Scientists monitoring an asteroid have warned it could collide with Earth in just over a decade. The newly discovered asteroid, known as 2003 QQ47, is around two-thirds of a mile wide and has been classified as "an event meriting careful monitoring" by astronomers. It is around one tenth fo the size of the meteor that is thought to have wiped out dinosaurs on Earth 65 million years ago. In the event of it hitting the Earth, the rock would have the force of 350,000 mega tonnes - around eight million times more powerful than the bomb dropped at Hiroshima at...