What killed the dinosaurs and where did they come from?

It changed history forever when it crashed on Earth about 66 million years ago.

The Chicxulub attack, as is well known, left behind a crater off the coast of Mexico that stretches over 93 miles and runs 12 miles deep. Its devastating impact has brought the government of the dinosaurs to a sudden and disastrous end by bringing about their sudden mass extinction, along with the end of nearly three-quarters of the plant and animal species that live on earth.

The lasting mystery: Where did the asteroid or comet originate, and how did it hit the earth? Now some researchers from the Center for Astrophysics | Harvard & Smithsonian believe they have the answer.

In a study published today in Nature’s Scientific reports, Harvard University’s undergraduate astrophysics student Amir Siraj and astronomer Avi Loeb have put forward a new theory that could explain the origin and journey of this catastrophic object.

Using statistical analysis and gravitational simulations, Siraj and Loeb calculate that a significant fraction of long-term comets from the Oort cloud, an icy strip of junk on the edge of the solar system, can be knocked off course during Jupiter’s gravitational field. orbit.

“The solar system serves as a kind of pinball machine,” explains Siraj, who holds a bachelor’s and master’s degree in astrophysics, in addition to a master’s degree in piano performance from the New England Conservatory of Music. “Jupiter, the most massive planet, kicks incoming long-term comets into orbits that bring them very close to the sun.”

During sin, comets, nicknamed ‘sungrazers’, can experience powerful tidal forces that break pieces of rock apart and eventually produce comet grenades.

“In a solar moving event, the part of the comet closer to the sun feels a stronger force of attraction than the part that is further away, which results in a tidal force over the object,” says Siraj. ‘You can get the time-disrupting event, in which a large comet breaks up into much smaller pieces. And on the journey back to the Oort cloud, there is a greater probability that one of these fragments will hit the earth. ‘

The new calculations from the theory of Siraj and Loeb increase the chances that long-comets will have an impact on Earth by a factor of about 10, and show that about 20 percent of long-term comets become a songwriter.

The pair say their new impact rate is in line with the age of Chicxulub, which provides a satisfactory explanation for its origins and other impacters like it.

“Our paper provides a basis for explaining the occurrence of this event,” says Loeb. “We suggest that, if you break up an object while it is approaching the sun, it could give rise to the appropriate rate and also the kind of impact that the dinosaurs killed.”

Evidence found at the Chicxulub crater indicates that the rock consisted of carbonaceous chondrite. The hypothesis of Siraj and Loeb may also explain this unusual composition.

A popular theory about the origin of Chicxulub claims that the impact comes from the main belt, which is an asteroid population between the orbit of Jupiter and Mars. Carbonaceous chondrites, however, are rare among asteroids in the main belt, but are possibly widespread among long comets, providing additional support to the hypothetical impact hypothesis.

Other similar craters display the same composition. These include an object that struck about 2 billion years ago and left the Vredefort crater in South Africa, which is the largest confirmed crater in Earth’s history, and the impact that the Zhamanshin crater left in Kazakhstan , which is the largest confirmed crater within the last million years. The researchers believe that the timing of this impact supports their calculations on the expected rate of comic disrupted comets of Chicxulub size.

Siraj and Loeb say their hypothesis can be tested by further studying these craters, others like them, and even on the lunar surface to determine the composition of the impactors. Space missions to sting comets can also help.

Apart from the composition of comets, the new Vera Rubin Observatory in Chile can observe the tidal disturbance of long-term comets after it takes effect next year.

“We need to see smaller fragments coming to earth from the Oort cloud on a regular basis,” says Loeb. “I hope we can test the theory by having more data on long-term comets, getting better statistics and maybe seeing evidence for some fragments.”

Loeb says that not only is it important to solve a mystery of the Earth’s history, but that it could play an important role if such an event were to threaten the planet.

“It must have been an amazing sight, but we do not want to see it again,” he said.