The Hunt for E.T. Comes Home — to Earth
hey might not be green or spit out cute catchphrases, but there could be forms of "alien" life right here on Earth.
If life arose not just once, but multiple times on Earth, life as we don't know it could be here on our own planet, perhaps using different chemical processes than we've ever seen before. And because scientists have only studied a tiny slice of the world's microbes in depth, the microscopic remnants of a second (or third or fourth) biogenesis could be hiding right beneath our noses.
"If life did happen many times, there could be something like a shadow biosphere that either was, or is, all around us," Arizona State Univeristy astrobiologist Paul Davies said here Sunday at the American Association for the Advancement of Sciences meeting. "It's entirely possible that some fraction of microbial life could turn out to be alien or 'weird' life as we prefer to call it."
