All language subtitles for BBC.A.Day.in.the.Life.of.Earth

ALARM RINGS

Every morning when you
wake up and start your day,

you might think the world around you
hasn't changed much since yesterday,

but you'd be wrong.

Because while we're going
about our normal day,

our Earth is altering itself in
ways we couldn't even imagine.

We're going to spend 24 hours
with our planet,

to watch what it's really getting up
to in the course of an average day.

Across the globe, a new breed of
scientists are showing us our home

as we've never seen it before -

an Earth that is constantly
reinventing itself.

Things are always active.

The Earth is really living
and breathing all the time.

Every second of every day,
it's growing, shrinking and moving,

and each change has surprising
consequences for our lives.

Every hour, the Earth is making
mountains of new rock...

Never gives up, just never stops.

..in a way that is crucial
to our daily survival.

By the time you've stopped
for lunch, tonnes of dust from

the Sahara will have landed
in a faraway ocean.

That dust is still coming.

Every day, yeah.
All the time, every day.

Dust from a desert that will help
give us the air we breathe.

And before we go to sleep,

glaciers will have changed
the face of the planet,

and helped trigger a mass
movement of animal life.

So, this is enormous.

This is like the largest migration
on Earth.

In this programme we'll reveal
the myriad different ways

in which the planet transforms
itself every single day...

Whoa!

..and how they come together to
make life on our world possible.

You can forget about the Earth
taking millions of years to change,

because it is changing
as fast as we are.

Quite a lot can change in a day.

Families can grow,
you can move house,

fortunes can be won or lost.

But a single day can be just
as transformative for our planet.

Even something we think of as solid
and unchanging,

like the land we stand on -
it's not.

Across the world, land is being
made and rearranged

on an extraordinary scale,
on a daily basis.

And if you live here in Stromboli,
off the west coast of Italy,

you can see it happening.

Here, they wake up to a new view
every morning.

Stromboli's almost continual
eruptions might shake up the locals,

but scientists are drawn here
despite the obvious dangers.

Although as a geologist I shouldn't
really be nervous, there's still

something about being so close
to so much heat and energy.

For geologists Chris Jackson
and Giuseppe DeRosa,

this is the place to study what
volcanoes are really capable of.

You feel all of the ash raining down

from that last eruption now,
can't you? Yes.

Gosh!
HE LAUGHS

Wow. A giant eruption there,
lots and lots of lava coming out.

Huge volumes just being
blown out of the top.

Lava that, in fact, plays a vital
role for all of us on the planet,

because this lava is
about to become land.

It's amazing seeing these car-sized
lava bombs being hurled out of

this volcano.

Magma bursting to the surface,
becoming lava, becoming rock,

and ultimately becoming land.

You can see all down the flanks,

that orange glow of lava
which has just been kicked out.

Over the course of just 24 hours,
this volcano can throw out

enough lava to fill 80 Olympic-size
swimming pools.

Volcanoes build land
in different ways,

depending on the type
of stuff that's coming out.

Lots of different minerals in here,
this green colour's...

Yes, this is all living. Yes.

The mineral content of the lava
makes it behave in different ways.

Basically, there are two types.

The first, lava low
in a mineral called silica

that can build big
areas of land quickly -

the runny stuff.

It very quickly runs all the way
down the sides and builds new land

all the way around the edges.

On the islands of Hawaii, the runny
stuff spills into the ocean

and turns to rock,

creating an average of six square
metres of new land every hour.

Half a tennis court in a day.

So, you have the runny lava,

but there's also the sticky stuff...

It's too sticky to even come out.

..which has a higher silica content

and builds land in
a more explosive way.

LOUD EXPLOSION

Like, some of the things
that are coming out right now,

these bombs of lava rolling all the
way down the sides of the volcano

and building the crater itself.

Over thousands of years, the sticky
lava erupting from this volcano

built this island up out of the sea,

and formed its classic cone shape.

But sometimes, a volcanic island
can appear almost overnight.

In 2014, this volcano in Tonga
sprang out of the Pacific Ocean,

building 60,000 square metres
per day.

Right now, as you're watching this,

between 10 and 20 volcanoes are
erupting, spraying out new land

across the surface of the Earth,

making a real difference
not just in millennia,

but in minutes.

In fact, in just one hour, the time
it takes most of us to get out

of the house, it's estimated
the planet has made

3 million cubic metres of lava.

Enough to build an island
200 metres tall.

Without this process, the people
of Stromboli wouldn't have a home.

But then again, neither would we.

Every day, you have got volcanic
activity creating new land.

But every day, you also have wind

and water eroding land away.

Now, if volcanic activity didn't
create land as quickly as it does,

then erosion would win that battle
and the world would be left

as one giant ocean.

So, volcanic activity
keeps us all above water,

but it's only possible because of
the heat that's generated

deep beneath our feet.

We have two sources
of heat in the Earth -

primordial heat, that's coming
from the core, white hot,

6,000-7,000 degrees Celsius, so,
similar to the surface of the sun.

Outside of that region,
here in the mantle and in the crust,

we also have heat that's being
produced by radioactive decay.

This heat produced by radioactive
decay drives volcanic activity

and is best explained by popcorn.

A heavy element like uranium

becomes lighter by emitting
a particle from its atomic nucleus.

As it does that, a burst of energy
is released in the form of heat

and it is that heat that drives the
geological processes deep beneath

our feet and at the Earth's surface.

Ooh!

Every time a heavy atom decays
into a lighter one,

there's another burst of energy.

It's the very same process that
we use to create nuclear energy.

And it's everywhere.

The smaller dark spots on this map
are nuclear power plants.

Everywhere else,

radioactivity is coming from atoms
decaying underground.

And it all adds up.

In just three hours, before you've
even had your mid-morning coffee,

the Earth has generated heat energy
from radioactive decay

equivalent to 4,000 Hiroshima bombs.

That's about one
every three seconds.

So, every minute of every day,
the Earth changes from within.

But once land is made,
it doesn't stay put.

As we continue on our day, it's time
to see how the land is being warped

and moved right under our noses.

First, we have to look to the water.

In particular, the tides.

We're all familiar with sea levels
going up and down twice a day.

Well, every 12 hours 25 minutes,
to be precise.

But what's less obvious is that this
process is changing the shape of

the planet,
and it's all caused by the moon.

Here in the Amazon,
this shape change is so dramatic,

you can actually see it,

and they've even given it a name...

..the Pororoca.

Pororoca, meaning great roar,
is in fact a tidal bore.

When the tides are at their highest,
the water rushes into this stretch

of river so fast, it creates a wave
large enough to surf,

and they do.

Woohoo!

Other than the piranhas
and hidden logs in the water,

this is perfectly safe.

But in fact, it's not just
the water that's getting pulled out

of shape by the moon.

We can't forget about the other 29%
of the Earth's surface.

You know, the stuff we walk on.

Every person knows that there are
tides in the ocean, but what many

people don't realise is that the
moon also causes tides in the Earth,

so what are called
solid earth tides.

We can now prove that the moon
moves rock as well as water,

causing a tidal bulge in the very
land we stand on, which is

up to 50 centimetres high.

Solid earth tides, or rock tides,
they can be measured with GPS.

They cause the GPS station to go
up or down, so we can measure

how high the stations are rising
all along the globe.

And this is happening
about twice per day.

Which means that in about
six hours' time, I'm actually

going to be up here.

Now, normally, I don't need
an extra 50 centimetres in height,

but I'm embracing change today,
so I'm going to go with it.

You'd think you'd notice
these waves of solid earth,

but they happen over such
a huge area that they are

imperceptible to us.

But that doesn't mean
they do not affect us.

In fact, research suggests that
earth tides can trigger
earthquakes.

If earthquake faults are really
close to failing and creating

an earthquake, then this tiny change
may be enough just to tip that fault

off to failing.

By the end of the morning the moon's
pull on the Earth has caused

a half-metre wave of solid rock

to travel 9,000km around the planet,

and you hardly even felt a thing.

The changing shape of Earth
has another side effect

you might not have clocked.

It makes every day a bit longer.

Let me show you what I mean,

but I'm going to need
something for this...

Ooh! Guys, can I borrow
your ball for a second?

Handy.

Now, this is going to represent
our squashed Earth

spinning on its axis.

Going to need a moon, too, though.
Guys, have you got anything smaller?

Thank you.

Now, this tidal bulge stays
ever so slightly ahead of the moon

at any one point.

The moon is acting almost
like a brake on a bicycle wheel,

slowing down the spinning
of the Earth and making our days

ever so slightly longer.

Throughout our morning,
the moon has been slowing down

the Earth's spin,

with a force equivalent
to 6,000 jumbo jets,

and has caused a tidal bulge
to travel through water and rock,

What with tidal bores,
earthquakes and land waves,

you might think that the moon's
influence on us isn't a great one,

but the chances are that without it,
none of us would even be here,

because in amongst everything else
that the moon does,

it also stabilises the Earth
spinning on its axis.

Without the moon there, the Earth
would be wobbling all over

the place, which would change our
seasonal relationship with the sun,

make the climate completely
different and quite possibly mean

that the conditions never arise
for complex life to evolve.

Can we get the ball back?
Oh, yeah, sorry.

But when it comes to moving land
around every day, the moon

has nothing on the Earth itself,

and yet our planet's work goes
largely unappreciated.

Well, we all know that feeling.

The Earth, if it could talk,
would probably agree with me,

because one of the barely visible
things that it does every single day

may well have given birth to some of
humanity's greatest civilisations.

This is the Sahara.

Morocco, to be precise.

And in this part of the world,
land doesn't just move,

it can actually fly.

It's stunning, the landscape here
is peaceful and remote,

but at the other way, it's dynamic.

You get to experience how nature
is moving every day.

Geologist Charlie Bristow spends
his time trying to figure out

how solid earth can cross an ocean.

The story begins on
a dried-out lakebed.

How dry?

It's very dry. Very, very dry.

And this isn't just any old mud.

It's special.

This place appears dead,
there's nothing here,

it's dried out,
it's completely desiccated.

But the lake was here

and in the lake, there were little
animals living here.

There's something called an
ostracod, a little crustacean,

they're kind of cute little things.

And their remains are still there,

so within the mud,
there are nutrients.

Nutrients that are about to find
themselves

on the other side of the world.

Hello, Veronica.

Hello.

I'm Veronica Llaneza.

I'm Ramon Llaneza.

Ready to go dive?

We decided to take a trip to the
Bahamas and it was a four-day trip

and it was pretty amazing.

This was not your average
father and daughter day out.

Veronica and Ramon are technical
divers and were exploring

an underwater cave system -
not for the faint-hearted.

Out of nowhere, you see this hole.

A small hole. Yeah.

And then it opens up
to these beautiful caves

with all of these stalactites and
stalagmites and it's just beautiful.

Alien world, an alien world. Yeah.

Deep into the caves,
something caught their eye.

Something that didn't belong.

Suddenly, you start to see pink.
Yeah.

And red.

You would see this red dust.

It's very, very fine.

I said, "What is this,
where is it coming from?"

The answer is far from
what they might have expected,

because this is exactly
the same stuff

as Charlie Bristow was turning up

6,500 kilometres away on his
dried-out lakebed in the Sahara.

People say, how do you know
that that's from the Sahara?

How do you know?

A lot of geology is detective work,
so in order to link the dust

sediments from the Sahara with those
that were found in the Caribbean,

you can use a variety of rarer
elements found in minute amounts.

They're good for fingerprinting
the dust and show that the dust

that leaves Africa is the same
as the dust that arrives

in the Caribbean.

But how does this nutrient-rich,
rock-hard, sun-baked mud take off

and fly across an ocean?

That's what Charlie has now
figured out.

And it starts with the wind,

which blows over this
desert almost daily,

and is strong enough to make Saharan
dunes some of the fastest moving

land on Earth.

Wind usually blows
from one direction,

over the windward side of the dune

and then it deposits it on
the leeward side of the dune.

This is making little avalanches
down the front of the dune,

and these dunes really motor.

Get a really strong howling gale and
that will drive the dune forwards,

maybe over a metre in a single day.

They're like the F1 cars
of the dune world.

Sorry. Made a bit of mess!

Fast moving, maybe, but the sand in
these dunes isn't about to take off

and cross the Atlantic -
it's too heavy.

But it is going to help send
the nutritious mud in this lakebed

on its way west.

Obviously, we need the wind
in order to transport it,

but it helps to have that third
ingredient of the sand to sandblast

the surface and break it up.

Turning this mud into a fine dust.

So, in this hand, I have got some
great big chunks of lakebed,

otherwise known as brown sugar,

and in this hand I have got some
lakebed that has been smashed up

into tiny little bits
by sandblasting.

And me, I'm going to be the wind.

This process of sandblasting
is called saltation,

and it's really the key
behind launching

great big chunks of earth
into the sky.

Carried by the wind,
the fine nutritious dust rises

thousands of metres into the
atmosphere and then the trade wind

carries it west across
the Atlantic Ocean.

Nasa satellites have
measured that each day,

half a million tonnes of it
leaves the Sahara and heads west.

Some of it arriving
here in the Bahamas.

That dust came and is still
coming all the time, every day.

But most flying further west, where
it finally comes back to ground and

fertilises the Amazon rainforest,
the lungs of the planet.

When you have this red dust in your
hand and you think about where it's

come from, it makes you think of who
else grabbed this or touched this.

That's just amazing
and it's happening every day.

By six hours into your day,
125,000 tonnes of dust

will have become airborne
and left the Sahara.

And in those same six hours,

25,000 tonnes of dust
will have landed here in the Amazon.

But this isn't the only place
receiving a daily dose of nutrients

from far away.

And when you plot them on a map,
they tell the story of humanity.

So, I've drawn a map
of the world here for you.

It's not my best work,
but I did do it upside down,

and above here, it's almost
like you've got this invisible

conveyor belt that's depositing
this stuff in northern China,

across the great plains of America,
also all over Russia,

and in Central Europe, too.

And it's no coincidence that these
really are the places

where some of our greatest
civilisations were born.

Because the so-called lowest soil
has provided fertile ground to feed

all these huge populations
and really to power some

of our most innovative minds.

Oh, I didn't think you'd mind...

OK...

If wind can move lakebeds
and feed civilisations,

just imagine what solid ice can do.

Glaciers can break out the nutrients
from the toughest of rocks,

a process which not only changes
the landscape, but helps us

all breathe more easily.

They're incredibly beautiful

and when the sun lights the ice and
creates all these beautiful colours,

it is extremely emotional,
actually, to get to work with this.

Now, when we say glacial,
we tend to mean slow,

but Heidi's measurements prove
we've got glaciers wrong.

These glaciers can move at speeds
of up to 70 metres per day,

so you can see the whole thing
moving in front of you.

This is incredible.

So, what happens when
a trillion-tonne block

of fast-moving ice
meets the land beneath?

There's only one way to find out -
get under one.

Local guide Snorri has found
a way down to the very base

of this glacier in Iceland.

What a cool cave!

Quite beautiful, huh?
That's awesome.

Really stunning colours.

I like how it changes.

And you get these pockets that are
formed by the wind, scallops.

It's fantastic, isn't it?

It's incredible to get access
to the belly of a glacier,

to really be inside it.

You can feel that
the glacier's alive here.

It's cool, there are rocks inside.

Yeah, exactly, all these little
sediments and pebbles

that are being carried by the ice,

and glaciers are these massive
conveyor belts constantly moving

forward and reshaping
the landscape around them.

So, there's a lot happening
even right now, yeah.

And the clue to how these huge
blocks of ice manage to move

and grind down mountains

is all around - water.

So, ice, when it's really
dry and cold,

struggles to move,

but as soon as you get a little bit
of water at the base of the ice,

as soon as it starts to melt,
then very quickly, the ice can start

sliding over the bedrock.

And you can even hear the moving.

ICE RUMBLES

What you're listening to is
an actual recording of a glacier

as it ploughs its way through
a mountain range.

Glaciers are very noisy.

They're very noisy because
actually, they're constantly moving

and the sounds you can hear
are really special.

It can be like gunshots,
it can be the ice cracking,

it can be the noise
of the ice against the rocks,

the kind of crashing sound, and when
you're quiet for a few minutes and

you start to really being careful
and listening to these sounds,

you realise that
there's a lot happening.

Minute by minute, these giant blocks
of ice are breaking mountains

into boulders, boulders into rocks,

and rocks into dirt.

A global system totalling 200,000
glaciers, a combined bulldozer

bigger than France, working 24-hour
shifts to reshape the land.

In the space of just seven hours,
if you add them all together,

the world's glaciers grind out
2.5 million tonnes

of minerals from mountains.

Nothing glacial about that.

By lunchtime,
quite a lot has happened.

A whole mountain's worth of new land

has spewed from the bowels
of the Earth.

There's also a nutrient-rich dust
cloud the size of a continent

that has left the Sahara and
is heading across the Atlantic.

And all kinds of ice and water

that is slowly breaking mountains
down into dirt.

And the result of all that is...

Ta-da!

A nourishing mix of minerals
and nutrients that fuels

a whole new wave of daily change
to life.

Cheers.

Oh, that's disgusting.

These are phytoplankton -
a type of plant you won't have seen

they live in the ocean.

There, they thrive on a diet
of nutrients from the Earth

and light from the sun.

Individually, they are small,
but together,

they have a big effect on all of us.

Take a deep breath in...

..and out.

And another - in...

..and out.

One of those breaths
was made by phytoplankton.

Together, they create more oxygen
than the entire Amazon rainforest.

Trees...

..algae.

Luckily for us, phytoplankton
are one of the most abundant forms

of life on our planet.

Satellite imaging shows
how they envelop pretty much

the whole world.

And they're growing all the time.

In just eight hours,
over 3 billion tonnes

of phytoplankton have been added
to the world's oceans.

Gathered together in one place,

that is a mountain of plant life
1.5 kilometres high.

And this daily explosion
of phytoplankton triggers

one of the greatest mass
movements of animals on Earth.

This happens every day
all over the world,

but only the most determined
ever get to see it.

I'm very excited about it,
because it's my first time

diving at night.

It's a better way for me
to understand the behaviour.

Dr Claire Paris-Limouzy
is a marine biologist

who's hitching a ride with a group
of photographers.

So, are you ready?
Yeah. It's getting dark.

They're going on what's known
as a black-water dive.

For the photographers -
Linda Ianniello and Noe Sardet -

it's a chance to capture
a global feeding frenzy.

A lot of people think we're crazy -
float in the middle of nowhere.

It's 500ft deep,

you don't know...is there a shark
out there that you can't see?

You have to be aware
and you have to be careful.

These black-water dives
are a great opportunity to capture

video of these creatures.

Who's going first?

If you're afraid of the dark
and afraid of the depths,

this is definitely not for you.

The divers are floating above
150 metres of pitch-black ocean...

..waiting for creatures
to rise from the abyss.

Tiny animals called zooplankton
rise from the deep every night

to feed on the phytoplankton

that exploded in number
during the day.

When I see the plankton,
this incredible colour and light

and movement and all the energy
that is there, it's extraordinary.

At first, you're looking
around and you don't know

where to start. There's all this
plankton flying around,

floating around in
the water column,

and they're all there to feed.

It's challenging.
It's not easy photography,

but it's worth it.

This immense cloud of zooplankton
is made of everything from

larval forms of larger animals,
like squid and crabs and rays,

to fully grown creatures,
like sea angels.

This is my favourite shot.

Very rare. It's a paper nautilus,
also called an argonaut.

You must have been excited.

I was very excited.
I chased it to 84 feet

and this is a typical shot
it wanted to give me,

which is a butt shot!

I think these animals
are deep dwellers,

so they have migrated
hundreds of metres.

This migration happens
in the entire oceans,

every day, so this is enormous.

This is like the largest
migration on Earth.

We know of no greater daily movement

of animal biomass
anywhere on the planet.

And as the zooplankton rise,

they cause another huge daily change
to the Earth.

They might be small,
but Claire has found

they have serious appetites.

Claire's research has shown
that some plankton can eat as much

as their own body weight
in food in a single day.

And to put that in human terms,

that is the equivalent
of me having to eat

this many sandwiches every hour
of every day.

Can I at least get a glass
of water with this?

This feeding frenzy travels
around the world's oceans

as night falls - a Mexican wave of
binge eating that never ever stops.

After nine hours,
over 3.5 billion tonnes

of zooplankton have completed
their daily migration

and they have eaten around
3.4 billion tonnes of phytoplankton.

That's almost eight times the weight
of all the people on Earth.

And if life can change
so much below the water,

what's going on up above?

Life on land never stands still -
not even trees -

and scientists are finding new ways
to keep tabs on it

and figure out what
it all means to us.

I really love going into forests.

Trees are, in some ways, the basis
of life, and they're beautiful.

That one looks good.

Yeah.

Professor Lola Fatoyinbo
and David Lagomasino are tackling

a seemingly impossible task.

This one. All right.

Keeping track of all of the trees
in the world.

18 metres.

I'll start the scan now.

We scan one tree
from one direction. Just like that.

Then, we'll move around a little bit
to another spot. Scan two done.

Scan another tree and then we
stitch all those images together.

Scan three.

We get a nice 360-degree view
of what the forest looks like.

By the time they're done
with their lasers

and 360-degree cameras,

they've created a digital copy
of the forest accurate enough

to measure every tree and shrub
and calculate their growth.

20g per day.

Every single day.

There's a huge range in scales
of how fast plants can grow.

There are some bamboos that can grow
up to 90 centimetres a day,

where oak trees, on the other hand,
will grow

about a millimetre or so a day.

Driving this daily growth
is a transformation

that only plants can achieve -

turning sunlight into sugar.

That clever quirk of chemistry
called photosynthesis allows plants

to convert that into this.

That simple process
of photosynthesis is the only thing

that is keeping us fed down here.

The only reason why we have got
energy that we can use.

And if you add all the plants
in the world together,

guess how much sugar
they make from sunlight?

Daily, photosynthesis produces
hundreds of thousands of billions...

SHE LAUGHS

Well, that's a tough one!

Fortunately, David and Lola aren't
trying to work it out alone.

They work for Nasa and have access
to a fleet of Earth-observing
satellites.

So, here, we're starting
to see the global picture

of photosynthesis.

Satellites can show us
what we can't see,

like photosynthesis in action
across the entire world.

Earth-observing satellites
are really important,

because we can use them
to look at changes in forest cover,

and they give us any idea
of what's happening globally

every single day.

A partnership between boots
on the ground and eyes in the sky -

that's how scientists like Lola
and David are finally able to put

numbers on the colossal changes
happening on our green planet -

changes that provide us with food
to eat and air to breathe,

from the amount of CO2 plants
consume and the oxygen they release,

to the weight of new plant life
that every hour brings.

By mid-afternoon, when I'm taking
a well-deserved nap after my pile

of sandwiches and cake,
scientists with satellites

have worked out that if you took all
the new growth in all the forests

and put it in one imaginary plant,
you'd get a giant tree

two kilometres high, and in case
you're wondering,

the same forests have also made
180 million tonnes of sugar.

Sweet!

But there is a flipside
to all of this creation.

Every part of the plant -
all the leaves, the branches,

the trunk, the roots - all have
this solar energy locked up

inside of them. The problem is,
that process is reversible.

All that energy can be released
back as heat and light.

This is a film about daily change,
and that means destruction,

not just growth.

Because you can't have
one thing without the other.

Hello. Hey, mum - I just texted you
a picture.

I'm standing right now,
right in the middle of the house.

They'd bought this house
when it was built new in 1975,

so they've lived here for 42 years.

Um...

The file cabinet is
still standing there.

Super nice neighbourhood -
it was where I was raised.

But there's going to be
very little, if anything.

I'll dig around here,
see what I can find, and, er...

All right, love you guys.

In California, they're facing
the worst wildfires

in living memory.

Major Baird, this is
geo-rectified, right?

Can you show him where
the bird is on the map?

This particular fire has grown
14 miles in one day,

which, relative size, is about twice
the size of San Francisco County.

It's down all the way
into suburban areas,

all the way down into
cities and structures.

The fire doesn't care
what it burns.

The power went out. My parents
are awakened by the neighbour

and the police saying,
"You've got to go right now,"

and they left my mum's car,
because they couldn't get the door

open easily and in a hurry, and you
can see what happened with that.

A freak event for LA,
but for the Earth as a whole,

this is business as usual.

Right now, as you watch this,
somewhere on Earth,

a wildfire is raging.

It's a natural process,

and we've learned the hard way
that trying to stop it

only makes matters worse.

About 100 years ago,
we adopted a philosophy

where we were going to put
every fire out immediately.

That has led to a cumulative effect
where the vegetative matter,

the ecosystem has begun to build up,
and it's built up for so long

in so many places,
these areas are essentially

tinderboxes, ready for a spark.

THUNDER CRASHES

And with 4 million
lightning strikes every day,

there are a lot of ways
for the energy harnessed from years

and years of sunlight
to be let loose.

Fires are an inevitable consequence
of growth -

an unstoppable agent of change.

The problem for us is
that we've chosen to live

where fires are most likely.

People in California love
the Mediterranean climate,

and it's a wonderful place to live.

The problem is that it's had
a fire history

that goes back millennia.

We know that fire's going to happen.

It WILL burn here.
It's supposed to burn here.

We're just trying to do
our best to contain it.

By the time most of us
have completed a full day's work,

wildfires have raged through
5,000 square kilometres of forest,

turning to ash an area the size
of the Grand Canyon National Park.

Earthquakes, fires,

landslides and floods all seem

like things we could do
with a lot less of,

but actually, there is a theory
of evolution

that says that with the right
amount of change,

you can create the right conditions
for new life to come through.

But you don't want too much
disruption,

otherwise life won't have a chance
to get started at all.

In an environment where
nothing much changes,

there's less diversity of species,
but throw in a bit of disaster,

and it mixes things up a bit.

And for the planet as a whole,
disasters can clear the way

for new species to emerge -

like the way that mammals
could flourish after the loss

of the dinosaurs,

which worked out rather well for us.

Over the course of our day,
we've seen how Earth's constant

reinvention makes our world
go around, but at night,

something else is revealed.

Our planet isn't a self-contained
system with the same old ingredients

getting mixed up over and over.

We're part of a much bigger system
where cosmic influences

stir things up a bit.

WHIRRING

And at the end of each day,

the Earth isn't quite
what it used to be.

It's quite amazing scene to see -
the sky just goes on fire.

I can see a handful of stars, so...

It's kind of strange to see so much
power and feel that you're part

of something bigger, part of a huge
nature, which is quite amazing.

Astronomer Saevar Helgi Bragason
and photographer Oli Haukur Myrdal

are hoping to witness a cosmic light
show caused by a storm in space.

And if you want to know
the space weather forecast,

these are the people to ask.

So it looks like it erupted
yesterday morning,

but I'm not sure...

The weather in space may not seem
like our problem, but it can cause

chaos for us earthlings.

When activity is
particularly strong,

the kinds of impacts would include

equipment failure, equipment damage.
It can also include a blackout.

Bad space weather comes
from the sun, which sends a constant

stream of charged particles called
the solar wind towards the Earth

at up to 3 million kilometres
an hour, and sometimes,

there are more violent outbursts
that can fry satellites

and knock out power grids.

This is the sun
just 15 minutes ago.

But for Saevar and Oli,

a forecast for bad
space weather is exactly

what they've been waiting for...

..so they can witness what happens
when the solar wind collides

with our planet.

Now, the solar wind is just
a stream of charged particles

and when these particles hit
the Earth, they are channelled

by the magnetic field
towards the poles,

where they excite the atmosphere.

It's time to get the drone
airborne...

..ready for when the solar wind
hits our atmosphere to create...

..the aurora borealis...

..or northern lights.

It's amazing. It looks good.
It looks really good.

But there's a price to pay
for this spectacle.

The latest science is revealing
how the lights are actually

a symptom of a huge daily change
to Earth.

I hate to break it to you,
but our atmosphere is leaking.

When we have the particles
that flow from the sun,

they not only excite the atoms
in the atmosphere of the Earth,

but they're also causing
some of the particles to stream

out into space, like helium.

So when you're looking at,
or rather through, an aurora,

you're actually looking at
helium ions being lost to space.

In 2010, people were worried
that our supply of helium

was running out.

There were even some concerned
newspaper reports that a single

party balloon would end up costing
as much as £80,

all because our helium
was just floating off into space.

And once it's gone, it's gone.

But thankfully, in 2016,

a new deposit of helium
was discovered, meaning

that for a while yet,
the party can continue.

Since you woke up this morning,
about 80 tonnes of atmosphere

have been lost into space...

..including enough helium to fill

800,000 reasonably priced
party balloons.

A kilogram every second -
that's a pretty drastic weight loss,

but you'll be pleased to know the
planet is offsetting some of that.

As we hurtle through the cosmos,

we put a bit of weight back on by
picking up a few fellow travellers.

It looks pretty clear out here
right now.

Do you think that'll hold
for tonight? Sure hope so.

We're looking for a wonderful
night under the stars.

Dave Powell is waiting
on a special delivery,

shipped express from outer space.

Tonight is the night of the Geminid
meteor shower and there's no better

way to see it than in the clear
night skies of the desert

with some like-minded friends.

Apparently, they're
happening all the time,

but you can only really
see them at night.

THEY EXCLAIM

Where was it, Dave?

LAUGHTER

A lot of people think
they're really big,

but they're actually only about
the size of a common blueberry.

Ooh! Ooh!

Blueberries are the size of meteors.

THEY EXCLAIM
Wow! That was a really good one.

Every time I look at blueberries,
I'm going to think that now

for the rest of my life.

There are a lot of
blueberries out there.

This is what's happening
during the meteor shower.

The Earth is moving through space
at over 100,000 kilometres per hour

on a collision course
with this dust.

The best way I could describe
the meteor shower

would be that the sky
is raining diamonds.

Whoa!

It's just magical.

A good meteor shower
is, like, 60 an hour.

Here, we are over 100 an hour
average.

Oh-oh!

I couldn't even count
how many we saw tonight.

Whoa!

Every time you switched a direction,
you'd see another one.

You'd look left, look right.

There were points where we saw
eight, ten in a single minute.

All the blueberries coming on down.

Oh, nice bright one!

They're tiny, but a lot
of them come down.

These meteors burn up
in the upper atmosphere,

finally falling to
our planet as space dust.

There's so much of it,
it adds up, making the Earth

a little bit heavier each day.

Whoa!

And if you added up all the space
dust and all the meteorites

that hit our Earth,
by the end of the day,

you'd have a single meteorite
55 tonnes in weight.

And there's one last change
that's probably the biggest change

of all, and you definitely
won't have noticed this one.

As we all know, it takes the Earth
one year to go around the sun

and return to what we think
is our original location,

but that's not quite right.

We're also part of the galaxy,
which is spiralling through space

at over 2 million kilometres
an hour.

The actual galaxy itself
is also in motion.

That means in the course of one day,
we have moved

over 50 million kilometres
from the day before,

so all of us are never going to
return to where we were yesterday.

It makes you realise
there's something a lot bigger

than your day-to-day life
going on here.

We're all in this together,
moving forward through space.

By the time you watch this,
we're already somewhere else

and also somewhere else now.

Since we woke up this morning,
so much has happened,

but things won't stop
just because we head off to bed.

While you're sleeping tonight,

spare a thought for what the planet
will be doing.

New land will be created

and tugged into day-altering tides
by the moon.

Lakebeds will take flight
and fertilise distant continents,

as mountains are broken down into
nutrients for the most

abundant form of life on Earth.

Trees will capture enough sunlight

to keep the entire planet fed
with sunbeams,

and wildfires will burn acres
of forests to allow

new life a chance.

And all the while,
we're leaking atmosphere

and careering through the cosmos.

Whoa!

As we recharge our batteries,

the Earth will still be keeping
life ticking,

changing enough to keep us alive,
but not so much we can't survive.

So, be glad that it's a new world
tomorrow, because if it wasn't,

you wouldn't be on it.