Not So Privileged Planet

Just as Privileged Planet  premieres June 23 at the Smithsonian comes this discovery of a rocky exoplanet as reported by news @ nature.com:

The hunt for worlds outside our Solar System has found its smallest planet yet: it weighs in at just seven-and-a-half times the size of the Earth.

Astronomers have already found more than 150 extrasolar planets, also known as exoplanets. But all of them are larger than Uranus, which has 15 times Earth's mass. The recent find is so small that it is likely to be rocky, its discoverers say, rather than a gas giant.

"This is the smallest extrasolar planet yet detected," says team member Paul Butler of the Carnegie Institution in Washington DC. "It's like Earth's bigger cousin."

Is there more to come? Probably.

"The fact that you have a rocky planet inside two gas giants makes it look a lot like our own Solar System," agrees Alan Boss, an astronomer at the Carnegie Institution who was not involved in the research.

Boss adds that the prospects of finding similar planetary systems are good, because stars like Gliese 876 are extremely common. "They're all over the place," he says, adding that of the 400 or so stars within 33 light years of Earth, about 300 of them are in the same class as Gliese 876

The team now hopes to find rocky planets around other red dwarfs in our Galaxy.

Artwork Credit: Trent Schindler/NSF