10-01-11 NASA discovers smallest planet outside our solar system

NASA has discovered the smallest planet ever seen beyond our solar system a rocky world just 1.4 times larger than Earth using its planet-hunting Kepler observatory.The planet,called Kepler-10b,is also the first rocky alien planet to be confirmed by NASA's Kepler mission using data collected between May 2009 and early January 2010. But, while Kepler-10b is a rocky world, it is not located in the so-called habitable zone a region in a planetary system where liquid water can potentially exist on the planet's surface."Kepler-10b is the smallest exoplanet discovered to date,and the first unquestionably rocky planet orbiting a star outside our solar system," said Natalie Batalha,Kepler's deputy science team leader at NASA's Ames Research Center in Moffett Field,Calif.,at a press conference here at the 217th American Astronomy Society meeting."It's an important milestone for our team,and I think it's an important milestone for humanity," said Batalha,who also led the study that discovered the newfound world.The research will appear in an upcoming issue of The Astrophysical Journal.Kepler-10b is the latest in the growing legion of extrasolar planets scientists are discovering around alien stars.To date,more than 500 exoplanets have been confirmed.Kepler-10b orbits its parent star once every 0.84 days,which means it is more than 20 times closer to its star than Mercury is to our sun,which places it outside the parameters of the habitable zone.Kepler-10 is located about 560 light-years away and is approximately the same size as our sun.The star's age is estimated to be 8 billion years old.The exoplanets star,Kepler-10,was the first one identified as capable of harboring a small transiting planet,placing the star at the top of the list for ground-based observations using the W.M. Keck Observatory 10-meter telescope in Hawaii.Scientists waiting for a signal to confirm Kepler-10b as a planet were not disappointed. Keck was able to measure tiny changes in the star's spectrum,called Doppler shifts,caused by the telltale tug exerted by the orbiting planet."The discovery of Kepler-10b is a significant milestone in the search for planets similar to our own," said Douglas Hudgins,Kepler program scientist at NASA headquarters in Washington,D.C. "Although this planet is not in the habitable zone,the exciting find showcases the kinds of discoveries made possible by the mission and the promise of many more to come."