We have heard the rationales offered by the nuclear superpowers. We know who speaks for the nations. But who speaks for the human species? Who speaks for Earth?

Imagine we could accelerate continuously at 1 g-what we're comfortable with on good old terra firma-to the midpoint of our voyage, and decelerate continuously at 1 g until we arrive at our destination. It would take a day to get to Mars, a week and a half to Pluto, a year to the Oort Cloud, and a few years to the nearest stars.

Billions and billions.

Modern Darwinism makes it abundantly clear that many less ruthless traits, some not always admired by robber barons and Fuhrers - altruism, general intelligence, compassion - may be the key to survival.

We seem, these days, much more willing to recognize the perils before us than we were even a decade ago. The newly recognized dangers threaten all of us, equally. No one can say how it will turn out down here. But this is also, we may note, the first time that a species has become able to journey to the planets and the stars. Sailors on a becalmed sea, we sense a stirring of the breeze.

[S]cience has itself become a kind of religion.

How is it that hardly any major religion has looked at science and concluded, “This is better than we thought! The Universe is much bigger than our prophets said, grander, more subtle, more elegant?” Instead they say, “No, no, no! My god is a little god, and I want him to stay that way.” A religion, old or new, that stressed the magnificence of the Universe as revealed by modern science might be able to draw forth reserves of reverence and awe hardly tapped by the conventional faiths.