Perseverance sample shows possible signs of ancient life

NASA announced Wednesday that its Perseverance rover has collected a Martian rock sample that may contain the clearest signs yet of ancient microbial activity on Mars. The specimen, cored last July from a one meter by 0.6 meter outcrop nicknamed Cheyava Falls in Neretva Vallis inside Jezero Crater, contains a pattern of mineral deposits and organic molecules that researchers say are consistent with biological processing but not yet conclusive proof of life.

Scientists reported in a peer reviewed paper published in Nature that the sample, called Sapphire Canyon, shows concentric "leopard spots" and smaller "poppy seed" flecks that correspond to chemical reaction fronts. Using the rover's SHERLOC instrument, the team detected a strong G band signal indicative of organic carbon. PIXL, the rover's X ray lithochemistry imager, mapped minerals concentrated in the spots, identifying an iron phosphate likely to be vivianite in the dark rims and an iron sulfide likely to be greigite in the lighter cores. On Earth, those minerals commonly form as byproducts when microbes metabolize organic matter.

"All we can say is one of the possible explanations is microbial life," Joel Hurowitz, lead...