A crater of monstrous dimensions located in Mexico marks, scientists suppose, the point at which the world of dinosaurs came to an end, as well as about three quarters of life on Earth. Among the countless mysteries surrounding the Chicxulub Crater event, the origin of the asteroid, whose impact on the surface of our planet would have started the catastrophe in question, scientists have long wondered. However, two Harvard researchers argue that they have come up with a promising answer to that question, published in Scientific Reports.
Avi Loeb and Amir Siraj, using statistical analysis and simulations, found that a significant fraction of a comet in the Oort cloud, a large concentration of objects believed to exist at the edge of the Solar System, may have been diverted from its course by the field gravity of Jupiter and directed towards the Sun. The confusion, in turn, would have fragmented the rock. In fact, bits and pieces of the type hit us (at intervals that can go from 250 million years to 730 million or more).
“Jupiter acts, basically, as a kind of arcade machine, ‘kicking’ these celestial bodies”, exemplified Siraj. “In the case of the shallow comets, few melt in relation to the total mass they present, except that the strong gravitational attraction exerted by the star causes the so-called tidal interruption, in which the objects are divided into smaller parts, separated between the region closest to the star and the other, more distant “, he added.
Also according to Siraj’s explanation, as the most distant parts move away from the Sun, there is a statistical chance that these smaller comets collide with Earth – and this may have happened more than 60 million years ago, a period in which we said goodbye to “lizards” without even knowing them.
Approximately 20% of comets from the aforementioned region become shallow, that is, they pass very close to the Sun, becoming candidates for collision generators. Then, those responsible for the study made some adjustments in calculations, increasing the chances of impact to 1 in 10, trying to understand what are the possibilities that this would bring.
Although the technique seems like a ruse to guide the intended results, this information is in line with surveys by other astronomers. Furthermore, according to both, the new rate is consistent with the age of the visitor to Chicxulub, which would provide a satisfactory explanation for the enigma and also for the composition of many of these space outsiders – which would be primitive, contrary to what was expected of conventional asteroids, from the main belt, between the orbit of Jupiter and Mars.
Knowing the age of the specimens helps to determine their origin because evidence found in the Chicxulub crater and similar ones suggests that only about a tenth of all asteroids in the main belt are formed by carbonaceous chondrite, unlike those in the Oort cloud, with a much more expressive population.
An object that hit Earth about 2 billion ago and left the Vredefort crater in South Africa, which is the largest confirmed crater in Earth’s history, contained the suggested properties, as well as the one that left its mark in Zhamanshin, Kazakhstan (largest crater confirmed in the last million years).
“Our article provides a basis for explaining the event,” said Loeb. “We are suggesting that, in fact, if you break an object when it approaches the sun, it can generate the appropriate consequence rate and detail the type of impact that killed the dinosaurs,” he said.