Capturing Dust Particles
Dust particles released from comets are thought to float around in the coma for a few hours before they are dispersed into space. Stardust will fly to within 75 miles [120 kilometers] of Wild 2's main body, close enough to fly through the coma.
"By gathering pristine dust within hours or less from when it was released from the comet Wild 2, we can perform detailed analyses of these particles on Earth to understand the chemical composition of Wild 2 and comets in general," said Duxbury.
This knowledge, he says, will give scientists a better understanding of the role comets played in the formation of our solar system and the Earth.
Stardust will capture particles with a blue, lightweight, high-tech glasslike substance known as aerogel. The particles are caught as they impact into the gel and slow down, forming an inverse carrot-shaped trail in the glass as they come to rest.
"Aerogel is a very exotic material with many remarkable characteristics," said Brownlee.
The scientists chose aerogel because it can capture the comet particles without damaging them, even though at impact they will be traveling at about six times the speed of a bullet fired from a shotgun.
The aerogel aboard the Stardust spacecraft is fitted into a collector shaped like a tennis racket. After the comet Wild 2 flyby, the collector will fold into a capsule that will be dropped on the desert floor of Utah on January 15, 2006.
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