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Of: TT
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Perhaps it was a comet and not an asteroid that struck Earth 66 million years ago, which spelled the end of the dinosaurs.
Was it a decomposing comet that crashed into the earth and caused the extinction of the dinosaurs 66 million years ago? It’s not impossible, according to new research.
In the research community, the vast majority fully agree that it was a heavy impact that caused the dinosaurs to suddenly disappear. The impact was so severe that traces of the crater that formed, the Chicxulub crater, still exist, although deeply buried under the sea and the northern part of the Yucatan Peninsula in present-day Mexico.
However, researchers are not so sure what exactly struck and caused such devastation. However, the prevailing theory has been (and still is) that it was an asteroid, that is, a large piece of rock that originated in the so-called asteroid belt between the planets Mars and Jupiter.
Shattered
However, research student Amir Siraj and astronomer Avi Loeb from Harvard University in the US believe that it was a comet. Using statistical analysis and simulations of gravity, they have succeeded in showing that long-distance comets, from the Oort comet clouds at the edge of our solar system, can break away from the gravitational field of the giant planet Jupiter and strike Earth.
“The solar system works a bit like a pinball game in which Jupiter, which is the biggest planet of all, spews long-term incoming kilometers very close to the sun,” says Amir Siraj in a Harvard-Smithsonian press release. Center for Astrophysics.
If such a celestial body gets too close to the sun, the gravity of the star in the comet shakes and tears, so it can break apart. According to the new calculations, presented in Scientific Reports, the risk of such comet debris hitting the earth clearly increases when these debris return back to the comet Oort cloud.
Studies of the crater in the Yucatan Peninsula have also shown that the object that crashed there was a carbonaceous chondrite, something that most asteroids in the asteroid belt are not. A chondrite is a rocky meteorite that has changed by fusion and not by geological processes. Long-distance comets, on the other hand, are believed to consist of this carbonaceous substance.
True in time
Two other craters on Earth have also been formed by carbon-containing chondrites, one of which is the largest of all: the so-called Vredfort crater in South Africa, which is believed to have had an original radius of up to 300 km when it formed then ago. about two billion years. The other is the Zhamansin Crater in present-day Kazakhstan, which was formed around 900,000 years ago.
Together these three craters form a timeline that is in accordance with the probability with which a comet near the Sun can be thought to break apart and then hit Earth.
This, the researchers write, suggests that it was a comet, and not an asteroid, that spelled the end of the dinosaurs.
“We think that if an object (a comet) of this type breaks when it approaches the sun, it could lead to / … / an impact that is in good line with what killed the dinosaurs,” says Avi Loebi to the press release.
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