Star Wars Gets Real
Here's a movie-geek screening test: What is Tatooine? If you said Luke Skywalker's home world, a desert planet with two suns, you pass. In September, researchers announced the discovery of a planet, now dubbed Kepler 16b, that, just like Tatooine, orbits a binary star system. Binary stars are not uncommon in the galaxy, but they were always thought to be gravitationally dangerous places for a planet to be. When two elephants are waltzing, you don't want to be the mouse that gets underfoot. With the help of the Kepler space telescope, however, scientists from the SETI (Search for Extraterrestrial Intelligence) Institute found subtle dips in the light coming from a binary system about 200 million light years from Earth. The dips were an average of 229 days apart — a pretty solid sign that a planet is orbiting both stars, passing first in front of one, then in front of the other. No droids or galactic cafés are likely there, however. Unlike the real Tatooine, this one is deep-frozen at about –100°F (–73°C).