LOS ANGELES, Mar. 7 (Xinhua) -- Kepler, a telescope that will scour the Milky Way for evidence of Earth-like planets, is orbiting the sun on Saturday, according to NASA's Jet Propulsion Laboratory (JPL).
Aboard a three-stage Delta 2 rocket, the Kepler telescope blasted off from Cape Canaveral, Florida about 7:50 p.m. Friday and successfully reached its orbit about an hour later.
When fully operational in a couple of months, the craft will embark on a 3 1/2-year mission, during which it will scan more than 100,000 stars, looking for winks in the light emanating from them -- a telltale sign of a planet passing in front of the light source. said JPL which monitors the mission.
Astronomers will monitor stars ranging from the smaller, cooler ones -- whose planets orbit closer to them -- to the larger and hotter stars, whose planets must orbit farther away to survive, according to JPL, based in Pasadena of Los Angeles.
By analyzing the spectrum, scientists can get a rough idea of the size and planet and its composition, JPL said, adding that the goal is to find planets in "habitable zones," regions where pools of surface water are possible.
Finding extrasolar planets is a daunting task because light from the stars they orbit swamps the reflected light of the satellites, according to the JPL.
Most of the 340 planets discovered beyond our solar system are gas giants similar to Jupiter and too hot for human life. By December 2010, scientists should start seeing some results worthy of further investigation.