Researchers at The University of Western Ontario (Western) and the University of Calgary (U of C) -- working with colleagues from Canada, the United States and the United Kingdom -- have found that meteorites recovered in northern British Columbia may be one of the most primitive solar system materials ever examined.
Peter Brown, a professor in Western's Department of Physics and
Astronomy, and Alan Hildebrand, a professor in the Department of Geology and Geophysics at U of C, are the lead authors of the report featured on the cover of the Oct. 13, 2000 issue of the international journal Science.
The meteorites, recovered by B.C. resident Jim Brook in late January, and scientists at Western and the U of C during April and May, were found on Tagish Lake, B.C. It was the largest meteorite fall in Canadian history.
"We can now say that this may be the 'crown jewel' of meteorite finds," says Brown. "This discovery will aid scientists in the reconstruction of the early solar system."
"The standard composition of the solar system is partly defined by the most primitive meteorite in existence," says Neil MacRae, earth sciences professor at Western and a co-author on the Science paper. "If our results are proven correct, this new discovery will ultimately change that definition."
The Tagish Lake Meteorite is a new type of carbonaceous chondrite -- a rare, organically rich, charcoal-like class of meteorites. Carbonaceous chondrite meteorites make up about three per cent of meteorite finds in the world. The chemical class most closely resembling this meteorite constitutes less than 0.1 per cent of all meteorites recovered to date, though the Science paper suggests the Tagish Lake Meteorite to be even more primitive and therefore may represent a new class.
The first recovered pieces of the Tagish Lake Meteorite have been kept frozen, which will allow researchers to identify the full range of compounds in a primitive, carbon-rich meteorite for the first time. These organic materials may help scientists better understand chemical processing in the outer part of the solar nebula. The meteorite is also rich in interstellar grains. Coupled with the limited aqueous alteration on the parent asteroid of the Tagish Lake Meteorite, this may mean that new things will be learned about the nuclear furnaces of stars.
"The most significant and exciting things to be discovered in this meteorite may not yet be known," says Hildebrand. "We, together with Jim Brook, are supplying material to dozens of researchers located around the world for their studies. It is a delightful and somewhat rare situation for scientists when we can't predict what may be learned."
Other members of the research team include Michael Mazur, Tina
Rubak-Mazur, Michael Glatiotis, and J. Andrew Bird at U of C; Michael Zolensky at NASA Johnson Space Center; Monica Grady at the Natural History Museum in England; Robert Clayton and Toshiko Mayeda at the University of Chicago; Edward Tagliaferri at ET Space Systems in California; Richard Spalding of Sandia National Laboratories in New Mexico; Margaret Campbell, Robert Carpenter, Heather Gingerich, Erika Greiner, Phil McCausland and Howard Plotkin at Western; Eric Hoffman at Activation Laboratories Ltd. in Ancaster, Ontario; David Mittlefehldt at Lockheed Engineering and Science Co. in Houston; and John Wacker at the Pacific Northwest National Laboratory, Richland, Washington.
For more information, please contact:
Peter Brown at (519) 661-2111 ext. 86458
Alan Hildebrand at (403) 220-2291 or cell (403) 874-1434
For B-roll footage, a copy of the Science paper or to arrange interviews, please contact:
Communications and Public Affairs, The University of Western Ontario (519) 661-2111 ext. 85468
Research Communications, University of Calgary
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