Don’t freak out, but a recent report says extraterrestrial life possibly living on Earth-like planets will find out about us sooner than you think.
The planets could be suitable to potentially support life, but if anything is living there with the same kinds of technology that we have, they wouldn’t be able to detect Earth… yet.
This will change in just 29 years, according to a report published yesterday (June 23) by British scientific journal, Nature. Stars are constantly in motion, and a particular star, called Teegarden’s Star, will soon slip into the precise location to be able to watch our sun and notice the slight dimming that occurs when Earth passes in front of it.
Per NPR, Lisa Kaltenegger, director of the Carl Sagan Institute at Cornell University in Ithaca, N.Y. said, “If they have the same technique as we do, and if there is a ‘they,’ then they wouldn’t know yet that we exist. In 29 years, they would be able to see us.”
She and Jackie Faherty, a senior scientist at the American Museum of Natural History in New York City, started using a new catalogue of stars and their movements to find out what solar systems could potentially detect Earth in the past, present and future.
Their work assumes that “alien planet-hunters” would rely on the same kinds of technologies that people have used to discover more than 4,000 planets orbiting far away stars. Most of those findings have been made by watching stars and waiting for a tell-tale dip in brightness that means an orbiting planet has briefly moved in front of the star and blocked some of its light. This planet-finding trick only works when everything is lined up just right.
Since the Earth orbits around the sun, this same practice could possibly be used by curious aliens to find our planet. Back in 2009, René Heller, an astrophysicist and expert in planet detection at the Max Planck Institute for Solar System Research in Germany, started working with a coworker to create a sky map with stars with passing planets that astronomers could discover. One day, the two of them started joking around about alien scientists making a similar map that would lead them to Earth.
Heller recalled, “While we were working, we had this fun idea — if someone else out there is trying to make the same with their sky maps, and whether they would be knowing that we were making sky maps of them. We were trying to turn the tables, in our heads.”
In 2016, Heller and a colleague published a paper with a list of 82 stars that would have the right viewpoint to make finding Earth possible. “They might have seen us or might be seeing us passing by the sun,” Heller said.
Kaltenegger said, “I wanted to know who can see us now, but also who could have seen us in the past, and who will see us in the future.”
Kaltenegger and Faherty looked at the closest stars within 300 light years of the sun. Faherty said, “When it comes to exploring worlds, the nearest ones to us are going to be the most exciting.”
“It made me feel very vulnerable,” added Faherty, “because I started to think how easy we are to detect, in some ways. We’re just a dot, this rock that spins around our Sun and blocks the light every 365 days for an amount of time. We’re a classic transiting planet that somebody could find, and then we’ve got this radio signature that we give off.”
She noted that no one knows if any nearby worlds have intelligent life and they are all extremely far away: “Maybe none of them have anything like us.”