The best way to search for extraterrestrial life may be to assume that aliens are already attempting to contact Earth, a new study published in the journal Astrobiology reports.
This theory comes from a pair of researchers at McMaster University in Ontario, Canada, who suggest that the best hope of communicating with any potential extraterrestrials is to radically modify our current approach.
So far, NASA’s Kepler spacecraft has discovered more than 1,000 exoplanets. To do this, the ship watches the light of a star dim as an orbiting planet passes by, The Christian Science Monitor reports.
Earth also can be detected by watching it transit the sun, but only from a small strip of space known as Earth’s “transit zone.” Though tiny compared to the rest of the universe, the zone is home to more than 100,00 potential alien habitats.
So, if intelligent extraterrestrial beings are searching for inhabited planets like Earth, focusing on the transit zone could provide the best chance of Earthlings finding out about it.
“It’s impossible to predict whether extraterrestrials use the same observational techniques as we do,” says study author Renee Heller in a statement. “But they will have to deal with the same physical principles as we do, and Earth’s solar transits are an obvious method to detect us.”
Instead of trying to scan the entire universe, this strategy confines the search to a much more manageable area. If successful, researchers think scientists could discover whether or not extraterrestrial lifeforms are attempting to contact Earth in less than a human lifespan.
The study also suggests that endeavors, such as the $100 million Breakthrough Listen Initiative — a 10-year hunt for extraterrestrial life — should specifically focus on the transit zone.
“If any of these planets host intelligent observers, they could have identified Earth as a habitable, even as a living world long ago and we could be receiving their broadcasts today,” add the authors.