In a Rock on Mars, NASA Sees ‘Clearest Sign of Life’ So Far

In a Rock on Mars, NASA Sees ‘Clearest Sign of Life’ So Far: The agency’s scientists are still not saying they found fossils of Martian microbes, but analysis of the specimen collected by the Perseverance rover raises that possibility. By Kenneth Chang Life, especially the microbes too small to see, has left an indelible mark on rocks on Earth, creating minerals that would otherwise not be there. If