Events | 2010.03.05
Dinosaurs were killed by Isle of Wight-sized asteroid
After studying 20 years of data, panel of 41 scientists rule out volcanic explosions as cause of dinosaurs\' demise
A mere 65 million years after the demise of the dinosaurs, a panel of the world\'s most eminent scientists have finally got to the bottom of the extinction. The creatures were wiped out by a large asteroid slamming into the Earth, they insist.
After studying 20 years\' worth of research and data, a panel of 41 scientists came to a conclusion which will sound more than just a bit familiar to most schoolchildren who paid attention in science class.
The new finding flies in the face of claims by other scientists that the extinction was caused by volcanic explosions. According to the new international study, the asteroid that did for the dinosaur struck the Earth at an angle of 90 degrees and a speed of about 12.4 miles per second – about 20 times faster than a speeding bullet.
The asteroid generated a force one billion times greater than the atomic bomb dropped on Hiroshima at the close of the second world war, the scientists say.
It crashed into the Earth in what is now Mexico, at Chicxulub, off the Yucatán peninsula.
Dr Gareth Collins, one of the scientists from Imperial College London, said: "The asteroid was about the size of the Isle of Wight and hit Earth 20 times faster than a speeding bullet. The explosion of hot rock and gas would have looked like a huge ball of fire on the horizon, grilling any living creature in the immediate vicinity that couldn\'t find shelter.
"While this hellish day signalled the end of the 160 million-year reign of the dinosaurs, it turned out to be a great day for mammals, who had lived in the shadow of the dinosaurs prior to this event."
The effect of the strike was to create a global winter, and geological records reveal that it rapidly destroyed marine and land ecosystems.
Scientists say there was an abundance of iridium in geological samples dating back to the time of extinction, which is commonly found in asteroids, but little of which is found in the Earth\'s crust.
Joanna Morgan, of Imperial College, a co-author of the review, described the effects of the asteroid strike: "This triggered large-scale fires, earthquakes measuring more than 10 on the Richter scale and continental landslides, which created tsunamis.
"However, the final nail in the coffin for the dinosaurs happened when blasted material was ejected at high velocity into the atmosphere. This shrouded the planet in darkness and caused a global winter, killing off many species that couldn\'t adapt to this hellish environment."
For more information, please visit
http://www.guardian.co.uk/science/2010/m[...]steroid-science-climate-change
