An asteroid impact wiped out the dinosaurs 66 million years ago. Researchers have now found out why the asteroid was so deadly.
- An asteroid impact wiped out the dinosaurs 66 million years ago
- Researchers are studying the Chicxulub crater in Mexico to learn more about it
- The new finding: The asteroid struck the earth at a particularly deadly angle
An asteroid impact 66 million years ago wiped out the dinosaurs and numerous other animal and plant species and left Mexico with a crater some 200 kilometers in size: the Chicxulub crater , which is partly on the Mexican peninsula Yucatan and partly under water in the Gulf of Mexico lies. This crater repeatedly attracts researchers who uncover further details of the large extinction after the asteroid impact .
So far, only one question seemed to be unanswered: At what angle did the asteroid hit Earth? A study published in the journal "Nature Communications" is now addressing this question. The researchers from Great Britain, the United States and Germany had examined the Chicxulub crater in Mexico and created 3D simulations with which they examined four possible angles of impact of the asteroid : 90 degrees, 60 degrees, 45 degrees and 30 degrees.
Asteroid hit Earth at a deadly angle - and wiped out the dinosaurs
The researchers' result: the asteroid hit Earth at an angle of 60 degrees and at a speed of 43,200 kilometers per hour. This angle is particularly fatal, explains study leader Gareth Collins from Imperial College in London. Due to the asteroid impact at this angle, large amounts of dust and gas were thrown into the atmosphere.
Tiny sulfur particles blocked the sun's rays and caused a rapid change in the global climate - which ultimately three quarters of all animal and plant species did not survive. In the simulation, the asteroid impact is called a "worst-case scenario for the lethality of the impact from the generation of climate-changing gases".
What happened on Earth in the 24 hours after the asteroid impact
Only last year, researchers published a study that showed what happened in the 24 hours after the asteroid impact *. For this purpose, the researchers evaluated a drill core from the impact crater in Mexico and were able to show that a 130-meter-thick deposit layer had formed in the first 24 hours after the asteroid had impacted.
From this layer, they could see, among other things, that bush fires were triggered by the asteroid impact . In addition, a tsunami drove the water far inland. When the water flowed back into the sea, it carried with it everything it could take. The researchers had found only one thing in the crater: sulfur - although the bedrock should actually contain 30 to 50 percent sulfur.
Asteroid impact darkened the atmosphere - food chains collapsed
This find is a crucial indication of what ultimately led to the extinction of many animal species after the asteroid impact : Sulfur-like aerosols came into the atmosphere - including by evaporation - and thus darkened the sun. This affected the photosynthesis of the plants and caused entire food chains to collapse. Another study found that the asteroid impact 66 million years ago was "solely responsible" for the extinction of the dinosaurs *.
The asteroid that struck Earth 66 million years ago shows it very impressively: asteroids can be very dangerous for Earth and humanity. That is why Nasa and Esa will be testing an asteroid defense mission * in the future.
The collision of two asteroids 466 million years ago * shows that asteroids can also bring about positive changes: It triggered an ice age on Earth - which, however, ensured that new species were created on Earth. The difference: The earth darkened over a long period of time - this gave the living organisms a chance to adapt and develop.
By Tanja Banner, with material from afp.
* fr.de is part of the nationwide Ippen-Digital central editorial office.
Rubric list picture: © picture-alliance / dpa