An illustration showing the seven Earth-like planets of Trappist-1, a nearby star system astronomers say will be able to view Earth in transit roughly 1,600 years from now. | Image: NASA / JPL-Caltech / R. Hurt (IPAC)
For decades, astronomers have probed the universe for signs of life by watching distant planets glide past their host stars, studying the tiny dips of starlight that give away clues about an exoplanet’s atmosphere. Hundreds of those worlds could bear life. And if there’s life, what’s to say it isn’t looking back at us?
New research published Wednesday entertains that question, finding nearly 2,000 star systems that have had a front-row seat to observe Earth in recent millennia. The study suggests that hypothetical extraterrestrial civilizations in those star systems could’ve been in the right position to watch Earth transit our Sun and look at us the same way we attempt to look at other planets.
