For decades, the dinosaur extinction theory prevailed that an asteroid from the belt between Mars and Jupiter crashed into the planet, causing a cataclysmic devastation that wiped out most life on the planet.
But new research from Harvard University theorizes that the object challenged by Armageddon originated far beyond what was originally believed.
According to this new theory, the destruction did not come from a relatively nearby asteroid, but from a kind of long-distance comet that came from the edge of the solar system, into an area known as the Oort cloud.
Gravity from Jupiter pulled the comet into the solar system. At the time, according to Amir Siraj, a Harvard student who co-authored an article with Professor Avi Loeb, “Jupiter acts like a kind of pinball machine.”
The theory says: Jupiter’s gravity ejected this incoming comet into orbit, bringing it closer to the sun, whose tidal forces caused the comet to collapse. Some of the comet’s fragments entered Earth’s orbit, and one of them, 50 miles, about the size of Boston, hit the coast of Mexico.
The theory also claims that larger impact craters, such as the so-called Chicxulub crater caused by that impact, are more likely to be made of “carbon chondrite” – a primitive material dating back to the early solar system. Only about 10% of the asteroids in the belt are made of carbon chondrite, the researchers said.
“Our hypothesis explains the composition of the largest confirmed impact crater in Earth’s history, as well as the largest in the last million years,” the authors wrote.
Although the new theory of Siraj and Loeb raised eyebrows among the scientific community, it has also been criticized. “I believe their work has several fundamental problems,” Bill Bottke, a planetary scientist at the Southwest Research Institute in Boulder, Colorado, told the New York Times.
For example, Bottke says, the proposed model overestimates how often the sun separates for a long time. “There’s still room to blink if someone really wants it to be a comet,” he said. “I just think it’s really to bring out that case.”