New findings sharpen the case for ancient habitability on Mars
A new Nature study led by NASA and involving Imperial College London researchers reports a compelling set of minerals and organic matter in Martian rocks. The team argues these signatures are closely tied to ancient lake environments and may reflect microbial or biogeochemical processes that once occurred in Jezero Crater, Mars’s famed lake-delta system.
What the researchers found
The investigation centers on the Bright Angel formation, a distinctive light-toned outcrop within the Jezero Crater valley known as Neretva Vallis. Using data from the Perseverance rover’s Planetary Instrument for X-ray Lithochemistry (PIXL) and the Scanning Habitable Environments with Raman & Luminescence for Organics & Chemicals (SHERLOC) instruments, the team mapped rock types and chemical signatures with unprecedented detail. They detected a suite of minerals—particularly silica and clays—interwoven with organic-rich material distributed in fine layers and sedimentary textures that point to low-energy, water-lain conditions rather than fast-flowing river processes.
Imperial College London’s crucial role
Imperial College London’s Department of Earth Science and Engineering, including Professor Sanjeev Gupta and Dr Robert Barnes, contributed key sedimentological and stratigraphic analyses funded by the UK Space Agency. Co-author Alex Jones, a PhD researcher in ESE, highlighted the significance: “This is unusual but very intriguing, as we wouldn’t expect to find such deposits in Neretva Vallis. Our work indicates a past, low-energy lake environment—precisely the kind of habitable setting we have been searching for on the mission.”
How the data were collected
Perseverance has been exploring the 45-kilometre-wide Jezero Crater since 2021, a site selected for its ancient lake and river delta—a setting considered ripe for preserving signs of past life. The rover’s suite of instruments analyzes rock composition and texture in situ, while the mission’s broader aim is to collect and cache samples for eventual return to Earth. The Bright Angel outcrop provided a rare chance to examine sedimentary records that shed light on Jezero’s hydrological history and climate over geological time scales.
Implications for Mars’ hydrological past
By reconstructing depositional environments, the Imperial-led team suggests that Jezero’s valley may have been flooded at times, creating a lake at the base of a river valley. The resulting limestone-like mudstones and mud-rich conglomerates imply a calm, persistent water body rather than episodic flow. In turn, such an environment would have offered chemical conditions favorable to sustaining microbial life and preserving organic carbon over long periods. This aligns with broader Mars research that seeks stable, long-lived aqueous habitats as optimal targets for biosignatures.
What this means for the search for life on Mars
While the results significantly strengthen the case for a past habitable environment and potential biological activity, the researchers caution against equating signatures with life itself. “This is a very exciting discovery of a potential biosignature, but it does not mean we have discovered life on Mars,” said Professor Gupta. The work underscores the need for Earth-based analyses of these rocks to confirm any biological involvement. The return of carefully selected Martian samples to Earth—planned as part of NASA’s Perseverance-driven program—will allow more definitive testing of these hypotheses.
Next steps in the mission
The Bright Angel findings add to a growing body of evidence that Jezero’s ancient lake-bed environment could have supported microbial ecosystems. As samples are collected and stored for eventual shipment to Earth, scientists anticipate high-resolution analyses that can reveal metabolic byproducts, isotopic signatures, and other biosignatures at a level currently impossible on the Martian surface. The international collaboration—including Imperial College London and NASA’s Perseverance team—continues to push Mars science toward a clearer understanding of the planet’s biological potential.
In summary, the Bright Angel site has provided one of the strongest, most coherent stories yet for a habitable past on Mars, with organic-rich, lake-margin deposits forming the critical link between geology and biology. The coming years of sample return will be pivotal in determining whether life once flourished on the Red Planet.
