Driest Fierce Earth

We've journeyed 6,000 miles to the country of Chile.

This is the Atacama Desert - the driest place in the world.

Parts of this barren land have never recorded rain.

Human life needs water to survive, so we're in for a tough ride.

We're heading into the wilderness

to find out the secrets of this bone-dry desert.

Come with us on a journey through this, the world's driest place.

And this is what you'll see.

I'll take to the sky and then fall through the air to reveal

why the rain never makes it here.

We'll race one of Chile's toughest men

across this dangerous, barren land.

And I'll find out why the world's driest place,

is the perfect place to get close to the stars.

What happens when the ground shakes,

the seas rise up and the air tears itself apart?

The Fierce Earth team move in,

taking on the most powerful forces on the planet.

Get ready for Fierce Earth - the Earth and how to survive it.

I'm standing right in the middle of the Atacama Desert,

a bone-dry, barren strip of land

that runs right through the country of Chile.

Chile sits on the Pacific coast

and its neighbours are countries like Argentina, Bolivia and Peru

with their huge rainforests and epic rivers.

It's very different here.

All deserts lack moisture, but the Atacama takes it to another level.

Nothing survives here - it's more like Mars than the planet Earth.

So why is it so dry here?

That's a complicated one. There's three main rain-stopping forces

that have kept water away and have turned this into an empty desert.

Three Fierce Earth heads are always better than one,

and Clare, Leo and I are all going to work on this.

We'll identify the three forces

that stop moisture from reaching the ground here.

And to do that, we're diving deep and flying high.

Wish me luck. I'm boarding this bad boy and taking to the skies.

It's time to find out the details behind rain blocker number one.

We're up at 3,000 metres.

Over there to the east are the mighty Andes Mountains.

If you go over the top of the Andes,

you're in a totally different land to the bone-dry Atacama.

It's green and lush.

The clouds that carry the rain across South America

hit those mountains, they're like a barrier,

and the rain empties from those clouds.

The Andes shut the door on the rain that this part of the world

so desperately needs. And that is Dry Fact number one.

Dry Fact one - the Andes Mountains block rain from the east.

Dry Fact number two.

The second thing that keep the rain clouds away from the Atacama Desert.

To find out all about it, I'm heading out to sea -

the Pacific Ocean.

It's incredible to think that the Atacama Desert is just there

and it's devoid of life.

But, here, along the coast, it's teeming with wildlife.

But it's unusual to have a desert so close to the ocean.

This is what normally happens along the coastline.

The sun beats down and heats the ocean.

Water evaporates up into the sky and forms clouds.

The water then falls on to the land as rain as it cools.

But that does not happen here. And the reason why?

Well, I'm going to take a dip to find out.

This is weather science in action. Let's go.

Oh! It's absolutely freezing!

What a shock to my body!

I've got a dive watch here, let me have a look at the temperature.

I can't believe it. 13 degrees Celsius!

You'd expect this part of the Pacific Ocean to be much warmer.

But the water I'm swimming in now

has flowed all the way from the Antarctic,

up along the coast of South America.

This huge stream of cold water has a special name,

it's called the Humboldt current.

And it's the reason why

this water is so chilly.

And it's also the reason why the Atacama stays so dry.

This is what happens. Because the water is so cold,

there's little evaporation from the sea's surface.

And because of that, there's not enough water vapour to form clouds.

Without rain clouds, there's no rain.

And that's the reason why the Atacama Desert is so dry.

That is rain blocker number two.

Dry Fact two - the cold ocean and little evaporation

means there's no rain from the west.

Here's the third and final rain blocker

that keeps the Atacama so dry.

It's because of the air that flows over the land here.

1,000 miles to the north of here is a line called the equator,

which runs around the middle of our planet.

The sun beats down there with a huge amount of energy

and that warms the air, lifting it up and sending it in this direction.

Then, like a hot-air balloon without hot air, it starts to fall,

just like I'm about to!

After the hot air has moved away from the equator,

it falls back to Earth - just like me!

As the air falls towards the ground, it actually warms up

and any moisture that's in the air just dries out.

No moisture means no rain, and no rain means desert.

This desert below me is the driest in the world.

That was brilliant fun!

And that is the third reason

the Atacama Desert is the driest place in the world.

So here are the three forces

that keep water away from the planet's driest place.

Only small amounts of water

evaporate from the cold Pacific Ocean in the west.

The massive Andes Mountains stop rain from the east.

And falling air from the equator in the north

is the final bolt on the door.

So that's why the Atacama is so dry.

Now we're on a mission to find out what it's actually like here.

Coming up, we'll meet the local people who've got a magic trick

that pulls water from thin air,

and we'll find out what it's like

to try and cross the Atacama Desert on foot!

So dry. I can hardly swallow.

But first, I'm paying a special visit to Quillagua,

the driest town in the driest place in the world.

Let's see how they won that record.

It's simple really. Quillagua is the driest town in the world

because it almost never rains here.

And it's this bit of kit that measures the rain. Or lack of it.

Any rain that does come would come in here

and gets collected at the bottom of this bin.

But as I shake it, there's nothing in there.

Except for a little bit of dust.

They've received 15 millimetres of rain over the past 30 years.

That's it. That's all the rain they've received.

That's amazingly dry.

That looks like a tiny amount of water to me.

But how does it compare to somewhere it rains a lot,

like London in the UK?

Over the past 30 years,

Quillagua has received only 15 millimetres of rain.

In comparison to London, which has received over 11 metres of rain.

How do people survive in such a dry environment?

The tiny amount of rain that falls here

has meant that some settlements have not survived.

The place is littered with ghost towns.

People used to call these places home,

but the environment was so tough,

they packed up and headed to parts of Chile that were easier to live in.

How has Quillagua survived when life in these other towns dried up?

I'm heading into town to find out.

Quillagua is the only town for miles around.

It was a busy little place back in the 1940s

and was an important stopping point for trains travelling through Chile.

Over 800 people lived here

and Quillagua's tiny school had 120 kids in it.

But, with so little water available,

the town couldn't support that many people,

and today Quillagua is a lot quieter.

Look at this - there's only six kids in this whole school now

and I've got a couple of questions for them.

Do you know you live in the driest town in the world?

-TRANSLATION:

-Yes.

Have you ever seen rain before?

No, I've never seen it rain in my life.

How many times have you seen it rain?

Just the once.

'Imagine that - only seeing rain once in your lifetime!

'One of the students, Marisol,

'has taken some time out of school to teach me

'about where the water comes from in a town where it hardly ever rains.

'She told me how sometimes, she can turn the tap on at home

'and there's just no water.'

Is this is where you live?

And when you turn the tap and no water comes out, what do you think?

-TRANSLATION:

-I think it's a shame

because a town that is already dry is getting drier.

Where do they bring the water to, where does it go?

Right there, in the blue tanks.

Right there, in the blue tanks.

Do you know how many times per week the water gets filled into the tanks?

-Five times a week.

-Five times a week.

So, as Marisol says, all of the town's water

is stored in these tanks.

But with no rain, where does it come from?

Well, get this - it has to be brought in by truck.

HORN TOOTS

It's a 120-mile journey, twice a day, five times per week.

And it's driven by this guy - Jose.

You know, you take it for granted, water.

You go to the tap, you turn on the water - bam, water's there.

His job is so important because he's bringing water to the town.

If it wasn't for him doing that,

there's no way this town could survive.

This literally is the lifeline right here of Quillagua.

Imagine living somewhere that doesn't have water

other than when it's brought like this.

Pipes from the tanks run into the houses below

where people need it for washing, cooking and, of course, drinking.

Quillagua's people are careful with the small amount of water they get.

Because of that and, of course, this truck,

the driest settlement in the world

hasn't turned into an abandoned ghost town.

Job done.

Jose's off home and Quillagua's people have enough water

until the truck's next visit in 12 hours' time.

So that's what it takes to live in a place as dry as the Atacama,

but what is it like to travel across this barren land?

Well, Leo's about to find out,

because I've got a challenge for him -

a 15km trek across one of the most rugged stretches

of the Atacama Desert.

Nasty.

You don't just have to beat the desert,

you have to beat that guy over there.

Antonio is in one of the toughest regiments in the Chilean army.

He knows how to survive out here for weeks without any help.

Today is his day off, but he's ready to take Leo on.

-That doesn't sound like fun.

-SHE LAUGHS

Here are your supplies.

Let's have a look. A map.

One litre of water.

GPS.

And a compass.

Here is your competitor. This is Antonio.

'We're almost ready to go, but as the Atacama new boy,

'Leo gets a head start and some advice on the best route.'

When you sweat in a place like this, the sweat evaporates really quickly.

You need more water.

Leo only has one litre for 15km.

As a reward, there's some Fierce Earth drinks at the finish line,

and in case of an emergency there's a paramedic on standby.

OK. I've got a 15-minute head start, better make it count.

15km across the driest land in the world.

That's like walking the length of 160 football pitches.

I've only travelled 300 metres

but I can already see how tough this is going to be.

Normally, you'd need about 10 litres of water to travel this far.

I've got just one to get me to the end,

and now Antonio is in hot pursuit.

Antonio knows this place like the back of his hand,

but I'm only 45 minutes into the trek

and I'm really struggling to navigate.

There's so few identifying landmarks,

like hills or woods or rivers...

..so to figure out where you are you have to count your paces

and know how many paces it takes to do a kilometre.

I've counted my paces out, but I'm still getting lost.

And if I really were to lose my way in this desert

and I only had one litre of water,

I probably wouldn't survive for more than 24 hours.

That's how quickly things can become life-threatening here.

OK, I wonder how Antonio is doing.

I'm back on track, but that is one fast Chilean.

Travelling at over 5 kmph, he's gaining on me.

1,000 metres to Leo. I need catch.

The next level to the speed I catch very fast to Leo. Bye-bye.

Antonio is trained in wilderness survival

and he's eating the ground up.

What could I, and you, learn from him about staying alive out here?

Here's Antonio's Atacama survival guide.

For a start, he wouldn't be walking now.

We've set this test up during the day so you can see what's going on.

But the best time to march is at night.

It's much cooler and you don't lose as much liquid from sweating.

The second survival tip is to carry all the water you need.

You'll never find a natural water source

in the driest place in the world.

On a training mission, Antonio would be carrying

almost half his body weight in water!

That's about 40 litres!

The final survival tip would be to walk with a hat on

and your mouth shut.

Breathing through your nose loses less water,

and exposing your head makes your body work hard to stay cool.

Back to the race, and I've travelled 11km in three hours.

But I've run out of water. That's bad news

and means I've got just an hour before serious dehydration

and heat exhaustion set in.

OK. Three-and-a-half kilometres to go. I've run out of water.

My throat's quite tight.

It's hard to swallow.

I feel pretty rough. Ohh...

'After three-and-a-half hours, the torture's almost over.

'I can see the finish line.'

But here comes Antonio.

He's not far ahead. I've got to catch him.

400 metres to go. One last push!

15km across the driest place on the planet.

It was a tough challenge, but they are almost neck and neck.

Come on, Leo.

Come on, Leo!

Come on, Leo! Brilliant!

It's neck and neck!

Pipped at the post by Antonio.

Antonio, you won!

Time to rehydrate and get checked out by the paramedic.

It's so dry out here.

There's no water. You need water to survive.

Everything does. It's a hostile place.

Can we go home now?

As we've seen, finding water out here is nearly impossible,

but in another part of the Atacama

a group of people have found a way to do it.

This area gets barely any rain.

But what it gets a lot of is this - fog.

The fog comes from the Pacific Ocean and drifts inland.

I've got something here to show you how fog

is formed in the first place.

When you think of the word "desert", you think of a hot place,

but the Atacama at night is cold,

as is the air around the coast.

So, if the water here represents the air warmed by the Pacific Ocean,

and then this ice represents the cold air at night

and during the early morning,

see what happens as these two interact.

It starts evaporating and then condensating.

And that's exactly what happens out to sea -

the cold air and hot air interact and condense.

And there you have it - fog.

The only trouble is the fog hardly ever falls as rain.

It rolls over the land and, when the sun shines, it disappears again.

But, believe it or not,

these nets can catch the water before it vanishes into thin air.

The inspiration and design for the nets

comes from moss on these cacti.

You can see this moss captures the tiny little water particles

and it feeds the whole plant.

These nets are like massive versions of the cacti and moss.

The fog climbs up the hillsides

and then these huge nets catch the tiny little water droplets,

and then the water droplets become bigger as these nets rub together.

And then gravity takes over, the drops becomes heavier

and fall into this pipe,

and then roll down the mountainside into these big tanks.

We're not talking about a few drops. either.

These nets can catch about 500 litres a day!

That would be enough water for you to take 43 baths every week!

It's really clever, yet so simple.

Pipes transport the water down into the valley,

and once there

it's used by people in the local town to grow these aloe vera plants.

You can make a nice salad out of them

and even use them in sun tan cream!

Now, what I want to know is, we saw some water from up there

going through the pipes. Can you switch it on?

-Si.

-Excellent.

For the driest place on the planet,

it's a miracle, really, that this can happen.

Without this simple technology,

the locals could never grow these crops.

And there's enough water in those tanks

to make you 13,000 cups of tea!

So, should there be more fog-catchers like yourself?

-TRANSLATION:

-Definitely. The Atacama needs more fog-catchers.

We want to show other people how these nets work

and how they can change other people's lives.

This place is special. It shows it is possible to create life

in other parts of the dead and dry Atacama.

Let's hope it catches on.

People have cleverly tapped into an almost invisible

source of water in the driest place on the planet.

Look at this dry, empty place. It's almost like another planet.

But there is one thing about this barren land that is VERY special.

The air is so dry you hardly ever see any clouds,

and that's what makes the Atacama the best place in the world

to see the stars.

That's why, high on a mountain,

deep in the Atacama Desert,

you can find Paranal Observatory.

All of this special technology looks deep into space

and it's been brought to this remote area because it's so dry.

These are the most advanced telescopes in the world.

When it darkens, like a giant eye,

they're going to open up.

Telescopes are very important and these even have a great name - VLT.

Stands for "very large telescope".

And they allow us to look deeper

into the universe than anybody ever has.

Telescopes work by looking for the light that comes

from stars and planets in space.

To be able to see the stars and planets properly,

that light needs to be travelling in a straight line.

But the problem with having any moisture in the air

is that light is bent, which causes a distorted image.

I know all this sounds confusing,

but I'll show you what I'm talking about.

Look at this, a spoon in a glass. Looks pretty normal, doesn't it?

Watch what happens when I pour water inside.

Strange, isn't it? The spoon almost looks broken.

The light hitting the spoon is being bent, or refracted, by the water.

This happens anyway when light hits our atmosphere,

but the effect is reduced in the dry Atacama.

This is a great example of why

we don't want to have moisture in the atmosphere

and why the telescopes are here, where it's really dry.

Let's meet someone who uses the telescopes. This is Gabe.

He's an astronomer who loves the dry air

and clear skies here.

We're lucky to see him in the light

as he spends the long, dark Atacama nights exploring space.

Well, let me ask you,

having this view on top of the world,

do you feel like a space explorer sometimes up here?

It's very exciting.

At night, we're observing many different interesting things -

stars, very distant galaxies,

but just being here, you feel like you're on the surface of Mars.

You feel that while you're here

at the same time while you might be observing Mars through a telescope.

It does look like another world out there.

With the sun setting, it's time for Gabe

and an army of astronomers to start exploring the universe.

But first, the telescopes have got to open up,

and I've got a ring-side seat.

I've got to say, I'm starting to get butterflies.

I'm really anxious to see this.

Once open, these telescopes are so powerful

they will allow you to read a newspaper on the moon!

So now the doors are opening

and they're basically retracting, like this,

and it's going to get a view of that nice, dry sky.

So the telescope is completely set up and ready to go

for a long night of exploring outer space.

Working in the Atacama's super-dry environment,

these telescopes are four billion times more powerful

than the naked eye,

and they're used to discover planets and stars never seen before.

In a place like the UK, you can never see the stars so clearly.

Clouds would block the view of the telescopes

and moisture would blur the pictures of stars.

Now that it's dark out,

I can see why these are the clearest skies on Earth.

Just look at it - tens of thousands of stars twinkling in the sky.

It's beautiful.

The bright streak you can see in the sky is the Milky Way,

and the light from the stars has travelled

thousands of light years across space.

The astronomers may one day discover a planet just like Earth,

and who knows?

When we're looking at them,

they may be looking right back at us.

Our journey through the world's driest place is now complete,

and it's been epic.

We found out about the powerful forces of cold ocean currents,

high mountain barriers and warm, falling air that block the rain out.

I learnt the survival skills you need

to travel across the desert on foot.

And Mike saw how the world's most powerful telescopes

look through the clearest and driest skies on Earth.

Next time on Fierce Earth - get ready for the heavens to open.

It's pouring it down!

Because we're on a soaking journey

to the rainiest place on the planet.

-It's going to be wet.

-And wild.