Extinction of the dinosaurs : dangerous trajectory for the asteroid fatal
PARIS — one of The worst scenarios possible : the famous asteroid, in part, responsible for the extinction of the dinosaurs followed the path of the most dangerous that is to engulf the planet in a cloud of gas and dust, reveals a study published last week.
It is known that the crater Chicxulub, off about 180 kilometres, was formed 66 million years by the collision of a meteorite of a dozen kilometers in diameter, in present-day Yucatan peninsula in Mexico, a shock wave is unprecedented, which led to the fall of three-quarters of the species then living on Earth, including the dinosaurs. Its trajectory, which until today remained mysterious, has been reconstructed by researchers using a 3D simulation. Of the works which are the subject of a publication in Nature Communications.
“The impact of Chicxulub was a very bad day for the dinosaurs; our work shows that it was worse than we thought, summarizes the main author of the study, Gareth Collins: the car has an axis from north-east to south-west, and struck the ground at an angle of inclination of 60 degrees. It was previously suggested that the asteroid came from the south-east, and that its impact was less profound. However, according to the numerical simulations, the center of the crater bends slightly towards the south-west.”
Sixty degrees, “it is one of the angles the more fatal, because it is in this angle that it is possible to eject more material, at a speed high enough to engulf the planet in a cloud of gas and dust develops there. Impacts the near-vertical (at a right angle of 90°, editor’s NOTE) create craters larger, but projecting debris more slowly and less far. The opposite impact is more oblique would not have generated so much debris.”
According to the techniques of reconstitution in 3D, supported by geological data of the site, the shock has dug a hole so deep (30 km depth, near 100-km wide) — that he was able to remain open. It is, therefore, collapsed in on itself, bouncing the rock from the bottom to the surface, ” says Dr. Collins. Billions of tons of sulphur were ejected, forming in the atmosphere of aerosols that blocked Sunlight, reducing the photosynthesis and cooled the climate, causing a nuclear winter and mass extinction of non-avian dinosaurs.