Nestled in the Goldilocks zone of a small, sun-like star is a room-temperature world a little more than twice the size of Earth. Scientists do not yet know if it is rocky or gaseous and whether it has water or clouds, but they do know that it’s the right size, and in the right place, for liquid water to exist. If it does exist, it may be one of the best places to look for life outside of our solar system.
The new planet, Kepler-22, is about 600 light-years away and the smallest planet confirmed to exist smack in the middle of the habitable zone of a sun-like star. It’s one of the most stunning announcements from the Kepler Space Telescope, which stares at a field of stars in the constellations Cygnus and Lyra and looks for blips in brightness to find other planets. While Kepler has (as of today) found more than 2,000 possible planets, finding an Earth-like world in a sun-like environment has proved elusive — until now.