The nice thing about asteroids is that once you've found them, and once you have a good solid orbit on them, you can predict a hundred years ahead of time whether there is a likelihood of an impact with Earth.

We're not passengers on Spaceship Earth. We're the crew.

Americans who read the papers or watch Jay Leno have been aware for some time now that there is a slim but real possibility - about 1 in 45,000 - that an 850-foot-long asteroid called Apophis could strike Earth with catastrophic consequences on April 13, 2036.

When you look at the origins and evolution of life on Earth, it's been severely affected by asteroid impacts through history.

It would take an extremely large spacecraft to deflect a large asteroid that would be headed directly for the Earth.

An asteroid can literally destroy 80 or 90 percent of the species that are alive on Earth. These are big events. I mean, this is called extinction.