Rare CO Chondrite Meteorite Identified as Dinosaur Killer

A new study published in Science Advances has identified the meteorite that struck Earth 66 million years ago, wiping out the dinosaurs and 75% of species, as a rare CO chondrite—a type of carbonaceous chondrite that is among the most primitive and scarce in the solar system. Source: ABC, Infobae

How they identified it

Researchers from the University of British Columbia, the University of Paris, and other institutions analyzed the isotopic signature of nickel in the global clay layer left by the impact. The meteorite completely vaporized, but the nickel isotopes acted as a "fingerprint," revealing its origin as a CO (Ornans) chondrite. Source: ABC Only about 5% of meteorites are carbonaceous chondrites, and CO chondrites are an even smaller fraction. Source: Infobae

Key facts and implications

• The impactor was 10–15 km wide and hit at 64,000 km/h, forming the 200-km Chicxulub crater in Mexico. Source: ABC, Infobae
• CO chondrites contain fewer volatiles (e.g., sulfur, water, carbon) than other meteorites. This does not change the extinction theory but suggests that sulfur from the impactor was less critical than the debris ejected into the atmosphere. Source: Infobae
• “The fact that they were hit by such a rare and distant projectile really highlights how unlucky the dinosaurs were,” said Philippe Claeys, co-author of the study. Source: Infobae (EFE)

The findings pinpoint the impactor's composition more precisely than before, though its exact origin—possibly the outer asteroid belt or the distant solar system—remains uncertain. Source: Infobae (EFE)