Original subtitles

� dona nobis pacem �

Narrator: our universe seems a barren place,

Full of extreme conditions, hostile to living things.

Our own planet has such extreme environments,

Places where, until recently,

We believed nothing could survive.

[ choir vocalizing ]

[ wind whistling ]

Yet life is tenacious if it can just get a foothold.

We call the tiny organisms

Living in such inhospitable places "extremophiles,"

Microbes which thrive in the harshest of conditions.

Caves, long dismissed as dark and lifeless deserts,

Turn out to be ideal homes for these hardy life-forms.

Their scientific potential appears vast.

� dona nobis pacem �

This underground frontier holds an irresistible attraction

For two courageous young women.

[ choir vocalizing ]

The arizona desert -- bone-dry and scorching hot.

Perfect for extremophiles.

Nancy aulenbach and hazel barton are part of a small team

Exploring unmapped caves near the grand canyon.

The rest of the team, gordon brown and scott davis,

Search for other caves.

Hazel and nancy are almost certainly

The first cavers to explore this cave.

To get here, they rappelled 300 feet in 112-degree heat.

Ooh!

Listen, I'm gonna throw you this rope.

It'll help pull you in, okay?

You ready? Mm-hmm.

Oh!

Nancy aulenbach, from georgia,

Is the team's technical specialist.

I'm gonna let go of the belay line.

As an instructor in cave-rescue techniques,

Nancy's rope skills are finely honed.

You got it? Yeah.

At 98 1/2 pounds, she is well-suited

For rescuing cavers stuck in very tight places.

Aulenbach: in unexplored caves, we always do surveys.

Later, my husband will use our data

To draw the very first map of this cave.

He's a caver.

In fact, I come from an entire family of cavers.

28.4 feet.

Narrator: hazel barton, a native of England,

Has a phd in microbiology.

Okay, I'm getting positive 60 degrees, right?

Aulenbach: I found crystals, which only form in still water.

This cave probably formed millions of years ago.

Narrator: while nancy studies the cave wall

With a magnifying glass,

Hazel collects samples of tiny organisms

Which could help cure serious diseases.

Barton: you're never sure what speck of dust

Might contain the secret to new medicine

That could save lives.

Aulenbach: often, the most dangerous part

Of exploring caves is just getting to them.

Gordon will vouch for that.

[ choir vocalizing ]

Aulenbach: what turns this river so blue is dissolved limestone.

The limestone is gradually redeposited

To form travertine dams,

Which are first cousin to the stalagmites we see in caves.

Hey. Hey.

How's it going? Great.

You guys get up there? Oh, yeah.

Aulenbach: all this blue water and travertine

Is visible proof that caves are forming upstream right now.

I got time off from my job as a teacher's assistant

Because I promised to e-mail field reports

Back to my second-grade students.

Here's how hazel described her research to my second-graders.

Barton: the tiny organisms, called microbes, live in caves,

Might contain special chemicals

That we could make medicine from.

You know, caves are not only a place to visit,

They're a place where you can do a lot of research.

You can survey, you can do biological inventories,

You can find new species that people have never seen before.

Barton: I look for medical use for organisms everywhere,

Even in scum ponds.

After all, a rather useful medicine called penicillin

Was found in the same mold that grows on rotten cheese.

Oh, you know, it's just more boogers,

The smellier the better.

Girl: � I know you're out there somewhere �

Barton: while we were on navajo land,

Nancy and I heard about a medicine man

Making a sand painting.

Through these sand paintings, the navajo believe

That they can tap into the healing powers of the earth.

But, of course, that's what I do, too --

I go deep into the earth in search of unknown cures.

[ "I know you're out there somewhere" plays ]

[ laughter ]

Aulenbach: we're using kayaks on this expedition

Because the river is a good vantage point

For spotting unexplored caves on the cliff walls.

As my husband, brent, says,

"if you aren't wet, you aren't caving."

� 1, 2, 3! �

[ moody blues' "ride my see-saw" plays ]

� ride, ride my see-saw �

� take this place �

� on this trip, just for me �

� ride, take a free ride �

� take my place �

� have my seat, it's for free �

� I worked like a slave for years �

� sweat so hard just to end my fears �

� not to end my life a poor man �

� but by now, I know I should have run �

� whoo-ooh �

[ all cheering ]

� ride my see-saw �

Narrator: some rivers run through caves for miles

Before bursting onto the surface,

But that's of little concern as you approach a precipice,

Wondering, "is this a good idea?"

Unlike canyons, which are carved by fast-moving rivers,

Caves are formed by a subtler but equally effective force.

Most limestone caves start

When groundwater picks up carbon dioxide in the air and soil.

As the mildly acidic water leaks through cracks

In the earth's crust,

It dissolves the surrounding rock,

Leaving pockets, caves.

That's how a chamber 300 feet high

Can be carved from solid stone in less than a million years.

[ choir vocalizing ]

Aulenbach: walls are decorated

When trickling water deposits dissolved stone

To form stalactites, stalagmites,

And other flowstone formations.

Since the purest water on earth is found deep in pristine caves,

Sometimes we use rafts to explore,

Which cause less contamination than swimming.

Cave decorations are as delicate as fine crystal,

Easily shattered and impossible to repair.

That's why good cavers are trained

To move gently underground.

Barton: nancy, I've still got you on belay.

Narrator: when water leaves a residue of minerals,

They crystallize and gradually build up

To become delicate cave formations.

As hazel and her colleagues in the lab have found,

Extremophiles are tough.

Barton: we suspect that

Because of the environment in which they live,

Extremophiles produce potent chemical weapons.

If we can isolate these chemical compounds,

We can use them in the fight against disease.

Narrator: only the hardiest extremophiles could survive

Deep in the ice of the north pole.

To collect them, hazel and nancy have joined

An arctic expedition to greenland.

Greenland's ice cap is massive.

If melted, it would raise the world's oceans 18 feet.

[ shouting indistinctly ]

Aulenbach: when I first saw camp and saw these little, tiny specks

Out in the middle of nowhere, you know, I started thinking,

"we're gonna be here for a while."

Narrator: the expedition is led by frenchman janot lamberton.

Janot has gone deeper into ice caves than anyone else alive.

In summer, melting ice creates raging rivers,

Which plunge into the caves, cutting them deeper and deeper.

Aulenbach: heat from the sun can weaken the ice.

These jumbled blocks were once the roof of a cave,

Just like the one we're about to venture into.

We started early

So we wouldn't be inside when the roof collapsed.

Okay.

[ lamberton shouting indistinctly ]

Okay.

So...

Are we secure, your harness?

Yes.

You use your crampons very well.

Once I dropped into the cave, I focused on how awesome it was

To be one of the first people to ever see that place.

The ice is alive, and you could hear it creak and groan

As it all inches very slowly toward the sea.

Narrator: the ice is a data bank,

Storing centuries of information

For the team's glaciologist, dr. Luc moreau.

The ice is a memory of the climate.

You see different layer --

And white layer represent the winter,

So we can calculate the age of the ice here.

Narrator: a glacier is truly a time capsule.

The deeper you go,

The more the seasonal layers are compressed.

Only 60 feet down, hazel can collect samples

Which fell as snow centuries ago.

So far, we've found bunches of different bacteria --

Gram-negatives, gram-positive, cocci,

Spirochetes, all kinds of cool-looking stuff.

The thing is,

There's not much I can do with them here in the field.

The only thing I can do is freeze them down

And take them back with me.

Narrator: the bacteria hazel wants most

Lie buried beneath 500 feet of ice.

The team cannot descend that deep

Until there is a four-day cold snap to stop the flow of water.

They soon get their wish.

Aulenbach: the other day, it was minus 12 centigrade

With a windchill of minus 26 centigrade,

Which is colder than a freezer.

So it was very cold,

Bitterly cold.

Big time.

Too cold to be pleasant.

Aulenbach: waiting for the water to freeze up is the hardest part,

Because we're out in the middle of an ice cap.

There's not a whole lot to do.

This is definitely a caver's haircut.

� we can run �

� we can ride �

� we can fly �

Narrator: to prepare for the deep descent,

� nancy has to learn to measure the movement of the ice

As the cave walls are slowly pushed in

By the tremendous weight of the glacier.

Janot decided to risk perhaps his deepest descent ever

To get samples for hazel.

Only days ago, this was a deadly waterfall.

The deeper you go, the more unstable the ice becomes.

Janot has seen ice boulders

Burst from the walls like cannon shots.

10-foot spears can break loose without warning,

So he purges the walls of loose ice

To protect the team members who will follow.

[ man chanting indistinctly ]

Sometimes, to set ice screws in the safest spot,

Janot turns himself into a human pendulum.

Assisting janot on the descent,

Luc is concerned about dripping water

Icing up the rope at 200 feet.

Aulenbach: I've rappelled into hundreds of vertical pits around the world,

But never anything like this.

[ ice cracks ]

Ice adds an element of unpredictable risk.

[ men speaking indistinctly ]

Narrator: at just over 500 feet,

Janot grows increasingly concerned

By the instability of the ice.

This is the second-deepest ice cave janot has ever explored.

As hazel rappels,

Janot radios up and warns her not to descend too far.

Instead, he will bring her the deepest sample.

A large block of ice above janot seems ready to break loose.

He wastes no time in collecting the samples for hazel

Before starting the long climb back out.

[ choir vocalizing ]

Perhaps the microbes janot risked his life for

Will one day offer a cure for disease,

But it will take years of research to unlock that secret.

But I found a few weeks was quite my limit.

I knew I'd miss my new french friends, though.

When you go caving with someone,

You trust your life to them, and they to you.

You become friends for life.

Aulenbach: the hills near my home in georgia

Are ideal terrain for the formation of caves.

Just as extremophiles thrive in the ice cap of greenland,

Bats are well-adapted to classic limestone caves.

These flying mammals sleep all day

And come out at sunset to feed.

40% of all bat species are endangered,

But not this colony.

The 20 million bats here

Eat half a million pounds of insects every night.

Narrator: thanks to special training,

Nancy can introduce her class

To this underappreciated creature on a field trip.

Aulenbach: do you have any questions?

Girl: what do bats eat?

Well, this kind of bat eats scorpions.

Can you believe that?

I wouldn't want to eat a scorpion. Would you?

No. No. No. No.

And bats eat a lot of insects, too.

They get rid of those nasty mosquitos that bite your legs,

Make you itch.

Like bats, serious cavers will go a long way

To find a good cave, so when hazel invited me

On another far-flung search for extremophiles,

I was raring to go.

Narrator: southern mexico --

The yucatan peninsula juts defiantly into the gulf.

[ man singing indistinctly ]

These ancient mayan temples

Were built on one huge limestone plateau.

The plateau holds hundreds of miles of cave passage,

The longest underwater cave system in the world.

The caves are entered through "cenotes," natural wells.

How did it go? Did y'all find anything?

Hey, kids, I'm still down here in mexico with hazel,

And we're looking for something called a halocline.

A halocline is where the fresh water from a stream like this

Meets the salt water in the ocean,

And it forms this really blurry layer.

You see this blurry layer?

Hazel thinks that there are some special bugs

That live in this halocline, so that's why we're looking for it.

Well, that's about it for right now,

And I love y'all, and give yourselves a big hug for me.

Bye.

Bye. Bye. Bye. Bye.

Barton: to find an uncontaminated halocline,

Our guide, jorge gonzalez,

Led us to a remote cave deep in the jungle.

[ laughing ]

Narrator: if the fresh water in this cave

Flows all the way to the sea,

It must pass through a halocline.

To find out, nancy and hazel use fluorescein dye,

Which does not harm the environment.

Aulenbach: if this green dye comes out where we expect,

At a coastal lagoon,

Then we'll know this cave is connected directly to the sea.

Hazel retrieved the water collector she placed

At the mouth of the underground stream the day before.

The slightest trace of fluorescein will show up

Under my black light.

Barton: how's it look, nance?

I'm seeing green!

Barton: since the green dye went through to the ocean,

We went back to the cave the next day.

Whoo!

[ laughter ]

Hey, be careful, and have fun.

Aulenbach: I respect hazel's decision to take up cave diving,

But I promised my family I'd never do it.

Narrator: cave diving has been called

The most dangerous adventure in the world.

Survival takes training, caution, and luck.

[ moody blues' "water" plays ]

Barton: we're laying a dive line.

It's a bit like leaving a trail of bread crumbs

To find your way back home.

� aaaaaaah, aaaah �

� aaaaaaah, aaaah �

Narrator: jorge affixes arrows to the line

To guide the divers back to the exit.

� aaaaaaah �

Barton: there are rules that we never break.

We always turn around and head for the exit

When we've used up 1/3 of our air

So we have extra air

In case we run into problems on the way out.

Life in total darkness has made this species of fish blind.

To compensate, its other senses have become more acute.

When debris rains down from the ceiling,

You know that no one's even been this way before.

� aaaaaaah, aaaah �

If the silt gets kicked up in a huge cloud

And you lose sight of the dive line,

You may never find it again, and you could run out of air

Before you ever find your way out of the cave.

� aaaaaaaaaah �

When we reached a breakdown pile,

I wasn't sure if I could get through the small passage,

But the volume of water flowing through

Suggested that there was more cave on the other side,

So I had to find out.

Open-ocean divers wear scuba tanks on their backs,

But cave divers go side-mount

So we can squeeze through narrow passages.

In a really tight spot, you can remove your tanks,

Push them ahead, and then follow them through the hole.

We were approaching our turnaround,

And I will not break that rule no matter what.

Just when the cave seemed to be reaching the right depth

For a halocline, we hit a dead end.

In the few moments it took for us to hunt for an opening,

We kicked up a huge cloud of silt.

Narrator: as soon as hazel and jorge

Worked their way out of the silt cloud,

They headed for the exit.

Barton: just because fluorescein dye makes it through a passage,

That doesn't mean that we can.

You don't look too happy. What happened?

I wasn't in much of a talking mood, but my mind was made up.

We'd try a different cave.

Narratorof new medicines, due to its biological diversity.

The great variety of cave life

Is starting to prove just as productive.

You're wet. Get away from it.

Barton: I wanted more biological diversity,

But the arrival of the rainy season

Meant that time was running out.

We needed to find the halocline fast.

[ "I know you're out there somewhere" plays ]

Aulenbach: we saw a chain of cenotes,

Perhaps connected by an underground river.

I got gps coordinates on the biggest cenote in the chain,

A good starting point for the next dive.

[ dramatic music plays ]

Barton: we decided to use scooters

To give us more range in our hunt for the halocline.

Girl: � I know you're out there somewhere �

Barton: as the sunlight disappeared behind us,

I felt what all scientists feel in their gut --

"here I go again, into the black void."

[ man chanting indistinctly ]

There was already a dive line

For us to follow toward the ocean.

Someone had been here before us, but when?

It was spooky when the dive line ran out.

This must be where our mystery trailblazer turned back.

Aulenbach: we made an educated guess

As to where the underground river comes out.

That's where I'm headed with my gps.

Barton: still no halocline, but the cave was getting deeper,

So I had a good feeling

About our chances as we continued downstream.

The elusive halocline.

When we got our glimpse of it downstream,

We anchored our scooters

To keep the propellers from disturbing the halocline.

I knew from the blurry layer that this was definitely it,

A well-defined and uncontaminated halocline.

Anything living in this boundary

Between the salt and fresh waters is, by definition,

An extremophile with a unique system for survival.

I made sure to collect

From different levels of the halocline

To increase the variety of the samples.

� ooooh, ahhh �

� ooooh, ahhh �

My samples from the halocline are very precious.

Who knows what cures may be waiting

In the samples I collected today.

Unfortunately, I'll have to wait a long time to find out,

Because it can take years to approve

And test a safe, new drug.

For the moment, all I know is that I'm very, very happy.

Whoo! I got it!

You got it!

I got it!

It may seem I'm this free-spirited scientist,

But I'm really part of a research team.

My colleagues count on me

To bring back unique microscopic life.

Often, I don't find what we were looking for,

But I find something else totally unexpected

And just as useful.

[ choir vocalizing ]

Life is full of surprises.

A powerful microscope can reveal

A whole universe in a drop of water.

In just six short years,

The search for extremophiles has produced

A potential new treatment for leukemia

And added 12 new kingdoms to the tree of life.

Each kingdom is distinct from the others

As, say, a cabbage is from a dolphin.

Narrator: just when we think we've seen every inch of our planet,

We find somewhere else we haven't looked,

Remote, mysterious places of extreme potential,

Places where the horizon turns inward

And waits for cavers to expand it for us all.

[ choir vocalizing ]

Aulenbach: I am gonna be caving until my body completely falls apart.

I'm going to do everything possible

That I can contribute to the world of caving,

In my wheelchair if I have to.

I'm always gonna be caving in my heart, always.

� we can run �

� we can ride �

� we can fly �

� treasure every moment �

� never be apart �

� follow every footstep �

� take me to your heart �

� I want to feel the freedom �

� in our lives �

� we can run �

� we can ride �

� we can fly �

� no matter what they say �

� we can love �

� we can live �

� we can fly �