What does a comet nucleus look like? Yesterday the robot spacecraft Stardust [ http://stardust.jpl…] answered this question by returning the most detailed images [ http://stardust.jpl…] yet of the center of a comet. The icy centers of comets [ http://www.nineplan…] are usually hidden from Earth-bound telescopes by opaque dust [ http://antwrp.gsfc.…] and gas that boils off during approach to the Sun. Twice before, however, in the cases of Comet Halley [ http://antwrp.gsfc.…] and Comet Borrelly [ http://antwrp.gsfc.…], spacecraft dove through the debris cloud of a comet's coma to image the nucleus. Pictured above [ http://stardust.jpl…] is the nucleus of Comet Wild 2 [ http://science.nasa…] taken by Stardust when passing within 500 kilometers. Clearly visible are numerous craters [ http://antwrp.gsfc.…] and hilly terrain. The Stardust mission [ http://stardust.jpl…] is yet more ambitious -- it has captured particles from the coma [ http://www.ifa.hawa…] and will jettison them to Earth in 2006. Analyses of the images and returned particles will likely give fresh information [ http://stardust.jpl…] about our Solar System [ http://www.nineplan…] back near its beginning, when Comet Wild 2 formed.
Explanation
What does a comet nucleus look like? Yesterday the robot spacecraft Stardust [ http://stardust.jpl…] answered this question by returning the most detailed images [ http://stardust.jpl…] yet of the center of a comet. The icy centers of comets [ http://www.nineplan…] are usually hidden from Earth-bound telescopes by opaque dust [ http://antwrp.gsfc.…] and gas that boils off during approach to the Sun. Twice before, however, in the cases of Comet Halley [ http://antwrp.gsfc.…] and Comet Borrelly [ http://antwrp.gsfc.…], spacecraft dove through the debris cloud of a comet's coma to image the nucleus. Pictured above [ http://stardust.jpl…] is the nucleus of Comet Wild 2 [ http://science.nasa…] taken by Stardust when passing within 500 kilometers. Clearly visible are numerous craters [ http://antwrp.gsfc.…] and hilly terrain. The Stardust mission [ http://stardust.jpl…] is yet more ambitious -- it has captured particles from the coma [ http://www.ifa.hawa…] and will jettison them to Earth in 2006. Analyses of the images and returned particles will likely give fresh information [ http://stardust.jpl…] about our Solar System [ http://www.nineplan…] back near its beginning, when Comet Wild 2 formed.
