spacetoday.net: Free-floating planets may outnumber stars

Posted: Thu, May 19, 2011, 8:19 AM ET (1219 GMT)
Free-floating exoplanet in Milky Way (NASA)

The detection of a group of large planets not orbiting any stars has led a team of astronomers to conclude that there may be more such planets in our galaxy than stars themselves. Astronomers working on a microlensing survey detected as many as ten such planets, each roughly the mass of Jupiter, in a region near the center of the galaxy. Astronomers believe that these planets formed around stars and were later ejected due to gravitation interactions with other bodies. Because smaller planets are more likely to be ejected from developing planetary systems than larger ones, astronomers project that the total number of free-floating planets in the galaxy is at least twice the number of stars.