Astrophysicists have suggested a new approach to make sure we don’t miss signals from extraterrestrial observers trying to contact us.
René Heller and Ralph Pudritz at McMaster University in Canada say that extraterrestrials looking to make contact with Earth likely use similar methods for searching for life as we do, since they have to deal with the same physical principals of the universe. Their findings suggest that scientists should keep a close eye on the Earth’s “transit zone,” since it’s the most obvious way to learn about far away worlds.
When scientists on Earth want to detect distant planets and moons, they measure the dimming of starlight caused by the planet passing in front of it’s host star. This technique, known as a transit, allows astronomers to collect a wealth of information about the planet without ever observing it.
In a new study to be published in the journal Astrobiology, scientists ask, what if extraterrestrial observers discover Earth as it transits the sun?
If extraterrestrials are using the same techniques to search for life, as the researchers have hypothesized, then scientists suggest that we should be closely monitoring the “transit zone” of Earth. The transit zone is the thin slice of space where our planet’s passage in front of the Sun can be detected.
“It’s impossible to predict whether extraterrestrials use the same observational techniques as we do, 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,” said Heller.
With modern radio and space-faring telescopes, scientists say there are approximately 100,000 transit zones that we can observe from Earth. Depending on the level of technology, an intelligent observer within the Milky Way would likely have a similar amount of targets.
“If any of these planets host intelligent observers, they could have identified Earth as a habitable, living world long ago and we could be receiving their broadcasts today,” the scientists wrote.
Subsequently, researchers suggest that some of the searches for extraterrestrial life going on now, such as the Breakthrough Listen Initiative, can maximize its chances of success by concentrating its search on Earth’s transit zone.