Milky Way Has Tens of Billions of Habitable Planets These super-Earths are all over the galaxy, say scientists By Dustin Lushing, Newser Staff Posted Mar 28, 2012 3:36 PM CDT 73 comments Comments A file photo of the Milky Way galaxy. (AP Photo) (Newser) – Could aliens be hanging out in the Milky Way? A new discovery by astronomers shows they'd have plenty of possible homes in the galaxy, reports Reuters. The researchers found that tens of billions of planets reside in a habitable zone close to a star, allowing water to flow on the surface and the right temperature to sustain life. The European team found that habitable super-Earths—planets one to 10 times the mass of Earth—orbit roughly 40% of the 160 billion red dwarf stars in the Milky Way. It would still be tough for little green men to survive, though. In order for these super-Earths to have water, they'd need to be very close to the relatively cold red dwarfs, thus allowing lethal UV rays and radiation to permeate their atmospheres.