May 26, 2009

Meteorite Contains Record Amount of Organic Compounds

Scientists have reported the discovery of formic acid at record levels in a meteorite that splashed into Tagish Lake in Canada in 2000.

Formic acid is the simplest carboxylic acid. It is rich in carbon, and it has been linked to the origin of life. It is commonly found on Earth in the venom of bee and ant stings.

Scientists reported that the meteorite revealed four times more formic acid than previously recorded in other meteorite samples.

Researchers told BBC News that the cold temperatures of Lake Tagish helped preserve the chemical on the meteorite.

"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.

The meteorite was purchased in 2006 by a consortium of agencies including the Royal Ontario Museum.

Scientists had previously studied a meteorite that was discovered in Murchison 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 analyze a different portion of the asteroid belt and therefore a different portion of the Solar System."

The Murchison meteorite contains more than 100 amino acids. It holds common amino acids such as glycine, alanine and glutamic acid as well as more rare ones like isovaline and pseudoleucine.

Researchers told BBC News that the isotopes of hydrogen that are found in the formic acid suggest that it originated in the cold regions of space before our Solar System came into existence.

The formic acid is known as a "reducing agent" that serves as a magnet for oxygen atoms during chemical reactions. It may also be linked to the transformation of RNA to DNA, said Sephton.


On the Net: