科学家确认：杀死恐龙的是一颗极其罕见的陨石——来自太阳系遥远区域的CO碳质球粒陨石
Researchers from the University of British Columbia (UBC), Paris, Brussels, and Vienna reached that conclusion by analyzing nickel isotopes preserved in material left behind by the Cretaceous-Paleogene impact. Their findings were published in Science Advances.
A Rare Meteorite Behind the Dinosaur Extinction
“Carbonaceous chondrites of the Ornans class are definitely not like the typical meteors you find in museum collections,” says Dr. Philippe Claeys, who worked on the study as a visiting professor at UBC.
“A CO contains much less volatile elements — like carbon, zinc, water and particularly sulfur — than other classes of meteorites we’ve discovered so far on Earth. It doesn’t alter our theory of what caused the extinction event — but it makes it less likely that sulfur contained in the impactor was the smoking gun. The fine debris thrown into the atmosphere would have the primary factor.”
That difference in composition could help scientists better understand how the impact caused such widespread destruction. Because CO chondrites contain relatively little sulfur, the new evidence suggests that sulfur from the meteorite itself may not have been the main driver of the catastrophe. Instead, enormous quantities of fine debris blasted into the atmosphere may have played the dominant role.
Nickel Isotopes Reveal the Impactor’s Identity
Scientists from the Institut de Physique du Globe and Université de Paris carried out highly precise nickel isotope measurements on samples gathered over many years. The material came from a thin layer of clay deposited around the world after the impact.
原文来源：https://www.sciencedaily.com/releases/2026/07/260718010142.htm | 科学小舟·新科学 转载