A rare CO chondrite meteorite was the probable impacter that struck Earth 66 million years ago, wiping out 75% of Earth’s species, including nonavian dinosaurs. These findings are published in Science Advances. Researchers at the University of British Columbia (UBC), Paris, Brussels and Vienna, used advanced nickel isotope analysis of samples to narrow down the composition of the deadly Cretaceous-Paleogene meteorite.
“Carbonaceous chondrites of the Ornans class are definitely not like the typical meteors you find in museum collections,” says Dr. Philippe Claeys, who worked on the study as a visiting professor at UBC.
“A CO contains much less volatile elements—like carbon, zinc, water and particularly sulfur—than other classes of meteorites we’ve discovered so far on Earth. It doesn’t alter our theory of what caused the extinction event—but it makes it less likely that sulfur contained in the impacter was the smoking gun. The fine debris thrown into the atmosphere would have been the primary factor.”
