Nature: Murchison meteorite

Australian meteorite containing the oldest material found on Earth to date, silicon carbide particles, which have been determined to be 7 billion years old, about 2.5 billion years older than the 4.54-billion-year age of the Earth and the Solar System.

The Murchison meteorite is one of the most studied meteorites due to its mass (>100 kg or 220 lb) and the fact that it was an observed fall. It belongs to a group of meteorites rich in organic compounds.

On 28 September 1969 at approximately 10:58 am local time, near Murchison, Victoria, a bright fireball was observed to separate into three fragments before disappearing, leaving a cloud of smoke. About 30 seconds later, a tremor was heard. Many fragments were found scattered over an area larger than 13 square kilometres (5.0 sq mi), with individual mass up to 7 kilograms (15 lb); one, weighing 680 grams (1.5 lb), broke through a roof and fell in hay. The total collected mass of the meteorite exceeds 100 kilograms (220 lb).

Measured purine and pyrimidine compounds were found in the Murchison meteorite. Carbon isotope ratios for uracil and xanthine of δ13C = +44.5‰ and +37.7‰, respectively, indicate a non-terrestrial origin for these compounds. This specimen demonstrates that many organic compounds could have been delivered by early solar system bodies and may have played a key role in life's origin.