spacetoday.net: Stardust images reveal unusual surface of comet

Posted: Fri, Jun 18, 2004, 9:50 PM ET (0150 GMT)
Stardust image of Wild-2 nucleus showing features (NASA/JPL)

Images taken by NASA's Stardust spacecraft have revealed that the surface of the comet Wild-2 is far different than what scientists expected, with a diverse set of unusual surface features. Images taken in early January during the spacecraft's flyby of the comet nucleus show features such as pinnacles 100 meters tall and craters 150 meters deep. The sharp features are a surprise to scientists, who has expected a relatively bland, fluffy surface. One crater, dubbed Left Foot, is one kilometer across, while the entire comet is only five kilometers in diameter. Scientists also reported that the comet generates powerful jets of material that do not disperse as quickly as expected; the jets were so powerful that about a dozen particles, some larger than a bullet, were able to penetrate the top layer of the spacecraft's protective shield. Scientists aren't sure if Wild-2 is simply an unusual comet or is indicative of a larger number of comets. The results were published in a series of papers in Friday's issue of the journal Science.