Dinosaur-killing meteorite was a rare type, study finds

The meteorite that wiped out 75% of Earth's species 66 million years ago was a rare type of carbonaceous chondrite, a recent study reveals. Specifically, it belonged to the Ornans class, a group of meteorites that are exceptionally uncommon.

Philippe Claeys of the University of British Columbia, a co-author of the study, noted that these meteorites "don't look at all like the typical meteorites found in museum collections." Carbonaceous chondrites make up only five percent of meteorites found on Earth, and the Ornans class (CO chondrites) is an even smaller fraction of that group.

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The fact that they were hit by such a rare and distant projectile really highlights how unlucky the dinosaurs were.

"The fact that they were hit by such a rare and distant projectile really highlights how unlucky the dinosaurs were," Claeys stated. The impactor, estimated to be between 10 and 15 kilometers in diameter, struck Earth at approximately 64,000 kilometers per hour, creating the Chicxulub crater in Mexico.

Researchers analyzed nickel isotopes in marine clays from a thin layer formed globally by the impact. CO chondrites are among the most primitive materials in the solar system, containing significantly lower levels of volatile elements such as carbon, zinc, water, and sulfur compared to other meteorite types found on Earth. While the exact origin remains uncertain, it may have come from the outer regions of the solar system or the outer asteroid belt near Jupiter.

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don't look at all like the typical meteorites found in museum collections.