[meteorite-list] Specks of 'Fire and Ice' in Comet Dust (Stardust)

From: Ron Baalke <baalke_at_meteoritecentral.com>
Date: Tue Mar 14 10:31:04 2006
Message-ID: <200603132248.k2DMmuQ04573_at_zagami.jpl.nasa.gov>

http://www.cnn.com/2006/TECH/space/03/13/stardust.results.ap/

Specks of 'fire and ice' in comet dust
Associated Press
March 13, 2006

SPACE CENTER, Houston (AP) -- NASA scientists said Monday they have
discovered fire and ice in samples brought back as part of the $212
million Stardust mission, which collected comet dust that is providing
clues to the birth of the solar system.

"Remarkably enough, we have found fire and ice," said Don Brownlee, a
University of Washington astronomer who is the mission's principal
scientist.

"We have found samples in the coldest part of the solar system. We found
samples that have formed at an extremely high temperatures. So the
hottest samples that formed at an extremely cold place."

It is unclear whether the samples formed within the solar system or a
distant star before being cast into the solar system, Brownlee said.

Hundreds of microscopic specks of comet dust were collected and returned
to Earth after the robotic Stardust spacecraft flew past the comet Wild
2 in 2004.

A 100-pound (45-kilogram) capsule returned the samples to Earth in
January after a 7-year mission.

The specks of dust are described as glassy materials, crystals like
olivine and various trace elements such as magnesium, peridot and sulfides.

The spacecraft containing the Stardust canister looped around the sun
three times to capture the interstellar and comet dust, which hit a
specialized silicone-based material called aerogel at a speed six times
faster than a bullet fired from a rifle.

The mothership, which has traveled nearly 3 billion miles (4.8 billion
kilometers), remains in permanent orbit around the sun. The next time it
flies by Earth will be on January 14, 2009.

The grains are pristine samples of material which scientists say is
providing clues to the formation of the sun and nine planets.

About 150 scientists have been studying the dust since it arrived.

"If it is forming in our solar system, it had to be formed in the
hottest regions and transported to the coldest regions," Brownlee said.

The samples were the first extraterrestrial material returned to Earth
since a manned mission returned moon samples more than three decades ago.

When the comet dust particles were captured, they left tracks -- some
shaped like carrots, others like turnips -- in the gel which was
contained in a tennis racket-sized collector mitt.

Scientists spent hours using a computer-controlled needle to remove each
particle.
Received on Mon 13 Mar 2006 05:48:56 PM PST