A large asteroid collided with planet on the Yucatan Peninsula some 66 million years ago, as displayed in this illustration. (Image credit: mark GARLICK/SCIENCE photograph LIBRARY via Getty Images)

About 66 million year ago, an approximated 6-mile-wide (9.6 kilometers) object slammed right into Earth, triggering a cataclysmicseries of occasions that brought about the demise of non-avian dinosaurs.

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Now, scientists think they recognize where the object come from.

According to new research, the impact was brought about by a giant dark primitive asteroid native the external reaches that the solar system"s main asteroidbelt, situated in between Mars and also Jupiter. This region is home to many dark asteroids — space rocks through a chemical makeup that renders them appear darker (reflecting very small light) contrasted with other varieties of asteroids.


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"I had a hesitation that the outer half of the asteroid belt — that"s whereby the dark primitiveasteroids space — might be critical source that terrestrial impactors," stated David Nesvorný, a researcher native the Southwest research Institute in Colorado, that led the new study. "But i did not expect that the results it is in so definitive," adding that this can not it is in true for smaller impactors.


Clues about the thing that ended the power of non-avian dinosaurs have actually previously to be found hidden in the Chicxulub crater, a 90-mile-wide (145 km) one scar in Mexico"s Yucatan Peninsula left through the object"s collision. Geochemical analysis of the crater has said that the impacting thing was part of a class of carbonaceous chondrites — a primitive team of meteorites that have a relatively high ratio of carbon and also were most likely made an extremely early top top in the solar system"s history.


Based top top this knowledge, scientists have actually previously tried to pinpoint the impactor"s origin, but many theories have crumbled over time. Researchers have actually previously argued the impactor came from a family members of asteroids indigenous the inner component of the key asteroid belt, yet follow-up observations of those asteroids discovered they didn"t have the ideal composition. An additional study, this one published in February in the journal scientific Reports, suggested the affect was brought about by a long-period comet, Live scientific research reported. But that study has since come under criticism, according to a June file published in the newspaper Astronomy & Geophysics.

In the new study, released in the November 2021 issue of the newspaper Icarus, researchers developed a computer model to see how often main belt asteroids escape towards Earth and also if such escapees can be responsible because that the dinosaur-ending crash.

Simulating over thousands of millions the years, the model showed heat forces and also gravitational tugs from planets regular slingshotting huge asteroids out of the belt. ~ above average, an asteroid much more than 6 miles vast from the external edge that the belt was flung right into a collision food with earth once every 250 million years, the researchers found. This calculation makes such an occasion five times an ext common than formerly thought and consistent through the Chicxulub crater developed just 66 million years ago, i beg your pardon is the only known influence crater believed to have actually been created by such a large asteroid in the last 250 million years. Furthermore, the version looked in ~ the circulation of "dark" and "light" impactors in the asteroid belt and also showed fifty percent of the expelled asteroids were the dark carbonaceous chondrites, i m sorry matches the form thought to have actually caused Chicxulub crater.


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"This is just wonderful paper," said Jessica Noviello, NASA other in the postdoctoral monitoring program in ~ the Universities room Research association at Goddard room Flight Center, who was not associated with the brand-new research. "I think they do a great argument because that why could have come indigenous that component of the solar system."

In enhancement to maybe explaining the origin of the Chicxulub crater impactor, the findings also assist scientists know the origins of various other asteroids that have actually struck earth further in the past. Neither of the other two largest impact craters ~ above Earth, the Vredefort crater in south Africa and the Sudbury basin in Canada, have actually known impactor origins. The results might also assist scientists predict whereby future large impactors can originate..

"We discover in the study that some 60% of huge terrestrial impactors come native the outer half of the asteroid belt ... And also most asteroids in that zone space dark/primitive," Nesvorný said Live Science. "So over there is a 60% — 3 in 5 — probability that the following one will certainly come from the very same region."

Originally released on Live Science.

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Mara Johnson-Groh is a contributing writer because that Live Science. She writes about everything under the sun, and also even things beyond it, for a variety of publications consisting of Discover, science News, scientific American, Eos and more. Mara has actually a bachelor"s level in physics and also Scandinavian studies from Gustavus Adolphus college in Minnesota and a master"s level in astronomy indigenous the university of Victoria in Canada.