Researchers Surprised by Comet's Craters
By RANDOLPH E. SCHMID, Associated Press Writer
WASHINGTON - When scientists sent a spacecraft to get a close look at a comet, they thought they knew what they'd see. They were wrong. The Stardust spacecraft sent back pictures of broad mesas, craters, pinnacles and canyons with flat floors on the surface of comet Wild 2.
"It's completely unexpected. We were expecting the surface to look more like it was covered with pulverized charcoal," Donald Brownlee, a University of Washington astronomy professor and Stardust's principal investigator, said in a statement.
A description of Wild — pronounced "vilt" — and several analyses of the mission to study it are reported in Friday's issue of the journal Science.
Launched by NASA (news - web sites) in 1999, Stardust collected samples of material coming off the comet during a flyby in January. The spacecraft is bringing the dust back to Earth and landing is expected in 2006.
In addition to Brownlee's report, other papers on the comet describe jets visible on the comet's surface that spew material into space at supersonic speeds. The papers also describe the unexpectedly chaotic distribution of dust particles coming off the comet.
