# Nickel Isotopes Reveal Dinosaur-Killing Asteroid Was a Rare 'Oddball' Meteorite

*2026-07-20 02:02 UTC · Science · 1 min read*

> A new isotopic study identifies the Chicxulub impactor as an exceptionally rare CO chondrite, reshaping ideas about the dinosaur extinction event.

A new isotopic study published in Science Advances has identified the asteroid that wiped out the dinosaurs 66 million years ago as an exceptionally rare CO chondrite — a primitive, carbon-rich meteorite type that makes up only 3-5% of all meteorites found on Earth.

Researchers from the University of British Columbia, working with teams in Paris, Brussels, and Vienna, analyzed nickel isotopes preserved in the global clay layer left behind by the impact. The 10-15 kilometer object struck Mexico's Yucatán Peninsula at roughly 64,000 km/h, carving out the Chicxulub crater and triggering the extinction of about 75% of Earth's species.

The findings suggest the asteroid originated from a remote, icy region of the solar system, possibly near the outer asteroid belt or Jupiter. Because CO chondrites carry far less sulfur than previously assumed for the impactor, scientists now believe the catastrophic post-impact cooling was driven mainly by pulverized crustal dust rather than sulfur aerosols.

"Being impacted by such a rare, distant projectile really underscores how unlucky the dinos were," said Dr. Philippe Claeys, one of the study's researchers.

## Sources

- [sciencedaily.com](https://www.sciencedaily.com/releases/2026/07/260718010142.htm)

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TechTools News · https://techtools.cz/tools/news/article/2037-nickel-isotopes-reveal-dinosaur-killing-asteroid-was-a-rare-oddball-meteorite
Česká verze: https://techtools.cz/tools/news/clanek/2110-analyza-niklu-odhalila-asteroid-ktery-zabil-dinosaury-byl-vzacny-podivinsky