The wraps are off Kepler

NASA's planet hunting Kepler telescope launched March 6. Before it can find planets, its protective dust cover had to be jettisoned. that has been done, NASA announced yesterday.

"The cover released and flew away exactly as we designed it to do," said Kepler Project Manager James Fanson of NASA's Jet Propulsion Laboratory, Pasadena, Calif. "This is a critical step toward answering a question that has come down to us across 100 generations of human history â€" are there other planets like Earth, or are we alone in the galaxy?"

Kepler's mission is to spend more than three years gazing at more than 100,000 stars in our Milky Way galaxy for signs of Earth-size planets. Some of the planets are expected to orbit in a star's "habitable zone," a warm region where water could pool on the surface.

The mission's science instrument, called a photometer, contains the largest camera ever flown in space. Its 42 charge-coupled devices (CCDs) will detect slight dips in starlight, which occur when planets passing in front of their stars partially block the light from Kepler's view.