Recent analysis of nickel isotopes found in 66-million-year-old debris from the Chicxulub impact has led researchers to believe that the asteroid responsible for Earth’s last mass extinction likely originated from a rare category of protometeorite known as the Ornan type carbonaceous chondrite (CO chondrite).
The painting illustrates an asteroid impacting the shallow tropical waters of the sulfur-rich Yucatan Peninsula, now southeastern Mexico. This event, occurring around 65 million years ago, is believed to have triggered the extinction of the dinosaurs and many other Earth species. The painting features a pterodactyl, a giant flying reptile with a wingspan of up to 50 feet, gliding above the lush tropical clouds. Image credit: Donald E. Davis / NASA.
Carbonaceous chondrites constitute a mere 5% of all meteorites gathered on Earth, and CO chondrites represent a small subset of this collection.
These chondrites are some of the most ancient and pristine materials in our solar system.
“CO chondrites significantly differ from the typical meteorites curated in museums,” noted Professor Philip Crais from Free University and the University of British Columbia.
“CO chondrites contain much lower levels of volatile elements such as carbon, zinc, water, and particularly sulfur compared to any other meteorite types discovered on Earth.”
“While our hypothesis regarding the extinction event remains intact, it suggests that sulfur from the impact was less crucial than previously thought.”
“The primary factor for extinction was the fine microscopic debris ejected into the atmosphere.”
In their investigations, Professor Claeys and his team performed high-precision nickel isotope measurements on samples collected from thin clay layers deposited worldwide, resulting from the Chicxulub impact.
“This research is complex. The entire meteorite was vaporized during the impact, leaving only a small portion preserved in the planet’s KT clay layer,” explained Professor Craze.
Many questions about the origin of the Chicxulub impactor linger.
Potential sources for this asteroid include remote debris-rich areas of the outer solar system and regions of the asteroid belt near Jupiter.
“The Chicxulub impactor was approximately 10 to 15 kilometers in diameter,” said Professor Claes, “striking at an estimated speed of 64,000 km/h, creating a massive crater.”
“The impact site is buried beneath Mexico’s Yucatan Peninsula.”
“This rare event from such a distant projectile underscores the unfortunate fate of the dinosaurs.”
Read the study published in today’s edition of Scientific Progress.
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Georgy V. Mahatadze et al. 2026 The origins of the Cretaceous-Paleogene impactor revealed through nickel isotopes. Scientific Progress 12(29); doi: 10.1126/sciadv.aef4858
Source: www.sci.news
