UC Berkeley scientist investigating extraterrestrial life reserved but optimistic on chances of finding intelligent life outside of Earth

A University of California Berkeley scientist says we’re more likely to find evidence of intelligent extraterrestrials before bacteria in the soil on Mars or other planets.

Andrew Siemion gave a talk called “Hunting for Technosignatures” at the recent Association for the Advancement of Science conference in Seattle, and in his talk he said the simpler life forms one might expect – microscopic bacteria and simple organisms – might be very limited.

"There are two horses in the race to find life beyond Earth," Siemion said, as reported by Forbes. "The first is the search for chemical signatures from planets and the second is the search for extraterrestrial intelligence. Intelligent life has the edge, as it can be detected across the entire galaxy."

Part of the issue in finding those simpler organisms is that the technology we have now and what may be developed in the future restricts researchers to viewing and exploring the stars and the solar system.

"And we can never be sure that methane or similar chemicals which we detect are really produced by living things,” Siemion said. “It just comes down to statistics - basic life may be very common, but we are much less likely to find it.”

He says intelligent life can send evidence of its existence at the speed of light as forms of electromagnetic radiation, radio waves or even laser pulses. 

“I’m going to let x equal the probability of detection between 2011 and 2021 and I will say that the probability of detection confirmed between 2022 and 2032 is 1,000x,” Siemion said about the odds of finding alien life in the current decade. That x is edging closer to zero.

Siemion says he does believe in the other side of the equation and is optimistic.

“We’ve seen a dramatic explosion in the number of observatories, the number of scientists... that are working in this field,” he said.