The Breakup of a Meteorite Parent Body and the Delivery of Meteorites to Earth

• Published in: Science
• Main Authors: Benoit, Paul H., Sears, D. W. G.
• Format: Article in Journal/Newspaper
• Language: English
• Published: American Association for the Advancement of Science (AAAS) 1992
• Subjects: Antarc*; Antarctic
• Online Access: http://dx.doi.org/10.1126/science.255.5052.1685; https://www.science.org/doi/pdf/10.1126/science.255.5052.1685

Whether many of the 10,000 meteorites collected in the Antarctic are unlike those failing elsewhere is contentious. The Antarctic H chondrites, one of the major classes of stony meteorites, include a number of individuals with higher induced thermoluminescence peak temperatures than observed among non-Antarctic H chondrites. The proportion of such individuals decreases with the mean terrestrial age of the meteorites at the various ice fields. These H chondrites have cosmic-ray exposure ages of about 8 million years, experienced little cosmic-ray shielding, and suffered rapid postmetamorphic cooling. Breakup of the H chondrite parent body, 8 million years ago, may have produced two types of material with different size distributions and thermal histories. The smaller objects reached Earth more rapidly through more rapid orbital evolution.