By Ron Cowen
NASA’s planet-hunting Kepler mission is off to a precocious start. The first six weeks of observations recorded by the spacefaring telescope, combined with follow-up studies from the ground, have revealed five previously unknown extrasolar planets—one body roughly the size of Neptune and four low-density versions of Jupiter. All reside within roasting distance of their parent stars.
The findings appear to reinforce hints from ground-based observations that stars have relatively few close-in planets with a mass between that of Saturn and Neptune, says Kepler scientist Dimitar Sasselov of the Harvard-Smithsonian Center for Astrophysics in Cambridge, Mass.
Lead mission scientist William Borucki of NASA’s Ames Research Center in Mountain View, Calif., and his colleagues announced the findings on January 4 at the winter meeting of the American Astronomical Society in Washington, D.C. The team also describes its results online January 7 in Science.