While we didn't know the dinosaurs personally, we do know that they were wiped out by an asteroid impact.

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

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. We are going to learn how to relate to the Earth and our own natural environment here by looking seriously at space colony ecologies.

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.

We not only need to train people, we also need to develop deflection technologies.

It is not enough to do a desktop exercise of a Beethoven symphony. You need to practice with an orchestra. The musicians need to read the notes. Otherwise it will be a disaster.

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.