The impact of ancient asteroids on Earth can still be seen in a variety of impact craters across the globe. And, after the Chelyabinsk event in 2013, where an asteroid burst mid-air, it’s evident how deadly an “airburst” can be.
Now, researchers in Antarctica have found traces of a strange event, which is a combination of an impact and an airburst. The event was so disastrous, its impact is still apparent even 430,000 years later.
The team of scientists has found small black spherules in the Sør Rondane Mountains of East Antarctica that hint at a touchdown event. This impact was a result of an atmospheric entry and an asteroid airburst ranging between 100 and 150 meters wide.
Matthias van Ginneken from the University of Kent suggested the event was larger than an airburst but smaller than an impact event. The team’s paper, published in Science Advances, shows the vaporization of the asteroid while entering the atmosphere could have formed a superheated gas cloud, allowing extra-terrestrial spherules would have hit the ground very swiftly.
The new findings point towards a much worse event than the Chelyabinsk events. The researchers said it highlights the importance of reassessing the threat posed by medium-sized asteroids. If a similar touchdown event occurs in the future, it could produce similar particles and be devastating, to say the least.
“While touchdown events may not threaten human activity if occurring over Antarctica,” van Ginneken said, “if it was to take place above a densely populated area, it would result in millions of casualties and severe damages over distances of up to hundreds of kilometers.”
Ginneken also recommends that future studies should aim to identify reminiscing events on different targets all over the world– such as shallow ocean beds. This will give an idea of how often such events may have occurred in the past.
