Yesterday, NASA announced that it (along with international partners) had discovered seven Earth-size planets orbiting a single star. Even more importantly, three of them are located in the star's habitable zone, the range around a star where liquid water is possible. The solar system (named TRAPPIST-1) is unfortunately located 40 light-years away from Earth, so sending a probe or a person there isn't really possible for now.

Still, it's a very important discovery, and Google is commemorating the event with a Google Doodle.

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