It’s hard to imagine now, but before 1995, the planets in our solar system were the only ones that we knew for certain existed. Then PhD student Didier Queloz at the University of Geneva discovered the first planet circling an alien star, and soon the floodgates of discovery opened wide.

Now, with more than 3500 confirmed exoplanets out there, and counting, we’ve discovered an enormous variety of worlds, of all shapes and sizes, and with a range of surprising characteristics.

Stars with rocky, Earth-like worlds are especially appealing. Particularly if those exoplanets are in the Goldilocks zone, at just the right temperature to hold liquid water. The TRAPPIST-1 planetary system is a shining example, 40 light years away. Here’s how we’re going to find out if anything lives there.

To read more and view the video, click here.