[meteorite-list] Researchers Find Possible Precursors To Early Life On Earth In Tagish Lake Meteorite

From: Ron Baalke <baalke_at_meteoritecentral.com>
Date: Thu Apr 22 09:53:34 2004
Message-ID: <200212121820.KAA27861_at_zagami.jpl.nasa.gov>

http://www.jsc.nasa.gov/news/releases/2002/J02-122.html

December 11, 2002

Catherine E. Watson
Johnson Space Center, Houston, Texas
(Phone: 281/483-5111)

Release: #J02-122

RESEARCHERS FIND POSSIBLE PRECURSORS TO EARLY LIFE ON EARTH IN
METEORITE

In a study published today in the "International Journal of
Astrobiology," researchers state that a meteorite that fell to
Earth over northwestern Canada in January 2000 contains a
previously unseen type of primitive organic material that was
formed long before our own solar system came into being.

The Tagish Lake meteorite fell to Earth over the Yukon
Territory of Canada on Jan. 18, 2000. Parts of the meteorite
were collected and kept frozen in an unprecedented level of
cleanliness to ensure that it was not contaminated by any
terrestrial sources.

Through extensive testing using, in part, electron
microscopes, the researchers found numerous hollow,
bubble-like hydrocarbon globules in the meteorite. They
believe these organic globules, the first found in any natural
sample, are very similar to those produced in laboratory
simulations designed to recreate the initial conditions
present when life first formed in the universe.

"While not of biological origin themselves, these globules
would have served very well to protect and nurture primitive
organisms on Earth," said Dr. Michael Zolensky, an author of
the paper and a researcher in the Office of Astromaterials
Research and Exploration Science at NASA's Johnson Space
Center in Houston. "They would have been ready-made homes for
early life forms."

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
provided with these hydrocarbon globules at the same time life
was first forming here," Zolensky said. "We were exceedingly
fortunate that this particular meteorite was so large that
some pieces survived to be recovered on the ground."

Last year, researchers at NASA's Ames Research Center in
Moffett Field, Calif., announced that they had made basically
identical hydrocarbon globules in the laboratory from
materials present in the early solar system and interstellar
space.

"What we have now shown is that that these globules were in
fact made naturally in the early solar system, and have been
falling to Earth throughout time," Zolensky said.

The researchers believe the Tagish Lake meteorite came from
the outer asteroid belt, toward Jupiter, and that similar
organic materials may have been falling onto the moons of
Jupiter, including Europa.

"It is interesting to speculate about the presence of these
organics in the ocean we believe may be present under the ice
cap of this moon," Zolensky said.

A team of five researchers collaborated on the two-year study.
The team was led by Keiko Nakamura of Kobe University in
Japan, who was funded by the Japan Society for the Promotion
of Science. Nakamura is now working at JSC under a
postdoctoral grant from the U.S. National Research Council.
Co-authors of the study include Zolensky, who was funded by
the NASA Cosmochemistry Program; Satoshi Tomita and Kazushige
Tomeoka, both of Kobe University, who were funded by the Japan
Society for the Promotion of Science and the Japanese Ministry
of Education, Science, Sports and Culture, respectively; and
Satoru Nakashima of the Tokyo Institute of Technology, who was
also funded by the Japan Society for the Promotion of Science.

-end-
Received on Thu 12 Dec 2002 01:20:42 PM PST