Murchison meteorite

 The Murchison Meteorite

The meteorite shower that came to the town of Murchison, 160 kilometres north of Melbourne, on Sunday 28 September 1969, arrived just two months after the Apollo 11 Moon landing.

On the 50th anniversary of the Murchison meteorite impact, a stamp was issued by Australia Post on September 10. 2019 to commemorate this event. The stamp shows the meteorite in flight heading towards Murchison in Australia. The stamp was designed by Tim Hancock .

After an air explosion with a sonic boom, a few hundred fragment fell on around the town of Murchison. Over 100 kilograms were recovered from the fall area of the rare carbonaceous chondrite meteorite. 

These meteorites retain chemical properties from their time of formation some 4.56 billion years ago. Murchison contains an abundance of organic compounds including over 90 amino acids, the building blocks of our DNA, many of which are not found on Earth. The meteorite is also a rich source of pre-solar mineral grains, which formed in star systems and exploding star supernovae events from billions of years before our Sun and solar system formed. Understanding the composition of these grains helped to determine how the various elements of the Periodic Table have formed within stars.

The hexagonal shapes represent the amino acids found in the meteorite. It is generally accepted that the amino acids and other organic compounds in Murchison have formed through non-biological processes. They do, however, indicate that the carbon building blocks of life may be readily abundant in space. It has been hypothesised that meteorites may well have “seeded” life on Earth by bringing such compounds with them.

(by Nicholas Steggall)