For the first time, scientists have discovered an Earth-size alien planet in the habitable zone of its host star, an "Earth cousin" that just might have liquid water and the right conditions for life.

The search for extraterrestrial life zeroed in a bit today as NASA announced that its unmanned Kepler Space Telescope detected the most Earth-like planet yet found beyond the Solar System. Named ...

What if humanity could no longer live on Earth? Perhaps a catastrophic event forced us to find a new home among the stars.

Scientists analyzing data from the Kepler space telescope have discovered a first: an Earth-size planet orbiting in the habitable zone of its parent star, researchers announced Thursday. The planet is ...

Sifting through observations from tens of thousands of distant stars, astronomers say they have discovered the first definitive Earth-sized planet that orbits in a habitable zone where water could ...

NASA scientists say the Kepler space telescope may have discovered the most “Earth-like” planet yet. Circling a star about 500 light-years away, planet Kepler 186-F may be the right temperature to ...

With NASA's Kepler spacecraft having just recently discovered its 1,000th alien planet, the agency's Jet Propulsion Laboratory has decided to bring some of the most unique exoplanets into the ...

The diagram compares the planets of the inner solar system to Kepler-186, a five-planet system about 500 light-years from Earth in the constellation Cygnus. The five planets of Kepler-186 orbit a star ...

This artist illustration shows what it might be like to stand on the surface of the planet Kepler-186f, the first-ever Earth-size planet to be found in the habitable zone of its star. It's the brass ...

Kepler-186f is the first planet ever discovered that is both about the same size as the Earth, and orbits in the "habitable zone" around its star. This is the distance from a star at which a planet ...

Scientists analyzing data from the planet-hunting Kepler space telescope have chalked up another first, finding an Earth-size world orbiting in the habitable zone of its parent star, researchers ...