Could extraterrestrial civilizations leave their fingerprints as chlorofluorocarbons in planetary atmospheres, or the waste heat generated by industrial processes, or artificial bursts of neutrinos or gravitational waves?
That’s what a vanguard of astronomers would like to find out, and they’re hoping to win more support for an approach that widens the nearly 60-year-old search for alien radio signals to include other alien indicators.
Those indicators — which could include anomalous chemicals in exoplanet atmospheres or readings that hint at the presence of alien megastructures — have come to be known collectively as technosignatures. It’s a term that originated with Jill Tarter, one of the pioneers in the search for extraterrestrial intelligence, or SETI.
“When the astrobiology people started talking about ‘biosignatures,’ it just seemed obvious,” Tarter told GeekWire this week at the American Astronomical Society’s winter meeting in Seattle.
Tarter said the term crystallizes the idea that scientists should look for a variety of technological traces potentially pointing to intelligent life beyond Earth.
“We’re really talking about more than just searching for radio signals or optical signals,” she said. “What is it that technology does to modify its environment in a way that we can detect over interstellar distances, and distinguish from what life does?”