About 66 million years ago, an object 6 miles (9.6 km) wide slammed into the Earth, setting off a catastrophic chain of events that led to the non-bird’s demise. dinosaurs.
Now, scientists think they know where this thing came from.According to new research, the cause of the impact was a giant dark primordial asteroid from the outer reaches of the island Solar SystemThe main asteroid belt, located between Mars and Jupiter. This region is home to many dark asteroids – space rocks with a chemical composition that makes them appear darker (reflecting very little light) compared to other types of asteroids.
“I had a suspicion that the outer half of the asteroid belt – where the dark primeval part is located
Asteroids — may be an important source of Earth collisions — may be an important source of Earth collisions, said David Nesvorno, a researcher from the Southwest Research Institute in Colorado who led the new study. But I did not expect the results [would] Being too decisive,” he said, adding that this may not be true for the smallest of influencers.
Evidence for the object that ended the reign of non-avian dinosaurs has previously been found buried in Chicxulub Crater, a 90-mile-wide (145 km) circular scar in Mexico’s Yucatan Peninsula left by the object’s impact. Geochemical analysis of the crater suggested that the impacted body was part of a class of carbonaceous chondrites – a primitive group of meteorites which has a relatively high percentage of carbon They were probably made very early in the history of the solar system.
Based on this knowledge, scientists have previously tried to determine the origin of the probe, but many theories have collapsed over time. Researchers previously suggested that the probe came from a family of asteroids from the inner part of the main asteroid belt, but follow-up observations of those asteroids found they did not have the correct makeup. Another study, published in February in the journal Scientific Reports, indicated that the effect was caused by a long-lived comet, Live Science reported. But that research has since come under criticism, according to a research paper published in June in the journal astronomy and geophysics.
In the new study published in the November 2021 issue of the journal IcarusIn this study, the researchers developed a computer model to find out how often major belt asteroids escaped toward Earth and whether these escapees could have been responsible for crashing the dinosaurs.
Simulating over hundreds of millions of years, the model showed thermal forces and gravitational tugs from the planets periodically ejecting large asteroids out of the belt. On average, an asteroid more than 6 miles wide from the outer edge of the belt experiences a collision course with Earth once every 250 million years.And The researchers found. This calculation makes such an event five times more common than previously thought and is consistent with Chicxulub crater created only 66 million years ago, the only known crater believed to have resulted from such a large asteroid in the last 250 million years. Furthermore, the model considered the distribution of “dark” and “light” forcings in the asteroid belt and showed that half of the ejected asteroids were dark carbonaceous chondrites, which matches the type thought to have caused the Chicxulub crater.
“This is just an excellent paper,” said Jessica Novello, a NASA fellow in the Postdoctoral Administration Program at the Universities Space Research Consortium at Goddard Space Flight Center, who was not involved in the new research. “I think they make a good argument for why [the Chicxulub impactor] from this part of the solar system.”
In addition to potentially explaining the origin of Chicxulub crater, the findings also help scientists understand the origins of other asteroids that struck Earth in the past. Neither of the two other impact craters on Earth, the Vredefort crater in South Africa and the Sudbury Basin in Canada, knew the origins of the impact. The findings could also help scientists predict where large forcings may arise in the future.
“We found in the study that about 60% of the large terrestrial forcings come from the outer half of the asteroid belt … and most of the asteroids in that region are dark/primitive,” Nesvorno told Live Science. “So there is a 60% – 3 out of 5 – probability that the next one will come from the same area.”
Originally published on Live Science.