[meteorite-list] Earth's Atmosphere Came from Outer Space, Like Meteorites

From: Sterling K. Webb <sterling_k_webb_at_meteoritecentral.com>
Date: Fri, 11 Dec 2009 01:50:13 -0600
Message-ID: <84BD4E674B2D4AD2A63141DAD9383909_at_ATARIENGINE2>

Interestingly enough, the same scientists released
this same news story almost 5 years ago (Jan. 25,
2005) with the same conclusions. It appears to have
been less world-shattering than they think, possibly
because there is a hole in their logic that you could
drive a truck through, or possibly because there is
nothing to explain.

Their argument is that the gases from the interior of
the Earth are like that of meteorites that came from
outer space, but the Earth's atmosphere has a different
composition, which proves it must have come, yes,
from outer space...

Confused enough? Read on...

http://www.sciencedaily.com/releases/2009/12/091210153538.htm

Earth's Atmosphere Came from Outer Space,
Scientists Find

ScienceDaily (Dec. 10, 2009) - The gases which formed
the Earth's atmosphere -- and probably its oceans -- did
not come from inside the Earth but from outer space,
according to a study by University of Manchester and
University of Houston scientists.

The report published in the journal Science means that
textbook images of ancient Earth with huge volcanoes
spewing gas into the atmosphere will have to be rethought.

According to the team, the age-old view that volcanoes
were the source of the Earth's earliest atmosphere must
be put to rest.

Using world-leading analytical techniques, the team of
Dr Greg Holland, Dr Martin Cassidy and Professor Chris
Ballentine tested volcanic gases to uncover the new
evidence.

The research was funded by Natural Environment Research
Council (NERC). "We found a clear meteorite signature in
volcanic gases," said Dr Greg Holland the project's lead
scientist.

"From that we now know that the volcanic gases could not
have contributed in any significant way to the Earth's
atmosphere.

"Therefore the atmosphere and oceans must have come
from somewhere else, possibly from a late bombardment
of gas and water rich materials similar to comets.

"Until now, no one has had instruments capable of looking
for these subtle signatures in samples from inside the Earth
-- but now we can do exactly that."

The techniques enabled the team to measure tiny quantities
of the unreactive volcanic trace gases Krypton and Xenon,
which revealed an isotopic 'fingerprint' matching that of
meteorites which is different from that of 'solar' gases.

The study is also the first to establish the precise composition
of the Krypton present in the Earth's mantle.

Project director Prof Chris Ballentine of The University of
Manchester, said: "Many people have seen artist's impressions
of the primordial Earth with huge volcanoes in the background
spewing gas to form the atmosphere.

"We will now have to redraw this picture."

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Received on Fri 11 Dec 2009 02:50:13 AM PST