What is the Murchison meteorite?
Murchison is a carbonaceous chondrite that fell in Victoria, Australia, on 28 September 1969. It is famous for containing amino acids and many other organic molecules.
On the morning of 28 September 1969, a bright fireball crossed the sky over the state of Victoria in Australia. It broke apart, and fragments fell around the town of Murchison, north of Melbourne. More than 100 kilograms of stones were collected, the largest weighing about 7 kilograms.
What it is. Murchison is a CM2 carbonaceous chondrite, a dark meteorite made largely of water-bearing clay minerals, with chondrules, CAIs and abundant organic matter. It is rich in carbon, about 2 per cent by weight.
Organic chemistry. Murchison became famous because scientists found dozens of amino acids in it, including some used by life on Earth and many that are not. Their isotopes and the presence of unusual amino acids showed they formed in space, not from Earth contamination. Since then, studies have found tens of thousands of different organic compounds, including hydrocarbons, nucleobases, sugars and other molecules.
Stardust. Murchison contains presolar grains, such as silicon carbide. In 2020, researchers reported silicon carbide grains in Murchison that may be among the oldest solid materials known, formed around 5 to 7 billion years ago, before the Sun existed.
Timing. Murchison fell shortly after Apollo 11 returned the first Moon samples, so laboratories had new, clean techniques ready, which helped in its study.
Importance. Murchison is one of the most studied meteorites in the world. It supports the idea that meteorites could have delivered organic molecules to the early Earth, contributing to the ingredients for life.