By analyzing nickel isotopes preserved within the 66-million-year-old particles left by the Chicxulub affect, researchers conclude that the asteroid accountable for Earth’s final mass extinction most probably belonged to an exceptionally uncommon class of primitive meteorites known as carbonaceous chondrites of the Ornans sort (CO chondrites).
This portray depicts an asteroid slamming into tropical, shallow seas of the sulfur-rich Yucatan Peninsula in what’s immediately southeast Mexico. The aftermath of this immense asteroid collision, which occurred roughly 65 million years in the past, is believed to have triggered the extinction of the dinosaurs and plenty of different species on Earth. Proven on this portray are pterodactyls, flying reptiles with wingspans of as much as 50 toes, gliding above low tropical clouds. Picture credit score: Donald E. Davis / NASA.
Carbonaceous chondrites make up solely 5% of meteorites to date sampled on Earth. CO chondrites make up a tiny fraction of that group.
They’re a number of the most primitive and untouched supplies within the Photo voltaic System.
“CO chondrites are positively not like the everyday meteors you discover in museum collections,” stated Professor Philippe Claeys, a researcher at Vrije Universiteit and the College of British Columbia.
“A CO comprises a lot much less risky parts — like carbon, zinc, water and notably sulfur — than different lessons of meteorites we’ve found to date on Earth.”
“It doesn’t alter our idea of what triggered the extinction occasion, nevertheless it makes it much less possible that sulfur contained within the impactor was the smoking gun.”
“The nice particles thrown into the ambiance would have the first issue.”
Of their examine, Professor Claeys and colleagues carried out high-precision nickel isotope measurements of samples collected over years from a skinny layer of clay created throughout the globe by the Chicxulub affect.
“That is difficult work. Solely a minute fraction of the projectile is preserved within the planet’s KT clay layer as a result of the whole meteorite vaporized upon affect,” Professor Claeys stated.
Many questions stay in regards to the origins of the Chicxulub impactor.
Potential sources embrace distant, debris-rich areas of the outer Photo voltaic System and even the outer space of the asteroid belt close to Jupiter.
“The Chicxulub impactor was roughly 10 to fifteen km,” Professor Claeys stated.
“It hit at an estimated 64,000 km/h forming the huge crater.”
“The affect zone is buried beneath the Yucatán Peninsula in Mexico.”
“Being impacted by such a uncommon, distant projectile actually underscores how unfortunate the dinosaurs have been.”
The examine was revealed immediately within the journal Science Advances.
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Georgy V. Makhatadze et al. 2026 The origin of Cretaceous-Palaeogene impactor revealed by nickel isotopes. Science Advances 12 (29); doi: 10.1126/sciadv.aef4858
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