Sunday, November 21, 2010
A team of astronomers announced its first snow Thursday — not due to the approaching winter, but from a spacecraft that observed a peanut-shaped comet spitting fluffy ice balls into space.
The Deep Impact spacecraft flew within 435 miles of the comet known as Hartley 2 on Nov. 4, snapping images as it whizzed past about 27,000 mph. Images released that day revealed a nearly 1 1/2-mile-long body with a smooth middle and rough, bulbous edges that was spewing gas from its surface.
In the two weeks since, scientists noticed the white specks circling the comet, as if it were inside an invisible snow globe. When they analyzed the images, they were in for another surprise — the smooth, middle portion, which they expected to be relatively inactive, was emitting water vapor; while the ends released chunks of ice, some as large as basketballs.
The flurry of white specks surrounding the comet's body caused the astronomers' jaws to drop, Peter Schultz, a team scientist from Brown University, said in a news conference at NASA headquarters in Washington.