What Earth's Oldest Fossils Mean for Finding Life on Mars

If recent findings on Earth are any guide, the oldest rocks on Mars may have signs of ancient life locked up inside. In a new study, a team of geologists led by Allen Nutman, of the University of Wollongong in Australia, discovered 3.7-billion-year-old rocks that may contain the oldest fossils of living organisms yet found on Earth, beating the previous record by 220 million years. If that's the case, then it's possible that Martian rocks of the same age could also have evidence of microbial life in them, said Abigail Allwood, a research scientist at NASA's Jet Propulsion Laboratory in Pasadena, California.