My objection to organized religion is the premature conclusion to ultimate truth that it represents.

The Earth would only have to move a few million kilometers sunward-or starward-for the delicate balance of climate to be destroyed. The Antarctic icecap would melt and flood all low-lying land; or the oceans would freeze and the whole world would be locked in eternal winter. Just a nudge in either direction would be enough.

I'm sometimes asked how I would like to be remembered. I've had a diverse career as a writer, underwater explorer, space promoter and science populariser. Of all these, I want to be remembered most as a writer - one who entertained readers, and, hopefully, stretched their imagination as well.

The choice, as Wells once said, is the Universe-or nothing. . . . The challenge of the great spaces between the worlds is a stupendous one; but if we fail to meet it, the story of our race will be drawing to its close. Humanity will have turned its back upon the still untrodden heights and will be descending again the long slope that stretches, across a thousand million years of time, down to the shores of the primeval sea.

A well-stocked mind is safe from boredom.

I suspect that religion is a necessary evil in the childhood of our particular species. And that's one of the interesting things about contact with other intelligences: we could see what role, if any, religion plays in their development. I think that religion may be some random by-product of mammalian reproduction. If that's true, would non-mammalian aliens have a religion?

Those wanderers must have looked on Earth, circling safely in the narrow zone between fire and ice, and must have guessed that it was the favourite of the Sun's children.