Life needs light, right? Without a parent star, a planet stands little chance of developing the conditions under which comples chemistry can bootstrap itself into biological processes.
So goes the conventional wisdom, at any rate, but here’s a paper by two space boffins from the University of Chicago that posits the possibility of “Steppenwolf planets”, roaming the vast tracts of interstellar space with no star to call their own, but of sufficient mass and composition to harbour subsurface oceans heated by the still-active planetary core.
Technovelgy compares this to an old George RR Martin story with which I’m not familiar, but I seem to remember a more recent precedent in the latest Greg Egan collection, though the title of the story eludes me.And then there’s Peter Watts’ Blindsight… can anyone think of any others?
It occurs to me that, short of technological developments of a science fictional scale, the only real use we’ll ever be able to put these hypothetical Steppenwolf planets to would be… well, the settings for science fiction stories, basically. Oh, the irony!
But hey, lookit – I managed to write the whole post without a single “born to be wild” gag!
Ah, nuts.
Physicist 
