An Earth-Sized Planet Has Been Discovered in Alpha Centauri, the Star System Closest to Us

Holy sci-fi awesome space balls. European astronomers have discovered an alien planet in Alpha Centauri, the star system that's pretty much our neighbor. The planet, which is Earth-sized, is only 4.3 light years away.

The Earth-sized planet is orbiting Alpha Centauri B, one of the three stars in that star system, and is "also the lightest exoplanet ever discovered around a star like the Sun." How did they find the planet that's been in our metaphorical space backyard? It's actually a new technique that's quite amazing:

The European team detected the planet by picking up the tiny wobbles in the motion of the star Alpha Centauri B created by the gravitational pull of the orbiting planet. The effect is minute—it causes the star to move back and forth by no more than 51 centimetres per second (1.8 km/hour), about the speed of a baby crawling. This is the highest precision ever achieved using this method.


The planet isn't completely Earth-like as it's only 4 million miles away from its star (we're 93 million miles away) and it completes one orbit—or year—in only 3.2 days but still, finding a planet in Alpha Centauri is not just awesome (which it totally is) but important because the technique used could potentially lead to other planet discoveries too. [ESO, ABC News, MSNBC]

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