew."

Implications for life hunt?

When it comes to looking for extant life on Mars, "researchers mostly have thought about the deep subsurface, but the cost and difficulty of bringing a drill rig to Mars is not really feasible," McEwen said. "However, if there is extant life on Mars, it might be accessible in these brines, which gives us a new direction as to where to go."

The researchers caution their observations are not proof of liquid salt water on Mars. [7 Theories on the Origin of Life]

Still, "we've been trying to come up with alternate ideas, maybe some sort of dry avalanching process, but none of them work," McEwen said. "Why does this only seem to happen at certain temperatures and latitudes, and why darken and fade? Briny water seems to be the most viable explanation for these observations so far."

McEwen added that the ExoMars mission from NASA and the European Space Agency, planned for launch in 2016, is aimed to detect trace gases in the Martian atmosphere, including water, and might see whether these features really are caused by brines. "It could look for local enrichment of water and see if it corresponds to the times and places of these streaks," he said.

Follow SPACE.com contributor Charles Q. Choi on Twitter @cqchoi. Visit SPACE.com for the latest in space science and exploration news on Twitter @Spacedotcomand on Facebook.