Scientists have uncovered one of the strongest pieces of evidence yet that Mars may once have been home to microbial life.
A new study, led by NASA and featuring key work from Imperial College London, reports that rocks inside an ancient lake in Mars’s Jezero Crater contain minerals and organic matter that may be linked to biological processes.
The findings come from the “Bright Angel” formation, a light-colored rock outcrop inside Jezero’s Neretva Vallis, a valley that once carried water into the crater.
Using instruments on the Perseverance Rover, researchers analyzed the fine-grained mudstones and conglomerates in this area and found chemical signatures that strongly suggest a past habitable environment.
Perseverance has been exploring Jezero Crater since 2021 as part of NASA’s Mars 2020 mission.
The site was chosen because it once contained a vast lake and river delta, ideal places to look for past life. While driving through Neretva Vallis, scientists were surprised to discover that some of the rocks were typical of lake beds, not river channels.
Sediment analysis showed minerals such as silica and clays that would usually be washed away in fast-moving rivers. Their presence suggested that the valley itself may once have been flooded, creating a calm lake environment—exactly the kind of setting where life might flourish.
“This is unusual but very intriguing,” said Alex Jones, a PhD researcher at Imperial College London and member of the Perseverance team. “It points to a low-energy lake environment, which is exactly the kind of place we’ve been hoping to find.”
The real excitement came from what was found inside the rocks themselves. Perseverance detected small nodules and chemical reaction fronts rich in minerals like vivianite and greigite, which form through reactions involving iron, phosphorus, and sulfur.
These minerals appeared to be connected with organic carbon.
On Earth, similar reactions are often driven by microbial metabolism, suggesting that the Martian features could be potential “biosignatures”—chemical traces left behind by living organisms.
While non-biological chemistry could also produce them, the resemblance to Earth’s microbial by-products is striking.
“This is a very exciting discovery of a potential biosignature,” said Professor Sanjeev Gupta of Imperial College London. “But it does not mean we have discovered life on Mars. We now need to study these samples on Earth to confirm whether biology was involved.”
Perseverance has already drilled into the Bright Angel outcrop and collected a core sample named “Sapphire Canyon.” This and other samples are being stored for the future Mars Sample Return mission, a joint NASA-ESA project planned for the 2030s. Once brought to Earth, the rocks will be examined with far more sensitive instruments than the rover carries.
If scientists confirm that these features were created by ancient microbes, it would be the first evidence of life beyond Earth. For now, the discovery remains one of the most promising leads in the search.
“This discovery represents a huge step forward,” said Gupta. “It highlights the power of international collaboration and advanced robotics in planetary exploration.”
UK space leaders agree. Matthew Cook of the UK Space Agency called the results “the most promising evidence yet” of ancient Martian life, while stressing the need for careful verification.
He added that future missions, including the UK-built Rosalind Franklin rover, will help answer the ultimate question: are we alone in the universe?
