ALPHA CENTAURI HAS AN EARTH-SIZED PLANET!
OK, pardon me for shouting, but I'm pretty excited. :) Alpha Centauri - the closest star system in the sky - has been found to harbor an Earth-sized planet. Alpha Cen is a triple star, with two fairly Sun-like stars orbiting each other, and a third red dwarf orbiting much farther out. The planet was found to orbit the cooler of the two stars in the binary.
The planet, called Alpha Centauri Bb, is only 1.13 tines the Earth's mass, making it one of the smallest exoplanets yet found. Unfortunately, it orbits the star so close in - just 6 million kilometers - that's it's baking hot. We won't be finding any life there we would recognize.
BUT, this means the technique used to find it works for lower-mass planets, making it hopeful we're close to finding an Earth-sized planet orbiting in its star's habitable zone.
I have the details on my blog:http://blogs.discovermagazine.com/badastronomy/2012/10/16/alpha-centauri-has-a-planet/