Space hailstorm may explain extinction

AN hour-long hailstorm from space may have changed the climate of the Earth in 11,000 BC, leading to a freeze lasting more than 1,000 years.

The catastrophe, caused by a disintegrating comet, wiped out large numbers of animal species and disrupted human cultures.

A new theory suggests it occurred when the Earth strayed into a dense trail of fragments shed by a large comet.