They explain where the meteorite that killed the dinosaurs came from

DublinThe Chicxulub meteorite impact forever changed Earth’s history 66 million years ago, causing the extinction of 75% of its species, including dinosaurs, but where did it come from and how did it get to our planet?

The journal Nature will publish a new theory on Monday developed by experts at Harvard University (US) that could shed light on a catastrophic event that still raises many doubts.

In addition to its devastating consequences, the impact of that “asteroid or comet,” the authors say, is known to leave a crater in the Gulf of Mexico more than 180 kilometers in diameter and nearly 20 kilometers deep.

To complete the puzzle, experts Avi Loeb and Amir Siraj argue, through statistical analysis and gravity simulations, that a significant portion of a type of comet originated in the Oort Cloud – a sphere of space debris that forms the edge of the Solar System. its orbit because of Jupiter’s gravitational field.

That force moved the comet in the direction of the sun, which in turn broke it into more fragments, a phenomenon that increases the number of bodies that, like Chicxulub, can enter orbit and once between 250 and 750 million years. can fall to Earth, approx.

“Jupiter actually acts like a ‘pinball machine’. Jupiter propels these incoming comets (also called long periods) into orbits that bring them very close to the sun, ”Siraj explained in a statement.

Since these long-period comets take up to 200 years to orbit the sun, experts have called them “solar ruminants.”

“When we talk about these solar ruminants,” continues Siraj, “the main thing is not so much that they melt, which affects the total mass relatively little, but the fact that because they are so close to the sun, the closest part is. of the comet is subjected to a greater pull of gravity than the one further away, generating a tidal force ”.

This event, he emphasizes, causes the great comet to disintegrate into smaller fragments and “there is a statistical likelihood that they will affect Earth when it leaves orbit.”

Loeb and Siraj’s calculations suggest that the probability of long-period comets hitting our planet is “about 10-fold,” while indicating that up to 20% of these “become solar ruminants, according to studies by other astronomers. “.

They also argue that the “new impact ratio” is consistent with the age of Chicxulub crater, which provides a satisfactory explanation for its origin and that of other similar “impact comets.”

“What we’re putting forward is that if you break an object when it’s close to the sun, it can lead to a series of appropriate events and also the kind of impact that wiped out the dinosaurs,” Loeb emphasizes.