11.30.06

William Jeffs
Johnson Space Center, Houston
281-483-5111

RELEASE: J06-103

NASA SCIENTISTS FIND PRIMORDIAL ORGANIC MATTER IN METEORITE

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. &quot;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.&quot; 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.

	
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