Kepler-452b, announced Thursday, is the first near-Earth-size planet in the habitable zone of a star very similar to the sun. It's also known as an exoplanet, which is a planet that orbits a star that isn't our sun.
Here, the history of Kepler's search as told by some of the planets it's found.
Published:Caption:Eric MackPhoto:NASA Ames/N. Batalha and W. Stenzel
An older cousin
Because Kepler-452b is over a billion years older than Earth, it may also have fewer years before all its water dries up (presuming it has some now). Being bigger, though, will forestall the inevitable loss of any water it has now for perhaps 500 million years, says NASA.