The Dinosaur-Killing Asteroid Was a Rare 'Oddball' Meteorite, New Study Finds
Sixty-six million years ago, an asteroid roughly 10 to 15 kilometers wide slammed into what is now Mexico's Yucatán Peninsula at about 64,000 km/h (40,000 mph), carving out the Chicxulub crater and triggering the mass extinction that ended the age of non-avian dinosaurs. A study published July 17, 2026 in Science Advances has now identified exactly what kind of space rock did it — and it turns out to be a class of meteorite almost never seen on Earth.
Led by researcher Georgy Makhatadze with collaborators from the University of British Columbia, the Institut de Physique du Globe de Paris, and universities in Brussels and Vienna, the team ran high-precision nickel isotope analysis on the thin clay layer the impact deposited worldwide — the K-Pg boundary — using samples from Stevns Klint, Denmark. The isotopic signature pointed to a CO chondrite, a rare subtype of carbonaceous chondrite belonging to the "Ornans" class. As co-author Dr. Philippe Claeys put it, these are "definitely not like the typical meteors you find in museum collections." CO chondrites carry unusually low concentrations of volatile elements — carbon, zinc, water, and especially sulfur — compared to the carbonaceous chondrites collectors and museums see most often, and carbonaceous chondrites as a whole make up only about 5% of all known meteorite falls.
That rarity is what makes the finding notable: the object responsible for one of the most consequential single days in the history of life on Earth wasn't an ordinary rock. It belonged to a meteorite family so uncommon that identifying it 66 million years after the fact required isotope geochemistry rather than a simple look under a microscope.
It's a good reminder of how much information is locked inside even a small piece of extraterrestrial material — composition, origin, and history all preserved in the same fragment. If you'd like to hold a piece of that history yourself, browse our current meteorite specimens, including Campo del Cielo and Sikhote-Alin pieces available now.
Source: Phys.org, July 2026, reporting on Makhatadze et al., Science Advances, July 17, 2026 (DOI: 10.1126/sciadv.aef4858).
Written by Nic Scogna, a photographer and mineral collector based in Lexington, Kentucky, and the founder of Crystal Earth Gallery and Kyanite King Minerals. For over 25 years, he has traveled to mineral localities across the U.S. — from Maine to California — personally sourcing the specimens, gemstones, and photographic subjects featured here. When not out in the field, Nic writes about mineralogy, collecting, and the craft of turning raw stone into wearable art.