UK researchers have got hold of a fragment of one of the rarest meteorites ever to have fallen to Earth.

The scientists from the Natural History Museum hope the little chunk of space rock will tell them about the early formation of the Solar System 4.5 billion years ago.

The meteorite came down over Tagish Lake, a remote area in Canada, on 18 January, 2000.

The exceptionally long and bright fireball was seen throughout the Yukon, Northern British Columbia, parts of Alaska, and the Northwest Territories.

Several fragments were recovered and are now being studied in different labs.

Dr Sara Russell from the Natural History Museum told the British Association's Festival of Science: "This meteorite is extremely fragile and can disintegrate quite easily."

Diamonds and sapphires

It is from a class known as the carbonaceous chondrites - primitive, carbon-rich meteorites that contain organic compounds such as amino acids. Unlike rock on Earth, the Tagish Lake meteorite will not have experienced substantial heating sometime in its history.

Dr Russell is interested in tiny grains which should reveal new information about the material that came together to form the Sun and planets.

"I'm interested in where all the bits that made up the Solar System came from," she said. "I want to look for grains that I know are very old in this meteorite. Because it is very volatile-rich, the chances are that during its whole life time the meteorite has never been heated up very much and that means all this primordial stuff should be very well preserved."

Carbonaceous chondrites contain tiny jewels - presolar diamonds and sapphires. These would have been made around the stars that were the ancestors of our Sun, Dr Russell said.

These jewels can tell scientists about the processes that occur inside stars.