There are about 1,000 star systems where aliens, if they existed, could be watching us from afar, new research suggests.
Those 1,004 star systems are in a direct line of sight to our planet, and close enough to us that they could not only detect planet Earth, but also chemical traces of Earthly life.
Over the course of the last decade, astronomers have found exoplanets orbiting distant stars using a simple formula: Keep an eye on a star and wait for it to suddenly dim. That dimming is a sign of a planet passing between the star and the telescope. Analyzing how the light changes as the star dims can reveal the chemical contents of the planet’s atmosphere.