Scientists looking for habitable planets may not have to stray far from our galactic neighborhood, said a new study Wednesday, which calculated an Earth-size planet could be orbiting a red dwarf as near as 13 light years away. "We thought we would have to search vast distances to find an Earth-like planet. Now we realize another Earth is probably in our own backyard, waiting to be spotted," said Harvard astronomer and lead author Courtney Dressing.