About 66 million years ago, an asteroid collided with Earth and caused a mass extinction known as the Cretaceous-Paleogene (K-Pg) extinction. This event — among other things, wiped out the dinosaurs — was one of the most important in geological history. After all, how often do giant asteroids from outer space hit our planet?
It turns out, probably more often than you think.In fact, if the theory proposed by a new study in the journal Science Advances is correct, it’s entirely possible second The asteroid collided with Earth at about the same time as the one we know. This could have huge implications for explaining the history of the evolution of life on Earth.
The known asteroid — the one that wiped out the dinosaurs — landed on what is now Mexico’s Yucatan Peninsula and left an impact site known as Chicxulub Crater. The speculative asteroid will land on what is now the Guinean plateau in West Africa and leave behind the so-called Nadir crater, which lies more than 1,300 feet below ocean sediments.
“At present, we cannot expressly say that this Yes An impact crater – we can’t do that until we recover physical samples of impact minerals (formed under extreme pressure) from the bottom of the crater by drilling,” Uisdean Nicholson, an assistant professor at Heriot-Watt University, told Salon via email. However , the evidence, Nicholson says, is convincing: “However, the geophysical features are so striking that they are difficult to explain in any other way,” he added.
So are these two meteors related? Could they be part of the same piece of matter that was split in half sometime before hitting Earth?
Nicholson’s team made a number of hypotheses about how Nadir crater might be related to Chicxulub crater. One possibility is that the “asteroid stream” may have been caused by earlier collisions in the asteroid belt, of which these two impacts were only a part. Alternatively, the second impact could be unrelated — “part of a background asteroid cratering process that has occurred throughout Earth’s history,” Nicholson said. Furthermore, given the uncertainty window Nicholson’s team admits of “about 1 million years,” the asteroid may not even have collided with Earth at the same time as the one that killed the dinosaurs.
“However, the geophysical features are so striking that they are difficult to explain in any other way.”
“Distinguishing these hypotheses will require us to obtain high-precision dates from the craters, which also can only be achieved by scientific drilling,” Nicholson concluded.
Nicholson was well aware that even if a second, smaller asteroid hit Earth at the same time as the famous one, “it would be dwarfed by Chicxulub.” The potential implications of Coulson’s findings pale in comparison.
“The discovery of terrestrial impact craters is always important because they are very rare in the geological record,” Mark Boslow, a professor of Earth and Planetary Sciences at the University of New Mexico, told CNN. (Boslow was not involved in the study. ) “There are fewer than 200 confirmed impact structures on Earth, and there are quite a few possible candidate structures that have yet to be definitively identified.”
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Perhaps that’s why — no matter what other scientists learned about Nadir Crater after being able to drill — Nicholson was able to recall a feeling of joy when he realized what he had found.
“You realize, just for a few minutes, that you’re the only one who knows that and understands the implications,” Nicholson told Salon. “But you also want to share it and test the idea. I was so excited about this discovery that I gave up most of my other duties and wrote a proposal to drill right away – submitted in a few months (as early as April 2021)), but then go back to modeling and writing papers as we mature.”
Nicholson added: “I should also point out that this was really an accident – I wasn’t looking for craters when I came across this. But the more data/information you see, the luckier you are The greater the chance.”