Sixty-six million years ago, an asteroid the size of a small city crashed into Earth. This collision, which led to the end of the dinosaur era, left a scar on the surface of the planet several kilometers deep and more than 185 kilometers in diameter.
The Chicxulub crater, which lies beneath the Mexican Yucatan Peninsula, is the best-preserved impact crater on Earth, despite the fact that it was buried under a layer of rocks half a kilometer thick. It is also the only crater on the planet, showing the inner ring of mountains, located near the center of the crater. The origin of this unusual structure has been a subject of discussion for a long time, but a new study has shown that it is the product of extremely powerful vibrations, as a result of which the rocks turn into a substance capable of flowing like a liquid for several minutes after a collision.
When an asteroid hits Earth, it leaves behind a cup funnel. However, if the space stone is large enough, the depth of the resultant funnel can reach a critical value of 30 kilometers – after which the crater becomes unstable and collapses.
For some time, rocks behave like a liquid. To explain this fluidization of rocks, a large number of different hypotheses have been proposed, but now we know that the main reason for this process is the powerful vibrations that shake the rocks during a collision.
-Jay Melosh, a professor of earth sciences, atmosphere and planets at Purdue University, USA
This mechanism, known as acoustic fluidization, allows a ring of mountains to form in the center of the crater a few minutes after a collision with an asteroid. This mechanism was first proposed by Melosh in 1979. The same mechanism can participate in the formation of impact craters not only on Earth, but also on surfaces of other terrestrial planets, such as Venus, Mercury and Mars, the scientist believes.
In carrying out the work, Melosh and his colleagues used data from the analysis of rocks extracted from the Chiksuli crater from a depth of up to 1.5 kilometers.
An asteroid that caused dinosaur extinction, made the stones flow like water
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