Poof! The Planet Closest To Our Solar System Just Vanished
The disappearance of Alpha Centauri Bb raises questions for planet hunters looking for Earth-sized alien worlds.
By Devin Powell, for National Geographic
PHOTOGRAPH BY REUTERS
Scientists just made a planet disappear. According to a new study, Alpha Centauri Bb, a world in the nearest star system to us, was merely a ghost in the data.
The planet, thought to be perhaps similar in mass to Earth, was hailed as a “landmark” when it was announced in 2012 in the journal Nature. The discovery got people excited about finding neighboring worlds that might harbor life in the Alpha Centauri system 4.3 light-years away—already home to science fiction characters such as the Transformers and the creatures of Avatar.
This particular alien world wouldn’t have been a good place to look for life, though. It would have been roughly a tenth the distance to its star that Mercury is to the sun, with a scorchingly hot surface probably covered in molten rock.
Now it will serve as a cautionary tale for planet hunters, a reminder that planets as small as Earth are hard to find. Distinguishing subtle clues from background noise is incredibly difficult, as shown in a new paper recently posted at arXiv.org and due to appear in the Monthly Notices of the Royal Astronomical Society.
Even the team that originally reported the planet agrees. “This is really good work,” said Xavier Dumusque of the Harvard-Smithsonian Center for Astrophysics. “We are not 100 percent sure, but probably the planet is not there.”