It is possible that the asteroid that wiped out the dinosaurs came from the outer half of the main asteroid belt, A region that is thought to produce quite a few of the massive elements that wander around our solar system.
researchers from Southwest Research Institute (SwRI) showed that processes that send large asteroids to Earth from that region It spoke at least 10 times more than previously thought And that the composition of these bodies matches what we know about those that affected and killed the dinosaurs.
The team, which published the results of their studies in the journal Icarus, combined computer models of asteroid evolution with known asteroid observations to investigate the frequency of so-called Chicxulub events.. More than 66 million years ago, an object estimated to be 9 kilometers in diameter collided in what is now Mexico’s Yucatan Peninsula and formed the Chicxulub crater, which is more than 130 kilometers in diameter.
This massive explosion caused a mass extinction that ended the era of the dinosaurs. Over the past few decades, much has been learned about the Chicxulub event, but each progress has raised new questions. Two important questions remain unanswered:What is the source of the collider? and “How many times have these impact events occurred on Earth in the past?”, co-author William Bottke explains in a statement.
To explore the Chicxulub effect, geologists previously examined 66 million-year-old rock samples found on Earth and within the drill core. The results indicate that the collider was similar to the carbonaceous chondrite class of meteorites, some of the most pristine materials in the Solar System. Interestingly, while carbonaceous chondrites are common among many objects approaching Earth, none today is close to the size needed to produce a Chicxulub effect with any reasonable probability.
“We decided to find where the Chicxulub asteroid brothers might be hidingsaid David Nesvorny, lead author of a paper describing the research. “To explain its absence, several previous groups have simulated large rips of asteroids and comets in the inner solar system, observing waves of collisions on Earth, the largest of which produces the Chicxulub crater,” Bottke added.
“While many of these models have interesting properties, none have provided a satisfactory match with what we know about asteroids and comets. It looks like we’re still missing something important.” To solve this problem, the team used computer models that track how objects escape from the main asteroid belt, a region of small objects located between the orbits of Mars and Jupiter. Over eons, thermal forces allow these objects to drift into ‘holes’. Escape” dynamics where gravity “kicks” off planets can propel them into orbits close to Earth.
Using NASA’s Pleaides supercomputer, the team followed 130,000 models of asteroids that evolved in this slow and steady way over hundreds of millions of years. Particular attention has been paid to asteroids located in the outer half of the asteroid belt, the part farthest from the sun. To their surprise, they found that asteroids 9 km wide from this region hit Earth at least 10 times more than they did. It was previously calculated.
“This result is interesting not only because The outer half of the asteroid belt is home to a large number of carbonaceous traces of chondrites, But also because the team’s simulations can, for the first time, reproduce the orbits of large asteroids that are about to approach Earth,” explained co-author Simon Marchi.
“Our explanation of the Chicxulub Collider’s source fits perfectly with what we already know about how asteroids evolve.Overall, the team found that asteroids 9 km wide strike Earth once every 250 million years on average, a timescale that gives reasonable odds that the Chicxulub crater occurred 66 million years ago. In addition, nearly half was The effects are carbonaceous chondrites, which is a good match with what is known about the Chicxulub Collider.