[calm music playing]
[Freeman] Every year for just a few short months…
[birds squawking]
…fresh water flows into the Okavango Delta…
creating the perfect home…
for a small family of elephants…
and a playground for their two young calves…
Bosigo…
[calf whines]
…and her baby cousin, Metsi.
[whining continues]
[elephant trumpeting]
[Freeman] Bosigo and Metsi are only just beginning
their love affair with water.
[calm music swells]
But from now on,
their lives will be defined by it.
[whooshing, crackling]
This one precious molecule…
[intense music playing]
…delivered to Earth…
[exploding]
…by the astonishing forces at work in our universe.
[rumbling]
It has transformed this planet…
[whooshing]
…into a haven…
[sizzling]
…for life.
[dramatic music playing]
[tense music playing]
Summer has arrived.
And what was paradise is no more.
The fresh water that flooded the delta…
only stays for a few months.
And water holes are now vanishing.
[crackling]
Fast.
This means only one thing
for the thousands of elephants who've been living here.
[elephant trumpeting]
It's time to move on.
[pensive music playing]
[elephant grumbling]
[elephant trumpeting]
This has been the only home Metsi and Bosigo have ever known.
[Metsi whines]
But in a few weeks, all the water will be gone.
[Metsi grunts]
So they must leave the delta with the rest of their family.
A herd of females,
sisters, aunts, and cousins,
led by their grandmother,
the great matriarch, Pula.
[pensive music continues]
They're embarking on a journey along with thousands of other families…
out into the desert…
in search of water.
[whooshing]
[intriguing music playing]
For the next eight months,
they will migrate from water hole to water hole…
and navigate ancient elephant trails…
[elephant growls]
…using the matriarch Pula's knowledge,
handed down to her through generations.
[zebras yelping]
The trek will put all their lives at risk.
[calf whining]
And they'll need every one of their exceptional senses…
-[elephant trumpets] -…to endure the dangers.
[solemn music playing]
Making this journey is not a choice.
Without water, they will die.
Even on our blue planet,
fresh liquid water is scarce.
And if we search beyond the shores of our own planet…
it's rarer still.
Even the most arid desert on Earth
is nothing compared to the rest of our solar system.
[pensive music playing]
In the cold outer reaches…
[whooshing]
…the only surface water is ice.
Like Saturn's frozen moons…
where fountains of ice
shoot kilometers into space.
[whooshing]
[ethereal tinkling]
Closer to the Sun on Mars,
water is stripped away by savage solar winds.
[wind gusting]
[whooshing]
[rumbling]
And on Venus,
it simply boils away.
There's only one world we know of
that has the gift of liquid water on its surface.
[majestic music playing]
A pale blue dot.
Our home…
where right now,
water is driving one particular family
on a quest for survival.
[majestic music crescendos]
Just a month after leaving the delta,
only a scattering of muddy pools remain.
[solemn music playing]
And they're getting fewer and farther apart each day.
Pula is using her highly tuned memory to lead her family to a water hole.
[Pula screeching]
She can remember the exact route,
even decades later.
[elephant grumbling]
It's been a long day's march,
and all of them are desperate for a drink.
[calf whining]
[elephant trumpeting]
But so are the other 130,000 elephants
that live in Botswana.
[playful music playing]
[elephant trumpeting]
[calf purring]
[elephant grumbling]
The dry season has drawn herds from far and wide…
[elephants roaring, trumpeting]
…to this water hole.
[calf roars softly]
All competing for the same shrinking resource.
[elephants breathing heavily]
[elephant growling]
[trumpets]
[calm music playing]
[Metsi trumpeting]
The adults teach the young ones clever survival tricks,
like how to skim a muddy pool to get the freshest water.
And how to use some muddy water as refreshing sunscreen.
Their wrinkly skin is perfect for trapping water and keeping cool.
[Metsi trumpets]
But Metsi and Bosigo are also learning…
mud pools aren't just a place to drink.
They're water parks too.
[calm music continues]
[Bosigo purring]
With so many thirsty elephants,
the water hole has been drained.
[elephant moaning]
Pula's family must press on…
and try to make it to the next water hole before the blazing sun sucks it dry.
[solemn music playing]
This battle between sun and scorched earth
has raged ever since our world was born…
when our blue planet was anything but blue.
[tense music playing]
Four and a half billion years ago…
Earth was in its infancy.
A fireball of molten rock…
[rumbling]
…destined to become a dry, barren world.
[tense music continues]
But millions of kilometers out in the coldest reaches
of the solar system…
water crystals were forming
on the surface of dust particles.
[crackling]
[pensive music playing]
Over time, these grains of dust clumped together into asteroids.
Millions and millions of them.
And these became the asteroid belt.
A vast expanse of icy rocks.
Yet they've laid tantalizingly out of Earth's reach.
As luck would have it, however,
a giant was on the move.
[tense music playing]
Young Jupiter.
A monster of a planet.
Forces within the turbulent inner solar system
were slowly pulling it in toward the Sun.
A flight path that brought it into a collision course
with the asteroid belt.
[crashing]
[tense music continues]
As it thundered through the asteroids…
[crashing, rumbling]
…its massive gravitational force
flung rocks in every direction.
[tense music continues]
And yet, from all this chaos and destruction
came the ultimate cosmic gift.
[tense music crescendos]
[ethereal music playing]
Icy, water-rich rocks were hurled towards the Earth…
[elephants trumpeting]
…bringing the promise of life one step closer.
Over billions of years,
asteroids were woven into the fabric of Earth as it formed.
Caught in the turmoil wrought by Jupiter…
[dramatic music playing]
…driven deep into the Earth by asteroids,
water molecules did not have an easy journey getting here.
[exploding]
And they still had a long way to go,
imprisoned for millions of years,
locked within Earth's molten core…
waiting for another miracle…
to set them free.
Today, much of Earth's water is still trapped underground.
[intriguing music playing]
[elephants trumpeting]
So elephants have evolved special skills
to find it.
[elephant moaning]
[snorting]
Even the muddy pools are empty.
This dry season has become a full-on drought.
But Pula has a superpower.
[Pula roaring]
Her incredible trunk,
packed with millions of sense receptors…
can smell water from kilometers away…
and pinpoint its sources deep underground.
[Pula snorting]
But you have to dig for it.
[Pula snorts]
[grumbles]
Metsi isn't a big digger.
[Metsi trumpets]
But Bosigo is a natural.
And Metsi is offered a seat at the bar.
These few sips won't last them long.
[mysterious music playing]
[Metsi whining]
But if water had stayed trapped in the Earth,
there would be none to drink.
There would be no elephants.
No life at all.
[whooshing]
[mysterious music continues]
[crashing, rumbling]
After water was delivered here by asteroids
and consumed by the Earth…
it was locked into the rock as crystals
deep inside the planet.
[tense music playing]
It stayed buried for millions of years,
beneath a vast sea of magma.
[crackling]
[sizzling]
Until slowly but surely, Earth cooled.
And its surface hardened to a thick crust.
[whooshing]
Then, finally, the boiling interior broke through.
[explosion rumbles]
[thunder crashing]
Enormous volcanoes
blasted gas and vapor kilometers into the sky.
[exploding]
At last, water molecules…
[exploding]
…were set free…
[exploding]
…and formed the first clouds.
[energetic music playing]
Growing and building for millions of years,
becoming laden with water…
[wind howling]
[thunder crashes]
…until the temperature dropped just enough…
[thunder crashing]
…for the very first raindrop…
[ethereal tinkling]
…to form and fall.
[ethereal music playing]
[sizzling]
[raindrops pattering, sizzling]
[dramatic music playing]
What followed was a deluge…
that lasted thousands of years.
Puddles turned into rivers.
[wind whistling]
Lakes…
[thunder rumbles]
…became seas.
[dramatic music continues]
And great oceans flooded Earth's surface.
And here, water gave rise to something magical.
-[gurgles] -[ethereal tinkling]
The first life.
[ethereal tinkling continues]
From these first cells
sprang every living thing.
Water is the fundamental ingredient
of every cell of every creature on Earth.
[dramatic music continues]
And today…
the herd still carries this ancient water within them.
[elephant snorts]
[intriguing music playing]
[elephant grumbles]
[ethereal tinkling, whooshing]
It transports nutrients and oxygen.
[intriguing music continues]
-[whooshing] -[elephant trumpets]
[grumbling]
[whooshing]
It powers every heartbeat.
[heartbeat thumping]
[elephant roars]
[whooshing]
And drives every breath.
[breathing heavily]
Life evolved because of water,
which is why no life can survive without it.
[wind gusting]
[solemn music playing]
In Botswana, the drought is only getting worse.
[fire crackling]
The elephants' world is on fire.
[elephant grumbles]
[trumpets]
The herd manages to escape the burning forest…
but walks straight into a new threat.
[elephant huffs]
[lion growling]
In this drought, everyone is suffering…
[lion continues growling]
…from thirst and hunger.
[elephant grumbling]
And for lions, baby elephants would satisfy both.
[ominous music playing]
[Metsi trumpeting softly]
[lion growls]
The adults rally around Metsi and Bosigo.
[lion growling]
It's enough to keep the threat at bay.
[growling continues]
But lions are patient creatures.
And the herd still has to cross an unforgiving wasteland…
before the next water hole.
[wind gusting]
They need a lifeline.
[calm music playing]
And the Earth provides it
in the most unexpected of places.
[birds chirping]
The acacia tree is a beacon of hope.
And a haven for creatures of all kinds.
[calm music continues]
Its long roots reach much deeper underground
than an elephant could ever dig…
[crackling softly]
…drawing water up to its branches…
and leaves.
[elephant trumpeting]
It's just enough water to keep them going.
[elephant grumbling]
Especially vital for Metsi's mother,
still nursing her baby.
But this is so much more than just a local oasis.
It's the vital link in water's eternal cycle.
[elephant grumbling]
The acacia tree connects ground and sky…
[whooshing softly]
[intriguing music playing]
…breathing oxygen and vapor into the air.
[whooshing softly]
[thunder crashes]
Feeding clouds
and powering water's journey around the planet.
[wind gusting]
[ethereal tinkling]
[sizzling]
Ever since rain
fed the first green shoots…
and gave life to the first tree…
[birds chirping]
…plants have made our planet habitable…
[majestic music playing]
…bringing a once barren ball of rock
to life.
But the gifts our universe bestows
can also be taken away.
[solemn music playing]
A long time ago,
there was another planet
whose surface was covered in liquid water.
A water world just like ours.
[solemn music continues]
The same forces that delivered water to Earth
also gave it to Mars.
With an atmosphere in place,
clouds formed,
rain fell,
rivers flowed.
[calm music playing]
And an ocean surged across its surface.
It was a world of possibility.
It had the potential for life.
But it didn't last.
Because not far away was a raging nuclear inferno.
[fire roaring]
Our Sun.
It unleashes torrents of high-energy particles
so powerful and deadly…
[fire continues roaring]
…they can devastate planets.
[solemn music playing]
[wind gusting]
This solar wind streams through space…
at 400 kilometers per second.
[whooshing loudly]
And it ripped through the Martian atmosphere,
tearing water molecules apart.
Bit by bit,
over millions of years,
the planet's protective layer was stripped away by the Sun's fury…
[solemn music playing]
…until its ocean evaporated…
and its water was lost to space.
[solemn music continues]
Mars became a desolate, frozen shadow
of its former self.
[thunder crashes]
[wind gusting]
Consumed by dust storms.
Any chance of complex life…
gone forever.
[wind continues gusting]
This could have been our story too.
[solemn music continues]
[elephant grumbling]
[trumpeting]
But somehow, on Earth,
water and life have found a way to cling on.
[elephant moaning]
In Botswana,
after 200 days in the burning sun…
[wind gusting]
…there is no water to be found.
[solemn music continues]
[elephants howling]
Violent winds whip the scorched earth
into a dust bowl.
[wind continues gusting]
[elephant huffs]
And the elephants' struggle hasn't gone unnoticed.
[ominous music playing]
In daylight, adults can usually protect their young.
[elephants moaning]
But when night falls…
[sniffing]
[elephant grumbles, huffs]
…it's a different story.
[lion breathing heavily]
[elephants trumpeting]
Lions are masters of chaos and confusion.
[elephant trumpeting]
[elephant roaring]
[trumpeting]
[Bosigo squeals]
They pick the most vulnerable target…
[Bosigo trumpeting]
…working as a pack…
[Bosigo continues trumpeting]
…until there's nowhere left to run.
[Bosigo squealing]
[moans]
[lions growling]
Without the entire herd as protection,
the lions overwhelm their prey.
[lions continue growling]
The drought and endless search for food and water
have taken their ultimate toll on Bosigo.
[somber music playing]
[elephant cries out]
[grumbles]
Elephants form deep emotional bonds.
[elephant grumbles, huffs]
All the family mourn Bosigo's loss.
[elephant moaning]
[Metsi cries out]
[somber music continues]
The herd gathers to comfort Metsi,
who feels it hardest of all.
The never-ending fight to survive
plays out every year,
across the Okavango…
across our planet…
and beyond.
But in this battle for survival,
Earth got truly lucky…
with a secret guardian that protects it.
[whooshing]
Deep within…
[whooshing continues]
…the planet's raging molten furnace burns
and churns…
[ethereal music playing]
…generating a powerful magnetic field
that extends from the heart of the planet…
[ethereal humming]
…65,000 kilometers out towards the Sun.
A vital force field defending Earth…
[fire hissing]
…from the same savage solar winds
that stripped water from Mars.
[ethereal music continues]
Defeating them before they hit our atmosphere.
Safeguarding our essential water.
Hugging every drop close to our planet.
[ethereal whooshing]
This is what makes our pale blue dot
unlike anywhere else.
A place where life can thrive.
[majestic music playing]
Bringing relief to the elephants.
Ensuring rains return each year without fail.
[thunder crashing]
In the distance, storm clouds are building.
[Metsi grunts, moans]
[moans]
[elephant huffing]
Elephants can detect the low-frequency rumble of thunder
from 240 kilometers away.
[thunder rumbling]
[elephant grumbles]
[trumpets]
And it's telling them it's time to return to the Okavango.
[ethereal music playing]
From the highlands of Angola,
water is weaving its way through Botswana…
[whooshing]
…to rejuvenate the delta…
with the kiss of life.
[dramatic music playing]
Every step that brings the herd closer to home…
is a continuation of a much larger cosmic odyssey.
From tiny molecules hitching a ride on dust beyond Jupiter…
to surviving the crushing heat of early Earth.
[rumbling]
[whooshing]
Imprisoned in the planet's core…
[dramatic music swells]
…then set free…
[thunder crashes]
…to sow the seeds of life…
[elephant moaning]
-[exploding] -[thunder crashes]
…every drop of water has an amazing tale to tell.
Every molecule…
-[water gurgling] -…a link in an unbroken chain…
[elephant trumpets]
…cycling over tens of thousands of years…
[dramatic music continues]
…through air…
oceans…
rocks…
[dramatic music crescendos]
…and elephants.
[pensive music playing]
After eight months and hundreds of kilometers,
Metsi and her family have finally reached
the life-giving waters of the delta.
[majestic music playing]
[elephant trumpeting]
It's well past time to drink…
and play.
[elephant trumpets]
And then, drink some more.
[elephant grumbles]
[elephants trumpeting]
And show the newest member of the family…
[elephants continue trumpeting]
…how they do things in the delta.
[elephant trumpets]
[elephant grumbling]
[calm music playing]
Metsi and her new baby cousin
are the latest in a long line
to benefit from water's miraculous arrival
on this planet.
[calf whines]
[calm music continues]
They will forever be connected
to the universe
that gave our planet this magic ingredient
and gave us the ability to preserve and treasure it.
[intense music playing]
Next, the story of our universe concludes…
[rumbling]
…with the force that brings everything we've seen so far together.
The great sculptor of the cosmos,
gravity.
It's a force of attraction that built our planet.
[intense music crescendos]
[penguin squawks]
And we'll bring two penguins together at Earth's southern pole.
[majestic music playing]
But when did gravity start exerting its influence?
How does it create both order and chaos?
And why does it make ours the perfect planet for life…
[chick chirping]
…and love?
[penguin moaning]
[dramatic music playing]