Meteorite fragments provide scientists clues to life’s origin on Earth

Associated Press

WASHINGTON — In a search for new clues about the origin of life, researchers worldwide are analyzing bits of a bus-sized meteorite that blazed to Earth in January in a spectacular fireball, giving science the most pristine primordial matter ever recovered.

The meteorite, estimated to weigh about 220 tons when it smashed into the atmosphere, shattered before it hit the ground and sprayed bits of space rock over a frozen lake in British Columbia.

More than 70 eyewitness saw the fireball and a week later Canadian Jim Brook, while driving on the ice of Tagish Lake, spotted bits of the meteorite. Working in minus 20 degree temperatures, Brook collected about two pounds of the black, charcoal-like fragments in a plastic bag and stored them in a freezer.

Brook’s careful handling will allow scientists to study matter that is virtually unchanged since the solar system formed some 4.6 billion years ago, said Peter Brown of the University of Western Ontario in London, Ontario, Canada.

"These are the most pristine meteorite specimens on the planet right now," said Brown, who is first author of a study appearing toFday in the journal Science.

Later expeditions gathered some 410 additional fragments, but by then the material had been sitting in the open for weeks, was most likely contaminated and was beginning to erode. The material is about the consistency of dried mud, and rain can cause it to crumble and wash away.

Preliminary tests of the pristine material found it is loaded with organic molecules of the type that some experts have suggested could have been the original raw materials for the formation of life on Earth.

"Stuff like (the) Tagish Lake (meteorite) were pelting the early Earth," Brown said. "It is natural to assume that not only could organic molecules have been synthesized in the primordial soup on Earth, but they could have been brought here from an extraterrestrial origin."

The meteorite’s fireball was detected by satellites, enabling Brown and other others to estimate the path of the space rock and track it back into space. They believe the object came from the asteroid belt between the orbits of Mars and Jupiter. Brown said the object was probably jolted off a larger body and could have spent millions of years in orbit before being captured by Earth’s gravity.

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