Excerpt from:
Planetary Dreams: The Quest to Discover Life Beyond Earth (Wiley, 1999) p.259

"A LUNAR SANCTUARY"

Early in this book, I brought up our need for a new story; one that includes an accurate account of the scientific Universe, and generates a meaningful human future within it. The philosophy of Cosmic Evolution qualifies. It pictures our existence as the product of a linked series of events that have taken place since the Big Bang. In particular, the events on this planet which produced humans from self-organizing chemicals over the past four billion years represent a precious achievement. If we value the experience of human existence, and look forward to its continuation and improvement into the indefinite future, then we do not want to place the accomplishments of four billion years of evolution at risk.

But we stand at risk when our biosphere is confined to the surface of our home planet. An asteroid may descend with little warning and wreak havoc with our climate and civilization. Other natural catastrophes which remain unknown to us may have caused some of the earlier extinctions, and they may recur. Finally there is the threat of nuclear war, which has receded recently but certainly remains as a future possibility. Hopefully, we will escape all of these dangers, but we need an insurance policy.

Imagine that a secure, self-sustaining base existed separate from this planet. It supported a population of humans, together with those advanced species that we have come to depend upon. This modern Noah's Ark, unlike its predecessor, would also store the scientific and cultural heritage of our civilization. Computers would preserve most of this bulk, but perhaps some authentic manuscripts and works of art could find their way over as well. If some disaster swept over our home planet, this base could serve as a resource to reseed our civilization on Earth, once the conditions permitted it again.

The Moon would seem to be a logical place for such a base, though Mars or an artificial colony in space may have virtues as alternatives. The closeness of the Moon and its mineral resources give it obvious advantages. Above that, we have already invested our energy and our emotions in that world, and the construction of the base would bring those efforts to some good conclusion. The primary purpose of Moon Base would be to ensure human survival, but we could undoubtedly find other good uses for it while awaiting a Doomsday that we hope never arrives.