Meteorites a rich source for primordial soup

The analysis revealed that while one sample showed a relatively low abundance of amino acids, the other two meteorites had the highest ever seen in primitive meteorites—180 and 249 ppm (parts per million). Other primitive meteorites that have been studied generally have amino acid concentrations of 15 ppm or less. Because organic molecules from extra-terrestrial sources have ratios of carbon isotopes different from those of Earthly biological sources, the researchers were able to rule out contamination as a factor in their result.

“The amino acids probably formed within the parent body before it broke up,” says Alexander. “For instance. ammonia and other chemical precursors from the solar nebula, or even the interstellar medium, could have combined in the presence of water to make the amino acids. Then, after the break up, some of the fragments could have showered down onto the Earth and the other terrestrial planets. These same precursors are likely to have been present in other primitive bodies, such as comets, that were also raining material onto the early Earth.”

* Z. Martins, C. M. O’D. Alexander, G. E.Orzechowska, M. L. Fogel, and P. Ehrenfreund.

Indigenous amino acids in primitive CR meteorites. Meteoritics and Planetary Science. Available for free download at astro-ph. (http://arxiv.org/abs/0803.0743v2)

Funding for Fogel and Alexander provided in part by NASA's Origins of Solar Systems program and the NASA Astrobiology Institute.

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