All language subtitles for What.on.Earth.S03E04.1080p.DSCP.WEB-DL.AAC2.0.H.264-BTN_track3_[eng]

Narrator: they're watching you.

More than 4,000
Satellites circle the earth.

Every day, they uncover new,
Mysterious phenomena.

Some defy explanation.

Bam! This sticks out
Like a sore thumb.

There must be something
Very big and very bad.

Narrator: a giant dome spotted
On a remote pacific island...

It looked
Like something from

"Close encounters
Of the third kind."

Narrator:
A strange lunar landscape
Off the coast of africa...

It's like nothing
I've seen on earth.

Narrator:
A huge scar cut into the remote
Canadian wilderness...

You got to consider
That this could be

Some kind of biological attack.

Narrator: baffling phenomena,
Mysteries from space.

What on earth are they?

**

-- captions by vitac --
Www.Vitac.Com

Captions paid for by
Discovery communications

July 12, 2013,

6-year-old
Nathan woessner

Is out walking with his parents
On the mount baldy sand dunes,

Along the shore of
Lake michigan, indiana.

They are unaware
Of the danger awaiting.

This looks like
A nice place to go.

It's on the water.
It's right by a town.

The idea that something
Could happen here,

It's kind of crazy.

Narrator: what should have been
A fun afternoon

By the lake will spark a
Major scientific investigation,

Using state-of-the-art aerial

And satellite
Imaging technology.

Porges: nathan woessner
And his mother

Are walking across
The sand dunes

Along lake michigan when --

When suddenly,
He disappears.

Ah!

How does a boy
Get swallowed up,

Virtually instantaneously,
By a mound of sand?

Nathan?
Nathan!

Sand dunes don't
Just eat people.

What is going on here?

A 6-year-old boy
From sterling, illinois,

Is trapped under crushing sand.

Narrator: nearby,
Local geologist erin argyilan

Is out on the dunes,
Taking wind speed measurements.

She sees the drama unfold.

Argyilan: he slid down,
Out of sight.

And the hole filled
In right behind him.

Help!
Immediately, it was just panic.

And people were yelling
And screaming

And digging in the sand.

Woman: my friend's son,
He got stuck in a sand dune.

And he's, like, under the sand.
And they can't get him out.

People were arriving
From all different areas,

From the national lakeshore,
From the local police,

From the fire department.

First excavator
Wasn't able to even climb

A portion of the dune.

And at that point, I think
Everyone felt pretty desperate

And, uh, disheartened.

There was definitely
Concern and discussion

That this would probably
Be a recovery

And not a rescue.

Narrator: it takes police
And fire crews

More than 3 hours to dig down

And reach the trapped child.

Nathan was found around 11 feet
Below the surface.

Narrator: the young boy is
Brought out unconscious.

There was a lot of work
Left to do,

Because someone who's
Buried in the sand

Would have swallowed
A lot of sand,

Which is very dangerous
For their lungs.

Narrator: paramedics rush nathan
To the hospital.

The near fatal ordeal
Leaves a mystery.

How can a boy
Simply disappear into the sand?

Analysts turned to satellite
Imagery for clues.

Dark patches
On the dunes

Around where nathan disappeared

Immediately arouse suspicions.

It's natural to think,
Could this be quicksand?

Narrator:
Quicksand can be deadly,

Especially around
Coastal regions.

But there's a problem
With the theory.

Quicksand typically occurs
In low areas,

Where water collects and mixes

With the sand to produce
This high viscosity quicksand.

But this is on the flank
Of a high hill of sand.

If quicksand didn't
Swallow nathan, what did?

Narrator: with satellite images
Inconclusive,

Local geologist erin argyilan

Turns to ground-penetrating
Radar

To look into
The sand dune itself.

We've done quite a lot
With ground-penetrating radar.

And it can actually show
The underlying landscape.

Narrator: the radar reveals
66 potentially

Deadly holes lurking
Within mount baldy.

Somehow,
There are air pockets

All through this dune.

Narrator: the speed nathan
Disappeared suggest

He fell into a shaft

Or hollow cavity beneath
The surface of the sand.

But it's not clear
What could make

Such large subterranean holes.

At the time of the incident,

There were rumors
Of someone digging in the sand

Just before nathan disappears.

So could the holes
Erin found be man-made?

Closer study of the sand
On mount baldy reveals

It to be
So fine-grained

That digging large holes
Is near impossible.

You couldn't practically
Dig by hand very deep

In a location like that,
Essentially

Because the sand would
Keep collapsing down on itself.

Narrator: to investigate
The origin

Of the strange series
Of holes,

Argyilan studies
Satellite images

Dating back
To the mid-twentieth century.

Using the data to create
A computer simulation reveals

The sand dune is consuming
The nearby forest.

Sand, by it's very nature,

Moves by virtue
Of wind pushing it around.

And as that happens,
The entire dune moves.

Mount baldy is definitely
On the move.

It's been moving
Since the 1940s.

And it's buried
One parking lot

And is well on its way to
Burying a second parking lot.

Narrator: mount baldy is covered
With dead tree tops.

Argyilan believes
These are the key

To explaining the holes
Beneath the surface.

To test her hunch,

Argyilan turns to another
Advanced imaging technology.

She takes to the sky,
Using aircraft-mounted lidar.

This is a laser land
Scanning system

Which generates precise

Three-dimensional
Ground imagery.

Lidar imagery is
Where you can

Actually reconstruct
The elevation of landforms.

And if you have many images
From many different years,

You can then reconstruct
Your entire landscape.

Narrator: the aerial lidar
Reveals the entire sand dune

Sits directly on top of a forest
Of decaying trees.

Argyilan believes the hole
That swallowed nathan

Is the hollowed out trunk
Of a rotting tree.

Argyilan: this would've been
A fully-grown, mature tree

That is rooted
Into a landscape

With a soil that is about
3,500 years old.

Essentially, where nathan was
Walking, there were trees

Like this completely
Buried under the sand.

They are decomposing,

And oak trees in particular

Will decompose
From the center outward.

Narrator: argyilan calls
Her discovery

Dune decomposition chimneys.

These form a series
Of hollow shafts

Which can extend more
Than 10 feet deep.

Nathan fell into one
Of these hollow tree trunks.

After 11 days in the hospital,

Nathan woessner makes
A full recovery.

Today, nathan seems to be
A thriving young boy

Without a lot of damage.

Narrator: the potentially deadly
Cavities in mount baldy

Are still there,

Waiting for the footsteps
Of the unwary.

**

A surveillance satellite
Orbiting over the pacific ocean

Photographs a strange,

Circular shape
On an isolated island.

How long has this been here?
Is this ancient or modern?

From space, it looks
A lot like something

From "Close encounters
Of the third kind."

Narrator: september 2015,
A satellite captures

The image of a bizarre
Circular shape

On a remote island
In the pacific ocean.

From space, it looks
A lot like something

From "Close encounters
Of the third kind."

You don't see anything
Similar on the other islands.

Is it some kind of a launchpad
That was never finished?

Narrator: a declassified
Aerial photograph

Taken by
The u.S. Defense agency

Revels more detail.

The circular structure
Is a huge dome

Made of thick slabs of concrete.

Why would anyone build
A perfect concrete dome

In the middle of nowhere?

Narrator: the images come from
Just north of the equator,

From a remote group of islands

Known as the enewetak atoll.

This is a tiny island
In the middle of nowhere.

No major cities nearby.

No populated centers.

Narrator: the concrete dome
Is huge,

Spanning over 350 feet across.

And it's not alone.

Bizarrely, it sits next

To a deep blue hole
In the water

With exactly
The same dimensions.

The sheer scale of this
Is impressive.

Narrator: two giant disk shapes,
One on land, one in the sea.

A secret military base?

An abandoned rocket launch site?

The image poses a mystery.

At first glance,
The dome shape

Strongly resembles known designs

For nuclear blast shelters.

Pavelec: this kind of dome

Is structurally very,
Very strong.

It's the exact shape
You would use

If you wanted to make
Something very,

Very safe and durable.

Narrator: during the cold war,

Fear of nuclear annihilation

Drove the construction
Of elaborate dome shelters

Called survival condos,

Accommodation for
The end of the world.

**

Survival condos are basically

A multi-level hole
In the ground built,

In a lot of cases,
By people who were terrified

That we were going
To have a nuclear war.

Narrator: the structure's
Isolated location supports

The survival condo theory.

Pavelec: if you want to stay out
Of the way of nuclear holocaust,

This would be a fantastic place
To put a shelter.

Thousands and thousands of miles

Away from any civilization
Or other targets.

Most of them are still
In the ground,

But probably
Have been abandoned.

Narrator: while the dome
Does bear a strong resemblance

To some nuclear
Fallout shelters,

Further analysis casts doubt
On this theory.

There are problems with
The doomsday shelter argument.

If you look really closely,

There's no way in
Or out of this structure

And there are no air vents.

Narrator:
Access to the enewetak atoll

Has been highly
Restricted for decades,

Making it impossible to
Inspect the structure up close.

But the images
Offer further clues.

One of the striking things
In this image

Is the massive
Blue hole in the ocean

That's sort of the mirror
Of this dome.

It doesn't look natural either.

Narrator: satellite images
Reveal other deep holes

In the sea around
Nearby islands.

Similar looking sinkholes
Can occur naturally.

But documents from
U.S. Military archives

Reveal a chilling secret:

This was the location of a major
U.S. Atomic weapon test site.

The holes could
Be bomb craters

Produced during one
Of the darkest chapters

In the history
Of global warfare.

If everything
Goes according to plan,

We'll soon see
The largest explosion

Ever set off
On the face of the earth.

They started testing in 1948.

And they tested 43
Nuclear devices in the islands.

These were some of
The biggest hydrogen bombs

The united states
Has ever produced.

Narrator: the huge,
Round holes

And the concrete dome itself

Could be directly connected
To the testing

Of the world's largest
Atom bombs.

Pavelec:
In several of the tests,

They would explode
The nuclear bomb

And see how far out it
Would affect the ships.

Hansen: it required a huge
Concentration of people.

You had soldiers all over
The place to observe them.

And it extended through
Almost 10 years.

So there's a lot
Of activity going on.

Narrator:
The scale of the operation

And the destructive power
Of the bomb tests

Was at a level
Never seen on our planet

Before or since.

Hansen: the biggest bomb
Was called ivy mike,

Which was 500 times
More powerful

Than the bombs dropped
On hiroshima

And nagasaki in world war ii.

Narrator: some islands were
Simply wiped off the map.

Man: elugelab
Is completely calm.

Nothing there but water

And what appears
To be a deep crater.

Narrator: if the holes
Around the islands

Are craters left
By atomic bombs,

Then the giant concrete dome
Could be their grim legacy:

A storage dump
For radioactive waste.

This much concentrated
Atomic weapon testing

Is going
To generate fallout,

But also a lot
Of radioactive waste,

Including plutonium-239.

Hansen:
When the bomb exploded,

That radiation was scattered

All over the place on the ground
And in the water.

And the half-life of that
Is 24 thousand years.

So that means
That the radiation

Will stay very high
For long periods of time.

Narrator:
The radioactive debris

Threatens
Surrounding islands.

Capps:
It's not the sort of thing
You want to box up on a ship

And bring home
To the united states.

So could this dome be
Where they stored that waste?

Narrator:
Declassified records released

Under the freedom of information
Act reveal the truth.

Pavelec: american scientists
Very quickly figured out

That they needed
To collect all this debris

And radioactive material
And put it somewhere.

So eventually, the army corps
Of engineers goes to enewetak.

They dig this huge pit.

They line it with concrete.

They throw a whole bunch
Of radioactive material

In a big huge garbage can,

For want of a better term,

And they cap it off
With a concrete dome

18 inches thick.

Narrator: sealed off
From public access,

For decades the dome
Has kept the island safe.

But recent
Observations suggest

Cracks are now appearing
In the concrete.

Hansen: there are concerns
That there may be some leakage

Into the surrounding ocean.

If it's a slow leak,
It probably won't mean anything.

But if --
If the thing splits

And all this stuff comes out,

That's a bad thing.

Narrator: the worldview ii
Satellite captures

An image of a strange
Pock-marked landscape

On an island
Just off the coast of africa.

I'm trying to think
Of what kind of force

Would be so powerful
To create a landscape like this.

Honestly, I have no idea.

These c-shaped features
Are really strange.

I'm not sure
What they are.

Narrator: december, 2015.

The worldview ii
Satellite photographs

A bizarre landscape
Off the coast of africa.

The image baffles experts.

How strange.
What are these things?

What kind of force
Would be so powerful

To create a landscape like this?

Narrator: the image comes from
The island of lanzarote,

80 miles west
Of the african coast.

Image analyst amanda marketti
Takes a closer look.

The image itself is both
Weird and surprising.

It's like nothing
I've seen on earth.

It almost looks
Extraterrestrial.

Narrator: it might be possible
The bizarre shapes

Are a perfectly
Natural phenomenon,

A result of the islands
Own explosive origin, volcanoes.

Lanzarote and all of
The canary islands

Are volcanic islands.

You wonder, is this some
Remnant of its violent birth?

Narrator: lanzarote emerged
From the ocean

15 million years ago,

Born through huge
Volcanic eruptions.

Brand: lanzarote sits on top
Of a hot spot plume,

Which is where a massive
Upwelling of heat

Within the earth melts
The mantle, producing magma.

This magma can be
2,000 degrees centigrade.

Narrator: the volcanoes on the
Island are currently silent,

But their heat still rages
Beneath the surface.

Could the landscape
Of round pits

Be volcanic vents,
Known as fumarole?

Fumaroles are -- are very common
In volcanic landscapes.

They are essentially
Pathways through the crust

Where gas can escape.

Narrator: fumaroles often form
Circular shapes in the ground.

But other features
Seen in the image

Make this theory seem unlikely.

While you may find depressions
Associated with fumaroles,

You're certainly
Not going to find

C-shaped rims
That surround them.

Narrator: if the strange pits
Haven't been blasted out,

Maybe they've been bashed in.

Is this a field
Of impact craters?

The last eruption
Was only in 1824,

Which isn't that long ago.

Any time you have
An explosive volcanic eruption,

It's likely that
There will be projectiles

Ejected
From the volcano.

Narrator: these projectiles
Are called lava bombs.

When volcanoes erupt,
Gases blast these lumps

Of rock high into the air

And crash down to earth,
Forming craters.

They can be anywhere
From fist-sized

To the size of a volkswagen bug.

Narrator:
But in recent history,

None of the island's eruptions

Have been violent enough
To produce a rain of lava bombs

To scar the land.

Clearly, something else
Is to blame for these shapes.

Narrator:
If they're not natural,

The pits must be man-made.

These features were built

To be extremely similar
To one another.

They're at the same height,

And they're at
The same position.

So that tells me that they're

All probably being used
For the same purpose.

But what purpose that is,
I don't know.

Narrator: it's possible
That someone

Created this field
Of c-shapes.

They would have to physically
Transform the landscape.

And lanzarote was once home
To an artist famous

For doing just that.

The artist cesar manrique

Was a pioneer
Of large-scale land art.

His work can be found
All over the island.

Manrique was famous for
Creating huge architectural art

From natural
Volcanic landscapes.

For several projects,

Manrique planted trees
Inside giant lava domes.

Image analyst amanda marketti
Sees a resemblance.

So when I start
To look deeper,

I can see that there's a tree

At the center of each feature.

Narrator: but the satellite
Image shows

The pockmarked landscape covers
Nearly 8 square miles.

It's simply too big
To be art.

Even an artist
Like manrique

Could not have created
Something that fast.

It's a baffling mystery.

Narrator: low-level
Drone footage reveals

The true nature
Of the strange landscape.

What was thought to be
A tree in each hole

Is actually a grapevine.

Despite the barren
Volcanic landscape,

Lanzarote has a thriving
Wine industry.

What the satellite captured

Is the world's
Weirdest vineyards.

The plants here,
We have first to make holes

To find the soil.

The soil is 3 or 5 meters
Under the ash.

Then we make
All the holes.

And we put the roots
In the soil.

This ash can retain
The moisture 6 months.

All that rain in winter,
The plants have in summer.

Narrator: growing grapevines
In a lava field

Demands extraordinary ingenuity.

Each vine is surrounded
By its own protective wall.

And it's these that show up

As the bizarre
C-shapes visible from the air.

They were protected
From the wind

Because here is
A very windy island.

The walls are made
With volcanic stones.

The stones are put one-by-one.

Not as thick,

Because in the middle
We have some holes,

To aid with moisture
Coming to the plant.

Narrator: the c-shaped walls
Not only protect the vines

But also help capture moisture
To keep them watered.

But it's the love for this land
That the people make,

Um, make the wine.

This is really a genius system.

I know the next time
I have a glass of wine,

I'll be thinking
About how much effort

Goes into
Growing grapes in vines

On a tiny little
Windswept island

Off the coast of africa.

Narrator: october, 2007,

A satellite image reveals

A site of massive devastation

In the canadian wilderness.

Explorer rob mark investigates.

It's incredibly remote.

The park rangers in canada
Didn't even know it was there.

As an explorer,
That sparked my interest.

I really wanted to find
Out what this was.

And -- and --
And see it for myself.

You've got to consider
That this could be

Some kind of biological attack.

Narrator: october, 2007,

Explorer rob mark investigates

A disturbing
Satellite image,

Showing a swath of destruction
In the canadian wilderness.

Mark: people weren't sure
What it was.

The park rangers in canada

Didn't even know it was there.

Narrator: the image comes
From the remote

Forests of northern
Alberta, canada.

It appears that someone
Or something is really

Damaging this pristine
Environment beyond recognition.

When you see
A huge brown patch

In the middle
Of continuous forest,

You have to wonder
What's going on.

Narrator: to try to solve
The mystery,

Explorer rob mark sets off
Into the wilderness.

The journey was
Incredibly long.

The closest town is about,

And it's a small little town --

Is about 50 miles away.

You know, you have to take
A boat across lake claire.

Then I started walking.

It's only 10 miles,
Which doesn't sound like a lot.

I mean, that's one
Of my shorter treks.

It was the toughest
10 miles of my life.

[ camera shutter clicks ]

Narrator: the sinister stain
Is 3,000 feet long

By 500 feet wide.

Where there should be trees,
There is nothing.

You've got to consider
That this could be

Some kind of biological attack.

Are we looking at
An insect infestation?

Narrator: to kill
Such a huge area

Of forest would take
A plague of insects

On a biblical scale.

In parts of north america,

The plague has already begun.

Bark beetles are a horrible
Insect pest that are spreading

Over large areas
In western north america

And killing trees
For miles and miles.

Narrator:
These ravenous insects

Tunnel through
The trees' bark

And feed on the soft tissues,

Killing the trees
Where they stand.

Since 1999, they've killed over

70,000 square miles of forest.

That's an area
The size of washington state.

Narrator: but the pattern
Of destruction

Doesn't look right
For a beetle plague.

You would expect insects
To nondiscriminately start

Attacking the forest.

But that's not
The case here.

I mean, the surrounding
Forest is doing fine.

Kays: when bark beetles
Hit an area,

They destroy trees
For miles and miles.

It can't be
The bark beetles.

Narrator: explorer rob mark
Continues his punishing journey

Into the canadian wilderness.

The conditions
Are just horrific.

The mosquitoes are the worst
I've ever encountered anywhere.

They've bit through
All my clothes.

The only thing they didn't bit
Through was my jacket.

Narrator: in the wilds
Of central canada,

Nature rules supreme.

The foliage was so thick,

You couldn't see more
Than a couple yards

In front of you.

And a lot of it was swampland.

Narrator:
Studying the satellite image,

Investigators don't ignore
The obvious answer

To the missing trees,
Logging.

Now, this is inside
Of a national park.

Right in the middle.

But of course, that doesn't
Stop illegal loggers.

But felling trees,
Even illegally,

Needs a lot of groundwork,

And this would be
Visible from space.

Of course, loggers need
To bring in big machines,

They need to bring
In equipment to --

To get to a place like this.

That means roads
And there are none.

Narrator:
Rob mark struggles on

Towards
The heart of the mystery.

Mark: it took me 3 days
To go 10 miles.

And the last mile
Took me 5 hours.

Narrator:
When mark finally reaches
The bizarre stained patch,

He's completely unprepared
For what he finds.

It was just an
Incredible feeling,

Because all of a sudden

The foliage opened up
A little bit.

I could see the rise
In the earth.

So I climbed up on it

And I saw beavers
Swimming around.

It's a beaver dam,
A giant beaver dam.

Narrator: this is
A groundbreaking discovery.

No human has ever seen
A beaver dam on this scale.

One that's so big
It's visible from space.

This beaver dam is
Almost 3,000 feet long.

I've never seen
One this big.

In fact, it may be
The largest in the world.

This is off the charts
As far as size goes.

It would be 11
On a scale of one to 10.

I'm standing on top of it.

I can see a beaver lodge
Out in the distance.

And as far as the eye
Can see in either direction,

The dam just continued.

Narrator:
At half a mile long,

This colossal dam is
Too big for one beaver

To build in a lifetime.

It must be the work
Of generations of beavers.

The experts looked
At satellite imagery.

And they're saying that it was
Being built for about 40 years.

And when you're there
And you can see it,

That's not hard
To believe at all.

It truly is a natural wonder.

Narrator: 1967, israel captures
The golan heights,

A strategically valuable area
On the syrian border.

The israeli military conducts
The first aerial

Surveys of the former
Syrian territory.

They see a mysterious
Circular pattern on the ground.

They've discovered
A place of legend.

Mizrachi: a name was given
To this site,

Gilgal refaim --

The wheel of the giants.

Narrator: the golan heights
On the israeli/syrian border,

After the end of
The arab-israel war,

Aerial surveys spot
A huge circular

Stone pattern on the ground.

Prior to its discovery,

No written record exists
Of this mysterious structure.

Experts put forward
A number of theories.

Altaweel: this looks to me
A kind of ceremonial feature.

Did it have also
Practical functions,

Such as defensive,
Uh, a tower of some sort?

I don't see this
As being a fortress.

I see it as being sacred space.

What is really surprising

Is the perfection
Of these circles.

Narrator: the outer stone wall
Stretches 508 feet across,

The size of
The la dogers' stadium.

Experts are baffled
As to who built

The stone circles and why.

This is not primitive
People just saying,

"Let's build something
Roughly that shape."

They've measured
It out carefully.

And then, they've built it
Using gigantic stones.

That would've been
A major undertaking.

Narrator:
Thousands of years ago,

People would fear passing
Through this land.

According to ancient legend,
It was the home of giants.

The rephaim were
An ancient race of giants

Who were described
In the bible.

And they were said to live
In this very area,

In golan heights.

They're described
As these very large,

Tall kinds of creatures.

Narrator: according to legend,
The giants

Were fierce warriors
With superhuman strength.

The story goes that
Fallen angels

Came down onto mount hermon,

Which is next
To the golan heights

And mated with human women

And produced a race of giants.

Narrator: archaeologists
Name the site gilgal refaim,

The wheel of giants.

Yonathan mizrachi
Has spent 3 years

Excavating the mysterious ruins.

Mizrachi: we discovered a series
Of small artifacts

That were all dated
To the late bronze age.

We did find some arrowheads,

Three beautiful gold earrings

And some carnelian beads

That were used
As a ring, maybe.

Narrator: the layout of the site
Makes mizarchi suspect

The mysterious ancient builders

Could have used this
As an elaborate burial place.

Mizrachi:
Looking around us,

You can see here
The actual entrance

To the chamber tomb.

And from this opening,
We can get into the tomb.

Narrator:
But if this was a tomb,

Where are all the bodies?

We did not find
Actual bones.

Narrator: it's possible
The structure's builders

Used a gruesome burial tradition

Known as a sky burial.

Sky burials is a name
That is given

To a very special
Type of burials

In which the dead
Is not buried in the ground

But is bein' exposed

For the elements
Of the sky.

The bodies were places
In the center of the structure.

And they waited
For the vultures to come in

And to consume the bodies.

Narrator: so the site may
Have been a place

For the dead to be eaten.

Gilbert: their soul, of course,
Would be released

And would go to heaven,

Perhaps journeying through

The spheres
Of the planets

Symbolized also by the walls
Of this conce --

Concentric circular monument.

Narrator: looking again
At the circular layout,

Some archaeologists disagree
With the burial theory.

Instead, they see similarities
With other ancient structures,

Ones that could track
The passing of time.

My first reaction was,
This reminds me of stonehenge.

Narrator: stonehenge
In wiltshire, england

Was used
As an astronomical clock

To track the arrival
Of the solstice.

The wheel of giants

Is aligned to perform
The same function.

The northeast gate
Is due to the summer solstice.

There are two major stones

On the eastern
Part of the site,

Which are marking
The days of the equinox.

So we are forced to conclude

That there are relationship

Between the way
This site was constructed

And astronomical bodies

That were important
To those people.

Narrator: if the biblical giants
Of the rephaim

Ever trod these lands,

They could've used sites like
This to commune with their gods.

Often religious as well

As cultural activities
Are tied in together.

So gods become associated
With seasons, uh,

With times of the year,
Such as the harvest or planting.

Uh, so essentially,

Accomplishing both
Your ceremonial needs

Along with
Your agriculture needs.

Mizrachi: it was critical
To know the exact dates

Of the start
Of the rainy season

And of the end
Of the rainy seasons

Because these people could
Prepare themselves to collect

This round of water much
Like we do in our time.

Narrator:
Mizrachi has discovered
That the size of the stones

And the way they are
Cut is different

Between the outer walls
And the central mound.

This suggests they come
From different times.

This could explain the two
Conflicting theories

For the site's purpose.

Mizrachi: the earlier phase
And early bronze age

Was used as a ceremonial center

And as a calendar.

And then 1,500 b.C.
There were other people,

Nomads, that came here,
Built a burial tomb.

So two distinct phases,
Two different stories,

Two different cultures.

Biblical giants gave
Gilgal refaim its name.

If they left any other mark
Of their presence,

Archaeologists have
Yet to uncover it.

The worldview ii surveillance
Satellite passes

Over the southern ocean.

It captures a baffling image
Of a lake on an island

6 miles off the coast
Of australia.

Someone or something has turned
This entire lake bright pink.

Something very strange
Is going on here.

Narrator: august, 2012,

Passing high over
The southern ocean,

The worldview ii
Satellite captures

An image of a bright pink lake.

Something very strange
Is going on here.

Narrator: the image
Is of middle island,

Off the coast of
Southern australia.

The bright pink patch
Is a 40-acre

Body of water
Called lake hillier.

I've never seen
Anything like this,

A bubblegum pink lake.

The lake looks toxic.

Narrator: the pink color
Could be a sign

Of deadly contaminants

Or even unknown life forms.

Investigators
Scrutinize the satellite image.

Could the vivid color
Just be an optical illusion?

Water can look all
Sorts different colors.

Maybe that's what's
Going on here.

Is it just a trick
Of the light?

Narrator: when sunlight
Reflects off water,

It can make it appear
Shades of peach or gold.

This can also happen
In satellite images,

An optical phenomenon
Known as sun glint.

Sun glints occur
When sunlight reflects off

The water at the same angle
As a satellite viewing it.

When sunlight hits the water,
The colors change.

But this is always pink.

Narrator:
Examination of other images

Of the lake proves
The bright pink color

Is a genuinely
Strange phenomenon.

In every image,
It appears pink.

This is no optical illusion.

Narrator:
Aerial drone footage reveals

The lake's color
Is more vivid

Than the satellite images
First suggested.

The bizarre color sparks fears

The water could be contaminated.

We know that different

Pollutants will turn water
Different colors.

Iron can make
Rivers yellow.

Nickel can make
Rivers red.

And textile factories
Can actually turn them blue.

And in this case,
There was a mine

Near the lake in recent history.

Could industrial pollution
Be the answer?

Lake hillier
May be remote

But it's not untouched.

Industry was drawn here
In the past

Due to the high levels
Of salt in the water.

In the lake 19th century,
This lake, lake hillier,

Was subject
To salt mining.

Salt was a very valuable
Commodity then.

It was mined
For a number of years.

Narrator: while salt mining
Could discolor the water,

The lack of recent activity

Makes it seem
An unlikely explanation.

The island was used
For salt mining.

But that operation
Closed down over a century ago.

I've never seen a salt mine have
This kind of affect on a lake.

It doesn't usually
Change the color

To be a brilliantly pink
Almost bubblegum shade of pink.

So it's very unlikely
That this has come

From a long-extinct
Salt mine.

Narrator: historical records
Reveal the lake's color

Is not a new phenomenon.

This lake has been pink
For some time,

Even early explorers
Made notes of it.

Narrator: the earliest
Description of the lake

Dates back to 1802

When famous british
Explorer matthew flinders

Visited the remote island.

His journal records
The sighting.

In the northeastern part

Was a small lake
Of a rose color.

The lake has been this color
For at least 200 years.

If it predates
European colonization,

It must be a natural
Phenomenon of some kind.

Naturalists
Consider the possibility

There's something alive
In the lake

Causing
The vivid pink color.

Water samples reveal
Lake hillier

Has a very high salt content,

Similar to the dead sea.

This makes it deadly
For most living creatures

But not all.

There is another way that
You can get multicolored water.

And that is from microorganisms.

Bacteria and algae can live

In some of the most
Inhospitable places on earth.

So a salty lake is par
For the course.

Narrator: there is something
Alive in the lake.

The life form at the center
Of the mystery

Is a single-celled
Microalgae

Called dunalliella salina.

Dunalliella salina produces
A red pigment

That is called a carotenoid.

These are the same pigments
That grow in carrots.

Here, the carotenoids
Are not orange,

They're actually pink.

Narrator:
The orange-red pigments

Produced by the microbes
Are thought to protect them

From the sun's uv radiation.

For these weird life forms,

The highly-corrosive lake
Is a comfortable home.

The microscopic creatures
Are smaller than a human hair

But can still be seen
From space.