Impact statement: Is technology up to the challenge of protecting the planet from large meteor strikes?

摘要

For the inhabitants of the Russian city of Chelyabinsk, the events of 15 February 2013 will never be forgotten. Just after 9.00am, as commuters made their way to work along snow-covered roads and schoolchildren settled down for their lessons, a 20m-diameter meteorite-travelling at an estimated 12 miles per second-exploded above the city with a force equivalent to 30 Hiroshima bombs.