Several hundred billion stars fill our galaxy alone. Isn’t that amazing? The universe was born in the Big Bang, so we are given to believe. Perhaps the Bang was an accident, a matter of chance. We are unlikely ever to discover the guilty party.

It is curious how little unease or even interest this situation, this profound question, provokes.

Like a pack of landlocked sailors, we stand for ever on the shore, observing Mars and the other planets of our solar package, thinking about a modest trip there, yet going nowhere. It seems we cannot take the chance. Besides, there’s Afghanistan to be settled.

The brain often scurries away from the present as a rabbit scurries into a rabbit hole. Into fiction, into the past. We tend to edit our pasts as we go along, deluding others, deluding ourselves. We may believe we remember clearly and think clearly; but such matters are largely matters of chance. Chance is as all-pervasive as carbon dioxide. Sometimes we are lucky, sometimes unfortunate. Chance created the ambience in which we have lived for the past 65m years or thereabouts, since a stray meteor killed off the dinosaurs.

In the matter of investments and love and war, chance is active. You may win the sweepstake, you may have the person of your dreams coming to live next door; on the other hand, you may lose all your money gambling, or find you are living next to a rock group. One dark night, you may foolishly decide to invade Russia.

All religions were forged as defences against this virus, chance. Once you have dreamt up a god or a goddess, you can abase yourself, offer up burnt offerings, put your knees to the ground or your bottom to the air, all in the hope that by fawnings and repeated praise you may ward off ill fortune, or gain an imaginary better world.That this fancy sycophancy never works appears to disabuse nobody. It is chance that makes prophecy malfunction.

H G Wells wrote splendid novels of science fiction which, in the main, chastise human foolishness or human aggression. Later in life, Wells came to regard himself as a prophet. His books became more prolix (for example, The Shape of Things to Come, written in 1933). True, in 1914 he had predicted something very like an atomic bomb in The World Set Free, but his bomb is dropped manually from a biplane.

Much later on, Isaac Asimov also regarded himself as a prophet, his robots freely walking the land. That has yet to come about, except in the movies, where prophecy is not the intention. However, one can see that the Foundation he created (where learned men create a refuge for themselves against 30,000 years of barbarism) seems not entirely unlikely if one imagines a bastion for “western culture” built on Mars when Earth becomes too hot, or the forces of Chinese communism or Islamic opposition become too intolerable. A prophecy can hang in the air for centuries, just as flypaper is used to catch flies. The prophecies of the 16th-century Nostradamus are trotted out at every unpleasant significant event.

Any such event lies within the province of the zeitgeist, a fashionable word for change and chance. The idle frivolity deplored by Aldous Huxley in Brave New World has turned itself into today’s binge culture. George Orwell foresaw and dreaded everyone being under surveillance by television eyes. These very people now beg for more CCTVs.

After the second world war, when Britain and much of Europe were exhausted and impoverished, science-fiction writers predicted extensive space travel. SF magazines morphed into space-travel brochures, where men ventured to Pluto and beyond. The cosmos was explored. Galactic empires sprang up like mushrooms. But the reality of chance dictated otherwise.

At that time, Wernher von Braun imagined fleets of spaceships roaring off into the dark unknown. It was said that throughout the war, when von Braun worked at Peenemünde, he received his monthly copies of Astounding, the leading science-fiction magazine of the time, through neutral sources in Sweden. Whether this is true or not, the von Braunian future closed like a book and died, leaving only a trail of Nasa probes behind.

In July 1969, Nasa’s Apollo 11 achieved the first landing on the moon. What excitement! Like millions of others, the Aldiss family watched the event on television. Meanwhile, through our living-room windows, we could see the moon itself. A strange double vision. Prayers may indeed have been said, but it was science that got us there.

There was constant communication between the moon and Nasa HQ on Earth. In an earlier movie, one of the crew walked around a crater or two before someone said: “Better phone the president and tell him we’ve landed.” Space travel had been invented, but not mass TV… Moon landings had long been envisaged by SF writers. In one scenario, the astronauts find an empty Camel cigarette packet lying on the surface. The implication is that a previous culture reached the moon, collapsed, has been forgotten. This bears out my thumbnail description of SF as “hubris clobbered by nemesis”.

Mars was always regarded as of much greater interest than the moon, not least because of Professor Percival Lowell’s depiction of Mars as an abode of life. His book of that title was published in 1909. C S Lewis wrote his delightful Out of the Silent Planet in the late 1930s. Philip K Dick’s Martian Time-Slip appeared in the mid-1960s. This was probably the last novel to posit an autochthonous species living on the planet. Venus was of less interest than Mars. S Makepeace Lott’s Escape to Venus (1956) is all but forgotten, although I seem to recall that it was turned into a movie – generally a key to longevity.

While I had always been an ardent believer in space travel, my hope was less for conquest than for the chance to understand ourselves better.

Collaboration is always better than confrontation. In the book I wrote with Professor Roger Penrose, White Mars, we stranded 6,000 people on Mars. This was allegory rather than prediction.

Co-operation offers the world a better chance for happiness and survival than confrontation. The brain may hope for peace, but confrontation is in our bones.

Religions developed as defences against the virus of chance. Prayer had so often proved a false hope, destroying rationality. When the Romans left these shores, the inhabitants killed off all cats, suspecting them to be companions of witches. Rats multiplied. Rats brought in the Black Death. Thousands died. Thousands prayed. Cats did not return.

As a boy, I studied the night sky, with its profusion of stars, imagining that up there, among its elder planets, a great civilisation prevailed, more interested in philosophy than football.

Men and women there had long since rejected war and all forms of criminality. Rationality was all, as these young ancients travelled from one world to another, conversing, teasing out the problems of consciousness. Such was my form of religion, borrowed from ancient Greece and Christianity. Sadly, I no longer believe in my early agnostic version of heaven.

I do believe there is confusion everywhere on Earth – confusion probably caused by deficiencies in the human brain. Supposing we encountered a species of unruffled benevolence, it might act as our tutor – or possibly our psychoanalyst. It’s only natural for us to dream of other kinds of lives, better lives. A disturbing question (not discussed among our leaders) haunts us: the doubt that human consciousness is fit for purpose.

And what of space? We know it is full of raging particles, small but lethal. Somehow, life on Earth was born from them.

Harm, the latest novel by Brian Aldiss, is published by Duckworth, price £14.99. It is available at the BooksFirst price of £13.49, including postage and packing. Tel: 0870 165 8585