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

[Fred Caillou Noir]

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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