http://www.huffingtonpost.com/2013/0...ncid=webmail44Astronomers have calculated that 6 percent of the galaxy's 75 billion or so red dwarfs — stars smaller and dimmer than the Earth's own sun — probably host habitable, roughly Earth-size planets. That works out to at least 4.5 billion such "alien Earths," the closest of which might be found a mere dozen light-years away, researchers said.