Rusty Schweickart

Asteroids are deep-space bodies orbiting the Sun, not the Earth, and traveling to one would mean sending humans into solar orbit for the very first time. Facing those challenges of radiation, navigation and life support on a months-long trip millions of miles from home would be a perfect learning journey before a Mars trip.

The frontier in space, embodied in the space colony, is one in which the interactions between humans and their environment is so much more sensitive and interactive and less tolerant of irresponsibility than it is on the whole surface of 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.

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.

It is fantastic to think that one day we may be able to access fuel, materials and even water in space instead of digging deeper and deeper into our planet for what we need and then dragging it all up into orbit, against Earth's gravity.

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

We have the capability - physically, technically - to protect the Earth from asteroid impacts. We are now able to very slightly and subtly reshape the solar system in order to enhance human survival.

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

I don't want people to spend their nights worrying about getting hit by asteroids. But I do want them to encourage their political leaders to invest in the insurance, which will allow us to prevent it from happening.

Landing on the moon was a dream that millions of kids have had for hundreds of years.

There's no accepted global policy on what to do about asteroid impacts.

When you have an asteroid threatening Earth, it's uncertain where it's going to hit until the last minute; the decision to take action has to be coordinated by the international community.