Study identifies rare asteroid that killed dinosaurs as carbonaceous chondrite CO

A new study published in Science Advances has pinpointed the exact type of asteroid that struck Earth 66 million years ago, triggering the mass extinction that wiped out the dinosaurs. The impactor, which created the 180-km-wide Chicxulub crater in Mexico's Yucatán Peninsula, was a rare carbonaceous chondrite of the CO (Ornans) subtype Source: infobae, a class that represents a tiny fraction of known meteorites Source: elconfidencial.

The chemical fingerprint

Researchers led by Georgy Makhatadze analyzed nickel isotope ratios in a global clay layer marking the K-Pg boundary Source: elconfidencial. By comparing these with known meteorite compositions, they identified the unique signature of a CO chondrite Source: infobae. This type of asteroid originates from the outer solar system, possibly beyond Jupiter Source: infobae.

• The study resolves a long-standing ambiguity: while scientists knew the impactor was a carbonaceous chondrite, they could not specify which subtype Source: infobae.
• Nickel isotopes served as a "fingerprint" because different meteorite groups have distinct nickel compositions Source: elconfidencial.

Implications

The finding suggests that the sulfur released by the impact, crucial for the global winter, may have come from this specific meteorite type Source: infobae. Understanding the exact composition helps refine models of the extinction event and the origin of such rare impactors Source: elconfidencial.