See also:

Origin of Life

Chirality and the Origin of Life

External Links:

Murchison fragment photo

Murchison fragment photo - Museum of Victoria

Extraterrestrial Gases in Buckyballs

The Sinister Cosmos
(Scientific American)

On September 28th 1969 fragments of a meteorite fell in and around the small town of Murchison, Victoria (about 100 km N of Melbourne). This meteorite has transformed our ideas about organic material in the Universe. The meteorite was found to contain a wide variety of organic compounds, including many of biological relevance such as amino acids. Together with the subsequent discovery of organic material in molecular clouds in space, this showed that many organic molecules can be formed in space, and raised the possibility that such extraterrestrial material might have a role in the Origin of Life.

In the 1950s the Miller-Urey experiment carried out by Stanley Miller and Harold Urey had shown that amino acids were produced by passing electric discharges through a mixture of methane, ammonia and water, a process which could have occurred in thunderstorms in the earth's early atmosphere. The mix of amino acids found in the Murchison meteorite was found to be very similar to that produced in Miller-Urey type experiments, including many amino acids unknown from terrestrial biological sources. The Murchison results thus demonstrate that such abiotic production of amino acids does occur in nature.

The Murchison meteorite was not the first of its type, but the circumstances and timing of its fall led to it being by far the most important. Since the fall was witnessed and was close to the town of Murchison, fragments were collected by local residents soon after the fall, minimizing the chances of contamination. The fall occurred just two months after the Apollo 11 moon landing, and the laboratories set up to analyse the Apollo moon rocks were available to work on the meteorite samples. The initial work on amino acids in Murchison was done in the laboratories of NASA Ames research center, and led to the first convincing evidence of amino acids of extraterrestrial origin.

More than thirty years later analysis of Murchison samples continues to reveal exciting new results. These include the finding of an excess of the left-handed form of some of its amino acids (see also: chirality and the origin of life) and the finding of fullerene molecules containing trapped extraterrestrial helium.