[meteorite-list] NASA Scientists Find Primordial Organic Matter inTagish Lake Meteorite

From: Fred Caillou Noir <fred_at_meteoritecentral.com>
Date: Fri, 1 Dec 2006 18:28:18 +0100
Message-ID: <033101c7156e$19266140$0400a8c0_at_IBM>

Thanks for sharing this, Ron.
Very interesting!!!
Do you know whether more scientific work is to be done on this topic with Tagish Lake?
best wishes,

Frederic

----- Original Message -----
From: "Ron Baalke" <baalke at zagami.jpl.nasa.gov>
To: "Meteorite Mailing List" <meteorite-list at meteoritecentral.com>
Sent: Friday, December 01, 2006 6:17 PM
Subject: [meteorite-list] NASA Scientists Find Primordial Organic Matter inTagish Lake Meteorite


>
> http://www.nasa.gov/centers/johnson/news/releases/2006/J06-103.html
>
> William Jeffs
> Johnson Space Center, Houston
> 281-483-5111
>
> RELEASE: J06-103
>
> NASA Scientists Find Primordial Organic Matter in Meteorite
> November 30, 2006
>
> NASA researchers at Johnson Space Center, Houston have found organic
> materials that formed in the most distant reaches of the early Solar
> System preserved in a unique meteorite. The study was performed on the
> Tagish Lake carbonaceous chondrite, a rare type of meteorite that is
> rich in organic (carbon-bearing) compounds.
>
> Organic matter in meteorites is a subject of intense interest because
> this material formed at the dawn of the Solar System and may have seeded
> the early Earth with the building blocks of life. The Tagish Lake
> meteorite is especially valuable for this work because much of it was
> collected immediately after its fall over Canada in 2000 and has been
> maintained in a frozen state, minimizing terrestrial contamination. The
> collection and curation of the meteorite samples preserved its pristine
> state.
>
> In a paper published in the Dec. 1 issue of the journal Science, the
> team, headed by NASA space scientist Keiko Nakamura-Messenger, reports
> that the Tagish Lake meteorite contains numerous submicrometer hollow
> organic globules.
>
> "Similar objects have been reported from several meteorites since the
> 60's. Some scientists believed these were space organisms, but others
> thought they were just terrestrial contamination," said
> Nakamura-Messenger. The same bubble-like organic globules appeared in
> this freshest meteorite ever received from space. "But in the past,
> there was no way to determine for sure where these organic globules came
> from because they were simply too small. They are only 1/10,000 inch in
> size or less."
>
> In 2005, two powerful new nano-technology instruments were installed in
> the scientists' laboratory at Johnson Space Center. The organic globules
> were first found in ultrathin slices of the meteorite with a new JEOL
> transmission electron microscope. It provided detailed structural and
> chemical information about the globules. The organic globules were then
> analyzed for their isotopic compositions with a new mass spectrometer,
> the Cameca NanoSIMS, the first instrument of its kind capable of making
> this key measurement on such small objects.
>
> The organic globules in the Tagish Lake meteorites were found to have
> very unusual hydrogen and nitrogen isotopic compositions, proving that
> the globules did not come from Earth.
>
> "The isotopic ratios in these globules show that they formed at
> temperatures of about -260?? C, near absolute zero," said Scott
> Messenger, NASA space scientist and co-author of the paper. "The organic
> globules most likely originated in the cold molecular cloud that gave
> birth to our Solar System, or at the outermost reaches of the early
> Solar System."
>
> The type of meteorite in which the globules were found is also so
> fragile that it generally breaks up into dust during its entry into
> Earth's atmosphere, scattering its organic contents across a wide swath.
> "If, as we suspect, this type of meteorite has been falling onto Earth
> throughout its entire history, then the Earth was seeded with these
> organic globules at the same time life was first forming here." said
> Mike Zolensky, NASA cosmic mineralogist and co-author of the paper.
>
> The origin of life is one of the fundamental unsolved problems in
> natural sciences. Some biologists think that making a bubble-shape is
> the first step on the path to biotic life. "We may be a step closer to
> knowing where our ancestors came from," Nakamura-Messenger said.
>
> - end -
>
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Received on Fri 01 Dec 2006 12:28:18 PM PST