NASA’s Perseverance rover has uncovered what scientists describe as the most compelling evidence yet of possible life on Mars. A mudstone core drilled in July 2024 from a rock named “Chevaya Falls” within the Bright Angel region of Jezero Crater has revealed minerals and textures commonly linked with microbial activity on Earth. The sample contains vivianite, an iron phosphate, and greigite, an iron sulfide, both often formed in water-rich, oxygen-poor environments. These patterns, including “leopard spot” textures, suggest ancient chemical reactions that may have supported microbial life. While NASA stresses this is not proof of life, the findings represent the closest scientists have come to identifying a potential biosignature on the Red Planet.
What the NASA rover found inside Mars rocks
The drilled core revealed fine-grained mudstone with circular reaction fronts called “leopard spots” and nodules embedded within layered sediments. Instruments aboard Perseverance, SHERLOC and PIXL, mapped organic carbon alongside phosphate, iron, and sulfur arranged in repeating patterns. The minerals vivianite and greigite stood out because, on Earth, they form in microbial-influenced environments. This bullseye-like arrangement mirrors electron transfer reactions that microbes perform in oxygen-poor muds. Importantly, these features developed in water-laid sediments rather than volcanic rock, strengthening the case for ancient habitability.
Why NASA calls it a potential biosignature
While the mineral structures and organic compounds resemble microbial activity on Earth, NASA scientists remain cautious. Such signals are referred to as “potential biosignatures”—features that may indicate life but could also arise from non-biological chemical processes. To guide such discoveries, NASA uses the Confidence of Life Detection (CoLD) scale, which requires signals to be independently verified and alternative explanations excluded. At present, the Bright Angel findings rank low on this scale but mark an important milestone. Sealed samples from Perseverance are expected to be returned to Earth in the future, where advanced laboratory tests can help confirm whether life was truly involved.
Implications for Mars and the search for life
If confirmed, the discovery would suggest that Mars once supported microbial metabolisms similar to those on Earth, extending the timeline of habitability to an era when Jezero Crater contained rivers and lakes. Even if the minerals prove to be abiotic, the findings still provide insights into Mars’s chemical evolution and its ability to cycle elements essential for life, such as iron, sulfur, and phosphorus. The Perseverance rover will continue exploring and collecting samples, while NASA’s planned Mars Sample Return mission will be crucial for final answers. This cautious but promising breakthrough marks a major step forward in humanity’s search for life beyond Earth.