How Scientists at the SETI Institute Look for Alien Life

Nothing fires up the human imagination quite like the possibility that we are not alone in the universe. Even as we dream up alien civilizations in science fiction, researchers involved in the search for extraterrestrial intelligence (SETI) are scanning the skies for artificial megastructures, light signals, and other bonafide signs of intelligent life in the universe.

“We don't entirely know what we're looking for,” said Ann Marie Cody, a research scientist at NASA Ames and the nonprofit SETI Institute, in a new episode of Motherboard’s Space Show. “What kinds of structures would they build? We do have to be careful to not rule out things if we don't understand them.”

For this reason, SETI researchers have to cultivate an interesting balance between open-minded speculation about aliens and scientifically rigorous techniques to try to spot them. Should we prioritize searches for light-based messages from deep space, for example, or focus on detecting chemical signs of life on distant planets? And are we more likely to detect artificial intelligence before we ever make contact with a biological lifeform?

Watch the episode to learn more about how Cody and her colleagues in SETI decide what types of astronomical clues intelligent aliens might leave in space—such as “technosignatures” generated by advanced civilizations—and the importance of public outreach and engagement on this mind-boggling topic.

“We don't want science to be happening behind closed doors,” Cody noted. “We want the public to see that it’s a process. It's not just like you discover something instantly and there it is. You’ve got to follow-up and test all hypotheses.”