There were many surprises in store when NASA’s recycled Deep Impact spacecraft soared past its second comet earlier this month, but nothing was more unexpected than the weather: It was snowing.
BIG PIC: Flyby Reveals Stunning Complexity of Comet Hartley 2
Particles of ice, some as large as basketballs, were jetting off the surface of Comet Hartley 2, when the probe, now renamed EPOXI, flew by at a relative speed of 27,000 mph on Nov. 4.
“When we first saw this our mouths just dropped. The whole thing just looked like a snow globe,” Brown University’s Pete Schultz, a mission scientist, told reporters on a conference call Thursday.
SLIDE SHOW: Close Encounters With Comets
NASA recycled the comet probe after it released an 820-pound metal slug into Comet Temple 1 in 2005 as part of the Deep Impact mission. Scientists found only tiny particles of ice in the tons of material kicked up by the impact.
Comet Hartley 2, however, is pumping out something on the order of 300 tons of ice, gas and dust per second -- all on its own -- a rate that will deplete the body in about another 100 or so orbits around the sun, said lead scientist Mike A’Hearn, with the University of Maryland.
The spacecraft should be finished relaying the 120,000 images taken during the encounter by Thanksgiving. Among the long list of tasks for the science team is to figure out how much organic material is mixed into the snowballs.
Image: It's snowing comet ice. Credit: NASA
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