Detecting Rogue Planets

Finding planets orbiting other stars is tough enough. Finding planets that whiz through interstellar space on their own, unattached to any parent star-- rogue planets-- would seem to be even more difficult.

Well, it is. A new study, however, argues that extremely large rogue planets, several times more massive than Jupiter, could be detected by listening for radio noise associated with aurorae. That implies, of course, a rapidly spinning world with a strong magnetosphere, but such noise is likely our best bet to detect rogue planets anytime soon.