Kepler will monitor more than 100,000 stars for signatures of planets of various sizes and orbital distances. It has the ability to locate rocky planets like Earth, including those that lie in a star's 'habitable zone,' a region where liquid water, and perhaps life, could exist. If these Earth-size worlds do exist around stars like our sun, Kepler is expected to be the first to find them, and the first to measure their frequency.
'Kepler's mission is to determine whether Earth-size planets in the habitable zone of other stars are frequent or rare; whether life in our Milky Way galaxy is likely to be frequent or rare,' said William Borucki, the Kepler science principal investigator at NASA's Ames Research Center in Moffett Field, Calif.
Bonus: for more satisfying reading, the recommended musical pairing for this post is "Work" from the album "Good Monsters," Jars of Clay
Image credit: NASA/JPL-Caltech/Ball