Monday, March 03, 2008

Key to Life Before its Origin on Earth discovered

Researchers studying a special group of meteorites have found them to contain amino acids that have identical counterparts in terrestrial biomolecules. These meteorites are fragments of asteroids that are about the same age as the solar system (roughly 4.5 billion years.)

The discovery was made possible by the finding in Antarctica of an exceptionally pristine meteorite. Antarctic ices are good “curators” of meteorites. After a meteorite falls -- and meteorites have been falling throughout the history of Earth -- it is quickly covered by snow and buried in the ice. Because these ices are in constant motion, when they come to a mountain, they will flow over the hill and bring meteorites to the surface.
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Dr Sandra Pizzarello, a research professor at Arizona State University, who led the research team said: “Thanks to the pristine nature of this meteorite, we were able to demonstrate that other extraterrestrial amino acids carry the left-handed excesses in meteorites and, above all, that these excesses appear to signify that their precursor molecules, the aldehydes, also carried such excesses,.”

“In other words, a molecular trait that defines life seems to have broader distribution as well as a long cosmic lineage.” Pizzarello said.

(image courtesy Anders Meibom)




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