Killer Asteroids: A Real But Remote Risk?

It is almost certain that Earth will be hit by an asteroid large enough to exterminate a large percentage of our planet’s life, including possibly over a billion people, according to researchers. But as such cataclysmic collisions occur on average only once in a million years or so, are they really worth worrying about?

At some point in the geological future a large chunk of rock and ice will smack into Earth and destroy life as we know it. This is a cold, sober, scientific fact, according to Andrea Milani, a researcher at the University of Pisa in Italy.