Kepler finds planet orbiting two stars

For the first time, NASA's Kepler spacecraft found a planet outside our solar system that appears to be orbiting not one star, but two, according to a report published in Science on Wednesday.

Launched in 2009, the Kepler spacecraft was designed to keep constant surveiliance on tens of thousands of stars in a small patch of the night sky to look for evidence that those stars have planets orbiting them. Such evidence includes dips in the stars' brightness as their planets move in front of them in relation to Kepler.

"This discovery confirms a new class of planetary systems that could harbor life," NASA's Ames Research Center's William Borucki said in a NASA press release.

To date, researchers using Kepler have confirmed the existance of 21 planets and found evidence of hundreds more, according to the NASA's Ames website. Several hundred additional planets have been confirmed through other means to exist.