Forty light years away, a small, orange star called Trappist-1 sits unnoticed in the sky. You can’t see it with your bare eyes—it burns colder than the brightly shining stars that fill the night sky, the ones that have inspired millions of people to imagine life beyond Earth. But most stars in the galaxy are neither big nor bright. And it’s those abundant, dim dwarfs that might actually be the best place to look for worlds capable of supporting life.