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According to a new study by South West Research Institute (SwRI).
Known as the Chicxulub Impactor, this large object has an estimated width of 6 miles (9.6 kilometers) and has produced a crater in Mexico’s Yucatan Peninsula that stretches 90 miles (145 kilometers). After its sudden contact with Earth, the asteroid wiped out not only dinosaurs, but about 75 percent of animal species on the planet. It is widely believed that this created explosive force was responsible for the mass extinction that ended the Mesozoic era.
Related: Asteroid impact, not volcanic activity, killed dinosaurs, study finds
The researchers used computer models to analyze how asteroids are pulled from their orbit in different areas of the asteroid belt and attracted to the planets. Observations of 130,000 model asteroids, as well as data and behavior observed in other known impactors, have revealed that objects are 10 times more likely to reach Earth from the outer asteroid belt than previously thought. thought before.
Before crashing into Earth, the asteroid that caused the extinction revolved around the Sun with others, mainly Asteroid belt. This concentrated band lies between the planets Mars and Jupiter, with its contents usually held in place by forces of gravity. Before the publication of this study, scientists believed that very few land impactors had escaped from the outer half of the belt. But, SwRI researchers have found that “exit traps” can be created by thermal forces, which pull asteroids further out of orbit and toward Earth.
Objects found in these outermost parts of the asteroid belt include numerous carbonaceous chondritis impactors. These are dark, porous, carbonaceous rocks that can also be found on Earth. Before this research, other scientists tried to find out more about the object that doomed the dinosaurs. This included examinations of rocks 66 million years old. In doing so, geologists discovered that the asteroid Chicxulub had a composition similar to today’s carbonaceous chondrites.
In the solar system, many objects surrounding the Earth share a composition similar to this impactor, but they are all much smaller, with widths of around a mile. SwRI researchers used the Pleiades Supercomputer to analyze how the asteroids farthest from the sun would have evolved over hundreds of millions of years. One of the goals was to see where the biggest asteroids are today.
“To explain their absence, several earlier groups have simulated large ruptures of asteroids and comets in the inner solar system, examining the surges of impacts on Earth with the largest crater producing the Chicxulub crater,” the one of the study researchers, Dr William Bottke, said.
“While many of these models have interesting properties, none provided a satisfactory match with what we know about asteroids and comets. It seemed like we were still missing something important.
By examining wide timescales of the asteroid Chicxulub, scientists could predict that a 6-mile asteroid will likely make contact with Earth once every 250 million years. Their model showed that nearly 50 percent of these important impactors were of the same composition of carbonaceous chondrite.
Details of the new study were published in the November 2021 issue of the journal Icarus. One of its authors, Dr Simone Marchi, called the results “intriguing”.
“The team’s simulations can, for the first time, replicate the orbits of large asteroids about to approach Earth,” Marchi said. “Our explanation of the source of the Chicxulub impactor fits perfectly with what we already know about the evolution of asteroids.”
According to co-author Dr David Nesvorný, the new findings may tell us about other sizeable asteroids. “This work will help us better understand the nature of Chicxulub’s impact,” he said, “while also telling us where other large impactors of Earth’s deep past might come from.”
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