Lembit Opik, the Liberal Democrat MP for Montgomeryshire, has been granted parliamentary time for a debate on the threat posed to civilisation by the future impact of a chunk of wandering space rock.
Professor Mark Bailey, the director of the Armagh Observatory in Northern Ireland, is supporting Mr Opik in trying to raise the Government's awareness of an event that could ruin global agriculture by releasing millions of tons of dust into the atmosphere and blotting out the Sun. "Major cosmic impacts don't occur very often, but when they do they have the potential to kill billions of people," Professor Bailey said.
"An object one kilometre in diameter is generally accepted to be big enough to cause global devastation. No matter where they hit, they'll have a global effect," Professor Bailey said.
It is believed that a giant asteroid smashed into the Gulf of Mexico 65 million years ago and killed off the dinosaurs. A much smaller object destroyed hundreds of square miles of forest when it exploded over Siberia nearly 100 years ago.
Estimates of the number of asteroids bigger than one kilometre across have increased in the past 10 years through learning more about the orbits of near-Earth objects, he said.
Astronomers calculate there are at least 2,000 such objects that at some time will pass across the Earth's orbital path around the Sun, making it likely that at least one of them will strike the planet every 100,000 years.
Jonathan Tate, director of Spaceguard UK, an organisation dedicated to raising awareness about asteroid collisions, said the chances of being killed by an asteroid impact is twice as high as dying in an aircraft crash. "The whole subject suffers from a substantial giggle factor. However, it's now technically possible to avoid, or at least mitigate the effects of impacts," he said.
The most threatening objects arise from the main asteroid belt of the Solar System, between Mars and Jupiter, and their movements can be tracked from Earth using military satellites, Professor Bailey said. "Asteroid collisions can be predicted and can be potentially averted. A nuclear explosion just off the surface of the object is possibly the way it could be done," he said.
Last year scientists warned that a large asteroid could pass relatively close to Earth in 2028.Travelling at 17,000mph, the asteroid would release the same energy as several nuclear bombs if it hit the Earth.Reuse content