Kepler-22b

Kepler-22b is an exoplanet located in the constellation Cygnus. It was first observed by the Kepler Telescope in February 2011; the discovery was subsequently confirmed and announced on December 5, 2011.

This planet is the most "Earth-like" to be discovered to date. Its radius is roughly 2.4 times that of the Earth, and it orbits its host star in the 'habitable zone', where liquid water can exist. However, its composition is not yet known. If it does contain an ocean, it is possible that life could exist there.