Mars called key to quest for alien life San Francisco Chronicle

Chris McKay’s album of family photos opens with a picture of fossilized bacteria, entombed within rock billions of years old. “This is one of (my family’s) oldest, oldest, oldest ancestors,” declares the NASA scientist, showing a slide of the photo and drawing a big laugh from his packed audience. But he’s only half joking. The quest for “alien” life forms on the primeval Earth and their possible counterparts on Mars has consumed much of McKay’s career at NASA’s Ames Research Center in Mountain View, he said on the opening day of the space agency’s biannual Astrobiology Science Conference.