Scientists identify the rare meteorite that killed the dinosaurs 66 million years ago

Identifying the Impactor’s Chemical Fingerprint

The investigation, conducted by researchers from the University of British Columbia, the Vrije Universiteit Brussel, and institutions in Paris and Vienna, relied on highly precise nickel isotope measurements. Scientists analyzed samples taken from a thin layer of marine clay deposited globally following the impact. Because the massive object—estimated to be 10 to 15 kilometers (roughly six to nine miles) wide—vaporized almost entirely upon striking Earth at approximately 64,000 km/h, only a minute fraction of the projectile remains in the geological record. Despite the difficulty of working with these faint traces, the nickel isotope signature allowed the team to isolate the meteorite’s origin as a rare, primitive class of material. Tracing the precise chemical fingerprint of an impact that took place so long ago is a huge leap forward, said Professor Steven Goderis of the Vrije Universiteit Brussel. Using advanced isotope analysis, we can now determine with much greater precision the specific part of our solar system from which the devastating meteorite originated.

For more on this story, see New Jersey Homeowner’s Quick Action Preserves Rare Meteorite Discovery.

Refining Theories on the Extinction Mechanism

The chemical composition of the CO chondrite has provided new insights into why the impact was so catastrophic. Carbonaceous chondrites are known for being some of the most primitive and least altered materials remaining from the formation of the solar system. Dr. Philippe Claeys, a professor at Vrije Universiteit Brussel and visiting professor at the University of British Columbia, noted that CO chondrites contain significantly fewer volatile elements—such as carbon, zinc, water, and sulfur—than other meteorite classes found on Earth. This finding challenges the long-standing theory that sulfur contained within the meteorite itself was the primary “smoking gun” for the mass extinction. Instead, the research suggests that the enormous quantities of fine debris and dust ejected into the atmosphere by the force of the collision played the dominant role in triggering the global catastrophe.

This follows our earlier report, Chang’e-6 Lunar Samples Reveal Rare Water-Rich Asteroid Fragments.

A Rare and Distant Origin

The study underscores the statistical rarity of the event that ended the Age of Dinosaurs. Carbonaceous chondrites account for only about 3 to 5 percent of all meteorites sampled on Earth, and CO chondrites represent only a small fraction of that group. Carbonaceous chondrites of the Ornans class are definitely not like the typical meteors you find in museum collections, Dr. Claeys said. Being impacted by such a rare, distant projectile really underscores how unlucky the dinosaurs were. While the exact origin of the Chicxulub impactor remains uncertain, researchers believe it likely originated from the outer reaches of the solar system, potentially from the outer part of the asteroid belt near Jupiter or other distant, debris-rich regions. The impact site itself, the Chicxulub crater, remains buried beneath the Yucatán Peninsula in Mexico.

Read also: Meteorite That Hit US Home Reveals Alien Saltwater and Signs of Life.

Key Facts About the Impact

Feature	Details
Impactor Type	CO chondrite (Ornans-class carbonaceous chondrite)
Size	10–15 kilometers (approx. 6–9 miles) wide
Impact Speed	Approximately 64,000 km/h
Primary Extinction Factor	Fine atmospheric debris (rather than meteorite-borne sulfur)
Frequency	CO chondrites represent a very small fraction of the 5% of meteorites that are carbonaceous