Rare CO chondrite meteorite identified as Chicxulub impactor

New research published in Science Advances suggests that the asteroid responsible for the mass extinction of dinosaurs 66 million years ago was a rare type of meteorite known as a CO chondrite of the Ornans class. By analyzing high-precision nickel isotopes in the K-Pg clay layer found in Denmark, Spain, and Italy, an international team of scientists was able to reconstruct the identity of the object that vaporized upon striking the Yucatán Peninsula.

The findings challenge long-held assumptions regarding the primary driver of the extinction event. While sulfur released during the impact was previously considered a major factor, CO chondrites contain fewer volatile elements, including sulfur, than other meteorite types. This suggests that the immense cloud of dust blasted into the atmosphere, causing global cooling, may have played a more significant role in the die-off of approximately 75% of Earth’s species than previously thought.