In the search for extraterrestrial intelligence (SETI), we've often looked for signs of intelligence, technology and communication that are similar to our own. But as astronomer and SETI trailblazer Jill Tarter points out, that approach means searching for detectable technosignatures, like radio transmissions, not searching for intelligence. Now scientists are considering whether artificial intelligence (AI) could help us search for alien intelligence in ways we haven't even thought of yet. As we think about extraterrestrial intelligence it's helpful to remember humans are not the only intelligent life on Earth. Chimpanzees have culture and use tools, spiders process information with webs, cetaceans have dialects, crows understand analogies and beavers are great engineers.

The following essay is reprinted with permission from The Conversation, an online publication covering the latest research. In the search for extraterrestrial intelligence (SETI), we've often looked for signs of intelligence, technology and communication that are similar to our own. But as astronomer and SETI trailblazer Jill Tarter points out, that approach means searching for detectable technosignatures, like radio transmissions, not searching for intelligence. Now scientists are considering whether artificial intelligence (AI) could help us search for alien intelligence in ways we haven't even thought of yet. As we think about extraterrestrial intelligence it's helpful to remember humans are not the only intelligent life on Earth.

In the summer of 1957, the Earth stood witness as a meteorite cratered in rural Pennsylvania, bringing with it a people-eating plague never seen: an alien amoeba with the taste for human flesh. While we had Steve McQueen around for the first invasion, humanity is now defended against microbial marauders from outer space by NASA and its international counterparts. Biological contamination goes both ways, mind you. Just as important as keeping extraterrestrial organisms from reaching the surface (aka "backward contamination") is ensuring that our planetary probes carry as few microbial hitchhikers from Earth as possible ("forward contamination"). To that end, in 1958, the U.S. National Academy of Sciences (NAS) issued a decree urging "that scientists plan lunar and planetary studies with great care and deep concern so that initial operations do not compromise and make impossible forever after critical scientific experiments."