It is interesting that, theoretically speaking, a rogue planet can maintain an environment conductive to life: http://www.wired.com/wiredscience/2011/02/steppe

It is interesting that, theoretically speaking, a rogue planet can maintain an environment conductive to life: http://www.wired.com/wiredscience/2011/02/steppenwolf-planet/ http://www.wired.com/wiredscience/2011/02/steppenwolf-planet... It probably wouldn't be intelligent life, but maybe there are microbial lifeforms somewhere in the universe which call a rogue planet their home. That's awesome to think about, although it is extremely likely that such a planet will never be discovered. It's just really hard to track down a rogue planet, even a large one.