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About 1.2 billion years ago, the largest asteroid in the history of the British Isles would have crashed into Earth. Now the experts have identified where the exact point of impact could have been hidden all this time.
It is estimated that the point in question is about 15 to 20 kilometers from Enard Bay, in the Minch Basin, between Scotland and the Outer Hebrides. The huge asteroid would have crashed at a speed of about 65,000 kilometers at the time (over 40,000 mph).
However, no crater is visible today: there are 200 meters below the surface of the ocean, embedded in sediments. It is thought that the asteroid was huge: one kilometer wide.
According to the researchers' analysis, the crater would have initially been about 13 to 14 km (8.1 to 8.7 miles) wide and 3 km (1.9 miles) deep. .
"The impact would have sent huge clouds of dust and gas at several hundred degrees in all directions since the site of the impact," said geochemist Ken Amor of the & # 39; 39, University of Oxford in the United Kingdom to The Guardian.
The story of the discovery actually dates back to 2008, during a field visit to the Scottish Highlands. The expedition included a study of the formation of Stac Fada (SFM) members, where Amor noticed "strange green spots" in the rock.
These spots can be a sign of an asteroid attack and, after bringing the samples back to the laboratory, Armor was able to identify quartz crystals deformed by the shock of a huge shock. Platinum and palladium, well known meteorite metals, have also been detected.
A field photo showing laminar beds of sandstone at the bottom of the image. (Ken Amor / Department of Earth Sciences)
After determining that an asteroid had hit Scotland – which at that time was a dry landscape near the equator – the team analyzed the ancient rock patterns, as well as the orientation of the magnetic grains. in the geological record, to locate the site of the original smash.
"If you imagine debris flowing in a big cloud across the landscape, taking off the ground, they end up slowing down and stopping," Amor told BBC's Amos. "But it's the stuff in the front that stops first, while those behind are still moving forward and straddling what's ahead."
"That's what we see and it gives us a powerful directional indicator that we can trace back."
Events of this magnitude are thought to occur at least once every million years – and perhaps as often as once every 100,000 years.
The next step in the process will be a detailed geophysical survey in the Minch Basin target area, which should be sufficient to confirm whether the researchers' calculations are correct.
Previous research has suggested that the actual point of impact could be more in the West of Scotland itself; To be sure, scientists will have to deploy expensive technology similar to that used in oil exploration.
"Materials excavated during a giant meteorite impact are rarely kept on Earth because they erode quickly, so it's a truly exciting discovery," Armor said.
"It was purely by chance that it landed in an old Rift Valley where fresh sediments quickly covered the debris to preserve them."
The research was published in the Journal of the geological society.
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