NASA's rover Perseverance has uncovered rocks that may hold potential signs of ancient microbial life on Mars, according to research published Wednesday. Since landing on the Martian surface in 2021, the rover has been searching for signs of ancient life in Jezero Crater, a region in the planet's northern hemisphere that was once flooded and contained an ancient lake basin. NASA's science mission chief, Nicky Fox, acknowledged that the latest analysis "is certainly not the final answer," but said it's "the closest we've actually come to discovering ancient life on Mars." Vivianite is often found in sediments and peat bogs on Earth, as well as in areas with decaying organic matter. Some forms of microbial life can produce greigite.