NASA Perseverance confirms organic carbon in two ancient Martian rocks

NASA's Perseverance rover has confirmed organic carbon in two ancient rocks in the Bright Angel formation inside Jezero crater, according to a study published in Science Advances. The research was co-led by Ashley Murphy of the Planetary Science Institute and Kyle Uckert, deputy principal investigator of the rover's SHERLOC instrument. The finding follows a September 2025 report of a potential biosignature in the same rocks and moves the result from suggestive chemistry to a confirmed presence of carbon-bearing material.

The confirmation came from SHERLOC, a robotic-arm instrument that uses Raman spectroscopy, firing laser light at rock surfaces to map minerals and organic compounds without destroying samples. Measurements identified macromolecular carbon, large networks of carbon atoms known from Earth rocks and meteorites. The carbon was detected only a few microns below exposed Martian surfaces, the shallowest such detection reported on Mars, despite radiation, sunlight and oxidizing chemistry that normally degrade organics.

The rocks formed in an ancient river-fed lake, where fine sediments settled and hardened into mudstone, and the carbon appears alongside carbonate and sulfate minerals that formed later as water altered the rocks. That distribution suggests organic material may have entered or formed during at least two separate periods of Martian history. The study does not identify how the carbon formed, because macromolecular carbon can arise through biological activity or through non-biological chemical processes.

The result matters because it strengthens the case that Mars preserved organic material in accessible, near-surface rocks, not only deep underground where sample-return missions would need to dig. For astrobiology, it gives scientists a better target for analyzing carbon chemistry, mineral context and possible biological traces in returned samples. For the broader search for life, it shows that even harsh planetary surfaces can retain clues to ancient environments, but it stops short of proving life existed on Mars.