It was one shot in 66 million years.
The 6.2-mile-wide asteroid that crashed on the Yucatan peninsula at the end of the Cretaceous period did so at the “deadliest possible angle,” according to a new study. published in Nature Communications on Tuesday.
If it had come from any other direction, the dinosaurs could still be present today.
The doomed asteroid, which landed at a site in Mexico now known as the Chicxulub crater, is considered by many scientists to be the agent behind the disappearance of the dinosaurs and 75% of all life on Earth at the time.
The new report, compiled by engineers and geologists from Imperial College London, the University of Freiburg, and the University of Texas at Austin, is the first to reveal the final stages of Chicxulub crater formation. The researchers used three-dimensional simulations of the exact shape and structure of the 124-mile-wide hole to determine that the asteroid came from the northeast, at a lethal angle of about 60 degrees to the ground.
“For dinosaurs, the worst case scenario is exactly what happened,” said lead researcher Gareth Collins. in a press release. “The asteroid attack unleashed an incredible amount of climate-changing gases in the atmosphere, triggering a chain of events that led to the extinction of the dinosaurs. This was probably made worse by the fact that he hit one of the deadliest possible angles. “
They explain that the impact itself was no more devastating to the planet. Rather, scientists say it was a snowball of devastating weather effects that followed the event, which released billions of tons of vaporized rock, sulfur, carbon dioxide, and water vapor into the air, and enveloped the globe. The result was a breathless atmosphere and a darkened sun that lasted approximately 18 months, during which time photosynthesized plants and animals drowned, and the planet descended in a swift winter.
“We know this was one of the worst-case scenarios for impact fatality, because it placed more dangerous debris in the upper atmosphere and scattered it everywhere, leading to a nuclear winter,” Collins said.