A new angle on the Cretaceous asteroid

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brian livesey
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A new angle on the Cretaceous asteroid

Post by brian livesey »

The impact of the asteroid 66 million years ago was so devastating that it wiped out 75 per cent of life on our planet. New data from the impact site has led researchers to conclude that the asteroid's angle of entry, calculated at 66 degrees, was the most effective for the object to have wreaked such devastation.
The impact caused many tons of sulphur to be released into the upper atmosphere, shrouding the earth in a "nuclear winter" that blocked out the sunlight. Researchers from Imperial College, London, Freiburg University and the University of Austin, Texas, examined the geophysical structure of the Chixulub crater impact site off Mexico,then fed the data into 3D simulations of the event. This assisted the team in calculating the impact angle and direction of the asteroid.
Research Team Leader Professor Gareth Collins, of Imperial College,said: "Our simulations provide compelling evidence that the asteroid struck at a steep angle, perhaps 60 degrees, and approached its target from the north-west. We know that this was among the worst-case scenarios for the lethality of impact, because it put more hazardous debris into the atmosphere and scattered it everywhere - the very thing that led to a nuclear-winter."
Angle of entry might explain why there are a number of huge known impact craters ( e.g. In the Canadian Shield ) that don't seem to be associated with mass extinctions. Goodbye and hard luck dinosaurs.
brian
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