Tuesday, November 17, 2015

Astro FOTD: Lonely Planets

Our galaxy, The Milky Way, appears to have a couple of hundred billion "rogue" planets without any stars to call their own. Some of them were kicked out of their systems of formation early in their history (it is suspected that our own system lost one or more planets in this fashion) and some probably formed on their own, in a process analogous to star formation in giant molecular clouds.

See, e.g., http://www.dailygalaxy.com/my_weblog/2013/08/200-billion-free-floating-starless-planets-roam-the-milky-way.html