'One giant leap for mankind': The moon landings remembered

Legend has it that there were only 20 or 30 seconds of fuel left in the tank when Apollo 11's lunar landing module came to rest in the Sea of Tranquility.

It had overflown its scheduled landing site - a relatively smooth area of lunar surface - by about four miles. In the nerve-shredding last minute or so before touchdown, the module was flying over a crater. With the surface of the moon swinging past below him, Armstrong faced an agonising decision: should he go ahead and land, knowing that there was no coming back from any mistake? Or should he abort?

There really was only one way he was going to decide. Seconds later, his voice crackled over the radio to Mission Control in Texas. "Houston, Tranquillity Base here. The Eagle has landed."

Listening to recordings of that night today, you can almost hear the release of tension back at Mission Control. "Roger, Tranquility," comes the voice of CAPCOM Charles Duke. "We copy you on the ground. You got a bunch of guys about to turn blue. We're breathing again."

That landing was 50 years ago on Saturday. Just over six hours after touchdown, Armstrong himself suited up and climbed laboriously down the steps on the outside of the lunar module - and became the first man to set foot on the surface of another world.

"That's one small step for man, one giant leap for mankind," he said, over his radio.

Apollo 11 astronaut Edwin 'Buzz' Aldrin on the moon, WITH Neil Armstrong reflected in his faceplate. Picture: NASA/Neil Armstrong

That 'small step' was broadcast live on TV around the world. And it had an extraordinary effect. For a moment, a world divided by race and fear and inequality and mistrust was briefly united. It was us, we, mankind who had done this extraordinary thing. We'd broken the ties that bound us to the world on which the whole of human history had played itself out, and we'd taken the first step into the unknown.

Among those watching that night, from Barnsley in South Yorkshire, was nine-year-old Richard Darn. Now a North Yorkshire amateur astronomer who runs regular stargazing events from the North York Moors, he has never forgotten that moment.

"There was a man on the moon!" he says. "There really hasn't been a first like that since."

Also watching, down in Surrey, was 12-year-old Martin Lunn - who years later was to become the curator of astronomy at the York Museums Trust. "I was awestruck by it," he says. "I think most people at the time were."

Tom McLeish, today a Professor of Natural Philosophy in the Department of Physics at the University of York, was also watching, glued to his TV screen in Kent.

He was just seven back then. "But my dad woke me up at 2am in the morning so we could watch Neil Armstrong step out onto the surface," he says. "I have never forgotten it. I was completely enthralled."

It was that final approach to the moon's surface a few hours earlier which really gets him still today. "They were descending into another world's gravity well in an aluminium tin can with one engine and two football-sized fuel tanks," he says. "They were doing something nobody had ever done before. They were right on the edge."

Buzz Aldrin coming down the steps of the Apollo 11 lunar lander. Picture: NASA Apollo Archive

For him, however, the real significance of the Apollo missions wasn't the technology, the courage, the going to a place no man or woman had ever been before. It was something even more profound - the way Apollo changed our view of our place in the Cosmos.

Armstrong, not normally the most poetic of men, touched upon that in a interview long after his mission was over.

He recalled seeing the Earth from far away in space, a small, blue-green globe hanging in infinity.

"It suddenly struck me that that tiny pea, pretty and blue, was the Earth," he said. "I put up my thumb and shut one eye, and my thumb blotted out the planet Earth. I didn't feel like a giant. I felt very, very small."

It is that sense of perspective, and that realisation of how tiny and fragile our world is, that is perhaps Apollo's true legacy, says Prof McLeish.

It's a legacy that actually dates back to Apollo 8, six months before Apollo 11.

Until Apollo 8, we had only ventured 200 miles into space, astronauts precariously orbiting our planet just above the atmosphere.

Apollo 8, crewed by James Lovell Junior, William Anders and Frank Borman, changed all that. It broke away from Earth's gravitational pull and boosted off to the moon. Plunging round the far side of the moon, it came out the other side, and the crew saw the Earth from 250,000 miles away, rising above the rim of the moon. They took a series of photographs that are among the most iconic ever taken - the 'Earthrise' images.

For the first time, we were seeing the Earth as it really is - an insignificant blob in the vastness of space. Having seen that - having recognised the fragility and vulnerability of the world we call home - we could surely never view it in quite the same way again, Prof McLeish says. It made us aware of the duty of care we have to our own planet.

Earthrise over the Apollo 11 lunar landing craft. Picture: NASA Apollo Archive

And yet somehow, over the past 50 years, we seem to have lost sight of that, somewhere.

The moon landings themselves came to nothing - the last men to walk on the surface of the moon were Gene Cernan and Jack Schmitt of Apollo 17 in December 1972. We have never been back.

At the time, everyone watching Apollo 11 assumed that we'd soon have a base on the moon, and even men and women on Mars, admits Martin Lunn. It never happened.

We don't even seem to have become better custodians of our own fragile planet. We continue to pollute and despoil our world, and drive the plants and animals which share it with us to extinction, as though we don't realise it is the only planet we have.

Prof McLeish admits that he sometimes despairs at the wilful ignorance of climate change deniers, who choose to ignore the very good science which proves that climate change is real and is happening just because it is inconvenient to them.

But he also sees reason for hope.

We may be making slow progress - but we are making progress, he says. There is the International Panel on Climate Change, which is doing good, honest, exemplary science; there are the climate action campaigns, regular climate summits, the Paris Accord, the fact that Britain recently managed to run for two weeks without using any electric power generated by coal. And the Apollo programme has left us more aware both of the fragility of our world, and what we ourselves are capable of, he says.

There is now talk of a return to the moon. China recently landed a robot on the moon's dark side, and is said to want to send astronauts there. Donald Trump himself, meanwhile, is talking about Americans returning there by 2024, as a stepping stone to the further exploration of space.

Is that possible? Prof McLeish is sceptical that the US could get back to the moon by 2024 - though China may be able to, he believes.

Whoever goes, it will be hugely expensive. The Apollo missions of the 1960s which led to the moon landings ate up about 5 per cent of the US' entire GDP, Prof McLeish says - a huge amount of money.

So should we be going at all?

Martin Lunn certainly thinks so. Our planet is just too insecure, he says - too at risk from overcrowding, climate change, even the threat of being struck by an asteroid. "Earth is not secure, not safe," he says. "We do need to be going out there, exploring."

Prof McLeish isn't so sure.

The romantic in him would love to see men or women one day setting foot not just on the moon, but on Mars too, he says.

But the pragmatist in him thinks we'd be better off investing in looking after this planet.

That needn't mean we give up on exploring the solar system, he says. It's just that we can do that exploration much more quickly, cheaply and efficiently using robots, than by sending vulnerable human beings out into space. The Huygens probe that landed on Saturn's moon Titan more than a decade ago was an extraordinary achievement, he says.

Richard Darn, however, is fairly confident that within his lifetime, we will see men and women on Mars. It will be done differently, he says - with commercial businesses such as Richard Branson's Virgin Galactic, Jeff Bezos' Blue Origin and Elon Musk's Space X paying a big part.

His worry is that when we do get to Mars, we might just proceed to trash the place.

But he prefers to remain optimistic.

"Let's take the next step," he says.

Neil Armstrong would surely have agreed...