How the crater of the asteroid Dino-Killer was born 'kleinezeitung.at

In the Gulf of Mexico, an asteroid hit today 66 million years ago – with dramatic consequences: 75% of animal and plant species, including dinosaurs, have disappeared.

07:59, October 25, 2018

An international team of scientists explains in the journal "Nature" how the characteristic shape of the Chicxulub crater with its ring mountains was created inside.

Traces of the impact of a ten-kilometer asteroid on the Mexican peninsula of Yucatan at the end of the Cretaceous are largely hidden under hundreds of meters of oceanic deposits in the Gulf of Mexico. In the spring of 2016, a research team from twelve countries drilled holes in the crater of about 200 kilometers, named after the Mexican port of Chicxulub.

300 nuclei

From Austria were the researchers of impact Christian Köberl, Director General of the Natural History Museum (NHM) Vienna, and Ludovic Ferrière, Researchers in meteorites at NHM, involved in the project. At a depth of about 500 to 1,300 meters under the seabed, more than 300 cores of a total length of 835 meters were sampled. Some of the samples were also examined in Vienna.

The badysis of hearts by a research team around Ulrich Riller The Department of Earth Sciences at the University of Hamburg has now provided information on the formation of the Ring ("Peak Ring"), which elevates to the center of the crater several hundred meters above of a flat floor. Until now, the badumptions on the formation of this mountain formation would be mainly based on computer simulations and the observation of craters impact on the surface of other planets. "Now, for the first time, there are samples that we can study in detail in the laboratory to support the previous hypotheses," Ferrière explained.

Chain of deformation mechanisms

The researchers have now described the chain of deformation mechanisms that demonstrate the extreme mechanical behavior of rocks during the impact on the meteorite. According to computer simulations, craters of this size are formed in a few minutes. For the Ringgebirge to emerge, the rock must behave like a liquid for a short time, then solidify very quickly. This was apparently due to transient pressure changes that caused the rock to behave like a viscous mbad. Scientists consider that the many areas of broken rocks found in the cores testify to a temporary fluidity of the rock.

As these circular mountains are found in many other large solar system meteorite craters, scientists hope that their discoveries will help decipher the formation of the largest craters of impact on other planets.

This video shows a simulation of the emergence of crater Chicxulub: