NASA's Kepler Planet Hunter Blasts Into Night Sky

CAPE CANAVERAL, Fla.  NASA's planet-hunting spacecraft, Kepler, rocketed into space Friday night on a historic voyage to track down other Earths in a faraway patch of the Milky Way galaxy. It's the first mission capable of answering the age-old question: Are other worlds like ours out there? Its mission will last at least 3 1/2 years and cost $600 million. The goal is to find, if they're there, Earth-like planets circling stars in the so-called habitable zone — orbits where liquid water could be present on the surface of the planets. That would mean there are lots of places out there for life to evolve, said Kepler's principal scientist, Bill Borucki.