Last night, astronomers with the European Southern Observatory announced that they'd found a planet orbiting Alpha Centauri B — an orange star a little smaller and a little less bright than our own Sun. That's important, because, while more than 700 planets have been found outside our solar system, this one — Alpha Centauri Bb (yeah, I know) — is by far the closest. To give you an idea of what we're talking about in distance here, imagine that we are Kansas City and Mars is Toledo. Alpha Centauri Bb is like Tokyo — but you have to get there the long way around and nobody has invented the boat or the plane yet. Basically, it's closer than any other planet we know of outside our solar system, but not really close close. Just 4.37 light years is still more than 25 trillion miles, which is still a long ways away.
Likewise, Alpha Centauri Bb is classified as an "Earth-like" planet, but that shouldn't give you any ideas of colonizing it Zefram Cochrane-style. Bb is way too close to its star for that — closer, even, than Mercury is to our own Sun.
But you should still be excited about this. Terrible, filing-cabinet name aside, Alpha Centauri Bb is jeffing epic. Until now, we didn't think our closest neighboring solar system had any planets at all. And because of the way planets work, writes Lee Billings at the Centauri Dreams blog, this single find means we're much, much more likely to discover other Centaurian worlds. Read the rest