Possible Ancient Life on Mars

​NASA has not confirmed the discovery of previous life on Mars, but Perseverance rover has uncovered the strongest evidence yet of potential ancient microbial life: possible biosignatures in Martian rocks from a long-dry riverbed in Jezero Crater. The rover sampled a rock in 2024, dubbed “Cheyava Falls,” within the “Bright Angel” formation of Neretva Vallis, an ancient river valley that flowed into Jezero Crater. Scientists detected minerals and chemical combinations (including organic carbon, sulphur, oxidized iron, and phosphorous) commonly associated with life on Earth, preserved in clay and silt-rich sedimentary rocks.
 
The sample, nicknamed “Sapphire Canyon,” displays mineral “leopard spots” and chemical features that could be remnants of past microbial activity. These rocks are known to be excellent preservers of ancient microbial life on Earth, and their textures and chemistry are highly suggestive but not conclusive for life. Findings were published in Nature and presented by NASA’s administrators as the closest evidence yet for ancient Martian life.
 
NASA and independent scientists caution that abiotic (non-living) processes could also explain these features. True confirmation will require returning Martian samples to Earth for deeper analysis, a step still pending due to funding and logistical constraints. This discovery suggests Mars could have supported habitable conditions and possibly life billions of years ago, but further work is essential to confirm biological origins. 
 
Scientists are taking several key steps to verify whether the signs observed by NASA’s Perseverance rover truly indicate ancient microbial life on Mars. NASA and the European Space Agency (ESA) are planning to bring Perseverance’s rock cores, including the promising “Sapphire Canyon” sample, back to Earth for detailed laboratory study. These missions, tentatively set for the 2030s, will allow use of far more sensitive instruments and techniques than are currently available on Mars. NASA is revising its sample return strategy due to funding and engineering hurdles, exploring options like commercial partnerships and new lander designs to retrieve and deliver samples safely. The upcoming ESA Rosalind Franklin rover and additional NASA missions are planned to drill, sample, and analyse strata similar to those already surveyed, hopefully finding corroborative evidence or new environments that support life.
 
Findings from Perseverance’s instruments, especially PIXL and SHERLOC, have undergone peer review and are published for scrutiny by the global scientific community, ensuring validity and transparency. Only laboratory techniques on Earth, allowing for finer chemical, isotopic, and microscopic study, can decisively confirm if detected biosignatures have biological origins or are natural geochemical phenomena. Scientists will continue using advanced frameworks for weighing evidence, like the CoLD scale and other standards, as well as mapping more candidate biosignature sites around Jezero Crater and beyond.
 
References
Li, G. & Levey, S. (2025, September 10). Potential Biosignatures Found in Ancient Mars Lake. Imperial News.

​Smith, M. (2025, September 10). Mars Samples Must Be Returned to Earth to Prove if Life Existed There. Space Policy Online.Com

Strickland, A. (2025, September 12). Rock discovery contains ‘clearest sign’ yet of ancient life on Mars, NASA says. CNN Science. 
Taveau, J. (2025, September 10). NASA Says Mars Rover Discovered Potential Biosignature Last Year. NASA.
 
(2025, September 10). NASA-ESA Mars Sample Return. In Wikipedia, https://en.wikipedia.org/wiki/NASA-ESA_Mars_Sample_Return