http://www.space.com/18089-earth-size-alien-planet-alpha-centauri.html
The star system closest to our own sun hosts a planet with roughly Earth’s mass and may harbor other alien worlds as well, a new study reports.
Astronomers detected the alien planet around the sunlike star Alpha Centauri B, which is part of a three-star system just 4.3 light-years away from us. The newfound world is about as massive as Earth, but it’s no Earth twin; its heat-blasted surface may be covered with molten rock, researchers said.
The mere existence of the planet, known as Alpha Centauri Bb, suggests that undiscovered worlds may lurk farther away from its star — perhaps in the habitable zone, that just-right range of distances where liquid water can exist.
Newcastle Astronomical Society 