This story was updated at 2:40 EST. Astronomers on Tuesday (Dec. 20) announced the discovery of the first two Earth-size alien planets — a historic find for sure, but the newfound worlds didn't ...

NASA’s Kepler mission has discovered the first Earth-size planets orbiting a sun-like star outside our solar system. The planets, called Kepler-20e and Kepler-20f, are too close to their star to be in ...

WASHINGTON (Reuters) - NASA's Kepler mission has discovered the first Earth-size planets orbiting a sun-like star outside our solar system, a milestone in the search for planets like the earth, the ...

MOFFET FIELD, California - NASA's Kepler mission has discovered the first Earth-sized planets orbiting a sun outside our Solar System. NASA says the planets - Kepler-20e and Kepler-20f - are too close ...

Yahoo Racing is powered by Motorsport Network, providing expert reporting, analysis, and insider access across the world’s top racing series. Astronomers on Tuesday (Dec. 20) announced the discovery ...