I wrote this while it was breaking news and queued it for this morning. The debate would have overshadowed it.
Alpha Centauri, our sun's nearest neighbor, is actually three stars. Star C is a red dwarf with a real bad attitude. It's also the star that's currently closest to us of the trinary system. Star A is a solar analouge. Star B, a slightly cooler version of our sun, has a planet.
Did you say holy shit? I SO did.
This is part of the culmination of work that began in 2008. The planet was detected via the "tug-and-pull" method using HARPS---the planet tugs on its star back and forth. Over a period of time we can see these in action here on Earth. So, no, the planet has not been seen directly.
Installed on the 3.6-meter telescope at the European Southern Observatory in La Silla, Chile, HARPS looks for stars being gravitationally tugged by orbiting planets. Because this planet is so small, its gentle tugs pull only very slightly on Alpha Centauri B, shifting the star's position by about 50 centimeters each second. So finding the planet's signature in the star's wobbles meant the team needed to carefully filter out other sources of stellar variability such as starspots, bulges on the star's surface and gravitational interactions with Alpha Centauri A.
This is what has happened.
This planet is not a nice place. It screams around Alpha Centauri B every 3.2 days. It's so hot metals likely run like water. The planet is likely earth-sized. Mercury is more hospitable.
But the exciting things are the following:
1. There's a freaking planet in the star system next door.
2. It's an earth-sized planet.
3. We can detect them FROM EARTH.
4. THERE COULD BE MORE!
There's nothing here to preclude the existence of other worlds around either star in Alpha Centauri. None at all. If one exists, perhaps others do too.
The not so exciting news is all the near-Sol science fiction settings people have written that are now getting retconned. Also, it's out of our reach for now as FTL remains not possible despite exciting experiments underway. I just don't see how the proposed drive doesn't violate causality, which appears to be a necessity.
But this is really freaking exciting.
(Actual paper, which will be published in Nature, is here)