If There Are 17 Billion Earth-Sized Worlds In Our Galaxy, the Universe…

Astronomers have a mind-blowing new theory: that there are 17 billion Earth-sized planets in our galaxy. They don't yet know how many of these worlds are in habitable zones, but the implications of this discovery are amazing. So much that some claim the "quest for a twin Earth is heating up." » 1/08/13 10:11pm 1/08/13 10:11pm