Discovered! Most Earth-Like Alien Planet & 2 Other Possibly Habitable Worlds

This artist's concept depicts Kepler-62f, a planet 1.4 times the size of Earth that circles in the habitable zone of its host star. The small shining object at right is Kepler-62e, another potentially habitable world in the five-planet system.

NASA's Kepler space telescope has discovered three exoplanets that may be capable of supporting life, and one of them is perhaps the most Earth-like alien world spotted to date, scientists announced today (April 18).

That most intriguing one is called Kepler-62f, a rocky world just 1.4 times bigger than Earth that circles a star smaller and dimmer than the sun. Kepler-62f's newfound neighbor, Kepler-62e, is just 1.6 times larger than Earth, making the pair among the smallest exoplanets yet found in their star's habitable zone — the just-right range of distances where liquid water can exist on a world's surface.

Kepler-62e and f, which are part of a newly discovered five-planet system, "look very good as possibilities for looking for life," said Kepler science principal investigator Bill Borucki, of NASA's Ames Research Center in Moffett Field, Calif