Scientists Identify 10- to 15-Km Dinosaur-Killing Asteroid as CO Chondrite via Nickel Isotopes
Updated
Updated · ZME Science · Jul 17
Scientists Identify 10- to 15-Km Dinosaur-Killing Asteroid as CO Chondrite via Nickel Isotopes
3 articles · Updated · ZME Science · Jul 17
Summary
Nickel isotopes in 66-million-year-old boundary clay from five European sites point to the Chicxulub impactor as a CO chondrite, with a rarer CT-type meteorite a less likely match.
About 5% impact debris in the best samples from Spain and Denmark let researchers compare purified nickel against 11 carbonaceous meteorites, ruling out several leading asteroid candidates.
The finding narrows a 2024 result that had placed the asteroid broadly in the carbonaceous family formed beyond Jupiter, but it still cannot trace the object's exact route to Earth.
CO chondrites carry roughly half as much sulfur as the CM-type impactors used in many earlier models, suggesting the asteroid itself added fewer climate-altering gases than assumed.
That does not soften the extinction scenario: scientists say sulfur-rich Yucatán rocks and long-lived silicate dust likely drove the years of darkness that wiped out about 75% of species.
Scientists just confirmed the dinosaur-killer's identity. Why does it mean the impact's true lethal weapon was microscopic dust?
The dinosaur-killer was a rare asteroid type. How does knowing its composition now help us stop the next one?
The Chicxulub impact created a huge habitat for life. Could the event that destroyed the dinosaurs have also created new life?
Solving the K-Pg Mystery: CO Chondrite Meteorite Confirmed as Dinosaur-Killing Asteroid
Overview
Recent research has finally solved the mystery of what caused the Cretaceous-Paleogene (K-Pg) extinction event that wiped out about 75% of Earth's species, including the dinosaurs. Scientists identified the impactor as a rare CO chondrite meteorite by analyzing the unique ratios of Platinum Group Elements (PGEs) found at the K-Pg boundary. These ratios matched an asteroid impact rather than volcanic activity, ending decades of debate. This breakthrough not only clarifies the extraterrestrial origin of the disaster but also deepens our understanding of how such cosmic events can dramatically reshape life on Earth.