Home / Science / Dinosaur-killing asteroid hit in the deadliest corner

Dinosaur-killing asteroid hit in the deadliest corner

Artist's impression of the asteroid that hit Earth 66 million years ago.

Artist’s impression of the asteroid that struck Earth 66 million years ago.
illustration:: Chase Stone

When the asteroid that wiped out the dinosaurs hit Earth, it hit at an angle that maximized its potential for destruction, according to new computer simulations of the catastrophic event.

The results, published in new paper Show on Tuesday in Nature Communications that the dino-killing asteroid came from the northeast at an angle between 45 and 60 degrees. In a related press release, Gareth Collins, geophysicist at Imperial College London and lead researcher on the project, describes described It was a “worst case scenario” when it impacted 66 million years ago.

“The asteroid strike released an incredible amount of climate-changing gases into the atmosphere and triggered a series of events that led to the extinction of the dinosaurs,” he said. “This was probably made worse by the fact that it hit one of the deadliest angles possible.”

The impact released abundant carbon dioxide, water vapor and sulfur into the atmosphere, resulting in an impact winter that wiped out 75 percent of all life on Earth, including all non-bird dinosaurs. The buried remnant of this event, the Chicxulub impact crater, is located on the Mexican Yucatan peninsula and is around 240 kilometers wide.

Scientists have tried to determine the precise direction of incidence and the angle of impact of the asteroid. This knowledge gap prompted Collins and his colleagues to perform detailed computer simulations of the catastrophic event from the moment of impact to the formation of the Chicxulub crater.

Her models considered four different scenarios in which the asteroid entered at 90, 60, 45 and 30 degrees to the horizon. The simulations assumed a 17 km wide asteroid, a density of 2,630 kg per cubic meter and a speed of 12 km per second.

The authors also referred to existing and new geophysical evidence for the Chicxulub crater, which is buried about 1 km under sedimentary rock. They also analyzed rocks that were recently drilled from the crater.

Simulations provided the best agreement between 45 and 60 degrees, with the asteroid coming from the northeast. This turned out to be a devastating corner for life on earth. The asteroid ejected an almost symmetrical portion of the material from the impact point and released more climate-related gases into the earth’s atmosphere compared to other scenarios considered in the simulations.

“We know that this was one of the worst scenarios for the lethal impact on impact, as it would cause more dangerous deposits to get into the upper atmosphere and be scattered all over the place – exactly what led to it [an impact] Winter, said Collins.

In particular, the melting rocks released large amounts of carbon dioxide, water vapor and sulfur, the latter being particularly problematic for life. Sulfur is a so-called aerosol that blocks the sun’s rays. After the impact, it inhibited photosynthesis between plants, which in turn caused food webs around the world to collapse. Carbon dioxide and water vapor are greenhouse gases that have also contributed to the warming of the planet.

Clay Tabor, a paleoclimatologist from the University of Connecticut, said the new study provides insights into why Chicxulub’s effects on Earth were so devastating.

“Higher carbon dioxide emissions from the impact can help explain the post-impact warming that has been identified in several temperature reconstructions,” Tabor, who is not involved in the new research, told Gizmodo. “An important next step is to better understand how the ejection disrupted the earth system and led to extinction.”

In addition to the asteroid strike, other factors led to the death of the dinosaur. soot from the following forest fires has also been implicated in mass extinction by further blocking sunlight. volcanic eruptions could also have played a role

Steve Brusatte, paleontologist at the University of Edinburgh, said the new study shows how random the asteroid impact really was.

“Even if things had gone a little differently and the asteroid had been a near failure or if it had hit Earth at a slightly different angle, the dinosaurs might have survived,” said Brusatte, who is not involved in the new study said Gizmodo. “And that means they are probably still here, much more than just birds, and that probably means we have no place. Mammals would still be small and in the shade and we would never have had the opportunity to develop. “

As to additionally insult the injury, research from 2017 showed that the asteroid hit a pretty unfortunate spot. The Yucatan Peninsula is one of the few areas on earth where the precise proportions of chemical compounds, namely hydrocarbons, release so much carbon dioxide and sulfur into the atmosphere. A perfect storm.

Source link