London: Astronomers have discovered a new class of Jupiter-sized planets floating alone in the dark of space, away from the light of a star.
The team believes that these lone worlds were probably ejected from developing planetary systems.
The discovery is based on a joint Japan-New Zealand survey that scanned the center of the Milky Way galaxy during 2006 and 2007, revealing evidence for up to 10 free-floating planets roughly the mass of Jupiter.
The isolated orbs, also known as orphan planets, are difficult to spot, and had gone undetected until now. The newfound planets are located at an average approximate distance of 10,000 to 20,000 light-years from Earth.
“Although free-floating planets have been predicted, they finally have been detected, holding major implications for planetary formation and evolution models,” said Mario Perez, exoplanet program scientist at NASA Headquarters in Washington.
The discovery indicates there are many more free-floating Jupiter-mass planets that can’t be seen. The team estimated there are about twice as many of them as stars. In addition, these worlds are thought to be at least as common as planets that orbit stars. This would add up to hundreds of billions of lone planets in our Milky Way galaxy alone.
The study was led by Takahiro Sumi from Osaka University in Japan.
The study is detailed in the journal Nature.
First Published: Thursday, May 19, 2011, 12:09