GBH
"We are looking for remnants of past life," says Prof. Tanja Bosak in a discussion broadcast on GBH's Boston Public Radio of the NASA Perseverance rover’s mission on Mars. "There won't be anything that's a complex organism, so everything we have to look for is microscopic. All these rocks tell a story. Depending on their chemical properties and the way they look, we can tell a history and then decide which may have been good to preserve life."