[meteorite-list] Clues to Origin of Life Revealed in Tagish Lake Meteorite

From: Ron Baalke <baalke_at_meteoritecentral.com>
Date: Thu, 2 Jul 2009 11:49:36 -0700 (PDT)
Message-ID: <200907021849.n62Inaev023488_at_zagami.jpl.nasa.gov>

http://www.cbc.ca/technology/story/2009/07/02/bc-tagish-lake-meteorite-formic-acid.html

Clues to origin of life revealed in Tagish Lake meteorite
CBC News (Canada)
July 2, 2009

New research into a meteorite that crashed into northern British
Columbia nine years ago is revealing startling clues that could help
unravel the origins of life on earth.

Parts of the Tagish Lake meteorite were found on a frozen lake near the
Yukon border in January, 2000, after it fell to earth in a spectacular
blue-green fireball that was seen for hundreds of kilometres.

Parts of the meteorite were recovered still frozen after an extensive
search by researchers. Since then, scientists have repeatedly tried to
unlock the clues about the origins of life that the rare 4.5
billion-year-old carbon- and water-rich meteorite has long been
suspected to contain.

Now, a team at the University of Alberta has found some important
material nestled inside the rock. It's formic acid ??? the key ingredient
in bee stings, ant venom and stinging nettles, which may hold a key to
unlocking the mystery of how life on earth began.

U of A scientist Chris Herd says finding the molecule may have been
instrumental in kick-starting life on earth, making the meteorite the
most important rock ever found on earth.

"Four billion years ago, when the earth had kind of cooled off from its
initial hot state, and there was liquid water on the surface, we may
have had an influx of meteorites like Tagish Lake [that] delivered the
right mix of molecules to the earth's surface," he said.

How exactly that mix might have turned into actual life is still a
mystery, but Herd said the findings of formic acid on the meteorite may
provide important clues.

"It's a type of molecule known as a carboxylic acid. So it's sort of
like the shortest, smallest molecule in that group. The longer molecules
in this same group are actually what life uses in building cell walls."

In 2001, U.S. exobiologist Sandra Pizzarello, who was studying some of
the fragments from the Tagish meteorite at Arizona State University,
said they contained almost no amino acids but did contain high
concentrations of hydrocarbon molecules, along with a type of clay that
forms in the presence of water.

In 2006, Mike Zolensky, a cosmic mineralogist at the NASA Space Centre
in Texas, said tiny bubbles in the rock were organic globules where the
universe's earliest life forms could have been able to live.
Received on Thu 02 Jul 2009 02:49:36 PM PDT