(NewsNation) — Scientists have discovered new evidence that the rock that slammed into Earth and ended the age of dinosaurs belonged to a family of asteroids that originally formed beyond the orbit of Jupiter and rarely impact Earth.
An impact at modern-day Chicxulub, Mexico, 66 million years ago marks the boundary between the Cretaceous and Paleogene eras and coincides with the mass extinction of nonavian dinosaurs.
A new study in “Science,” a journal published by the American Association for the Advancement of Science, measures isotopes in the impact deposits and found that the Chicxulub impactor was an asteroid formed in the outer solar system. It was roughly 6 miles wide.
There has been a long-running dispute over whether the impactor was a comet or an asteroid, but new research reveals that its signature matches the makeup of a group of rocks called carbonaceous asteroids.
The research also took samples from five other impacts that occurred between 36 millionando 470 million years ago. These five other impact strictures have isotopic signatures that are more consistent with a different type of asteroid that forms closer to the sun called a siliceous asteroid.
