These rare and primitive space rocks, called carbonaceous chondrites, act as time capsules, providing astronomers with a window into the formation of the Sun and planets, four and a half billion years ago.

Carbonaceous chondrites also contain organic carbon molecules, materials that may be the precursors to life on Earth.

The meteorite was spotted as a fast moving fireball in the skies over California and Nevada on the morning of 22 April 2012, and tracked by US Air Force and doppler weather radar installations.

This allowed scientists to quickly recover several fragments in the Sutter's Mill area, before they were contaminated by rain, which would alter their composition.

Sutter's Mill became world famous in 1848 as the location that sparked the California gold rush.

An analysis carried out by researchers including Dr Peter Jenniskens from the SETI Institute and NASA's Ames Research Center, confirmed the unusually pristine condition of three fragments.

According to Jenniskens, the three and a half metre wide meteor, airburst with the force of a four kilotonne impact over the Sierra Nevada foothills.