0:00:06 > 0:00:11There are many moons in the solar system, but none like ours.
0:00:13 > 0:00:19It exerts an extraordinary influence on Planet Earth,
0:00:19 > 0:00:23keeping our world in balance.
0:00:25 > 0:00:30But why is it so powerful?
0:00:30 > 0:00:34I want to explore the relationship we have with our closest neighbour,
0:00:34 > 0:00:39to see how the Moon has sculpted our planet and shaped our evolution.
0:00:39 > 0:00:43Without the Moon, would we even be here?
0:00:43 > 0:00:47'I'm Maggie Aderin-Pocock.
0:00:47 > 0:00:51'I'm a space scientist and a lunar fanatic.
0:00:51 > 0:00:55'I've always been mad about the Moon,
0:00:55 > 0:00:59'convinced it plays a huge role in our lives.'
0:00:59 > 0:01:04But I've always taken for granted that it is where it is
0:01:04 > 0:01:08in the night sky, a quarter of a million miles away.
0:01:08 > 0:01:12In this film I'm taking nothing for granted.
0:01:12 > 0:01:19I'm going to find out what would happen if the Moon wasn't where it is now.
0:01:19 > 0:01:22What if the Moon was in a different position,
0:01:22 > 0:01:26closer or further away?
0:01:26 > 0:01:28How different would our world be?
0:01:56 > 0:01:59The Moon is a ball of rock out in space,
0:01:59 > 0:02:05but it has the power to create great tides here on Earth.
0:02:06 > 0:02:12This is Loch Etive on the west coast of Scotland.
0:02:13 > 0:02:20Twice a day, the Moon drags 66 million tonnes of sea water through this loch.
0:02:22 > 0:02:26The result, white water rapids.
0:02:29 > 0:02:33The head of the loch is like a bottleneck.
0:02:33 > 0:02:36Water is funnelled through a very narrow channel.
0:02:36 > 0:02:42And for an hour or two, this becomes one of the wildest, wettest rides in the world.
0:02:48 > 0:02:51These are the Falls of Lora.
0:02:51 > 0:02:53That's what the locals call them.
0:02:53 > 0:02:56In Gaelic, "Lora" means "noisy"
0:02:56 > 0:03:01because as the tidal waters rush out of the loch, it gets very, very loud!
0:03:09 > 0:03:14Kayakers come from all across the world to take the challenge of these waters.
0:03:14 > 0:03:17But they have to paddle like mad just to keep up.
0:03:17 > 0:03:20Even our outboard engine is struggling with the flow.
0:03:20 > 0:03:24This is what the power of the Moon looks like up close.
0:03:29 > 0:03:33My love affair with the Moon began as a child.
0:03:33 > 0:03:36# I wish I was a spaceman
0:03:36 > 0:03:39# The fastest guy alive... #
0:03:39 > 0:03:43I was born in 1968, in the age of Apollo.
0:03:43 > 0:03:49I took my first steps as Neil Armstrong took his giant leap.
0:03:53 > 0:03:55Of course I was too young to know what was going on.
0:03:55 > 0:04:00But the images became seared in my mind.
0:04:00 > 0:04:04From an early age, I wanted to go to the Moon.
0:04:05 > 0:04:11At school I struggled because I'm dyslexic.
0:04:11 > 0:04:16But then I discovered science, and something clicked.
0:04:16 > 0:04:20I wanted to become a scientist.
0:04:21 > 0:04:26And sure enough, today I build satellites.
0:04:26 > 0:04:30It's a mix of engineering and physics and I love it.
0:04:30 > 0:04:37But now that I'm a space scientist, hardly anyone is talking about the Moon any more.
0:04:39 > 0:04:41It used to be the new frontier,
0:04:41 > 0:04:43our future.
0:04:43 > 0:04:49Now it's seen as quaint, old-fashioned, irrelevant.
0:04:49 > 0:04:52I think that's wrong,
0:04:52 > 0:04:55completely wrong.
0:04:55 > 0:04:57I'm still mad about the Moon,
0:04:57 > 0:05:01not just because I want to be an astronaut and go there one day.
0:05:01 > 0:05:02No.
0:05:02 > 0:05:05I'm mad about the Moon because the more I find out about it,
0:05:05 > 0:05:08the more extraordinary it seems.
0:05:10 > 0:05:15The way its presence can conjure up this torrent of water,
0:05:15 > 0:05:16and these waves.
0:05:18 > 0:05:20And how does it do this?
0:05:20 > 0:05:23With the help of gravity.
0:05:25 > 0:05:29Gravity is a great universal force of attraction.
0:05:29 > 0:05:32It keeps us firmly in our place on Earth
0:05:32 > 0:05:35and keeps the Moon in orbit around us.
0:05:38 > 0:05:41But while the Earth is attracting the Moon,
0:05:41 > 0:05:44the Moon is also attracting the Earth,
0:05:44 > 0:05:46pulling at our oceans.
0:05:48 > 0:05:53So I have a set of scales, a metal block and a powerful little magnet.
0:05:53 > 0:05:57You see, the force of gravity is very similar to magnetism.
0:05:57 > 0:05:59They're both forces of attraction.
0:05:59 > 0:06:01If I put the metal block on the scales,
0:06:01 > 0:06:05you can see it weighs 1.3 kg.
0:06:05 > 0:06:09When I put the magnet in and nudge it closer,
0:06:09 > 0:06:12the block appears to weigh less.
0:06:12 > 0:06:16You can see the needle moving.
0:06:16 > 0:06:20That's because the magnet is attracting the metal towards it,
0:06:20 > 0:06:23pulling it upwards, off the scales.
0:06:23 > 0:06:25And that's what the Moon's doing.
0:06:25 > 0:06:31It's pulling on the oceans, moving them upwards, away from the surface of the Earth.
0:06:32 > 0:06:38The gravitational force of the Moon causes the oceans to bulge slightly.
0:06:40 > 0:06:42And as the Earth spins,
0:06:42 > 0:06:45this bulging produces high and low tides.
0:06:49 > 0:06:50The size of the tides
0:06:50 > 0:06:53depends on the distance between the Earth and the Moon.
0:06:59 > 0:07:03The laws of physics are very clear about this.
0:07:03 > 0:07:07The closer two things are, the more they attract each other,
0:07:07 > 0:07:10the greater the gravitational force.
0:07:10 > 0:07:17So we get the tides we do because the Moon is where it is, nearly a quarter of a million miles away.
0:07:17 > 0:07:20But what if the Moon were closer?
0:07:22 > 0:07:27If the Moon were a just a little closer than it is today
0:07:27 > 0:07:30the tidal bulge would grow.
0:07:31 > 0:07:33Low tides would be lower,
0:07:33 > 0:07:35high tides would be higher.
0:07:35 > 0:07:41And any low-lying coastline would be flooded.
0:07:41 > 0:07:44But what if the Moon were much closer?
0:07:44 > 0:07:50Five times, 10 times, 20 times closer than it is today.
0:07:50 > 0:07:54How would that affect the tides and life here on Earth?
0:08:00 > 0:08:03Another rush hour in London.
0:08:03 > 0:08:06But this evening, as the sun sets,
0:08:06 > 0:08:09a huge Moon rises,...
0:08:11 > 0:08:14..20 times closer than normal.
0:08:21 > 0:08:27This super-sized Moon exerts a super-sized gravitational force,...
0:08:29 > 0:08:32..400 times stronger than we're used to.
0:08:34 > 0:08:38And it creates a mighty tidal bulge.
0:08:41 > 0:08:45Sea water pours across the British Isles,
0:08:46 > 0:08:49London is flooded.
0:08:56 > 0:09:00Hours later, the same tidal bulge hits the east coast of America.
0:09:01 > 0:09:04And the story is the same.
0:09:06 > 0:09:09It's New York's turn to disappear underwater.
0:09:12 > 0:09:15A city submerged,...
0:09:17 > 0:09:19..and all the work of the Moon.
0:09:29 > 0:09:32Eventually, of course, the tide subsides.
0:09:34 > 0:09:37And the waters retreat.
0:09:44 > 0:09:51This scenario may seem rather far-fetched, like the plot of some disaster movie.
0:09:51 > 0:09:54But something similar has happened.
0:09:54 > 0:09:58Once upon a time, when the Moon was newly formed,
0:09:58 > 0:10:03it really was so close, and it really was so powerful.
0:10:05 > 0:10:10Let me take you back to the earliest days of our planet,
0:10:10 > 0:10:134.5 billion years ago.
0:10:15 > 0:10:18At this time, the Earth had no Moon,
0:10:18 > 0:10:21it was orbiting the Sun alone
0:10:21 > 0:10:24and it was being assaulted by rocks and comets.
0:10:29 > 0:10:34Today, there are no scars left from this cosmic pinball.
0:10:34 > 0:10:38But to get a sense of the damage that was done,
0:10:38 > 0:10:41I've come to the Arizona Desert,...
0:10:43 > 0:10:46..to a great hole in the ground.
0:10:47 > 0:10:50This is a beautiful crater,
0:10:50 > 0:10:54a near perfect circle a mile in diameter.
0:10:54 > 0:10:59It was formed when a meteorite crashed into the Earth a mere 50,000 years ago.
0:10:59 > 0:11:02That's nothing on the timescale we're talking about,
0:11:02 > 0:11:06but it's amazing how much damage that one passing rock can cause.
0:11:06 > 0:11:11The early Earth was bombarded with rocks. It must have been mayhem.
0:11:11 > 0:11:15And then along came something much, much bigger.
0:11:16 > 0:11:21Another planet the size of Mars, drifted into the path of Earth.
0:11:23 > 0:11:25It was on a collision course.
0:11:30 > 0:11:33It hit the young Earth with a glancing blow.
0:11:33 > 0:11:36Imagine the power released by such a collision.
0:11:40 > 0:11:44The impact sent a mass of liquid rock into orbit.
0:11:48 > 0:11:52This debris coalesced into a ball.
0:11:55 > 0:11:58And the Moon was formed,
0:11:58 > 0:12:02just 14,000 miles away from the early Earth.
0:12:04 > 0:12:09This was the closest point it could have been.
0:12:10 > 0:12:16Any closer, and gravity would have pulled the debris crashing back to Earth,
0:12:16 > 0:12:18and our moon wouldn't exist.
0:12:22 > 0:12:26Today the Moon is just a rock reflecting the sun's light,
0:12:26 > 0:12:31but back then it was a molten sphere, burning brightly.
0:12:31 > 0:12:37It must have looked amazing, an enormous orange disc in the sky.
0:12:39 > 0:12:42Imagine the scene.
0:12:42 > 0:12:46The first moonrise over the early Earth.
0:12:48 > 0:12:51Our world was no longer alone.
0:12:51 > 0:12:54It had a huge, powerful neighbour.
0:13:01 > 0:13:06And ever since, this has been a very different type of planet.
0:13:11 > 0:13:16The collision that created the Moon reset the basic chemistry of Earth.
0:13:19 > 0:13:25And Earth Mk II was a place on which life could begin.
0:13:26 > 0:13:32The collision released huge quantities of metal from the Earth's core,
0:13:32 > 0:13:38one particular metal that would help change the atmosphere of our planet.
0:13:41 > 0:13:44I'm talking about iron.
0:13:46 > 0:13:48Iron is incredibly reactive.
0:13:48 > 0:13:51Leave some out in the garden and it will rust.
0:13:51 > 0:13:54It also combines with other chemicals to release gases
0:13:54 > 0:13:57such as methane, carbon monoxide and hydrogen.
0:13:57 > 0:14:03Today we see these gases as toxic and rather unpleasant.
0:14:03 > 0:14:07But in the early Earth this was the very stuff of life.
0:14:11 > 0:14:19In the 1950s, American chemist Stanley Miller did a classic experiment.
0:14:20 > 0:14:25He took a cocktail of these gases and tried to simulate conditions on the early Earth,
0:14:26 > 0:14:31adding electricity to mimic the power of lightning.
0:14:32 > 0:14:38And what emerged, to everyone's surprise, was a flask of slime,
0:14:38 > 0:14:42which turned out to be full of amino acids.
0:14:44 > 0:14:48Like iron, amino acids are essential for life.
0:14:48 > 0:14:52They are the raw material from which proteins are made.
0:14:52 > 0:14:59And this great chemist was able to produce them using gases that were available on the early Earth.
0:15:00 > 0:15:06The collision that formed the Moon helped set the scene for life to begin.
0:15:08 > 0:15:10But there was still a way to go.
0:15:13 > 0:15:18Life didn't start immediately after the collision.
0:15:18 > 0:15:24It took up to 700 million years for the first living cells to emerge.
0:15:32 > 0:15:36During this time, the Earth was cooling down.
0:15:36 > 0:15:42It formed a rocky surface, water vapour condensed to form oceans.
0:15:45 > 0:15:49And these oceans were being tugged by the Moon.
0:15:51 > 0:15:53They were becoming tidal.
0:15:55 > 0:15:59According to the latest theory from one leading chemist,
0:15:59 > 0:16:03these early tides may have been the trigger
0:16:03 > 0:16:06that kick-started life into action.
0:16:09 > 0:16:12This seems like a very odd place to do some chemistry.
0:16:12 > 0:16:14- Why are we here?- On the beach?
0:16:14 > 0:16:21To investigate the effect of tides on chemistry taking place on the very early Earth, billions of years ago.
0:16:21 > 0:16:24'Professor John Sutherland believes the ebb and flow of the tides
0:16:24 > 0:16:27'may have played a crucial role in the origin of life.
0:16:27 > 0:16:30'And he's going to show me how it could have happened.
0:16:30 > 0:16:32We have to do some chemistry here.
0:16:32 > 0:16:38'He's mixing up the sort of basic chemicals found in the first oceans and adding water.
0:16:38 > 0:16:42'He's reproducing a tidal pool in his flask.'
0:16:42 > 0:16:46And that's your starting tidal pool at high tide.
0:16:46 > 0:16:50Then the tide goes out, the sun shines on the pool and starts drying it out.
0:16:50 > 0:16:54And rather than wait for that to happen here, because that would take
0:16:54 > 0:16:57a long time, I'm going to speed it up by using a burner here.
0:16:57 > 0:16:58So what are we trying to mimic?
0:16:58 > 0:17:00We're trying to mimic here the,...
0:17:00 > 0:17:03the power of the Moon in chemistry on Earth.
0:17:03 > 0:17:06So the Moon is responsible for the tides, the tides are filling these
0:17:06 > 0:17:11ponds up and then, when the tide goes down, the sun shines, dries it up.
0:17:11 > 0:17:16It's an inexorable process of wetting and drying and warming
0:17:16 > 0:17:19and that is driven by the Moon.
0:17:20 > 0:17:27Having created a soup of chemicals, washed and dried them, there's still one thing missing.
0:17:27 > 0:17:30I'm going to now transfer this into
0:17:30 > 0:17:32this other reaction vessel.
0:17:32 > 0:17:37He exposes the chemicals to a blue lamp
0:17:37 > 0:17:41that radiates ultraviolet energy
0:17:41 > 0:17:45simulating the sun's light shining on the early Earth.
0:17:47 > 0:17:53And as a result, he's changing the very structure of the chemicals,...
0:17:54 > 0:18:02..creating, as if from nothing, elements of RNA, ribonucleic acid,
0:18:02 > 0:18:05an essential component of all living cells.
0:18:07 > 0:18:12So we are, in this setup, making some of the building blocks of life?
0:18:12 > 0:18:17Yes! Just from simple tidal conditions and simple organic chemistry.
0:18:17 > 0:18:21- But it's all driven by the Moon? - It's ultimately all driven by the Moon.
0:18:21 > 0:18:23Life on Earth driven by the Moon.
0:18:28 > 0:18:33140 years ago, Charles Darwin wrote a letter to a friend suggesting that
0:18:33 > 0:18:39life probably began in what he called a "warm little pond".
0:18:39 > 0:18:41At the time, it was mere speculation.
0:18:41 > 0:18:43But now we think he might be right.
0:18:43 > 0:18:47These tidal pools represent Darwin's warm little ponds.
0:18:50 > 0:18:55Primordial chemistry labs where the raw materials of life can come together.
0:18:55 > 0:19:00And all beautifully orchestrated by the tidal power of the Moon.
0:19:02 > 0:19:08Once the first creatures had emerged in the oceans 3.8 billion years ago,
0:19:08 > 0:19:11evolution was in full flow.
0:19:13 > 0:19:17And ever since, the Moon has continued watching over us,...
0:19:20 > 0:19:23..casting a protective veil.
0:19:25 > 0:19:30When I was a teenager, I wanted a telescope so badly,
0:19:30 > 0:19:34mainly to look at the Moon, but I couldn't afford a decent one,
0:19:34 > 0:19:39so at the age of 14, I went to an evening class and I learnt to make my own.
0:19:39 > 0:19:46Now my telescope worked on a similar principle to this one, using a mirror to reflect the light.
0:19:46 > 0:19:51It took months to grind and polish those mirrors, but it was so worth it.
0:19:51 > 0:19:54I remember the first night when I pointed the telescope up at the Moon
0:19:54 > 0:19:57and I could see the craters in amazing detail.
0:20:03 > 0:20:10And the first thing you notice is you're always looking at the same craters.
0:20:10 > 0:20:17This is because the Moon spins very slowly, one rotation every 29 days,
0:20:17 > 0:20:21and that's exactly the same speed as the Moon orbits the Earth.
0:20:21 > 0:20:26So as the Moon travels around us, it's always showing us the same face.
0:20:26 > 0:20:30So we never see the far side, or the so-called dark side of the Moon.
0:20:35 > 0:20:40If we could, we'd see that it's riddled with craters.
0:20:40 > 0:20:46In fact, we now know there are more craters on the far side of the Moon than the nearside
0:20:46 > 0:20:48which is bit of a relief
0:20:48 > 0:20:52because each of them was formed by an asteroid impact
0:20:52 > 0:20:55that could otherwise have crashed into Earth
0:20:55 > 0:20:57and stopped life in its tracks.
0:21:01 > 0:21:06The Moon, which helped start life, may also have preserved it.
0:21:06 > 0:21:08Our guardian angel.
0:21:14 > 0:21:19This idea, that the Moon looks after us, is ancient.
0:21:21 > 0:21:285,000 years ago, people on the Outer Hebrides shaped these rocks into megaliths
0:21:28 > 0:21:32and placed them in a great circle.
0:21:33 > 0:21:37They didn't have metal tools,
0:21:37 > 0:21:40let alone cranes.
0:21:40 > 0:21:42It was a remarkable thing to do.
0:21:42 > 0:21:47It's been suggested that they were building a sort of observatory
0:21:47 > 0:21:50to mark a rare lunar event.
0:21:52 > 0:22:00Every 18.5 years, the Moon drops in the sky for a couple of weeks, and barely makes it above the horizon.
0:22:00 > 0:22:07It's known as a lunar standstill and it last happened in 2006, and it won't happen again until 2024.
0:22:07 > 0:22:10Bizarrely, the people who built Callanish
0:22:10 > 0:22:12probably knew about the lunar standstill
0:22:12 > 0:22:14and they aligned their stones to witness it.
0:22:16 > 0:22:24From this angle you can see the Moon rise above those hills over there and drop between those stones.
0:22:24 > 0:22:27It must look spectacular.
0:22:29 > 0:22:32To line up the stones accurately,
0:22:32 > 0:22:35they could only check their position every 18.5 years,
0:22:35 > 0:22:38at the next lunar standstill.
0:22:39 > 0:22:44It seems incredibly complex, so why do it?
0:22:47 > 0:22:51Across the ancient world, people revered the Moon
0:22:51 > 0:22:57and made up stories about the mysterious power of this disc in the night sky.
0:23:01 > 0:23:06Some stories have survived the test of time.
0:23:06 > 0:23:09Think of the classic werewolf movie.
0:23:09 > 0:23:12MAN SHOUTS, CREATURE GROWLS
0:23:13 > 0:23:17It's all about the strange, terrible magic of the Moon.
0:23:23 > 0:23:29Even today, it is often said that the full Moon casts a spell over us.
0:23:29 > 0:23:32# I see a bad moon rising... #
0:23:32 > 0:23:35It sends us a bit crazy.
0:23:35 > 0:23:39It's Friday night and I'm out with the police.
0:23:39 > 0:23:43It's always a busy time with people partying in clubs and bars.
0:23:43 > 0:23:45But tonight is also a full Moon.
0:23:45 > 0:23:47Does that make any difference?
0:23:52 > 0:23:55Over the years, there have been many studies.
0:23:55 > 0:24:00Some claim to show a link between the crime rate and a full Moon.
0:24:00 > 0:24:06They suggest that people become wilder and more violent when the Moon is full.
0:24:06 > 0:24:09It's called the Transylvania Effect.
0:24:12 > 0:24:14One police force in the south of England
0:24:14 > 0:24:18was so convinced, they put extra officers on the beat at a full Moon,
0:24:18 > 0:24:21just in case.
0:24:23 > 0:24:27But is it true? Does the Moon really change our behaviour?
0:24:30 > 0:24:33Well, sadly, I don't think so.
0:24:33 > 0:24:37For every study claiming an effect, there are many more dismissing it.
0:24:37 > 0:24:43The theory probably stems from the fact that when the Moon is full, the sky is much, much brighter.
0:24:44 > 0:24:51In the past, before electric lights, people were more likely to go out on a bright night,
0:24:51 > 0:24:54so there was more chance for trouble.
0:24:54 > 0:24:58These days, alcohol is surely a far more important factor
0:24:58 > 0:25:00than the light of a full Moon.
0:25:02 > 0:25:07But even if the Transylvania Effect is a bit of a myth,
0:25:07 > 0:25:10the Moon is still very powerful.
0:25:12 > 0:25:18There are many animals which react instinctively to the light of the full Moon.
0:25:18 > 0:25:22They become more active, more vocal,
0:25:22 > 0:25:24more fertile.
0:25:26 > 0:25:31Most remarkable of all are these tropical corals.
0:25:38 > 0:25:43Every year they synchronise their reproductive cycle,
0:25:43 > 0:25:46so on one night they all spawn together.
0:25:48 > 0:25:53And for these corals, it's triggered by the full Moon.
0:26:05 > 0:26:08The Sargasso Sea, off the coast of Bermuda.
0:26:11 > 0:26:18Marine biologist Dr Anne Cohen is studying how the Moon affects the growth of corals.
0:26:22 > 0:26:26She's looking for a species known as Diploria strigosa,
0:26:26 > 0:26:28the brain coral.
0:26:31 > 0:26:34Every 29 days, on a full Moon,
0:26:34 > 0:26:40brain corals grow a new layer of skeleton on top of the old.
0:26:40 > 0:26:45This growth spurt is dictated by the monthly orbit of the Moon.
0:26:45 > 0:26:47It's like clockwork.
0:26:49 > 0:26:53And the skeletal layers can be used as a lunar calendar,...
0:26:54 > 0:26:57..a record of time passing.
0:27:04 > 0:27:09So, this is the coral that we pulled out of the water today.
0:27:09 > 0:27:11And if we look under the microscope,
0:27:11 > 0:27:16you can see very fine ridges
0:27:16 > 0:27:20and we know that these are formed on the lunar cycle, these are monthly bands.
0:27:20 > 0:27:25- So it's a bit like the rings of a tree, you can use that to date it. - That's right.
0:27:25 > 0:27:31And we can count about 65 monthly bands in this coral,
0:27:31 > 0:27:34which makes it just over five years old.
0:27:34 > 0:27:36That's pretty amazing!
0:27:36 > 0:27:39'But some corals are even more revealing.
0:27:39 > 0:27:43'They allow us to peer into the distant past
0:27:43 > 0:27:49'and find out something extraordinary about the power of the Moon.
0:27:49 > 0:27:53'This is a fossil coral from the Devonian era.
0:27:53 > 0:27:57'It's 400 million years old
0:27:57 > 0:28:01'but still beautifully preserved.
0:28:01 > 0:28:06'As well as monthly growth bands, there are annual bands
0:28:06 > 0:28:12'and even daily bands, a quarter of a millimetre apart.'
0:28:12 > 0:28:18So this coral grew about a quarter of a millimetre every day 400 million years ago.
0:28:18 > 0:28:20400 million years ago.
0:28:20 > 0:28:25And if we took the time to count up all these daily growth bands,
0:28:25 > 0:28:30within the year we'd find...
0:28:30 > 0:28:33not 365 days
0:28:33 > 0:28:39but in fact in this coral there are 400 bands every year.
0:28:39 > 0:28:41400 days a year.
0:28:41 > 0:28:43- 400 bands?- Per year.
0:28:43 > 0:28:48- So that means that there were an extra 35 days every year?- That's right.
0:28:48 > 0:28:50That's quite mind-boggling.
0:28:50 > 0:28:57'If there were really 400 days in the year back then, how long was each day?'
0:28:59 > 0:29:04If you do the sums, and take the total number of hours in a year
0:29:04 > 0:29:07and divide by 400 days, then you come to the conclusion
0:29:07 > 0:29:12that in the Devonian period, when this fossil was alive,
0:29:12 > 0:29:17a day actually lasted 21 hours and 55 minutes.
0:29:17 > 0:29:20Now I must admit I find that really weird.
0:29:20 > 0:29:24The fact that in the past, a day wasn't 24 hours.
0:29:26 > 0:29:32The length of a day is simply the time it takes for the Earth to spin once
0:29:32 > 0:29:36and go from one sunrise to the next.
0:29:39 > 0:29:41If, in the past, days were shorter,
0:29:41 > 0:29:45then the Earth must have been spinning faster.
0:29:47 > 0:29:51In fact, back in time, back billions of years,
0:29:51 > 0:29:54the planet was spinning so fast
0:29:54 > 0:29:57that each day lasted just five hours.
0:29:59 > 0:30:03But why should the spin of the Earth have changed over time?
0:30:03 > 0:30:05Because of the Moon.
0:30:08 > 0:30:12When the Moon formed, it was so close to the Earth,
0:30:12 > 0:30:18and pulling so hard that it acted as a brake on our planet.
0:30:18 > 0:30:23The gravitational pull of the Moon was slowing the Earth's spin
0:30:23 > 0:30:25and it's still doing so.
0:30:25 > 0:30:28As the Earth spins,
0:30:28 > 0:30:32the effect of friction between the ocean bulge and ocean floor
0:30:32 > 0:30:35causes the Earth's spin to slow down.
0:30:36 > 0:30:39It means days have been getting longer.
0:30:41 > 0:30:45What was once was five hours now lasts 24.
0:30:47 > 0:30:50We humans have been around for such a short time,
0:30:50 > 0:30:53about 200,000 years,
0:30:53 > 0:30:56that we've only ever known 24 hour days.
0:30:56 > 0:31:00Our body clocks are completely geared for that length of day.
0:31:00 > 0:31:05And yet, we only have 24-hour days because of the Moon.
0:31:07 > 0:31:10It's amazing to think that the very rhythms of our planet
0:31:10 > 0:31:15have been set by this ball of rock out in space.
0:31:16 > 0:31:19But what about the Moon itself?
0:31:19 > 0:31:22How has it been affected by the spin of the Earth?
0:31:25 > 0:31:29One of the first things you learn in physics is that for every action
0:31:29 > 0:31:34there is an equal and opposite reaction.
0:31:34 > 0:31:37As the Earth has been slowing down all these years,
0:31:37 > 0:31:39something else has been accelerating,
0:31:39 > 0:31:43and that's the Moon.
0:31:43 > 0:31:45And to compensate for its acceleration,
0:31:45 > 0:31:49something's been happening to its orbit at the same time.
0:31:49 > 0:31:54Imagine the centre of this roundabout is the Earth, and I'm the Moon in orbit.
0:31:54 > 0:31:57As we speed up, I get slung outwards,
0:31:57 > 0:32:00and I feel as if my body wants to move into a wider orbit.
0:32:02 > 0:32:04And that, more or less,
0:32:04 > 0:32:06is what's been happening to the Moon.
0:32:09 > 0:32:14To balance out its acceleration, it's been spiralling outwards,
0:32:14 > 0:32:16into a wider and wider orbit.
0:32:18 > 0:32:22But is it still spiralling away?
0:32:22 > 0:32:23Or has it stopped?
0:32:26 > 0:32:28There's one way to find out.
0:32:36 > 0:32:39Apache Point Observatory in New Mexico...
0:32:41 > 0:32:45..one of America's largest telescopes.
0:32:45 > 0:32:51It's also one of the last outposts of the Apollo programme.
0:32:54 > 0:32:58Besides having a lot of fun on the Moon,
0:32:58 > 0:33:03the Apollo astronauts were running a series of scientific experiments.
0:33:06 > 0:33:11And on three of the missions they left behind retro-reflector units,
0:33:11 > 0:33:13packed with small mirrors.
0:33:15 > 0:33:17This one is from Apollo 15.
0:33:22 > 0:33:27And ever since, astronomers have been firing lasers at them
0:33:27 > 0:33:32to keep track of exactly how far away the Moon is.
0:33:32 > 0:33:36So once we're all centred up on Apollo 15,
0:33:36 > 0:33:40I can open the shutter and we're ready to shine the laser.
0:33:40 > 0:33:45Dr Russet McMillan carries out the laser ranging at Apache Point.
0:33:48 > 0:33:51So you're now sending pulses of laser-light out towards the Moon.
0:33:51 > 0:33:54That's right, they're going to travel to the Moon,
0:33:54 > 0:33:57get reflected, come back, and get detected by our detector.
0:33:57 > 0:34:00So how much of the light do we actually get back?
0:34:00 > 0:34:07Well, we're sending out about 100 quadrillion photons with each pulse.
0:34:07 > 0:34:10If we're lucky, for each pulse we might get back one photon.
0:34:10 > 0:34:12One photon back?
0:34:12 > 0:34:17One photon out of 100 quadrillion going out.
0:34:17 > 0:34:24A photon is a tiny particle of light and 100 quadrillion is...
0:34:24 > 0:34:28a phenomenally large number!
0:34:28 > 0:34:31But by capturing just a few photons,
0:34:31 > 0:34:33it's possible to measure
0:34:33 > 0:34:35the distance between the Earth and the Moon
0:34:35 > 0:34:37down to the last millimetre.
0:34:44 > 0:34:48As of right now, the distance to the Moon
0:34:48 > 0:34:53is 393,499km,
0:34:53 > 0:34:58257m and 798mm...
0:34:58 > 0:35:00precisely.
0:35:02 > 0:35:08Astronomers have been using lasers to measure the Moon's distance for nearly 40 years now.
0:35:08 > 0:35:14And what they're finding amongst all those photons is a very clear pattern.
0:35:14 > 0:35:18The Moon, which has been drifting away from us for billions of years,
0:35:18 > 0:35:20is still drifting,
0:35:20 > 0:35:24at a speed of 3.78 cm a year.
0:35:24 > 0:35:25In human terms,
0:35:25 > 0:35:29that's about the same speed that our fingernails grow!
0:35:30 > 0:35:35Does it matter that the Moon is drifting away from us?
0:35:36 > 0:35:38Well, for one thing,
0:35:38 > 0:35:44if it keeps going, we'll lose a great natural wonder.
0:35:48 > 0:35:53One of the benefits of astronomy is you get to stay up very late.
0:35:57 > 0:36:02And if you don't go to bed at all, you can catch the Moon setting
0:36:02 > 0:36:04while the sun rises.
0:36:09 > 0:36:12What an amazing sight.
0:36:12 > 0:36:17There the rising sun, and opposite the setting Moon.
0:36:17 > 0:36:19They both look exactly the same size,
0:36:19 > 0:36:21but that's an optical illusion.
0:36:23 > 0:36:25Let's take these two balls.
0:36:25 > 0:36:28The golf ball is much smaller than the tennis ball
0:36:28 > 0:36:30and you can tell that when they are side by side.
0:36:30 > 0:36:32But if I move the golf ball towards you,
0:36:32 > 0:36:35you can see it's getting bigger and at this point,
0:36:35 > 0:36:39they look to be the same size.
0:36:39 > 0:36:42Now, it's exactly the same with the Sun and the Moon.
0:36:42 > 0:36:45The Moon is actually 400 times smaller than the Sun.
0:36:45 > 0:36:48But it's also 400 times closer,
0:36:48 > 0:36:52and so they appear to be the same size.
0:36:52 > 0:36:58And that's what gives us the most mesmerising sight,
0:36:58 > 0:37:00a total eclipse.
0:37:02 > 0:37:06Because the Moon's disc is the same size as the Sun's,
0:37:06 > 0:37:09they line up perfectly,
0:37:09 > 0:37:16with just a halo of solar gases spilling out around the rim.
0:37:21 > 0:37:24I always thought there must be some astronomical reason for this,
0:37:24 > 0:37:27something in the physics to make it so.
0:37:27 > 0:37:32But no, it's just a cosmic coincidence.
0:37:33 > 0:37:36It happens because right now,
0:37:36 > 0:37:40the Moon is just the right distance from Earth.
0:37:40 > 0:37:45But in the future, as the Moon keeps drifting away,
0:37:45 > 0:37:49its disc will be too small to cover the sun
0:37:49 > 0:37:53and we'll lose the magic of the total eclipse.
0:37:55 > 0:37:57And then what?
0:37:57 > 0:38:01As the Moon moves away from us, how will life change here on Earth?
0:38:14 > 0:38:17New York City.
0:38:17 > 0:38:20The sun went down an hour ago,
0:38:20 > 0:38:22and the Moon is rising.
0:38:24 > 0:38:26It may look familiar enough
0:38:26 > 0:38:31but this Moon is smaller than normal in the night sky.
0:38:31 > 0:38:34That's because it's further away.
0:38:34 > 0:38:38Not much, an extra 10%,
0:38:38 > 0:38:41just 24,000 miles.
0:38:41 > 0:38:44But that makes a big difference.
0:38:46 > 0:38:50The spin of the Earth has slowed down
0:38:50 > 0:38:53and days are getting longer.
0:38:53 > 0:38:58The sun will not rise here for another 20 hours.
0:39:01 > 0:39:07The entire Western hemisphere has to endure a very long night.
0:39:07 > 0:39:10While on the other side of the world,
0:39:10 > 0:39:12there's an extra-long day.
0:39:14 > 0:39:16But things get worse.
0:39:16 > 0:39:19If the Moon were to really move by that 10%,
0:39:19 > 0:39:23then the very stability of the planet would be threatened.
0:39:26 > 0:39:28You see, the Moon,
0:39:28 > 0:39:31which controls our tides and the spin of the earth
0:39:31 > 0:39:33serves another critical function.
0:39:33 > 0:39:37It keeps us stable.
0:39:37 > 0:39:43To understand why, meet hoop wizard Jack Ryan.
0:39:45 > 0:39:50As Jack runs rings around me, look how he keeps that ball spinning.
0:39:50 > 0:39:52- Jack, what's the secret?- Speed.
0:39:52 > 0:39:56You got to keep it fast, it's got to be going fast.
0:39:56 > 0:39:59- Would you like to try? - I'd love to. What do I do?
0:39:59 > 0:40:01Just stay still. Let me see your finger.
0:40:03 > 0:40:04There you go.
0:40:04 > 0:40:08So the ball is just like planet Earth.
0:40:08 > 0:40:10The faster it spins, the more stable it is.
0:40:10 > 0:40:13- But what happens if it slows down? - Let's see.
0:40:14 > 0:40:19That's lots of wobble and, ooh, I lose control.
0:40:19 > 0:40:20So that's just like the Earth -
0:40:20 > 0:40:25when it's spinning very fast, it's very stable, but as it slows down,
0:40:25 > 0:40:28it loses stability and starts to wobble like crazy.
0:40:30 > 0:40:35Ever since the great collision that formed the Moon,
0:40:35 > 0:40:37the Earth has been tilted,
0:40:37 > 0:40:39spinning at 23 degrees.
0:40:43 > 0:40:49This tilt has played a crucial role in shaping our climate.
0:40:49 > 0:40:53If the Earth wasn't tilted, if it were upright,
0:40:53 > 0:40:58then the sun's light would shine evenly over the surface throughout the year.
0:40:58 > 0:41:00Always overhead at the equator,
0:41:00 > 0:41:03and barely reaching the North and South poles.
0:41:03 > 0:41:06The temperature would be constant throughout the year,
0:41:06 > 0:41:08there'd be no summer or winter.
0:41:08 > 0:41:10No variation at all.
0:41:10 > 0:41:14But because of that 23 degrees tilt,
0:41:14 > 0:41:18the light hitting the Earth's surface varies throughout the year.
0:41:20 > 0:41:24It's this variety of light that's so important.
0:41:24 > 0:41:26It means that throughout the year,
0:41:26 > 0:41:30conditions on the planet are always changing.
0:41:32 > 0:41:35In our summer, the light favours the northern hemisphere,
0:41:35 > 0:41:38giving us warmer temperatures and longer days.
0:41:38 > 0:41:40But six months later,
0:41:40 > 0:41:43as the Earth travels to the other side of the sun,
0:41:43 > 0:41:46the light now favours the southern hemisphere,
0:41:46 > 0:41:51leaving us in the cold and dark with shorter days and longer nights.
0:41:51 > 0:41:55In other words, we have seasons.
0:41:57 > 0:42:02The life cycle of so many animals and plants
0:42:02 > 0:42:05is driven by the beat of the seasons.
0:42:06 > 0:42:09A burst of life in spring.
0:42:09 > 0:42:13Balmy days of summer.
0:42:13 > 0:42:16Migration in autumn.
0:42:16 > 0:42:19A fight for survival in winter.
0:42:21 > 0:42:24But the Earth only stays at this 23 degree tilt
0:42:24 > 0:42:28because of the Moon's stabilising effect.
0:42:30 > 0:42:35As the Moon keeps drifting away, the angle of the tilt will change.
0:42:36 > 0:42:41And over time, the Earth will wobble.
0:42:41 > 0:42:44And what will happen then?
0:42:44 > 0:42:47It's possible we'll go the same way as Mars.
0:42:49 > 0:42:52Mars - our planetary neighbour.
0:42:52 > 0:42:56Today, it spins at an angle of 25 degrees,
0:42:56 > 0:42:58very similar to Earth.
0:42:58 > 0:43:02But it used to spin at a very different angle,
0:43:02 > 0:43:04anything up 60 degrees.
0:43:07 > 0:43:10You see, unlike Earth,
0:43:10 > 0:43:14Mars has no large moon to keep it stable
0:43:14 > 0:43:17so it wobbles chaotically.
0:43:17 > 0:43:21It could almost tip over onto its side.
0:43:23 > 0:43:28We may suffer the same fate if our Moon moved just that 10% further away.
0:43:28 > 0:43:33It makes me wonder what would our world be like?
0:43:33 > 0:43:35Probably very wet.
0:43:38 > 0:43:42If the Earth tipped over and spun on its side,
0:43:42 > 0:43:48then for three months of every year the poles would be exposed
0:43:48 > 0:43:51to direct unrelenting sunshine.
0:43:51 > 0:43:54Pretty quickly, the ice caps would melt.
0:43:56 > 0:44:01And a huge amount of fresh water would flood the world's oceans.
0:44:01 > 0:44:05Sea levels would rise by more than 60 metres.
0:44:05 > 0:44:10Every coastal city in the world would be gone.
0:44:11 > 0:44:15And inland areas that survived would be transformed.
0:44:18 > 0:44:20Las Vegas is dark
0:44:20 > 0:44:23and very cold.
0:44:23 > 0:44:25It's minus 20.
0:44:27 > 0:44:31Because the sun is pointing at Antarctica,
0:44:31 > 0:44:34Vegas is in the grip of a freezing winter.
0:44:38 > 0:44:42But in the spring, the snow melts,
0:44:42 > 0:44:45the sun rises higher and higher in the sky.
0:44:47 > 0:44:50Over the summer, the sun never sets.
0:44:51 > 0:44:54In autumn, it's high in the sky.
0:44:55 > 0:44:58And then it drops below the horizon again.
0:45:01 > 0:45:04And the freezing winter returns.
0:45:05 > 0:45:07Could we survive?
0:45:07 > 0:45:12Probably, with enough air conditioning and artificial light.
0:45:15 > 0:45:19But what of other life forms?
0:45:21 > 0:45:26Dr Lynn Rothschild is an astro-biologist working for NASA.
0:45:26 > 0:45:30Death Valley is the hottest place in North America.
0:45:30 > 0:45:33And it turns out that as the Moon recedes from the Earth,
0:45:33 > 0:45:34as it goes away,
0:45:34 > 0:45:37there are going to be times that the Earth
0:45:37 > 0:45:39tips over further on its side,
0:45:39 > 0:45:42and what's going to happen then is that there are going to be
0:45:42 > 0:45:46parts of the Earth that become excruciatingly hot in the summer,
0:45:46 > 0:45:48much hotter than Death Valley is today.
0:45:50 > 0:45:54And in the winter these same places are going to be bitterly cold,
0:45:54 > 0:45:56much colder than your freezer.
0:45:59 > 0:46:03There are organisms that can survive at reasonably low temperatures,
0:46:03 > 0:46:07think of penguins and whales, and so on.
0:46:07 > 0:46:10But high temperature is extremely tricky.
0:46:10 > 0:46:14When you get up at about 70 degrees centigrade which is hot,
0:46:14 > 0:46:18but it's nowhere near the boiling temperature of water, chlorophyll breaks down
0:46:18 > 0:46:20so all the greenery you see around you would be gone.
0:46:20 > 0:46:22So that means no photosynthesis?
0:46:22 > 0:46:27Absolutely, so no photosynthesis, and that's what drives life on Earth today, photosynthesis.
0:46:27 > 0:46:30Now, as you go up even beyond that,
0:46:30 > 0:46:33your nucleic acids end up breaking and unravelling,
0:46:33 > 0:46:35and this is your very genetic material.
0:46:35 > 0:46:37So, clearly, you cannot survive without these.
0:46:39 > 0:46:43There are some microbes with a very unusual genetic structure
0:46:43 > 0:46:47which can live in deep-sea vents and geysers
0:46:47 > 0:46:50at temperatures over 100 degrees.
0:46:50 > 0:46:54But they can't cope anywhere cooler.
0:46:54 > 0:46:57And that's the problem.
0:46:57 > 0:47:00If the Earth tips over,
0:47:00 > 0:47:05the seasonal shifts will be too fast and too extreme
0:47:05 > 0:47:07for evolution to keep pace.
0:47:09 > 0:47:13Even though there are a few organisms that can adapt to living in
0:47:13 > 0:47:16excruciatingly hot temperatures,
0:47:16 > 0:47:20and there are plenty of organisms that can live in very cold temperatures,
0:47:20 > 0:47:22much colder than your freezer at home,
0:47:22 > 0:47:25to have the same organism being able to shift between these extremes
0:47:25 > 0:47:29during the course of a single year is nearly impossible.
0:47:29 > 0:47:34And I suspect we're never going to evolve one that could do that.
0:47:34 > 0:47:36Let us be clear,
0:47:36 > 0:47:38we are in no immediate danger.
0:47:38 > 0:47:41It will take at least a billion years
0:47:41 > 0:47:45for the Moon to drift far enough away for the Earth to tip over.
0:47:45 > 0:47:48So we have a little time to prepare.
0:47:48 > 0:47:53But all this speculation makes me realise how lucky we are
0:47:53 > 0:47:55the Moon is where it is right now.
0:47:55 > 0:48:00A tiny shift and life on Earth could be so different.
0:48:03 > 0:48:07And what about life beyond Earth?
0:48:07 > 0:48:10Are we alone?
0:48:11 > 0:48:17Or are there other planets with lifeforms similar to ours?
0:48:20 > 0:48:28These radio telescopes are scanning the heavens, looking for any clues.
0:48:28 > 0:48:30But where do we look?
0:48:30 > 0:48:34Even our own galaxy has 100 billion stars
0:48:34 > 0:48:39and each one of those stars has who knows how many planets in orbit.
0:48:39 > 0:48:41I reckon, given what we now know about the Moon,
0:48:41 > 0:48:44how it's influenced life here on Earth,
0:48:44 > 0:48:49we should focus any future searches on planets with moons like ours.
0:48:52 > 0:48:55There are many moons in the solar system
0:48:55 > 0:48:57but they're not like ours.
0:48:57 > 0:49:02The moons of Jupiter are too small and far away
0:49:02 > 0:49:04to influence their planet.
0:49:06 > 0:49:11The same is true for the moons of Saturn, Neptune and Uranus.
0:49:12 > 0:49:18Only our moon is big enough and close enough to affect us,
0:49:18 > 0:49:21but not so big to make life here unbearable.
0:49:24 > 0:49:29It's not too big and it's not too small.
0:49:29 > 0:49:33Like Goldilocks and the porridge, it's just right.
0:49:36 > 0:49:42One day, I'm confident we'll find other planets with moons like ours.
0:49:42 > 0:49:45But will we ever visit them?
0:49:45 > 0:49:49Will we ever boldly go out into space?
0:49:50 > 0:49:54If so, then the Moon has a big role to play.
0:49:58 > 0:50:02So far, only 12 people have ever been there.
0:50:02 > 0:50:06And they brought back a very precious cargo.
0:50:08 > 0:50:10'That's 20 pounds of rock!'
0:50:11 > 0:50:16382kg of lunar rock.
0:50:16 > 0:50:19'Oh, Tony, it's got some beautiful crystals in it!
0:50:19 > 0:50:21'Good show.'
0:50:25 > 0:50:30When geologists analysed these rocks, they learnt a great deal
0:50:30 > 0:50:33about the composition of the Moon,
0:50:33 > 0:50:36and the history of the solar system.
0:50:36 > 0:50:39But they didn't find what they were looking for -
0:50:39 > 0:50:42any sign of water.
0:50:45 > 0:50:48The Moon, they declared, was bone dry.
0:50:53 > 0:50:57But now, they're changing their minds.
0:51:03 > 0:51:06The Moon rocks are stored in a clean room
0:51:06 > 0:51:10at NASA's Johnson Space Centre in Houston.
0:51:12 > 0:51:17Dr Gary Lofgren has the job of keeping them pristine,
0:51:17 > 0:51:22as if they were still on the lunar surface.
0:51:22 > 0:51:25So this is it, this is a piece of Moon rock?
0:51:25 > 0:51:28Yes, this is a piece of lava from Apollo 17.
0:51:28 > 0:51:31For me, this is a fantastic moment because I've always dreamed of
0:51:31 > 0:51:35going to the Moon, and so to be this close to a piece of Moon rock,
0:51:35 > 0:51:36this is brilliant.
0:51:36 > 0:51:41This is spectacular. If you look, you can see all the shiny crystals reflecting back at you.
0:51:41 > 0:51:47They're all very fresh. That's one of the unique things about Moon rocks.
0:51:47 > 0:51:50I was expecting it to be quite dull, but it looks so shiny.
0:51:50 > 0:51:56Yeah, shiny it is, it's because there's no water there to alter and weather the minerals.
0:51:56 > 0:51:59- So no reactions?- There's no reactions going on, that's right.
0:51:59 > 0:52:03So that gave us the idea the Moon was very dry, very inert.
0:52:03 > 0:52:07And we thought that for 40 years, but within the last few years,
0:52:07 > 0:52:11we discovered that there is a lot of water on the Moon, in fact.
0:52:11 > 0:52:15- It's water that's trapped. Because it's cold, it's frozen as ice.- Yes.
0:52:18 > 0:52:19Recently,
0:52:19 > 0:52:23probes have analysed some of the darkest craters on the Moon,
0:52:23 > 0:52:25at the lunar poles,
0:52:25 > 0:52:28and have found that they're packed with ice -
0:52:28 > 0:52:34frozen water that has come from comets crashing into the Moon over time.
0:52:36 > 0:52:41It now seems there's at least 400 billion litres of water
0:52:41 > 0:52:43in these craters.
0:52:43 > 0:52:47Having water on the moon opens up a whole area of possibilities.
0:52:47 > 0:52:49Oh, yes, it allows humans to survive.
0:52:49 > 0:52:52We need water to drink and water to survive up there.
0:52:52 > 0:52:54But just as importantly we can use that water
0:52:54 > 0:52:59to make rocket fuel, because rocket fuel is gaseous hydrogen and oxygen,
0:52:59 > 0:53:01and we can make that on the Moon.
0:53:04 > 0:53:05The Saturn V rockets
0:53:05 > 0:53:07used by Apollo
0:53:07 > 0:53:13burnt 2,500 tonnes of rocket fuel to escape Earth's gravity
0:53:13 > 0:53:15and get into space.
0:53:20 > 0:53:24But if we could produce fuel from lunar water,
0:53:24 > 0:53:27that would make all the difference.
0:53:29 > 0:53:33It would be far more efficient to travel into deep space
0:53:33 > 0:53:37by launching rockets from the Moon, not the Earth.
0:53:40 > 0:53:43Perhaps, one day,
0:53:43 > 0:53:47the Moon will become a springboard for exploring the solar system.
0:53:50 > 0:53:54Spaceships will make the short hop from Earth and then re-fuel here
0:53:54 > 0:53:57before setting off on the long journey ahead.
0:54:01 > 0:54:05But if this seems a bit too futuristic,
0:54:05 > 0:54:09then one man has more immediate plans for the Moon.
0:54:12 > 0:54:17For 30 years, space scientist Dr David Criswell has had a dream -
0:54:17 > 0:54:22to put thousands of solar panels on the Moon
0:54:22 > 0:54:25and harness the energy of the Sun.
0:54:25 > 0:54:28We can have solar panels on Earth, why take them to the Moon?
0:54:28 > 0:54:30You want to take them to the Moon
0:54:30 > 0:54:33because the sunlight on the Moon is absolutely predictable.
0:54:33 > 0:54:36There's no air, there's no water, there's no mechanical vibrations,
0:54:36 > 0:54:39so you don't have to build massive facilities like this.
0:54:39 > 0:54:45On the Moon, you could replace these with solar arrays that are the thickness of tissue paper.
0:54:47 > 0:54:53The plan is to build thin solar panels along the rim of the Moon
0:54:53 > 0:54:55so they get almost constant sunlight.
0:54:55 > 0:55:01The electricity would then be transmitted back to Earth using microwaves.
0:55:02 > 0:55:06He believes he can produce enough energy to meet global demand.
0:55:08 > 0:55:12The Moon receives 13,000 terawatts of power,
0:55:12 > 0:55:15solar power that's going to waste.
0:55:15 > 0:55:18By going to the Moon, we can collect that power at the cheapest cost
0:55:18 > 0:55:19and send it back here to Earth.
0:55:22 > 0:55:27He's hoping to create an unlimited supply of energy
0:55:27 > 0:55:29with the least environmental impact.
0:55:32 > 0:55:36You see, the plan is to make everything on the Moon itself
0:55:36 > 0:55:39from what's already there on the lunar surface.
0:55:39 > 0:55:44When you look at the Moon, basically what you see is dust.
0:55:45 > 0:55:52It's very, very finely ground-up rock and glass. You can make it into fibreglass,
0:55:52 > 0:55:57you can make into containers, you can make into rods and tubes and all of that sort of stuff.
0:56:00 > 0:56:04You make it sound so straightforward, so why aren't we doing it?
0:56:04 > 0:56:07Well, you've got to be on the Moon, we've got to go back to the Moon.
0:56:07 > 0:56:12Somehow we've lost the will to do this commitment,
0:56:12 > 0:56:17going back to the Moon and making it a permanent stay, rather than just a short visit.
0:56:18 > 0:56:23Now, this grand scheme would cost at least half a trillion dollars.
0:56:25 > 0:56:30But that's less than oil companies spend every two years
0:56:30 > 0:56:32getting oil and gas out of the ground.
0:56:33 > 0:56:39There's nothing to stop us building solar-powered bases
0:56:39 > 0:56:41on the Moon right now.
0:56:41 > 0:56:44And I, for one, can't wait for the day.
0:56:50 > 0:56:54For a few years during the age of Apollo,
0:56:54 > 0:56:57we were all mad about the Moon.
0:57:02 > 0:57:04It was fun,
0:57:04 > 0:57:09it was exciting, and for me at least,
0:57:09 > 0:57:11it was love at first sight.
0:57:24 > 0:57:29But then, all too quickly, we lost interest in the Moon.
0:57:29 > 0:57:32We moved on.
0:57:33 > 0:57:36I think that was a mistake.
0:57:36 > 0:57:39The Moon is far more important
0:57:39 > 0:57:43and far more useful than we ever realised.
0:57:45 > 0:57:49For billions of years, it's gazed down on us...
0:57:51 > 0:57:53..shaping and changing
0:57:53 > 0:57:56the course of life here on Earth.
0:57:56 > 0:58:02In so many ways, the Moon has been the making of us.
0:58:03 > 0:58:08Surely, it's time to re-think our relationship with the Moon,
0:58:08 > 0:58:10to stop taking it for granted,
0:58:10 > 0:58:12to fall in love again.
0:58:12 > 0:58:14Do we really need the Moon?
0:58:14 > 0:58:16Of course we do.
0:58:30 > 0:58:33Subtitles by Red Bee Media Ltd