There are billions of habitable planets in the Milky Way where aliens could be having their tea
right now, according to a new six-year study.
"Our results show that planets orbiting around stars are more the rule than the exception. In a typical solar system approximately four planets have their orbits in the terrestrial zone, which is the distance from the star where you can find solid planets." said astronomer Uffe Gråe Jørgensen from the Niels Bohr Institute.
http://www.theregister.co.uk/2012/01...bitable_zones/
http://www.nature.com/nature/journal...ture10684.html