The dinosaur-killing meteorite was one of the solar system's rarest rocks
Researchers led by the University of Paris have traced the Chicxulub impactor to a carbonaceous chondrite of the Ornans type, a class making up only three to five percent of all meteorites. Nickel isotope signatures in impact-age marine clay from sites worldwide point to an origin in the cold outer solar system, likely beyond Jupiter.
The rock that ended the dinosaurs 66 million years ago has been identified as an Ornans-type carbonaceous chondrite, among the rarest and most primitive material in the solar system. A University of Paris-led team measured nickel isotope signatures in marine clay laid down at the moment of impact, sampled around the world, and traced the origin to the cold outer reaches near or beyond Jupiter. A second finding reframes the extinction: this class of meteorite carries very little sulfur, carbon or water, so the years of darkness and cooling long blamed on the impactor's sulfur likely came mostly from dust ground out of Earth's own pulverized crust. Sources: ScienceDaily, phys.org, Discover Magazine, published in Science Advances.