Planets Need Friends?

by / Thursday, 19 May 2011 / Published in Blog - Space Log

Friends are one of the best things in the world and sometimes, when we haven’t seen our friends in awhile, we can get pretty lonely. Did you know that a bunch of planets are considered lonely too? A team of astronomers recently discovered that space is filled with hundreds of billions of these lonely planets, celestial bodies that were kicked out of their original planetary systems.


This came as a surprise to the scientists who had previously believed only about 10 or 20% of stars had planets of this type. In fact, there are 2 Jupiter-sized planets floating around for each of the 200 billion stars in the Milky Way galaxy. This knowledge helps scientists understand more about how such planets form.

In the last 20 years, 500 planets have been identified that are currently circling other stars and this year, scientists announced there are 1,235 more! This information was found using NASA’s Kepler satellite. The lonely planets were found with a method called gravitational microlensing. It uses gravitational fields of massive objects to bend light and act as a magnifying lens.

The light is then monitored for little spots of brightness which are caused by a planet and its host star passing by. Because of the mass of these planets being so close to that of Jupiter, scientists don’t feel there is much chance for life on them. All of this helps scientists understand more about our own solar system and will probably lead to several new theories about planetary formation.

(original image via flickr, with permission to remix)