Nadir Crater: why the asteroid that killed dinosaurs was not alone
- Author, Georgina Rannard
- Author’s title, Science reporter, BBC News
The huge asteroid that collided with Earth and wiped out the dinosaurs 66 million years ago was not alone, a team of scientists has confirmed.
A second, smaller space rock crashed into the ocean off the coast of West Africa, creating a large crater around the same time as the first.
According to the researchers, this would be “catastrophic event” capable of generating tsunami at least 800 meters highwhich was supposed to cross the Atlantic Ocean.
created a crater called Nadir, about 450-500 m wide and is believed to have hit the Earth at a speed of about 72,000 km/h.
Dr Wisdin Nicholson of Heriot-Watt University in Scotland discovered the Nadir crater in 2022, but it was not known how it actually formed.
Now Nicholson and his colleagues are confident that the 9-kilometer depression was caused by an asteroid falling to the seabed.
One of the problems was that scientists They were unable to determine exactly when this event occurred.and it is not said whether this was before or after the asteroid impact that wiped out the dinosaurs and left the Chicxulub crater in southeastern Mexico, which is 180 km wide.
Its destructive effect
Researchers who examined the African asteroid say this smaller rock also fell at the end of the period. Cretaceous periodWhen did the extinction of the dinosaurs occur? When it collided with the Earth’s atmosphere, a fireball was created.
“Imagine an asteroid hit Glasgow and you were in Edinburgh, about 50km away. The fireball will be around 24 times the size of the sun in the sky and will be enough to set trees and plants in Edinburgh on fire,” explains Nicholson.
Then it would be extremely strong air explosionbefore a seismic tremor the size of a magnitude 7 earthquake.
Huge amounts of water likely came up from the seabed and then flowed back down, leaving unique traces on the land.
It is unusual for two such large asteroids to collide with our planet in such a short period of time.
Researchers don’t know why these two rocks collided with Earth at close intervals.
Could this happen again?
The closest people came to an event of this magnitude was the Tunguska disaster in the skies over Siberia in 1908, when a 50-meter asteroid exploded.
The Nadir asteroid was approximately the size of Bennuwhich is currently the most dangerous object orbiting the Earth.
According to NASA, the most likely date for Bennu to impact Earth is September 24, 2182. But that’s still only a 1 in 2,700 chance.
There has never been an asteroid impact of this size in human history, and scientists usually have to resort to studying craters on Earth or images of craters on other planets to try to understand these events.
To better understand Nadir Crater, Nicholson and his team analyzed high-resolution 3D data provided by geophysics company TGS.
Most craters have been destroyed by erosion, but this one it is well preservedallowing scientists to dive deeper into the rock layers.
“This is the first time we can see the inside of an impact crater like this. It’s really interesting,” says Nicholson, adding that there are only 20 marine craters in the world, but none has been studied in as much detail as this one.
The results of their research were published in the journal Natural communications Earth and environment.
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