The system of Alpha Centauri B. Credit: L. Calcada, European Southern Observatory
I just got back from a presidential debate party and turned on the computer to see how the pundits were spinning it, when lo and behold, I found myself face to face with Alpha Centauri Bb!!!!
Those of us in the community of space geeks have been dreaming of this moment for just about as long as we've been dreaming of anything. And it was the HARPS program, once again, that came through with the amazing results: A bona fide Super Earth orbiting Alpha Centauri B, a K-type star in the closest system to our own, in a period of just 3.2 days.
I've only seen press reports so far, but according to Stephane Udry and Xavier Dumusque, members of the discovery team, the object has a mass a little larger than Earth's, making it the most lightweight planet yet detected by the radial velocity method.
As we have seen in recent years, low-mass planets tend to come in convoys rather than in isolation -- they typically belong to multiplanet systems. Or as Dumusque put it, “When you find one small planet, you find others.” So more small planets are likely to be lurking in the vicinity of our neighbor star.
Of course, a rocky Super Earth orbiting so close to its host star is bound to be a hellish place, completely inhospitable to any form of life. We can expect magma ponds and evaporating minerals rather than wise aliens who could show us how to govern ourselves wisely.