In the short term, some deadly virus might be more important, but in the long run there is hardly anything more important than asteroids.

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

By preventing dangerous asteroid strikes, we can save millions of people, or even our entire species. And, as human beings, we can take responsibility for preserving this amazing evolutionary experiment of which we and all life on Earth are a part.

You see the Earth as a bright blue and white Christmas tree ornament in the black sky. It's so small and so fragile - you realize that on that small spot is everything that means everything to you; all of history and art and death and birth and love.

We can both prevent asteroid impacts and address climate change. It's not either-or.

If we do our homework right, never again should an asteroid that can do damage on the ground impact the Earth. We're living in a time-with our technology-we have the capability to eliminate that major shaper of evolution . . . the evolution of life on this planet.

Asteroids have hit the Earth millions of times. We can see them as shooting stars every night. When they get bigger, things get complicated. It is only a matter of time until a big one hits us. And since we can do something about it, we should.