[meteorite-list] Hydrocarbon Bubbles Discovered In Tagish Lake Meteorite

From: Ron Baalke <baalke_at_meteoritecentral.com>
Date: Thu Apr 22 09:53:35 2004
Message-ID: <200212172014.MAA19493_at_zagami.jpl.nasa.gov>

http://www.newscientist.com/news/news.jsp?id=ns99993189

Hydrocarbon bubbles discovered in meteorite
Will Knight
New Scientist
December 17, 2002

Hollow hydrocarbon bubbles a few microns in diameter have been discovered in
a meteorite that crashed into a frozen lake in Canada in 2000.

The simple organic structures could have provided a sheltered environment
for the development of the first primitive organisms, suggests Michael
Zolensky, at NASA's Johnson Space Center.

He used an electron microscope to discover the globules, which are a few
microns in diameter. "These are ready-made homes," he told New Scientist.
"It shows that structures that could protect early life were present on
asteroids billions of years ago."

It is the first time that such bubbles have been found on a meteorite, but
laboratory experiments designed to simulate conditions in space have
produced similar structures.

"Some ideas for the evolution of life require a kind of membrane to hold
together all the chemicals that you want a cell to use," says Iain Gilmour,
of the UK's Open University. "If you have some sort of globular structure,
you've got the start of a potential cell structure."

Other researchers have suggested that tiny cavities in minerals could have
provided the containers from which the first cellular life emerged.

Quick freeze

The meteorite, a carbonaceous chondrite, was recovered from the frozen
waters of Tagish Lake in the Yukon Territory in January 2000, just a week
after it landed. The extreme cold of the lake and the speed at which it was
recovered prevented the contamination that spoils many meteorites found on
Earth.

The circumstances under which the cavities could aid the development of life
remain unclear. But Zolensky notes meteorites of this general type have been
crashing into Earth throughout its history.

They would have provided the early planet with these hydrocarbon globules at
the same time as water, carbon and organic molecules were being bought to
Earth on comets and meteorites, he says, and at the same time the first
terrestrial life was developing.

Much previous research into potential extraterrestrial triggers for life on
Earth has focused on meteorites that landed in Murchison, Southern Australia
in 1969. These contained amino acids, the building blocks of proteins and
life, and showed for the first time that the molecules could exist elsewhere
in the Solar System.

Gilmour says: "It means you've got the stuff you need to make proteins in
one extra-terrestrial sample and the stuff needed to hold them together in
another." Zolensky's research is published in the International Journal of
Astrobiology.
Received on Tue 17 Dec 2002 03:14:26 PM PST