[meteorite-list] Tagish Lake-- I, for one, wecome our new insect overlords

From: Darren Garrison <cynapse_at_meteoritecentral.com>
Date: Wed, 27 May 2009 00:32:57 -0500
Message-ID: <ltjp15limeooia1jul4ahkag901nbau4sv_at_4ax.com>

No word if this formic acid was produced by a master race of giant space ants--
but it probably was.

http://news.bbc.co.uk/2/hi/science/nature/8068049.stm

Space rock yields carbon bounty
By Jennifer Carpenter
Science reporter, BBC News, Toronto

Formic acid, a molecule implicated in the origins of life, has been found at
record levels on a meteorite that fell into a Canadian lake in 2000.

Cold temperatures on Tagish Lake prevented the volatile chemical from
dissipating quickly.

An analysis showed four times more formic acid in the fragments than has been
recorded on previous meteorites.

The researchers told a meeting of the American Geophysical Union that the formic
acid was extraterrestrial.

Formic acid is one of a group of compounds dubbed "organics", because they are
rich in carbon.

"We are lucky that the meteorite was untouched by humans hands, avoiding
contamination by organic compounds that we have on our fingers," said Dr
Christopher Herd, the curator of the University of Alberta's meteorite
collection.

Samples of the meteorite totalling 850 grams were collected from Tagish Lake in
Canada, purchased in 2006 by a consortium including the Royal Ontario Museum and
recently subjected to chemical analysis.

The scientists found levels of formic acid four times higher than had previously
been recorded on a meteorite. Studies have until recently focused on the
Murchison meteorite that landed in a town of that name in Australia in 1969.

"The interesting thing is that we do see this variability between meteorites,
seeming to have increased enrichments of one particular compound over another,"
said Mark Sephton, a meteorite and geochemistry professor at Imperial College
London.

"This has for a while been overlooked as we concentrated predominantly on the
Murchison meteorite, but now we've got another fresh sample and we can start to
analyse a different portion of the asteroid belt and therefore a different
portion of the Solar System."

Primordial kitchen

The particular types, or isotopes, of hydrogen that are found in the formic acid
show that it most likely formed in the cold regions of space before our Solar
System existed.

On Earth, formic acid is commonly found in the stings of insects such as ants,
but Professor Sephton it is likely to have been an important "ingredient in the
kitchen" on Earth before life began.

The acid is known to act as a "reducing agent" - acting as a magnet for oxygen
atoms during chemical reactions - and facilitate the conversion of some amino
acids into others.

It may also be implicated in the transformation of the more primitive RNA into
DNA.

Only one of the four "nucleobases" that make up RNA and DNA is different between
the two: uracil is present in RNA while thymine takes its place in DNA.

Professor Sephton's team found uracil in the Murchison meteorite, but no
measurable amount of thymine. However, formic acid is known to help along the
reaction that converts the uracil into thymine.

The reaction, he said, is "one of the ways in which you can take some simple
molecules and increase the chemical diversity of the pool of pre-biotic
molecules".

Video:

http://www.videosift.com/video/I-for-one-welcome-our-new-insect-overlords
Received on Wed 27 May 2009 01:32:57 AM PDT