Ancient life may have existed in Mars' clay layers.

One of the most fascinating geological mysteries of the Red Planet is the existence of thick, planet-wide clay sheets. Scientists have long considered these deposits to be possible time capsules for ancient life because clay only forms when there is an abundance of liquid water present.

During her postdoctoral study at The University of Texas in Austin, planetary geologist Rhianna Moore led the team in searching through high-resolution photos and topographic data for 150 clay outcrops that had already been catalogued.

Mars's serene clay terraces

Throughout Mars, thick clay layers exhibit a startlingly common set of characteristics. The majority are located next to the remains of long-gone lakes at low elevations. However, they are still very far from the old river valleys that used to sculpt the highlands.

Moore stated, "These areas are very stable because they have a lot of water but not a lot of topographic uplift." Such stability, she continued, would have prevented damaging erosion by swiftly flowing water.

Instead of being scoured away, this would have permitted clays to build up layer after layer. "If you have stable terrain, you won't disrupt the potentially habitable environment. It could potentially maintain favorable conditions over a long period," she said.

Education from the Earth Tropics

Research co-author Tim Godge and Assistant Professor in the Department of Earth and Planetary Sciences at Earthtin sees echoes of Earth analogues from the distant past.

"On the planet, there are places where we are in the thickest sound mineral sequences in wet environments and where there is minimal physical erosion that can remove new weathered products," Goudge said.

The Mars pattern fits almost perfectly into the second half of this recipe, as he found. "These results suggest that the latter element also applies to Mars, and there are also signs of the former." Because Mars lacks flat tectonics, its surface is not constantly stirred like Earth's.

This relative silence, combined with a climate, for billions of years, produced a mild pelvis was produced. There, precipitation and standing volcanic rocks slowly decomposed into clay minerals. The new sediment was not wiped out by violent floods and could not accumulate over time.

Carbonate Puzzle

The same conditions that prefer to form sounds can also explain the rarity of carbonate rocks, one of Mars' long-term mysteries. On Earth, volcanic CO2 reacts with the crust of fresh basalts, eventually trapping carbon in vast beds of limestone and dolomite. However, on Mars, without a structural conveyor belt for recording fresh lava, this cycle remained closed.

This study suggests that CO2 remained longer, heated the planets, promoted slow and sustained weathering, and contributed to the formation of tones. At the same time, sound growth may be the environment of the components necessary to form carbonates, primarily by capturing this weathering bypass with the required impermeable mineral layer.

"It's probably one of many factors that contribute to this strange shortage of Mars' predicted carbonates," Moore said. Signs of a life-friendly condition. To summarise, the results show vast, mild aqueous habitats that exist long enough to concentrate on minerals and perhaps organic molecules.

Thick tones help astrobiologists by conserving biochemical evidence and protecting them from radiation and geological disorders. Moore is currently part of the Artemis program of the NASA Artemis program and highlighted work from the UT Austin's Planetary Systems Center for Planetary Systems.

The study provides a shortlist of tempting targets for upcoming rover missions or even human explorers searching for fossilised biosignatures by examining mild clay basins that are close to lakes.

circumstances in which life might have flourished

More than three billion years ago, when these clays developed, Mars was probably dotted with lakes and seas, but now it is cold and dry. According to the latest investigation, the water bodies weren't merely temporary puddles that were nourished by devastating floods. Rather, slow-developing chemical processes lasting millennia may have taken place in shallow, long-lived basins.

Rather, much of the old surface was shaped by chemical breakdown rather than physical abrasion. Under a thicker, more greenhouse gas-rich atmosphere, that equilibrium produced warm, quiet conditions that could have supported life.

Looking for hints in clay

Researchers seek to improve models of how water circulated through early Mars as orbiters continue to return ever-finer data. Future mission drill cores could confirm the newly mapped clay fields' duration, chemistry, and age.

In the meantime, Earth-based labs will investigate whether stable, low-energy ponds can indeed produce the mineral fingerprints seen from orbit by simulating Martian circumstances.

The largest clay coverings on Mars stayed away from the valleys themselves, even as valley networks carried water downhill. This shows that the main architects were not sediment-choked streams or turbulence.

According to the study, the most promising habitats on Mars may not have been found in raging river deltas. Instead, they might have been on peaceful lakeshores where mud slowly settled season after season, enclosing the planet's biological secrets as well as its aqueous ones.