20 July 1969: On this day the first man walked on the moon. This is how the Guardian reported the event.

Men are on the moon. At 3 39 a.m. this morning - nearly four hours ahead of schedule - Armstrong, the lunar module commander, opened the hatch and clambered slowly down to the surface of the moon.

Minutes later Aldrin followed him down the steps of the ladder - already renamed Tranquillity Base - to join in this moving, clumsy culmination of eight years of intense dedication. It was the fulfilment of a dream which men have shared since the beginning of recorded history.

The decision to walk early was made three hours after the lunar module Eagle made a perfect landing at 9.17p.m., four miles downrange from the chosen site. The spacecraft was steered manually to clear a boulder-strewn crater "the size of a football pitch." It was a moment of extraordinary tension and silence. The lunar module curved gently down over the Sea of Tranquillity, the drama heightened by the calm, almost casual voices of the astronauts and the mission controller at Houston.

The casualness was deceptive ; from 500ft above the surface and all too aware that an error could lead to irretrievable disaster, Aldrin brought the spacecraft down under Armstrong's direction. At the moment of approach Armstrong's heartbeat rose from its normal 70 to 156. Yet his voice was calm and flat :"Contact light :engines stopped . . . the Eagle has landed."

The landing was perfect. Spaceflight Centre and the world seemed momentarily stunned by emotion: only Armstrong, Aldrin - and above them, Collins - seemed unmoved at the end of the drama which began with a characteristically laconic acceptance of the "go" for separation of the lunar module shortly before 7 p.m.

"You got a bunch of guys who're about to turn blue," said the Houston space controller, when the module had landed. "We're breathing again. Thanks a lot."

Within a few minutes of landing Armstrong was saying they did not know exactly where they had landed. Houston replied "We'll figure it out for you."

Armstrong reported that the site was pitted with craters "in the five to fifty feet range" with rocks of five to 10ft, and ridges of five to 30ft.

Ten minutes later after landing Aldrin radioed: "We'll get to the details of what's around here, but it looks like a collection of every variety of shape, angularity, granularity, a collection of just about every kind of rock."

"Colour depends on what angle you're looking at . . . rocks and boulders look as though they're going to have some interesting colours."

Loud and clear

The close look already began to belie the image gained from centuries of examining lunar reflectivity - for that is what we see by - and the more detailed examination from orbit by man and camera. And from there, in the Sea of Tranquillity, the colourful earth is simply bright. "It's big, and bright, and beautiful," said Armstrong.

They said they had no difficulty in adapting to the moon's gravity. The conversation from the moon's surface came through loud and clear.

Separation began on this side of the moon, but the descent itself - the journey to which President Kennedy committed his nation eight years ago - began with a firing of the lunar module's motor after a long separating half-orbit on the far side of the moon and out of touch with the control centre back at Houston.

The world waited for the static-filled radio silence to be broken by an astronaut's affirmative. After what seemed on earth to be an age, the disappointed millions who had hoped to watch the first steps of separation on television, at last heard a calm and distant Armstrong confirm that the landing trajectory was good. The first minor miracle had been performed.

From that moment, with the tension mounting second by second and with the minimum of interrogation from earth, or from the orbiting Collins, the lunar module bore Armstrong and Aldrin downward, using its motor as a brake and slowly tilting until it was upright and ready for landing.

On and down, past "highgate" at 7,000 ft, with the braking phase complete and the spacecraft rotated so that its windows faced forward - the point at which the final approach began.

Still onward and down, but more slowly now, the spacecraft moved with the astronauts checking, checking and checking again that all systems were "go."

Visual approach, but still under automatic control, began at 500ft. up with the spacecraft still nosing slowly forward. At 250ft. with all forward motion stilled and the descent rate only 2 1/2 feet a second, the spacecraft seemed to pause and wait as Armstrong searched the ashen-grey landscape for the hidden flaws, sudden rock, which would shatter the landing.

With a permitted tolerance of 12 degrees about the horizontal - a tilt of 6 degrees in any direction - if the spacecraft was ever to rise again, the search for a landing area had to be as knowledgeable and as perfect as man could make it. A few minutes later, although time seemed to have slowed down, we knew that it had been good. The tilt was 4 1/2 degrees. A second minor miracle had been worked.

This was the moment at which all activity throughout yesterday had been aimed. The briefly worrying flaw of the loss of nitrogen pressure, during the firing of the service module engine on Saturday, was dismissed early in the day.

High pressure nitrogen is used to operate the valves controlling the flow of fuel in the rocket motor, and a single operation had led to large pressure drop in the nitrogen bottle. The loss is still unexplained but, since there is an emergency nitrogen supply on board and the rate of loss was not large enough to exhaust even the prime supply, flight control did not regard the fault as serious.

The service module motor will be used to accelerate the astronauts back on to a trajectory for earth but, as Armstrong told journalists before he left, the worrying moments are those of descent and ascent. Now, there remains only the ascent.

Jump ahead

Every step of the preparation for landing yesterday went smoothly. Armstrong and Aldrin transferred from the command module - codenamed Columbia - to the lunar module "Eagle" during the tenth orbit, and on the eleventh orbit Glynn Lunney, the flight controller at Houston, told the world that all spacecraft systems were "operating just fine."

With the deceptive casualness which is now a hallmark of spacecraft control, he added that the astronauts were "a jump ahead in their work." They took only six hours sleep instead of eight and were in their lunar module spacesuits ahead of schedule.