Article: Deep Impact collision ejected the stuff of life
- From: "Robert Karl Stonjek" <rstonjek@xxxxxxxxxxxxxx>
- Date: Thu, 8 Sep 2005 17:21:50 -0400 (EDT)
Deep Impact collision ejected the stuff of life
13:10 07 September 2005
Maggie McKee
Millions of kilograms of fine dust particles and water and a "surprisingly
high" amount of organic molecules sprayed into space when NASA crashed its
Deep Impact spacecraft into Comet 9P/Tempel 1 on 4 July 2005, reveal a trio
of new studies.
The observations bolster theories that comets may have seeded Earth with the
raw materials for life and suggest they may be sponge-like - rather than
hardened - at their cores.
On 4 July, about 80 telescopes on Earth and in space trained their sights on
Comet Tempel 1 when a 370-kilogram copper impactor was sent hurtling into
its path. Just after the smash, a bright vapour plume spewed from the
surface at about 5 kilometres per second, followed quickly by a stream of
particles that spread into a cone.
The cone appeared to remain attached to the comet's surface for about 22
hours before separating into a detached arc. Researchers used this
gravitational attraction to estimate the mass and density of the comet's
main body, or nucleus. They found that the 72 trillion kilogram-nucleus was
extremely porous, with as much as 80% of its volume taken up by empty space.
"That tells me there is no solid layer all the way down to the centre," says
Mike A'Hearn, the mission's principal investigator at the University of
Maryland in College Park, US. He says he had expected that the ice might
become denser towards the core of the nucleus, but that instead "probably
all the way in, ice is all in the form of tiny grains".
Full Text at NewScience
http://www.newscientist.com/article.ns?id=dn7961
Comment:
Further down we read
"This supports theories that comets may have brought water and the building
blocks of life to Earth, and the team hopes to eventually 'identify all the
species comets brought in abundance to early Earth', says A'Hearn."
Posted by
Robert Karl Stonjek
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