Anytime we can save lives or prevent the destruction of property, we should do it.

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

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

This whole issue of limits to growth, which provides a psychological, as well as a physical, cap on potential expansion of activity and awareness, has had a very depressing effect on many people.... I don't for a moment think that there's any concept which anyone's working with now which will be followed as a straightforward scenario. But the idea embodied in concepts such as space colonization or space industrialization, or availability of nonterrestrial resources, is fundamental, and it will change the way in which people look at the future.

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

Anytime we can save lives or prevent the destruction of property, we should do it.