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Ice is one of the most mesmerising
and beguiling substances
in the world.

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It's very familiar and yet
never ceases to be other-worldly.

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Always a little bit strange.

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Ice is full of contradictions.

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It's transparent

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but it can glow with colour
like nothing on earth.

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It's powerful enough
to shatter rock and sink ships.

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But can just melt away
in the blink of an eye.

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I'm Dr Gabrielle Walker.

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I trained as a chemist,
but now I'm a science writer.

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And for a long time,
I've been obsessed by ice.

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Ever since I first set foot
on Arctic sea ice,

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I've been drawn back
year after year.

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I've been trying to discover
the secrets hidden deep within ice.

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I think the ice crystal has
something extraordinary to reveal

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about how the world works.

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How it does that

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and what it tells us is what I want
to explore in this programme.

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This is it. Wow!

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Welcome to Nigarsbreen.
It's magnificent!

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I'm going to find out how something
so ephemeral is powerful enough
to carve solid rock.

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How ice has led to the evolution
of some of the most extraordinary
creatures on our planet.

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This is a really small one.

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How ice in space might lead us to
discover extra-terrestrial life.

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If we've got an ocean underneath
the surface of the moon,

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that's a place to search for life.

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And how its astonishing ability
to store ancient atmospheres

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is helping us understand
our climate.

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When they invaded Britain in 1066,
this is the air they were breathing!

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Do your worst!

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And I reveal how its power
to preserve our past

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and inform our future

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lies deep within the ice crystal.

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First of all,
I've come to southern Norway...

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..to visit an enormous glacier
called Jostedalsbreen.

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It's the biggest piece of ice
in continental Europe.

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It covers nearly 500 square
kilometres of mountain.

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Glaciers are one of the most
powerful forces in nature.

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They turn fragile ice into enormous
grinding machines

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that can erode mountains.

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I'm going to explore
one of Jostedalsbreen's many
glacial tongues, Nigardsbreen.

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I'm meeting local glaciologist,
Evan Lowe.

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Hello, Evan!

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Hello. Welcome to Jostedalsbreen.
Thank you.

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Gosh, it's gorgeous!

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We have a kayak to take us
across the lake.

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I want to find out exactly
what makes glaciers so powerful.

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How something as malleable as ice

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can carve out such a spectacular
landscape.

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From the sculpted walls
of the valley

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to the colour of the lake.

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And full speed onto land.
Full speed.

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Even though it's just ten per cent
of the Jostedalsbreen's glacier,

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Nigardsbreen covers nearly
50 square kilometres of mountain.

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It rises steeply to almost
two kilometres above sea level.

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Down here in the valley,
where the temperatures are warmer
than in the high mountains,

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the glacier melts abruptly
in a ragged wall.

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It's only when you get this much ice
that you can witness
something spectacular.

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This is it! Wow!

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'Its full range of colours.'

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It's magnificent! The blue colour
is absolutely amazing.

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It's like looking into the heart
of the glacier.

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Yes, it goes from completely white
and all the way to very dark blue,

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depending on how the light
hits the surface

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and how far into the ice the light
penetrates

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before it's reflected to us.

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The surface of the glacier
looks white

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because its jagged crystals
are deflecting sunlight
in all directions.

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Close up, the ice seems transparent.

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But it's not.

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Pure ice crystals absorb light
at the red end of the spectrum.

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So as sunlight travels deeper
into the ice,

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a new blue light is reflected back.

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When it's in a huge chunk
like a glacier, it looks blue.

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But if you grab a chunk of it, it's
just white, ordinary boring ice!

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Ice is never boring. Never, ever!

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The ice in this front wall
is at the end of its journey
down the mountain.

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It's now at the point
of melting away.

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Every moment it's changing,

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like a moving sculpture.

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Melt water is raining down on me

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and it's making
the most amazing shapes.

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You can see it's eating
into the walls here

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and making all these curves
and round parts

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and that's why it looks like
the moon outside with all those
incredible curves.

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It's beautiful.

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Although glacial ice is a solid,

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it actually flows like a river.

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It's incredible to think
that this much ice

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is constantly on the move.

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I've been climbing up to see
what drives the glacier.

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And it's the phenomenal weight
of this enormous ice pack,

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over nine kilometres long,

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and up to 500 metres deep.

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Millions of tonnes of ice
crammed into this valley.

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Built up from layer upon layer
of snow,

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this monumental river of ice
is constantly being topped up

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by fresh snowfall.

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And that keeps it flowing downhill.

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It makes very slow progress.
But there is a way to see it move.

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A time-lapse camera shows that
Nigardsbreen's surface ice

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travels at around 275 metres
per year,

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carving away the rock as it goes.

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When you're here, the only clues
you see of the glacier's movement

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are crevasses.

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Deep gashes that split open
the surface of the ice.

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These open up at the top of the ice.

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One of the reasons is the top
of the ice is brittle and tough.

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Further down, where it's been
squeezed, it's plastic and soft.

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But as the glacier moves,
the brittle part breaks open

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and creates these great crevasses.

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When a crevasse has opened up in the
ice, melt water can gather in it

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and start hollowing its way down
towards the bedrock.

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Here, it carves out a hidden world
of icy caverns deep within
the glacier.

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I'm going to try to abseil right
into the heart of the glacier

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to see for myself how it moves.

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That was amazing!

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We're in the engine room
of the glacier.

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You can see just down here right
where the ice melts the ground.

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And this is where everything
important happens.

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I'm getting wet
with the melting water,

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but it's that that helps the glacier
slide on its belly,

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one of the things that makes it
so dynamic.

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Nigardsbreen's temperate
mountain climate

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means the ice at the lower end
of the glacier exists very close
to melting point.

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As well as the melt water
flowing beneath the ice,

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which helps lubricate the glacier
on its journey down the mountain,

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there's melt water within the ice
itself,

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seeping out of these walls.

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That melting water also makes
this cave, and other caves like it
all around.

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I bet this cave wasn't here last
year and it probably won't be here
next.

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It's transient, part of the signs
that the glacier is dynamic

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and moving and changing
all the time.

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When you look at the slick blue ice
in these caves,

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it's hard to imagine it began
its life as snowflakes.

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But hundreds of years of compression

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have gradually turned it into this
glittering mass of ice crystals.

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Look at that!

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The sides of the ice here are just
like they were in the cave.

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They really look like solid
squashed together lumps and cubes.

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And here you can really see that.

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Like someone's taken a bunch of
cubes and squeezed them together.

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And that's what I'm walking on.
Like walking on a giant Slushie!

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Every single one of these ice
crystals has an unusual property.

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If you throw them into water,
they float.

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That's something we take completely
for granted.

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But it's incredibly rare in nature.

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It's what helps to make ice special.

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And what gives it the power
to transform our world.

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The secret lies at the heart
of the ice crystal.

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I'm going to witness
the very instant it forms,

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with chemist and fellow
ice enthusiast, Dr Andrea Sella.

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Ice breaks all the rules
that we learn.

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Andrea believes this moment is key
to understanding the mysterious
world of the ice crystal

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because of the curious way
that water turns from liquid
to solid ice.

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Let me show you something
really amazing.

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We've got some mineral water here
that we've been cooling for a bit.

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I want you to take these bottles
quite gingerly.

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Take this and bang it on the table.
Just bang it? Bang it.

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There it goes! Look at that!
Instant ice!

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It's spreading out these fingers
and shards of ice all the way down.

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It's quite amazing. You can see
the crystals growing before
your very eyes!

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Ice is a crystal in which the water
molecules are very carefully
arranged.

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If you think of guards on parade,

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all lined up in neat rows,
that's what a crystal is,
and that's what ice is.

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Like any crystal,
ice doesn't form spontaneously,

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even in this super-cooled water,

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which is well below zero degrees
centigrade.

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It needs a seed, a template.

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You need someone to kind of blow
the whistle

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and provide an initial point,
saying start here.

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So I bang it, you get bubbles and
each of those bubbles is a place for
the crystals to form. Absolutely.

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You can do it in other ways, too.

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Take another bottle,
and this time what we'll do

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is try dropping another piece of ice
into it.

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Just pop it in.

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Ready, steady...

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It's really the ice which is acting
as the initial starting point

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on which the rest of the ice grows.

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It's the way the ice crystal forms
that is the key to why it floats.

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Water molecules are loosely
held together by bonds

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which are constantly making
and breaking.

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When the temperature drops to zero,

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these bonds begin to hold. Fast.

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Creating a hexagonal lattice,
an ice crystal.

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In the lattice, the bonds hold
the molecules far apart.

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It's that sudden opening out

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that makes ice lighter, less dense,
than liquid water.

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In water, the approaches
are quite close.

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When we get to ice,
suddenly it expands a bit.

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And we end up with a strangely
spacious open structure

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which is less dense
and therefore it floats.

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It's really quite miraculous.

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That's all down to the structure
of the crystal? Absolutely.

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Ice is incredibly special.

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The irony is that to us
it's completely common.

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We take an ice cube and drop it
into a drink and it floats.

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Well, it is almost unique

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00:15:11,960 --> 00:15:16,280
in the enormous, the millions
of compounds and materials
that we know about,

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00:15:16,280 --> 00:15:19,680
in being a solid that floats
on its melt.

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If ice didn't float, the world
would be a very different place.

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Instead of forming on the surface
of the ocean,

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allowing marine life
to survive beneath,

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ice would form on the sea bed,

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oceans would freeze
from the bottom up

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and life as we know it might never
have evolved at all.

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We also wouldn't have developed
an elegant British pastime

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that began on frozen lakes
and rivers hundreds of years ago.

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Every Sunday morning,
members of the Royal Skating Club

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00:16:14,000 --> 00:16:19,440
meet at Guildford ice rink
to skate in what is called
"the English style".

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00:16:23,680 --> 00:16:27,640
Once considered England's highest
form of skating art,

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"the English style" originates from
the early 19th century.

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00:16:31,880 --> 00:16:35,680
It combines a Victorian sense
of elegance and understatement

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00:16:35,680 --> 00:16:38,600
with a high level of skill.

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00:16:38,600 --> 00:16:41,920
Around a centre marked by an orange,

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00:16:41,920 --> 00:16:45,840
the skaters perform perfectly-shaped
geometric figures

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in absolute unison, holding
their bodies stiff and straight.

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00:16:52,480 --> 00:16:55,440
Centre change, sub circle.

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In keeping with the Victorian horror
of showing off,

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the challenge is to make these
complex manoeuvres look graceful

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and effortless.

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These are lovely.

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00:17:13,960 --> 00:17:18,320
Elaine Hooper, historian for the
National Ice Skating Association,

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00:17:18,320 --> 00:17:21,520
has some Victorian pictures
of the English Style.

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00:17:21,520 --> 00:17:26,880
It was very much a more polite style
of skating. It was very dignified.

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00:17:26,880 --> 00:17:32,480
The ladies had long dresses and big
hats on and the men had top hats
in Victorian times.

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That was the style of skating

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that evolved on the frozen lakes
and rivers

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as early as the 1600s.

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Over the years, different moves were
added when people wanted to make it
more difficult.

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00:17:47,480 --> 00:17:50,640
The English Style developed
amongst the upper classes

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00:17:50,640 --> 00:17:54,920
while Britain was experiencing
what became known as
"the little ice age".

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From the 13th century to the middle
of the 19th century,

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British winters were up to
two degrees cooler.

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Many lakes and rivers regularly
froze over.

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Pepys himself talks about skating
with Nell Gwyn on the Thames

237
00:18:12,600 --> 00:18:17,200
in one of the great frost fairs
where they would roast hogs
and skate.

238
00:18:17,200 --> 00:18:20,720
It was just a way of life then.
It was much colder.

239
00:18:20,720 --> 00:18:24,680
The Thames doesn't tend to freeze
over now so we can't have that
again.

240
00:18:30,040 --> 00:18:32,800
We can skate because of another
quality of ice.

241
00:18:32,800 --> 00:18:34,600
Its slipperiness.

242
00:18:39,320 --> 00:18:43,600
This may seem completely normal, but
it's actually very rare for a solid.

243
00:18:47,560 --> 00:18:52,880
The reason we can skate is to do
with what happens when ice is
squeezed by a blade.

244
00:18:54,120 --> 00:18:56,240
The way it reacts to pressure.

245
00:19:01,080 --> 00:19:05,640
So Andrea Sella and I are going to
put ice under a lot of pressure

246
00:19:05,640 --> 00:19:07,640
in a classic experiment.

247
00:19:09,960 --> 00:19:15,200
OK, we need to lift it up
and get it onto our platform.

248
00:19:15,200 --> 00:19:17,920
It is pretty heavy.
I'm strong, don't worry!

249
00:19:17,920 --> 00:19:19,840
Good. There we are.

250
00:19:19,840 --> 00:19:22,040
So now we need to unpack things.

251
00:19:24,280 --> 00:19:26,720
Ooh, that's lovely! Gorgeous!

252
00:19:28,760 --> 00:19:30,520
I'll lift it and you pull.

253
00:19:30,520 --> 00:19:31,840
That's great.

254
00:19:33,000 --> 00:19:37,200
What we're going to do is sling
this wire over the top

255
00:19:37,200 --> 00:19:42,320
and hang these two really
rather heavy weights,

256
00:19:42,320 --> 00:19:45,160
we're talking about
seven kilos here.

257
00:19:45,160 --> 00:19:46,800
There we go.

258
00:19:46,800 --> 00:19:49,440
It's now suspended.

259
00:19:49,440 --> 00:19:53,320
What we have to do is wait for
the pressure of the wire

260
00:19:53,320 --> 00:19:55,440
to work its magic on the ice.

261
00:20:01,000 --> 00:20:04,360
As we wait, the wire works its way
through the ice.

262
00:20:04,360 --> 00:20:06,360
Almost cutting it in two.

263
00:20:08,160 --> 00:20:11,640
And behind the wire,
the ice is sealing up again.

264
00:20:11,640 --> 00:20:14,760
Something very strange is going on.

265
00:20:19,560 --> 00:20:21,280
It's amazing. Look at it!

266
00:20:21,280 --> 00:20:23,840
So how's it gone through
the ice like this?

267
00:20:23,840 --> 00:20:29,120
Of course, the wire has the weight
on it. And because the wire's
very thin,

268
00:20:29,120 --> 00:20:32,400
what it does is apply really
quite a large pressure

269
00:20:32,400 --> 00:20:34,520
on a local area of the ice.

270
00:20:34,520 --> 00:20:37,640
We know that ice expands
when it freezes

271
00:20:37,640 --> 00:20:42,640
so if you squeeze it, you can drive
it back towards that molten state.

272
00:20:42,640 --> 00:20:45,800
So when you put pressure on it,
it turns it back to water.

273
00:20:45,800 --> 00:20:47,840
You can re-melt it back to water.

274
00:20:51,560 --> 00:20:54,480
That's one of the key reasons
we can skate.

275
00:20:54,480 --> 00:20:59,120
The pressure of the blades is enough
to melt the top layer of ice
into water

276
00:20:59,120 --> 00:21:02,680
which lubricates the skates.

277
00:21:04,760 --> 00:21:07,280
Friction can also help melt the ice.

278
00:21:09,440 --> 00:21:13,640
In our experiment, as the wire
passed through the block,

279
00:21:13,640 --> 00:21:16,160
the ice sealed up behind.

280
00:21:16,160 --> 00:21:21,000
This shows how ice can engulf
something solid

281
00:21:21,000 --> 00:21:23,800
leaving barely a trace.

282
00:21:25,320 --> 00:21:30,280
I was expecting the wire to cut
through it. And it's completely
sealed.

283
00:21:30,280 --> 00:21:35,400
It looks as though it ought to fall
apart. It's an extraordinary
process.

284
00:21:35,400 --> 00:21:39,760
Effectively, underneath the wire,
the ice melts

285
00:21:39,760 --> 00:21:42,040
and then behind it,
it re-freezes again.

286
00:21:42,040 --> 00:21:44,640
So this whole process is making
the ice

287
00:21:44,640 --> 00:21:48,880
move between those two points
on that knife-edge between
liquid and solid.

288
00:21:48,880 --> 00:21:51,040
The pressure squeezes it,

289
00:21:51,040 --> 00:21:54,280
take the pressure off and it freezes
again. Absolutely.

290
00:21:58,320 --> 00:22:02,120
This formidable ability
to swallow up another solid

291
00:22:02,120 --> 00:22:05,840
is a real insight into just how
peculiar ice is.

292
00:22:05,840 --> 00:22:11,640
It also explains how ice can do
seemingly impossible things

293
00:22:11,640 --> 00:22:13,320
in nature.

294
00:22:20,080 --> 00:22:23,520
In Norway,
at the foot of Nigardsbreen,

295
00:22:23,520 --> 00:22:27,280
glaciologist Evan Lowe
has some local stories to tell

296
00:22:27,280 --> 00:22:32,720
of how glaciers can engulf things
much bigger than a thin metal wire.

297
00:22:33,600 --> 00:22:40,440
From where we're sitting now we can
see a place where a farm used to be,
250 years ago.

298
00:22:40,440 --> 00:22:45,120
Until it was knocked down
by this glacier behind us

299
00:22:45,120 --> 00:22:49,520
and all the buildings and farm
were just swallowed by the glacier.

300
00:22:49,520 --> 00:22:52,360
If something goes into the ice,
what happens to it?

301
00:22:52,360 --> 00:22:56,960
A bit further south, there's a plane
with a pilot who crashed in the '70s

302
00:22:56,960 --> 00:22:58,720
on top of the glacier.

303
00:22:58,720 --> 00:23:03,760
Before the rescuers could get there,
the whole thing was covered by snow.

304
00:23:03,760 --> 00:23:06,320
And it never appeared again.

305
00:23:06,320 --> 00:23:10,800
Some guy calculated that it should
come out of the glacier

306
00:23:10,800 --> 00:23:15,640
some 25 years later,
but they're still waiting for it.

307
00:23:15,640 --> 00:23:20,920
No-one's seen any trace of it.
So there's a plane, body
and everything.

308
00:23:20,920 --> 00:23:21,960
Somewhere!

309
00:23:21,960 --> 00:23:25,720
That's a spooky ghost story to tell
just before bed!

310
00:23:37,000 --> 00:23:39,840
When it comes to a glacier shaping
the landscape,

311
00:23:39,840 --> 00:23:42,120
this ability of ice to absorb things

312
00:23:42,120 --> 00:23:44,840
is a real secret to its strength.

313
00:23:47,400 --> 00:23:52,280
Ice on its own is far too fragile
to leave any mark on solid rock.

314
00:23:52,280 --> 00:23:55,960
It can only carve out a valley
by picking up tools.

315
00:23:58,840 --> 00:24:04,440
The ice engulfs rocks and boulders
as it moves down the mountainside.

316
00:24:04,440 --> 00:24:08,800
They pass through the ice and get
dragged along in its underbelly.

317
00:24:08,800 --> 00:24:13,160
Together they scrape and chip away
at the rock beneath.

318
00:24:16,640 --> 00:24:21,560
It's easy to imagine that this was
once just one big mountain.

319
00:24:21,560 --> 00:24:25,360
And now all this space
that we are in now

320
00:24:25,360 --> 00:24:27,760
is the result of the glacier

321
00:24:27,760 --> 00:24:32,160
taking its bites like this
during thousands of years.

322
00:24:32,160 --> 00:24:37,000
I like the way you say, "taking
bites". The rocks are the teeth
of the glacier

323
00:24:37,000 --> 00:24:39,280
and that's what it's using
to grind away.

324
00:24:39,280 --> 00:24:44,200
It's still doing it up there,
making the valley bigger and wider.

325
00:24:44,200 --> 00:24:48,600
If it were some other solid
like steel or rock,

326
00:24:48,600 --> 00:24:51,120
it would just sit there.
It couldn't do this.

327
00:24:51,120 --> 00:24:53,080
That's one of the secrets of the ice

328
00:24:53,080 --> 00:24:56,800
that it's strong enough to carry
big rocks to work on the surface

329
00:24:56,800 --> 00:24:59,840
but it's also soft enough to move.

330
00:25:08,560 --> 00:25:14,400
Over the thousands of years that
Nigardsbreen has been advancing
and retreating,

331
00:25:14,400 --> 00:25:16,360
it's been grinding down the rock

332
00:25:16,360 --> 00:25:18,680
like an enormous sheet
of sand paper.

333
00:25:20,840 --> 00:25:25,720
Gradually, it's turned boulders
and bedrock into dust so fine

334
00:25:25,720 --> 00:25:27,760
that when it's washed into the lake,

335
00:25:27,760 --> 00:25:29,880
it remains suspended there.

336
00:25:29,880 --> 00:25:32,240
And it's the minerals in this dust

337
00:25:32,240 --> 00:25:35,000
that give the lake its colour.

338
00:25:47,000 --> 00:25:49,640
So that piece of ice there
has done everything.

339
00:25:49,640 --> 00:25:52,040
It's shaped and smoothed these rocks

340
00:25:52,040 --> 00:25:54,760
and it's made these scrape marks
and teeth marks

341
00:25:54,760 --> 00:26:00,360
and down there, the bigger boulders
and the pebbles and the silt

342
00:26:00,360 --> 00:26:02,840
all the way through to the colour
of the lake,

343
00:26:02,840 --> 00:26:04,560
even the shape of the valley,

344
00:26:04,560 --> 00:26:08,760
everything about everything I see
has been dictated and defined
by the ice.

345
00:26:16,720 --> 00:26:19,520
But ice itself is ruled
by temperature.

346
00:26:20,640 --> 00:26:24,400
That's what determines everything
from how long it lasts

347
00:26:24,400 --> 00:26:26,800
to how and where it forms.

348
00:26:26,800 --> 00:26:30,800
And nowhere is this more true
than in the sky,

349
00:26:30,800 --> 00:26:33,800
where ice is at its most
unpredictable.

350
00:26:36,680 --> 00:26:38,960
Clouds are usually made
of water vapour.

351
00:26:38,960 --> 00:26:43,040
But if it's cold enough, you can get
clouds entirely made of
ice crystals.

352
00:26:43,040 --> 00:26:46,920
When you get ice in the sky, that
can cause havoc with the weather.

353
00:26:50,240 --> 00:26:53,000
One of the most treacherous forms
of icy weather

354
00:26:53,000 --> 00:26:55,480
is an ice storm.

355
00:26:58,560 --> 00:27:02,360
11 Canadians have been killed and
two million are without electricity

356
00:27:02,360 --> 00:27:05,280
after devastating ice storms
swept the country.

357
00:27:05,280 --> 00:27:10,680
In 1998, eastern Canada was hit
by a massive ice storm,

358
00:27:10,680 --> 00:27:12,880
its worst on record.

359
00:27:15,520 --> 00:27:20,160
Over five days, freezing rain turned
into a slick glaze of ice

360
00:27:20,160 --> 00:27:24,000
and built up to 7.5 centimetres
thick in some places.

361
00:27:27,600 --> 00:27:32,120
It became heavy enough to bring down
trees and power lines.

362
00:27:35,080 --> 00:27:40,440
The ice storm forced the government
to declare a state of emergency.

363
00:27:48,840 --> 00:27:53,120
Ice storms can begin
high in the atmosphere.

364
00:27:55,000 --> 00:27:59,400
Here, ice crystals grow into
delicate snowflakes

365
00:27:59,400 --> 00:28:02,400
with stunningly symmetrical
branches.

366
00:28:07,320 --> 00:28:11,000
If snowflakes fall into
a warmer band of air,

367
00:28:11,000 --> 00:28:14,080
they'll melt away into rain.

368
00:28:14,080 --> 00:28:18,720
But in the unusual circumstances
that lead to an ice storm,

369
00:28:18,720 --> 00:28:22,200
there's much colder air
beneath this warm layer

370
00:28:22,200 --> 00:28:24,520
and it's very close to the ground.

371
00:28:27,040 --> 00:28:29,640
As the rain falls through
this cold air,

372
00:28:29,640 --> 00:28:31,720
it becomes super-cooled,

373
00:28:31,720 --> 00:28:34,280
ready to freeze again in an instant.

374
00:28:35,440 --> 00:28:38,440
It crystallises as soon as
it touches something,

375
00:28:38,440 --> 00:28:43,240
creating layer upon hazardous layer
of ice.

376
00:28:45,440 --> 00:28:48,720
MAN: Millions of people here
in Montreal are affected.

377
00:28:48,720 --> 00:28:51,640
WOMAN: It's like a war scene,
almost.

378
00:28:51,640 --> 00:28:57,760
We're going round house to house
suggesting to people that it'll be
a while before the power's back

379
00:28:57,760 --> 00:29:01,080
and it might be wise to relocate
to a shelter.

380
00:29:05,160 --> 00:29:07,920
The damage cost the country
3 billion.

381
00:29:07,920 --> 00:29:11,760
In some areas, the ice didn't melt
for three months.

382
00:29:22,120 --> 00:29:25,000
Temperature is truly the master
of ice.

383
00:29:25,000 --> 00:29:29,400
And there's a mysterious phenomenon
called hot ice,

384
00:29:29,400 --> 00:29:32,520
which freezes at room temperature.

385
00:29:34,720 --> 00:29:39,240
Hot ice is created by putting water
under enormous pressure,

386
00:29:39,240 --> 00:29:42,960
far greater than any glacier
on our planet.

387
00:29:44,080 --> 00:29:47,760
This is ice that we wouldn't
normally find anywhere on Earth.

388
00:29:52,360 --> 00:29:57,360
Professor Paul Macmillan
is going to show me how to make
this high-pressure ice.

389
00:29:57,360 --> 00:30:01,080
What we've got is a little drop
of liquid water

390
00:30:01,080 --> 00:30:03,960
and it's placed between
two diamonds.

391
00:30:03,960 --> 00:30:09,280
Inside here we've got two tiny
diamonds that are pressing together.

392
00:30:09,280 --> 00:30:12,680
You're going to turn this knob here
very gently.

393
00:30:12,680 --> 00:30:17,640
Because otherwise you'll force
the two diamonds together too fast
and they'll break.

394
00:30:17,640 --> 00:30:19,640
I'll be very careful.

395
00:30:21,120 --> 00:30:24,840
I'm about to put a tiny drop
of water under more pressure

396
00:30:24,840 --> 00:30:28,120
than occurs naturally anywhere
on the Earth's surface.

397
00:30:28,120 --> 00:30:30,760
When this gets to around 12,

398
00:30:30,760 --> 00:30:33,200
I want you to start to watch
the screen. OK.

399
00:30:33,200 --> 00:30:35,960
Nine and a half now. Yes.

400
00:30:35,960 --> 00:30:38,720
So what's happening is
the pressure is going on

401
00:30:38,720 --> 00:30:41,960
and the diamonds are squeezing
that drop of water. Yes.

402
00:30:41,960 --> 00:30:45,480
It's close to 12. I would slow it
down just a wee bit.

403
00:30:45,480 --> 00:30:51,160
At the moment this is liquid water,
but it's really squeezed now.

404
00:30:51,160 --> 00:30:53,240
The pressure's going up...

405
00:30:53,240 --> 00:30:55,080
Look at that!

406
00:30:55,080 --> 00:30:56,840
It's crystals!

407
00:30:56,840 --> 00:31:01,200
Yeah. Oh, that is cool. You've just
made ice crystals in there.

408
00:31:01,200 --> 00:31:03,840
They're growing as well,
not just sitting there.

409
00:31:03,840 --> 00:31:06,240
It's a whole faceful
of tiny crystals.

410
00:31:08,040 --> 00:31:12,080
The ice has formed even though
it's way above zero degrees.

411
00:31:13,240 --> 00:31:17,000
See the room temperature
is 25 degrees.

412
00:31:17,000 --> 00:31:20,040
So we've made water freeze
at 25 degrees C? Yes.

413
00:31:20,040 --> 00:31:24,040
These are icebergs floating
in dense water.

414
00:31:26,040 --> 00:31:29,960
'The hot ice is at a pressure
of 15,000 atmospheres.

415
00:31:29,960 --> 00:31:33,480
'That's 15 times more pressure

416
00:31:33,480 --> 00:31:37,320
'than you find at the bottom
of the deepest ocean on Earth.'

417
00:31:37,320 --> 00:31:41,000
What would it be like, then? I know
we can't take it out and look at it

418
00:31:41,000 --> 00:31:43,960
or do things with it
because it's under that pressure.

419
00:31:43,960 --> 00:31:46,600
But how is it different from real,
normal ice?

420
00:31:46,600 --> 00:31:51,840
The first thing is that it doesn't
melt at normal temperatures.

421
00:31:51,840 --> 00:31:58,240
This one here, you'd have to take
this up to well over 100 degrees
centigrade

422
00:31:58,240 --> 00:32:00,600
for it even to start to melt.

423
00:32:00,600 --> 00:32:03,520
So you can go above boiling
point and it doesn't melt?

424
00:32:03,520 --> 00:32:06,320
Exactly. This is a high-density form
of ice.

425
00:32:06,320 --> 00:32:10,240
The structure is very like
a little cube.

426
00:32:10,240 --> 00:32:14,800
You would never get
the hexagon snowflake shapes

427
00:32:14,800 --> 00:32:17,400
that you get with normal ice.

428
00:32:17,400 --> 00:32:22,240
'This kind of ice might occur
naturally out in space.'

429
00:32:23,880 --> 00:32:28,160
We think that it probably does exist
in the solar system,

430
00:32:28,160 --> 00:32:32,560
deep inside some of the icy moons
out there

431
00:32:32,560 --> 00:32:36,040
like Titan, which is the large moon
of Saturn.

432
00:32:36,040 --> 00:32:39,040
And we know that the pressure inside

433
00:32:39,040 --> 00:32:41,760
gets to these pressure values.

434
00:32:41,760 --> 00:32:46,240
So it's like having a telescope
to look into the heart
of Saturn's moon. Exactly.

435
00:32:49,680 --> 00:32:53,880
We know already that the surfaces
of some of the moons of Jupiter
and Saturn

436
00:32:53,880 --> 00:32:58,120
are covered in more normal ice, the
type we're familiar with on Earth.

437
00:33:01,120 --> 00:33:04,480
Recently, we've been able to get
close enough to see it

438
00:33:04,480 --> 00:33:06,040
in more detail.

439
00:33:06,040 --> 00:33:09,360
And that's revealed something
startling.

440
00:33:09,360 --> 00:33:14,640
It might be protecting oceans
of liquid water out in space.

441
00:33:17,880 --> 00:33:22,800
Professor Michele Dougherty
is a space physicist
who explores these outer planets.

442
00:33:27,480 --> 00:33:29,880
It was Jupiter's moon, Europa,

443
00:33:29,880 --> 00:33:32,160
that first attracted her attention

444
00:33:32,160 --> 00:33:36,160
thanks to a surprising photograph
taken by the Galileo spacecraft.

445
00:33:39,840 --> 00:33:43,160
This image shows us what looks like
an ice shelf

446
00:33:43,160 --> 00:33:45,760
which is floating on a liquid.

447
00:33:45,760 --> 00:33:49,520
We could almost say it was
the Antarctic or Greenland.

448
00:33:49,520 --> 00:33:55,400
What you can clearly see are these
icebergs which look as if they're
moving around on the surface.

449
00:33:55,400 --> 00:33:59,440
The only way for that to happen is
for there to be liquid underneath

450
00:33:59,440 --> 00:34:02,720
that's helping shift them around
on the icy surface.

451
00:34:06,080 --> 00:34:08,200
By studying data from Galileo,

452
00:34:08,200 --> 00:34:12,160
scientists reckon that Europa's ice
is covering an ocean

453
00:34:12,160 --> 00:34:13,840
of liquid water.

454
00:34:17,000 --> 00:34:20,400
If true, this will be
an amazing discovery.

455
00:34:20,400 --> 00:34:25,960
But frustratingly, there's no way
yet of penetrating the surface

456
00:34:25,960 --> 00:34:27,720
to confirm it.

457
00:34:34,400 --> 00:34:36,600
However, in 1997,

458
00:34:36,600 --> 00:34:39,520
an unmanned probe called Cassini

459
00:34:39,520 --> 00:34:41,120
was sent into space.

460
00:34:42,560 --> 00:34:48,280
Its mission, to explore Saturn,
700 million miles from Earth.

461
00:34:50,640 --> 00:34:55,520
When it flew by a tiny ice-covered
moon called Enceladus,

462
00:34:55,520 --> 00:35:00,360
it gave a reading that Michele and
her team simply couldn't explain.

463
00:35:01,880 --> 00:35:07,160
So she asked the mission planners if
Cassini could make a closer fly-by.

464
00:35:08,160 --> 00:35:09,840
And this revealed a spectacle

465
00:35:09,840 --> 00:35:12,040
that had never been seen before

466
00:35:12,040 --> 00:35:14,360
anywhere in the solar system.

467
00:35:16,280 --> 00:35:20,320
This is the image we took when we
went really close to Enceladus.

468
00:35:20,320 --> 00:35:23,560
You can clearly see this large plume
of water vapour

469
00:35:23,560 --> 00:35:26,320
coming off from the south pole.
A gorgeous image!

470
00:35:26,320 --> 00:35:32,120
As Cassini has shown us that water
definitely exists under
Enceladus's ice,

471
00:35:32,120 --> 00:35:38,920
that makes it a fantastic place
to search for evidence of
extra-terrestrial life.

472
00:35:39,840 --> 00:35:43,000
The reason that this discovery
is so amazing

473
00:35:43,000 --> 00:35:48,160
is that it's telling us there's
water under the surface of Enceladus

474
00:35:48,160 --> 00:35:51,400
and in the plume itself
there is water vapour,

475
00:35:51,400 --> 00:35:53,240
there are ice crystals

476
00:35:53,240 --> 00:35:56,840
and there are organic compounds -
nitrogen, carbon, hydrogen -

477
00:35:56,840 --> 00:36:00,560
all the things that you need for
the basic building blocks of life.

478
00:36:02,520 --> 00:36:07,360
Michele and her colleagues
are currently working on building
much smaller probes

479
00:36:07,360 --> 00:36:11,720
that will be able to analyse the
plumes jetting out from Enceladus.

480
00:36:13,040 --> 00:36:15,480
They'll look for more evidence
of life.

481
00:36:16,920 --> 00:36:21,400
Ice in space may bring us one step
closer to finding out

482
00:36:21,400 --> 00:36:24,800
if other life forms have evolved
in our solar system.

483
00:36:40,280 --> 00:36:43,280
Although icy environments
even on our own planet

484
00:36:43,280 --> 00:36:45,720
seem too hostile to support life,

485
00:36:45,720 --> 00:36:50,440
in fact they can be
a very favourable place
for life to flourish.

486
00:36:53,800 --> 00:36:57,320
Under the sea ice around the edges
of the Antarctic continent,

487
00:36:57,320 --> 00:37:00,800
at temperatures that would kill
most living things,

488
00:37:00,800 --> 00:37:03,880
live some of the most intriguing
creatures on Earth.

489
00:37:05,360 --> 00:37:08,520
In total, I've been to the Antarctic
13 times.

490
00:37:08,520 --> 00:37:12,720
'At the laboratories of
the British Antarctic Survey,

491
00:37:12,720 --> 00:37:16,200
'Professor Lloyd Peck studies
these creatures to find out

492
00:37:16,200 --> 00:37:17,880
'just how they survive

493
00:37:17,880 --> 00:37:22,200
'and what makes the icy ocean
so advantageous for some forms
of life.'

494
00:37:23,320 --> 00:37:25,240
If we move down here,

495
00:37:25,240 --> 00:37:27,800
we can see some of our
really special animals.

496
00:37:27,800 --> 00:37:30,400
These little fish are called
the plunder fish.

497
00:37:30,400 --> 00:37:32,520
I haven't seen this.

498
00:37:32,520 --> 00:37:36,560
That's a beauty! Is it all right?
Yeah, they're fine.

499
00:37:36,560 --> 00:37:41,000
If a predator comes along,
they open their mouth, push
their gill cases out

500
00:37:41,000 --> 00:37:43,560
and push their spines out
to stop being eaten.

501
00:37:43,560 --> 00:37:49,080
They breed in our tank.
They're one of the classic types
of Antarctic fish.

502
00:37:49,080 --> 00:37:52,200
How cold is it?
The water is below zero degrees.

503
00:37:52,200 --> 00:37:54,440
But it's sea water
so it doesn't freeze.

504
00:37:54,440 --> 00:37:57,240
What you see here is,
those animals living there

505
00:37:57,240 --> 00:38:00,400
are permanently living
below zero degrees.

506
00:38:00,400 --> 00:38:03,520
Why don't they freeze?
Well, the fish would freeze

507
00:38:03,520 --> 00:38:08,600
except for the fact they've got
antifreeze in their blood,
their tissues and their bodies.

508
00:38:08,600 --> 00:38:11,720
They need antifreeze to live
in these temperatures.

509
00:38:11,720 --> 00:38:17,840
They have antifreeze in their blood?
They make their own antifreeze.
They have antifreeze proteins.

510
00:38:17,840 --> 00:38:20,800
There's antifreeze everywhere
because without it,

511
00:38:20,800 --> 00:38:24,560
ice crystals would grow inside
their cells and inside their blood

512
00:38:24,560 --> 00:38:26,720
and it would rip their tissues
apart.

513
00:38:28,400 --> 00:38:31,240
OK. I've got another animal here
to show you.

514
00:38:31,240 --> 00:38:33,080
This is a sea spider.

515
00:38:33,080 --> 00:38:35,120
Oh, look at him!

516
00:38:35,120 --> 00:38:38,920
In Antarctica, the sea spiders
get really big.

517
00:38:38,920 --> 00:38:42,240
The biggest ones are 40 centimetres
from leg tip to leg tip.

518
00:38:42,240 --> 00:38:45,480
So that's twice the size
of this one? About twice the size.

519
00:38:45,480 --> 00:38:48,080
And the biggest sea spiders
in the Antarctic

520
00:38:48,080 --> 00:38:51,840
are a thousand, maybe two thousand,
three thousand times heavier

521
00:38:51,840 --> 00:38:55,440
than the biggest sea spiders
in Europe. Why do they get so big?

522
00:38:55,440 --> 00:38:59,800
Well, the reason they get big
is because it's cold!

523
00:38:59,800 --> 00:39:02,440
Two things happen when sea water
gets cold.

524
00:39:02,440 --> 00:39:06,840
One is that the amount of oxygen
you get in the water goes up.

525
00:39:06,840 --> 00:39:11,280
There's nearly twice as much oxygen
in the sea in Antarctica
as in the tropics.

526
00:39:11,280 --> 00:39:16,160
Because it's cold, their metabolic
rates run much slower than animals
elsewhere.

527
00:39:16,160 --> 00:39:18,600
So it's like live cheaper,
grow bigger?

528
00:39:18,600 --> 00:39:22,240
Live cheaper, grow bigger.
And it's not just the sea spiders.

529
00:39:22,240 --> 00:39:25,400
This is a 40-arm starfish.

530
00:39:25,400 --> 00:39:29,440
Its Latin name is Labidiaster.
Oh, my God!

531
00:39:29,440 --> 00:39:31,280
Have a hold of that.

532
00:39:31,280 --> 00:39:33,760
OK? This is a really small one.

533
00:39:33,760 --> 00:39:39,520
The big ones get up to 70, 80
centimetres across. They're huge.

534
00:39:39,520 --> 00:39:43,080
They're one of the big predators
in the Antarctic on the sea bed.

535
00:39:43,080 --> 00:39:48,640
There's his stomach. They crawl
over the top of animals, put their
stomachs out and eat them.

536
00:39:49,480 --> 00:39:54,200
What is it about the ice that makes
all these weird adaptations
and strange animals?

537
00:39:54,200 --> 00:39:57,800
The ice helps keep the temperature
constant in the seas.

538
00:39:57,800 --> 00:40:01,640
What it's done is kept that
temperature low and constant

539
00:40:01,640 --> 00:40:03,880
for maybe 25 million years.

540
00:40:03,880 --> 00:40:06,200
So it's not just cold,
it's also steady.

541
00:40:06,200 --> 00:40:11,680
It is. The Antarctic Ocean
is possibly the most constant
temperature place on Earth.

542
00:40:11,680 --> 00:40:16,120
And it's been there for such a long
time that animals have been able
to adapt to it

543
00:40:16,120 --> 00:40:20,760
in a very fine-scaled way,
in a way that hasn't happened
anywhere else on Earth.

544
00:40:24,480 --> 00:40:27,880
These creatures are the product of
a unique eco-system

545
00:40:27,880 --> 00:40:30,160
that revolves around ice.

546
00:40:31,880 --> 00:40:35,320
By studying how they managed not
just to adapt, but to thrive,

547
00:40:35,320 --> 00:40:38,120
we can learn about the impact
of cold

548
00:40:38,120 --> 00:40:41,480
and how well icy environments
can support life.

549
00:40:50,720 --> 00:40:55,480
Antarctica is the coldest,
windiest continent on the planet.

550
00:40:56,600 --> 00:41:01,320
It's covered by the largest single
mass of ice on Earth.

551
00:41:16,960 --> 00:41:19,040
Back in the 1950s,

552
00:41:19,040 --> 00:41:22,960
a team of scientists set out
with a seemingly impossible dream,

553
00:41:22,960 --> 00:41:26,840
to discover how thick
the Antarctic ice sheet was

554
00:41:26,840 --> 00:41:29,640
and what might be lying beneath.

555
00:41:32,680 --> 00:41:37,280
Part of that team was glaciologist,
Dr Charles Swithinbank.

556
00:41:39,360 --> 00:41:42,240
He's a legend in the world
of Antarctic science.

557
00:41:42,240 --> 00:41:46,440
He's spent a lifetime exploring
the heart of the white continent.

558
00:41:48,600 --> 00:41:50,600
That's it. That's you?

559
00:41:50,600 --> 00:41:53,800
That's me. I was mad keen
and always have been.

560
00:41:53,800 --> 00:41:58,720
Here was a chance of real adventure
and real exploring

561
00:41:58,720 --> 00:42:02,800
in a really unknown part
of the Antarctic.

562
00:42:06,120 --> 00:42:09,560
It was Charles' job to try
to measure the depth of the ice.

563
00:42:10,840 --> 00:42:14,880
Taking a sled loaded with dynamite
out onto the ice,

564
00:42:14,880 --> 00:42:19,360
he and his colleagues set off
an explosion at the surface.

565
00:42:21,000 --> 00:42:24,640
They measured how long it took
for its echo to bounce back.

566
00:42:24,640 --> 00:42:28,760
From this, they could work out
how far it had travelled

567
00:42:28,760 --> 00:42:31,440
and how thick the ice sheet was.

568
00:42:33,960 --> 00:42:37,800
We found thicknesses
up to 2,500 metres.

569
00:42:37,800 --> 00:42:42,400
That's nothing nowadays.
People have found a lot deeper.

570
00:42:42,400 --> 00:42:44,200
But it staggered us

571
00:42:44,200 --> 00:42:47,840
because here we were,
walking over solid ice

572
00:42:47,840 --> 00:42:50,720
without any idea how thick it was.

573
00:42:52,680 --> 00:42:55,840
But as it took a day to make
one single measurement,

574
00:42:55,840 --> 00:42:59,440
mapping the whole continent
was going to take decades.

575
00:43:02,320 --> 00:43:08,120
Until another ice secret was
unlocked by American army engineer,
Amory Waite.

576
00:43:11,400 --> 00:43:17,880
In the 1950s, experienced pilots
were crashing into the Antarctic
ice sheet and no-one knew why.

577
00:43:20,120 --> 00:43:25,960
Waite knew the planes' altimeters
used radar to measure how high
they were above the ground.

578
00:43:26,880 --> 00:43:31,520
He started hitting ice with
different frequencies of radio waves

579
00:43:31,520 --> 00:43:35,720
and realised some of them were
going straight through the ice.

580
00:43:35,720 --> 00:43:39,880
This could have given the pilots
a false reading of their height.

581
00:43:41,880 --> 00:43:44,320
Waite realised that despite being
a solid,

582
00:43:44,320 --> 00:43:47,200
ice was transparent to radar.

583
00:43:49,560 --> 00:43:52,680
Once this was known,
planes stopped crashing,

584
00:43:52,680 --> 00:43:54,440
saving countless lives.

585
00:43:55,560 --> 00:43:59,480
But it also revolutionised
Charles Swithinbank's job

586
00:43:59,480 --> 00:44:03,360
of surveying the Antarctic ice sheet
and the land beneath.

587
00:44:05,960 --> 00:44:09,480
His team could now criss-cross
the continent in a plane,

588
00:44:09,480 --> 00:44:12,560
using radar to see through the ice

589
00:44:12,560 --> 00:44:15,400
by bouncing radio waves
off the bedrock below.

590
00:44:15,400 --> 00:44:20,320
And he could now take hundreds
of readings every second.

591
00:44:25,120 --> 00:44:26,920
It was staggeringly exciting

592
00:44:26,920 --> 00:44:30,840
because we were getting
a cross-section of the ice sheet
as we flew over it.

593
00:44:30,840 --> 00:44:36,200
We went to a number of places
where I'd worked on the ground

594
00:44:36,200 --> 00:44:38,880
and dreamed and wondered
how thick the ice was.

595
00:44:38,880 --> 00:44:41,080
And in the matter of a minute -

596
00:44:41,080 --> 00:44:44,280
pow! - we'd measured
how thick it was.

597
00:44:44,280 --> 00:44:46,440
It was very, very exciting.

598
00:44:48,040 --> 00:44:51,040
Beneath the white and pristine
Antarctic surface,

599
00:44:51,040 --> 00:44:53,880
an entire new world was uncovered.

600
00:44:54,880 --> 00:44:58,720
A world made of valleys,
mountains and plateaus

601
00:44:58,720 --> 00:45:02,640
hidden in parts by ice
more than four kilometres thick.

602
00:45:05,280 --> 00:45:09,840
And all laid bare thanks to
discovering another secret
of the ice crystal.

603
00:45:19,360 --> 00:45:22,240
While the Antarctic lies
on mountainous bedrock,

604
00:45:22,240 --> 00:45:26,640
on the other side of the world,
the Arctic is a treacherous ocean

605
00:45:26,640 --> 00:45:28,680
of floating sea ice,

606
00:45:28,680 --> 00:45:32,480
where exploration has often been
driven by commerce.

607
00:45:42,280 --> 00:45:47,880
For hundreds of years, sailors
searched for a short and lucrative
trade route through these waters

608
00:45:47,880 --> 00:45:50,800
between Europe and the Pacific.

609
00:45:50,800 --> 00:45:54,920
One that would be cheaper than
the long route via India and China.

610
00:45:54,920 --> 00:45:58,720
The elusive North-West Passage.

611
00:46:03,400 --> 00:46:08,160
For the expedition that found it,
there was a prize of thousands
of pounds.

612
00:46:09,520 --> 00:46:13,360
I'm interested in the story
of one particular expedition.

613
00:46:13,360 --> 00:46:16,760
It was led by a celebrated
naval officer, Sir John Franklin.

614
00:46:16,760 --> 00:46:22,920
But it turned out to be
the worst disaster in the history
of British polar exploration.

615
00:46:25,160 --> 00:46:26,840
What draws me to this story

616
00:46:26,840 --> 00:46:29,680
is that it plays out
like a detective mystery

617
00:46:29,680 --> 00:46:32,120
with ice as the key witness.

618
00:46:33,120 --> 00:46:39,160
And some of the clues are here, at
the Scott Polar Research Institute.

619
00:46:40,440 --> 00:46:43,800
This is the leader of the
expedition, Sir John Franklin.

620
00:46:43,800 --> 00:46:47,240
In 1845, he was already
59 years old.

621
00:46:47,240 --> 00:46:50,120
He'd fought with Nelson
at the Battle of Trafalgar.

622
00:46:50,120 --> 00:46:53,760
He'd been to the Arctic three times
and mapped thousands of miles
of coastline.

623
00:46:53,760 --> 00:46:57,760
The British public had been
captivated by stories of how he
and his men

624
00:46:57,760 --> 00:47:00,960
staved off hunger by eating
their own leather boots.

625
00:47:04,040 --> 00:47:06,360
Franklin was clearly the man
for the job.

626
00:47:07,680 --> 00:47:13,160
Before he set off, he arranged to
have portraits taken of himself
and his senior officers

627
00:47:13,160 --> 00:47:15,560
with the very latest technology.

628
00:47:17,960 --> 00:47:22,280
Curator Heather Lane has these
precious early daguerreotypes

629
00:47:22,280 --> 00:47:23,920
for me to see.

630
00:47:23,920 --> 00:47:26,960
If you'd like to pick it up
and open it. I'd love to.

631
00:47:26,960 --> 00:47:28,880
Very happy.

632
00:47:28,880 --> 00:47:31,480
And there he is.

633
00:47:31,480 --> 00:47:38,200
Quite extraordinary to think you're
seeing him on the day they set off.

634
00:47:39,760 --> 00:47:44,920
'Franklin had assembled a team
of experienced officers to sail
with him to the Arctic,

635
00:47:44,920 --> 00:47:47,440
'many of whom had been there
before.'

636
00:47:47,440 --> 00:47:52,120
They all look quite sure
of themselves. Franklin had been
sensible.

637
00:47:52,120 --> 00:47:55,720
He's pulled together a team he knows
will actually obey orders

638
00:47:55,720 --> 00:47:59,240
in what are likely to be
quite difficult circumstances.

639
00:48:03,240 --> 00:48:07,360
In total, 133 men set sail
with Franklin from Kent

640
00:48:07,360 --> 00:48:11,320
in two sturdy ships,
the Erebus and the Terror,

641
00:48:11,320 --> 00:48:15,080
both of which had seen service
in the Polar regions before.

642
00:48:17,560 --> 00:48:20,440
They were expecting to sail
from the Atlantic Ocean

643
00:48:20,440 --> 00:48:23,400
through the ice-bound islands
of Northern Canada

644
00:48:23,400 --> 00:48:28,000
to the Pacific Ocean,
and return within three years.

645
00:48:31,200 --> 00:48:36,360
They'd refitted these ships
with state-of-the-art equipment.
They were steam-powered,

646
00:48:36,360 --> 00:48:40,160
they had water purification,
they had central heating on board.

647
00:48:40,160 --> 00:48:44,600
They really put a huge amount
of effort into ensuring

648
00:48:44,600 --> 00:48:50,480
that this was the expedition that
was going to make it all the way
through the North-West Passage.

649
00:48:50,480 --> 00:48:53,200
Then suddenly, they disappear.

650
00:48:53,200 --> 00:48:56,000
The ice has swallowed
this expedition whole.

651
00:48:56,000 --> 00:49:02,320
And it's the beginning of a great
Victorian mystery - what has
happened to Franklin and his men?

652
00:49:03,680 --> 00:49:05,640
Over the next few years,

653
00:49:05,640 --> 00:49:10,120
more than 30 rescue missions
searched the icy Arctic
for survivors

654
00:49:10,120 --> 00:49:11,920
but failed to find any.

655
00:49:14,560 --> 00:49:19,480
It wasn't until 1858 that the likely
fate of Franklin's men was confirmed

656
00:49:19,480 --> 00:49:25,320
by a message discovered in a can
on a small uninhabited island.

657
00:49:28,640 --> 00:49:30,520
Written by two senior officers,

658
00:49:30,520 --> 00:49:35,240
it announced that Sir John Franklin
had died in 1847,

659
00:49:35,240 --> 00:49:37,280
two years after he'd set sail.

660
00:49:39,160 --> 00:49:42,680
Both ships had been abandoned
in the ice

661
00:49:42,680 --> 00:49:48,080
and second-in-command
Captain Crozier was attempting
to lead 105 survivors to safety.

662
00:49:50,600 --> 00:49:55,160
But why had an expedition
with experienced Polar navigators

663
00:49:55,160 --> 00:49:57,040
in state-of-the-art ships,

664
00:49:57,040 --> 00:49:59,000
ended up like this?

665
00:50:00,240 --> 00:50:02,880
Well, although the records end here,

666
00:50:02,880 --> 00:50:05,240
the detective story doesn't.

667
00:50:05,240 --> 00:50:09,040
What I find fascinating
about the Franklin story

668
00:50:09,040 --> 00:50:13,320
is it doesn't seem to die.
Clues keep on showing up in the ice.

669
00:50:15,760 --> 00:50:20,000
And eventually, it would be the ice
that would provide the answer.

670
00:50:27,920 --> 00:50:31,960
In 1986, a team of
forensic archaeologists

671
00:50:31,960 --> 00:50:35,160
travelled to Beachy Island
in northern Canada.

672
00:50:35,160 --> 00:50:37,840
This was where, in 1850,

673
00:50:37,840 --> 00:50:41,160
a search party had found
empty food cans,

674
00:50:41,160 --> 00:50:43,960
evidence that the expedition
had wintered here.

675
00:50:46,680 --> 00:50:50,560
And not far from them, three graves.

676
00:50:55,520 --> 00:50:58,800
Over two intense weeks,
Dr Owen Beatty and his team

677
00:50:58,800 --> 00:51:01,600
exhumed the bodies of able seaman
John Hartnell

678
00:51:01,600 --> 00:51:03,480
and Private William Brain

679
00:51:03,480 --> 00:51:05,960
to try to find out how they'd died.

680
00:51:08,040 --> 00:51:12,640
The forensic team had no idea
what to expect. What condition
the bodies would be in.

681
00:51:12,640 --> 00:51:15,880
They had to pick-axe their way
through the frozen ground

682
00:51:15,880 --> 00:51:21,520
which is what the grave-diggers must
have had to do when they buried
the bodies in the Arctic winter.

683
00:51:25,640 --> 00:51:29,400
They found that the ice
had preserved the bodies
almost perfectly.

684
00:51:29,400 --> 00:51:33,600
When they released them,
using warm water,

685
00:51:33,600 --> 00:51:38,360
there was so little decay, it was
relatively easy to investigate
how they'd died.

686
00:51:40,600 --> 00:51:46,680
John Hartnell had had tuberculosis,
but he was also incredibly thin.

687
00:51:46,680 --> 00:51:50,080
He had no food in his stomach
or intestines.

688
00:51:53,160 --> 00:51:58,440
Scattered around the camp, Beatty
had found empty cans that had been
soldered with lead.

689
00:51:58,440 --> 00:52:01,240
He put two and two together.

690
00:52:01,240 --> 00:52:03,600
He tested the men's bodies

691
00:52:03,600 --> 00:52:06,800
and found dangerously high levels
of lead

692
00:52:06,800 --> 00:52:09,880
in their hair, bones
and soft tissue.

693
00:52:12,440 --> 00:52:15,560
To date, about 17 more
of Franklin's men

694
00:52:15,560 --> 00:52:19,120
have been found to have had toxic
levels of lead in their bones.

695
00:52:22,200 --> 00:52:26,600
New research suggest the lead might
not have come from the cans at all

696
00:52:26,600 --> 00:52:32,120
but is more likely to have leeched
out of the new lead piping
in the ship's water system

697
00:52:32,120 --> 00:52:34,400
and contaminated their water.

698
00:52:40,560 --> 00:52:43,080
Lead poisoning is a horrible way
to die.

699
00:52:43,080 --> 00:52:47,680
It paralyses your muscles and eats
away at your brain and central
nervous system.

700
00:52:47,680 --> 00:52:51,760
So then what you get is
disorientation and anorexia.

701
00:52:51,760 --> 00:52:55,960
The worst things that can happen
if you're trying to survive
an Arctic winter.

702
00:53:09,440 --> 00:53:12,760
We know so much about the tragic
fate of Franklin and his men

703
00:53:12,760 --> 00:53:15,760
because of the miraculous ability
of ice to preserve.

704
00:53:15,760 --> 00:53:19,880
But it doesn't just preserve history
by slowing down decomposition.

705
00:53:19,880 --> 00:53:24,320
It also has the ability to preserve
something much more delicate
than bodies.

706
00:53:24,320 --> 00:53:28,200
And one that might prove
even more valuable.

707
00:53:35,280 --> 00:53:40,000
In the Antarctic, teams
of scientists have been
reaching back into history.

708
00:53:42,800 --> 00:53:46,240
They've been drilling thousands
of metres into the ice sheet

709
00:53:46,240 --> 00:53:50,320
to remove columns of ice
that can bear witness to our past.

710
00:53:53,920 --> 00:53:59,800
These ice cores preserve air from
hundreds of thousands of years ago.

711
00:54:01,960 --> 00:54:06,200
They're helping us understand one of
the most complex aspects of nature,

712
00:54:06,200 --> 00:54:07,880
our climate.

713
00:54:12,920 --> 00:54:15,280
I'm with Dr Robert Mulvaney

714
00:54:15,280 --> 00:54:19,040
at the British Antarctic Survey's
ice core freezer in Cambridge

715
00:54:19,040 --> 00:54:21,080
where he studies this ancient ice.

716
00:54:27,040 --> 00:54:28,760
So if I take a piece of this out.

717
00:54:28,760 --> 00:54:31,200
Let's put that down on here.

718
00:54:35,000 --> 00:54:38,040
You can probably make out
the tiny air balls in there.

719
00:54:38,040 --> 00:54:42,160
It's the magic of the ice that it's
able to take these air molecules

720
00:54:42,160 --> 00:54:47,480
into its matrix without altering
them, and release them back to us
later. A storage box. Yes.

721
00:54:47,480 --> 00:54:51,760
What we'll do is cut a piece off and
see if we can see the air bubbles.

722
00:54:52,680 --> 00:54:55,440
The deeper you go,
the older the ice gets.

723
00:54:55,440 --> 00:54:58,640
Scientists are able to date
each layer of ice

724
00:54:58,640 --> 00:55:01,720
from chemical markers
within the ice crystal itself.

725
00:55:03,080 --> 00:55:07,680
It's starting to clear. I think you
can see the air bubbles in that.

726
00:55:07,680 --> 00:55:10,240
Fantastic, isn't it?

727
00:55:10,240 --> 00:55:12,440
This air is about 1,000 years old!

728
00:55:12,440 --> 00:55:15,520
So when they were invading Britain
in 1066,

729
00:55:15,520 --> 00:55:18,160
this is the air
they would have been breathing!

730
00:55:18,160 --> 00:55:20,640
The Saxons and Normans.
Saxons and Normans.

731
00:55:20,640 --> 00:55:22,440
That is wild! It is, isn't it?

732
00:55:24,320 --> 00:55:26,920
This is quite a long way down
in the ice sheet.

733
00:55:26,920 --> 00:55:31,480
This is about 80,000 years old. You
can probably see the air in that.

734
00:55:31,480 --> 00:55:35,160
So this is before... This fell
as snow and trapped air

735
00:55:35,160 --> 00:55:37,360
before human civilisation?

736
00:55:37,360 --> 00:55:40,240
That's right. Fascinating, isn't it?

737
00:55:42,320 --> 00:55:44,800
As well as preserving
past atmospheres,

738
00:55:44,800 --> 00:55:48,280
the ice crystals preserve
another important secret.

739
00:55:48,280 --> 00:55:51,480
Tiny variations in their chemistry

740
00:55:51,480 --> 00:55:55,320
reveal the temperature of the
climate when they originally formed.

741
00:55:55,320 --> 00:55:59,080
This has allowed us to see
in more detail than ever before

742
00:55:59,080 --> 00:56:02,120
how our climate has changed
throughout history.

743
00:56:04,520 --> 00:56:07,120
It's also enabled us
to explore a link

744
00:56:07,120 --> 00:56:10,800
between temperature and levels
of atmospheric carbon dioxide.

745
00:56:13,440 --> 00:56:17,560
Our oldest ice core goes back
800,000 years.

746
00:56:17,560 --> 00:56:20,600
In that period, we've been in
and out of an ice age eight times.

747
00:56:20,600 --> 00:56:26,120
And all through that period,
the atmosphere and the temperature
have been very closely linked.

748
00:56:26,120 --> 00:56:31,200
So as we go into an ice age,
the levels of carbon dioxide,
greenhouse gases, decrease,

749
00:56:31,200 --> 00:56:34,160
and as come out of an ice age
they start to increase.

750
00:56:34,160 --> 00:56:41,440
The ice core record shows that there
was a strong relationship between
temperature and carbon dioxide.

751
00:56:41,440 --> 00:56:46,400
They've moved in tandem throughout
history for 800,000 years.

752
00:56:49,080 --> 00:56:54,480
To many scientists, this historical
record supports current theories
of global warming,

753
00:56:54,480 --> 00:56:58,960
suggesting that if carbon dioxide
levels rise, as they're doing today,

754
00:56:58,960 --> 00:57:01,680
temperatures will also rise.

755
00:57:01,680 --> 00:57:05,800
It's a warning from the past
that many find hard to ignore.

756
00:57:05,800 --> 00:57:09,400
And all because of
the unique ability of ice

757
00:57:09,400 --> 00:57:11,960
to capture air and preserve it.

758
00:57:20,960 --> 00:57:24,960
Ice is one of the most enigmatic
substances in nature.

759
00:57:24,960 --> 00:57:29,280
A solid can pass through it,
without leaving a trace.

760
00:57:31,520 --> 00:57:34,560
It can shatter rock
and sculpt our planet.

761
00:57:37,600 --> 00:57:41,320
In space, its protective shell
may conceal life forms

762
00:57:41,320 --> 00:57:43,360
just waiting to be discovered.

763
00:57:45,480 --> 00:57:48,040
It can last for millions of years

764
00:57:48,040 --> 00:57:50,760
or just melt in an instant.

765
00:57:54,080 --> 00:57:56,920
I'm drawn to ice because of
its contradictions.

766
00:57:56,920 --> 00:58:02,280
Although is seems so fragile, it's
capable of carving out landscapes
and preserving histories,

767
00:58:02,280 --> 00:58:05,360
even giving us warnings
about the future of our world.

768
00:58:05,360 --> 00:58:08,520
But what's really struck me
about making this programme

769
00:58:08,520 --> 00:58:11,200
is discovering where all that power
comes from.

770
00:58:11,200 --> 00:58:15,600
Because actually, the very thing
that makes ice seem fragile
and vulnerable,

771
00:58:15,600 --> 00:58:18,640
the fact that it's always
on the point of disappearing

772
00:58:18,640 --> 00:58:21,640
turns out to be the source
of all its strength.

773
00:58:49,440 --> 00:58:52,480
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