Anyone who's played Civilization should be familiar with the words "Alpha Centauri". That goes double for anyone who's played, um, Civ's spin-off Alpha Centauri. It's the name of the closest star system to our own, and in Civ (and many other works of popular fiction), it's the first stop on humanity's inevitable march across the universe.

Well, that fiction just got a little more real today, with the discovery of an "earth-sized" planet orbiting one of our neighbouring suns (the system actually has three!). It's not exactly a mirror image of our own blue ball of dirt—it orbits Alpha Centauri B in just 3 days—but a planet is a planet.

While it's important because people can dare to dream of parking spaceships on the rock, it's actually more important for the methodology used to detect it in the first place, because it was picked up via "tiny wobbles in the motion of the star Alpha Centauri B created by the gravitational pull of the orbiting planet".

Alpha Centauri, Nearest Star, Has Earth-Sized Planet [ABC, via Gizmodo]