NASA's Kepler mission finds 5 new planets
Jan 11, 2010
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Opening a new chapter in planet hunting, NASA scientists reported Monday the discovery of five worlds orbiting nearby stars, using the space agency's Kepler space telescope.

Kepler science team leader William Borucki of NASA's Ames Research Center in Moffett Field, Calif., made the announcement of the "roaster" planets, ones larger than Neptune and orbiting extremely close to their stars, at the American Astronomical Society annual meeting in Washington, D.C. Launched last year, the 1 million Kepler eyeballs some 156,000 stars within 3,000 light years of Earth for planets, according to a study in the upcoming Science journal. One light year is about 5.9 trillion miles.

Kepler detects planets by spotting light-dipping eclipses, or 'transits', of stars by their companion planets. Four of the newly-detected planets are 1.3 to 1.5 times wider than Jupiter in our solar system, while the last one, dubbed Kepler-4b, is only about 0.6 times as wide as Jupiter and weighs only about 8% as much, about the heft of Neptune.

All of the planets, which orbit their stars once within every four day's time because of their closeness, bake at temperatures above 2,240 degrees Fahrenheit. Such close-in planets are the easiest to detect, but Kepler scientists expect to find more Earth-like ones in the next three years. In testing the satellite's optics, the team has determined it should be able to spot any Earth-sized planet transits with 99.4% certainty, if they are orbiting the stars observed by Kepler, according to the study.