A 6-mile (9.6 km) wide object crashed into Earth about 66 million years ago. This caused a series of cataclysmic events that led to the death of all non-avian dinosaurs.Scientists now believe they know the origin of that object.New research has revealed that the impact was caused a large, primitive, dark asteroid from the Solar System's outer reaches. It is located between Mars and Jupiter.This area is home to dark asteroids space rocks that have a chemical makeup which makes them appear darker (reflecting very few light).Related: 5 Mass Extinction Events That Shaped Earth's HistoryDavid Nesvorn, an American researcher at the Southwest Research Institute, Colorado, led the study."But I didn't expect that the results would be so definitive," he said, adding that this may not be true for smaller impacts.Clues to the object that ended non-avian dinosaurs' reign were previously discovered in Chicxulub, a circular scar of 90 miles (145 km) in Mexico's Yucatan Peninsula. It was created by the object's collision.Geochemical analysis of this crater suggests that it was part of a group of carbonaceous, chondrites. These are primitive meteorites with a high carbon ratio and were probably made early in the Solar System's history.This knowledge has allowed scientists to attempt to identify the origin of the impactor, but many theories have failed over time.Although researchers had previously believed that the impactor was a result of a family of asteroids in the inner part of the main Asteroid Belt, follow-up observations revealed that they did not have the correct composition.Live Science reported that another study was published in February in Scientific Reports. It suggested that the impact was due to a long-periodcomet. However, the research has been criticized in a June paper in Astronomy & Geophysics.Researchers created a computer model that allowed them to determine how often main belt asteroids escape towards Earth. This was published in the November 2021 issue Icarus.The model was simulated over hundreds of millions years and showed that large asteroids were periodically being slung out of the belt by gravitational tugs and thermal forces. Researchers found that an average of six miles from the belt's outer edge, an asteroid was launched into collision with Earth once in 250 million years.This calculate makes it five times more likely that previously thought. It is consistent with Chicxulub's crater, created just 66 millions years ago. It is the only known impact site thought to have been formed by an asteroid this large in the last 250,000,000 years.The model also looked at the distributions of "dark", and "light" impactors within the asteroid belt. It showed that half of expelled asteroids were dark carbonaceous, which is consistent with the type believed to have caused Chicxulub.Jessica Noviello (NASA fellow in the postdoctoral program at Goddard Space Flight Center's Universities Space Research Association) said, "This is an excellent paper.""I believe they make a strong argument for why [the Chicxulub Impactor] could have originated from that part the Solar System."Scientists have been able to determine the origin of Chicxulub's crater impactor. They also now know how other asteroids may have reached Earth in the past.The impactor origins of the two other largest impact craters on Earth (the Vredefort crater, South Africa, and the Sudbury Basin, Canada) are not known. These results may also be used to help scientists predict the origins of large future impactors.Nesvorn stated that the study revealed that 60 percent of large-sized terrestrial impactors are from the outer half the asteroid belt. "Most asteroids in this zone are dark/primitive," Nesvorn said to Live Science."So, there's a 60% chance that the next one will be from the same area."Similar contentWipe Out: History's 7 Most Mysterious ExtinctionsPhotos: A fresh look at T. Rex and its relativesDino graveyard: Photos from Dinosaur National MonumentLive Science originally published this article. You can read the original article here.
