Lisa Kaltenegger, an astronomer at Cornell University, enlisted the help of Jackie Faherty, an astrophysicist who works at Hayden Planetarium, and together they took on the task of identifying stars that might host alien worlds where the residents—past, present, or future—would have a chance of detecting Earth as a transiting exoplanet.
In other words, these planets would have just the right vantage point to observe a slight dip in the brightness of our sun as Earth crosses, or transits, in front of it. It's actually the most successful method we use to find planets beyond our solar system as they orbit around their own host stars, creating tiny blips in the light we can see with astronomical instruments.
In June, Kaltenegger and Faherty announced their results in Nature with an extensive list of stars that have either had, or will later have, the required orientation to discover our planet. Using a time range from 5,000 years ago (a period when civilizations on Earth first began to sprout) to 5,000 years into the future, the duo identified over 2,000 stars.
Not only does their study provide a resource to exoplanet hunters by highlighting which stars they can pay attention to, but it also reminds about our unique—and a bit unsettling—visibility to the rest of the universe. "I felt spied on a little bit," Faherty told WIRED, remembering the uncanny sensation of being overexposed. "Do I want to be on a planet that can be found?"
Do you? Who knows, maybe Out of Context Human Race aren't the only ones watching us.
