Murchison Meteorite

Carbonaceous Mighei-like chondrite which exploded into fragments over Murchison, Australia, located ~200 km north of Melbourne, on Sept. 28, 1969. About 82 kg of the meteorite were recovered. Eyewitnesses reported smelling something like methanol or pyridine, an early indication that the object might contain organic material. Subsequent analysis by NASA scientists and a group led by Cyril Ponnamperuma revealed the presence of 6 amino acids commonly found in protein and 12 that did not occur in terrestrial life. All of these amino acids appeared in both dextrorotatory (right-handed) and laevorotatory (left-handed) forms, suggesting that they were not the result of Earthly contamination. The meteorite also contained abiogenic hydrocarbons enriched with a heavy isotope of carbon, confirming their extraterrestrial origin. Initial studies suggested that the amino acids in the Murchison meteorite showed no bias between left- and right-handed forms. However, in 1997, John R. Cronin and Sandra Pizzarello of Arizona State University reported finding 7-9% excesses of left-handed versions of four amino acids, a result confirmed independently by another group. More than 70 amino acids have been identified in Murchison altogether. To this organic mixture, in 2001, was added a range of polyols – organic substances closely related to sugars such as glucose.

Some or all content above used with permission from J. H. Wittke.

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