Was there ever such a high summer as that of '69? The portentous events of eight brief weeks - 28 June to 23 August - changed the perceptions of the post-war generation to an extent equalled only by the fall of the Wall and the end of the Cold War in 1989.

What thread links the birth of the gay movement out of the Stonewall riots in Greenwich Village on 28 June, the first manned landing on the Moon on 21 July, and the three days of the Woodstock festival that began on 15 August? A quarter of a century on, we struggle to make sense of these happenings.

They were all turning points. The Stonewall riots acquired significance only with hindsight, but the other two events garnered huge publicity and appeared at the time to herald the dawn of a new age. In fact, we can now see that Woodstock and the lunar landing marked the end of an era. Subsequent decades turned inwards, away from the hippie counter-culture and the frontier spirit of the Apollo programme to a preoccupation that dominates still: environmentalism. A quarter of a million miles out from Earth, dollars 25bn spent, a man stepped out on to the lunar surface. But from the moment those images were beamed back to Earth, the most impressive sight was not the the Moon itself, or Neil Armstrong bobbing across its rocky terrain. It was the blue and white disk of the Earth hanging there in space.

The message of the Apollo programme for those who watched live on television, and to subsequent generations, was simple: the Earth is fragile; it is vulnerable; it is all we have. That was not the intended outcome.

At that moment the Gaia hypothesis - that the Earth is a living entity within the solar system - began to make more sense. With hindsight, it is not surprising that humanity should have travelled to the Moon only to look back upon itself. The Moon, after all, dominates our night sky, so it was inevitable that the Earth would dominate the lunar sky. But no one was prepared for the sheer psychological power of the images Apollo II sent back.

The very complexity of the technology employed to send men to the Moon, the conspicuous consumption of rocket fuel by the mammoth Saturn V engines, the sophistication of the spacesuits, demonstrated for all to see that outer space is a void, inaccessible, desolate and irredeemably hostile; that there is no place other than the Earth where humanity can hope to survive. No wonder the Seventies were the decade of the environmental movement.

In the title sequence of You Only Live Twice, the 1967 James Bond film, our hero is seen wrestling with a baddie in space. But it is a space oddly devoid of the Earth. It had not occurred to film-makers that the Earth was the most interesting thing to look at up there.

Once we knew what we looked like from the Moon, however, that image burned into the psyche. Athena posters of it became the biggest seller of the Seventies; fabrications of those first pictures were the big cliche of science fiction films; and in music, whole careers were forged on the new vision. David Bowie, for instance, with 'Space Oddity', 'Starman' and 'The Man Who Fell to Earth', was forever astonished by the oddness of the new view. Indeed, the word Earth became a fixture in pop songs, from Sparks' 'Never Turn Your Back on Mother Earth' to Duran Duran's 'Planet Earth'; the word became charged with a sense of magic, strength and celestial beauty.

Humorists, too, took to the Earth. The Bonzos had laughed at the lunar race with 'The Urban Spaceman'; now Monty Python would stage a whole sequence of The Meaning of Life floating about like moon walkers.

The Apollo programme, however, had been conceived as the 20th-century extension of the American frontier spirit. The Moon was to be won for free enterprise and the American way, just as the wild west had been in the 19th century. It was to be the visible expression of what science fiction writer John Wyndham called 'the outward urge'.

Eventually, science fiction, in the shape of Stanley Kubrick's 2001: A Space Odyssey, released the year before the lunar landings, translated the entire enterprise into a messianic Pilgrim's Progress. The film portrayed the voyage through space as a spiritual odyssey culminating in redemption and the rebirth of humanity as children of the stars and future masters of creation.

In Britain, we were still living through the political illusion of the 'white heat' of Harold Wilson's technological revolution. During the Sixties, scientists and engineers had seen the future and it worked. It was no accident that BBC television launched a popular science series called Tomorrow's World - with the implication that, thanks to science, tomorrow would be better than today.

So, in its fictional and physical guises, the space programme was intended to carry the moral certainties of the Fifties and early Sixties beyond the cradle of Western civilisation. But above all, it was the embodiment of a liberal-scientific idea of progress that was falling apart even as it reached its apogee with Armstrong's lunar walk.

And those eight summer weeks were presenting other potent symbols of how the old order was passing. Sometime during the night of 18 July, Senator Edward Kennedy drove his car off a bridge into the sea at Chappaquiddick. His passenger, Mary Jo Kopechne, drowned, and with her the presidential hopes of the Kennedy clan. Three weeks later, during the night of 8 August, Charles Manson and his 'family' murdered and mutilated the bodies of a pregnant Sharon Tate and four others.

The death of Ms Kopechne destroyed public acceptance of traditional political leadership; the Manson murders revealed the inadequacy of the hippie counter-culture that was supposed to be offering an alternative way of living. And all the time, the Vietnam War was tearing the fabric of American society, whose divisions were epitomised by the shooting dead of four student anti-war protesters at Kent State University on 4 May 1970.

The old order finally collapsed on 8 August 1974 when Richard Nixon resigned the presidency of the United States. How ironical that the plaque Apollo II carried to the Moon bears the signature of the only US president to

be publicly disgraced because of his


These subsequent events coloured our perception of the lunar landings. The passage of time has dulled the memory of the generation which saw live on television the flickering black and white image of a man walking on the Sea of Tranquillity. For following generations, the lunar landings are but an entry in the history books, and space spectaculars have become routine. But it is not only the passing of years - it is the zeitgeist that has changed.

That is why it seems worth taking a fresh look at the significance of that man's small step 25 years ago. The Earth and the Moon have existed for about 4.5 billion years, and there has been life, of some sort, on the face of the Earth for about 3.5 billion years. On 21 July 1969, Neil Armstrong became the first living creature in the history of evolution to stand on the surface of another planetary body. That first step was, simply, unique.

Journalists and science fiction writers, of course, hyped it further, promising, like Kubrick, that the journey to the Moon would be a step towards the stars. That old ham Ronald Reagan was still at it in 1986 when, after the Challenger explosion, he called the crew 'our seven star voyagers' who had 'slipped the surly bonds of Earth to touch the face of God'.

Yet those haunting images of the Earth, seen from the desolation of the lunar landscape, show clearly that on a cosmic scale the Moon is not far from the Earth - only 250,000 miles - whereas the nearest star is 28,500 billion miles away.

So although Armstrong's step was unique, the pictures he took showed how small it was in astronomical terms. The stars are still unreachable. Mankind is still alone.

Science, page 21

(Photograph omitted)