Original subtitles

♪♪

narrator: A secret, underground military research station

frozen in the middle of nowhere draws attention 60 years later.

Camp century was one of the most elaborate cover stories

in the history of the cold war.

Somara: You have to ask yourself,

what is the purpose of this underground city?

♪♪

narrator: A bizarrely disfigured corpse in an ancient tomb

full of sacrificial victims.

♪♪

to be honest, it looked like he had been tortured.

It's like, who did this guy piss off?

Narrator: And the mysterious reappearance

of a long lost airliner on a glacier in the andes

raises suspicions.

Bellinger: The strange thing is the last time anyone heard from stardust,

they were just a few miles away from the airport.

Narrator: These are the strangest mysteries,

trapped in the coldest places.

Lost relics,

forgotten treasures,

dark secrets,

locked in their icy tombs for ages.

But now as ice melts around the world,

their stories will finally be exposed.

-- Captions by vitac -- www.Vitac.Com

captions paid for by discovery communications

[ wind whistling ]

♪♪

northern greenland, 700 miles above the arctic circle,

feels like no other place in the world.

This is one of the most desolate places on the planet.

♪♪

narrator: With the wind chill,

temperatures can plummet to minus 80.

Exposed skin freezes in less than a minute.

When it's this cold and this isolated,

being out here messes with your mind.

It's a psychological test of endurance.

[ wind whistling ]

narrator: Not even caribou can survive this far north on the ice sheet.

But if you look closely in the middle of this icy desert,

you can see a small collection of tents.

[ wind howling ]

o'keefe: It's just so strange.

What's so special about this spot? Why here?

[ engine whirring ]

narrator: A group of danish and american scientists

are keeping a close watch

on something lying dormant deep within the ice

now in danger of reawakening.

Bellinger: What on earth could be down there

that would need so much surveillance?

Narrator: Buried around 30 feet beneath the surface

are the remains of an abandoned american military base

with a long forgotten secret.

♪♪

♪♪

in 1959, at the height of the cold war,

america wanted to experiment

with new concepts of polar construction.

In a remote region of greenland,

they set about building a city under ice called camp century.

♪♪

this type of construction had never been attempted before,

but the u.S. Army engineers were confident in the design.

♪♪

a system of 23 trenches would be dug into the ice cap

and then covered with steel arches and snow.

[ rumbling ]

o'keefe: There was nothing simple about this project.

The nearest port is 150 miles to the west,

and the only way to transport supplies is over the ice.

♪♪

macferrin: You have an extremely wide expanse

of heavily crevassed ice --

deadly crevasses.

Entire vehicles could fall into these crevasses.

And it's extremely cold.

You get temperatures negative 40, negative 50.

It takes specialized equipment,

and it takes a lot of effort and a lot of money

to get anything out to the middle of the ice sheet.

♪♪

somara: A project of this scale and scope

would have been so expensive and so risky.

You have to ask yourself, "why are they doing this?"

what is the purpose of this underground city?

♪♪

narrator: Many now ask,

was there another, more ominous reason

the u.S. Military decided to build a city under the ice

at the ends of the earth?

♪♪

if the engineers knew the true intent, they weren't talking.

They were busy battling the effects of the arctic sun,

which blazes around the clock in the summertime.

Somara: It's called the midnight sun,

and it posed a constant threat

to the stability of the walls they were creating.

But the upshot with building with snow

is that you never run out of supplies.

♪♪

narrator: Once the steel arches were in place,

crews put snow blocks on top for support.

Then they sprayed the whole structure with powdered snow,

which hardened under the sun into a durable surface.

♪♪

macferrin: So when snow first falls, it's kind of fluffy.

We know that.

But when it compresses, it becomes more like cinder block,

and you can actually build buildings with that material.

[ saw whirring ]

narrator: Once the trenches were complete,

they cut passageways between the tunnels

and then closed off the ends with walls of snow,

ensuring nothing gets in and nothing gets out.

♪♪

bellinger: The design of this station was ingenious.

This had never been done before.

But very few people were privy

to the real purpose behind this space.

What was the reason for all the secrecy?

♪♪

narrator: It took a little more than a year

to build camp century,

which included barracks for 200 men,

mess halls, maintenance shops,

kitchens capable of feeding hundreds,

state of the art scientific labs,

a church,

and even a barbershop,

all powered by a state of the art mobile nuclear reactor,

the first of its kind.

♪♪

macferrin: The u.S. Army only had 6 of these,

and it was by far the most expensive component.

It was roughly three quarters of the cost of the entire base

was just that reactor.

♪♪

narrator: All told,

the underground city cost u.S. Taxpayers

$8 million to construct.

Bellinger: To put that into perspective,

it's the equivalent of about $71 million today.

Narrator: Within a few weeks,

the crew that built the city were shipped out,

and the scientists moved in and started work.

At least that's what the u.S. Military told the world.

America's public message was simple and innocent --

camp century studies snow.

But just a few miles from the station,

another project was taking place,

one of a more sinister design.

They were building a one and a half mile long

railway track under the ice.

The strange thing was the track led nowhere.

Narrator: A railway track leading nowhere,

a research station that had no business being there,

and a group of scientists worried about it decades later.

None of it adds up.

The disturbing truth would take years to come out.

[ wind whistling ]

♪♪

narrator: Buried deep in the ice

of the most isolated part of greenland

lies the remains

of a secret american scientific research station

called camp century, built in the late 1950s.

So why is it still being monitored today?

♪♪

in the late 1950s,

america was involved in an arms race with russia.

As cold war relations intensified,

the united states was looking for a way

to be able to launch a nuclear strike

more quickly and effectively.

O'keefe: The american government told the world

that the sole purpose for camp century

was to conduct advanced, scientific polar research.

But newly declassified documents now reveal its true purpose.

Bellinger: Camp century was one of the most elaborate cover stories

in the history of the cold war.

Its true identity?

Project iceworm.

Narrator: The u.S. Army brain trust

calculated that they could launch a nuclear attack

on russia from greenland

in half the time it would take from the american mainland.

♪♪

project iceworm's ultimate objective

was to build a military launch site hidden under the ice

big enough that it could house 600 nuclear missiles

all aimed at moscow.

[ whirring ]

♪♪

narrator: But it never happened.

The only nuclear device that ever made it to greenland

was the reactor that powered the camp itself.

Narrator: Why didn't the americans arm the underground station?

It turns out they should have done a little more research

on the greenland ice cap.

[ crackling ]

macferrin: The greenland ice sheet moves in a couple of ways.

The ice flows under its own weight towards the coast,

and it flows at different speeds in different places.

But also, the snow compacts down into glacial ice.

Anywhere you are on the ice sheet,

it's in a constant state of motion.

Narrator: U.S. Army engineers miscalculated

how fast the ice sheet was moving.

So by the late 1960s,

camp century was starting to collapse.

As the ice shifts, straight tunnels become curved,

and the tunnels close in on each other as the snow is compacting.

[ ice groaning ]

somara: I think they realized pretty quickly

that this environment was never going to be safe enough

to house hundreds of nuclear warheads.

Bellinger: With camp century having been abandoned over 50 years now,

why are scientists camping out, keeping an eye on it?

Narrator: The answer is in how they abandoned the base.

While the military removed the nuclear reactor,

they left everything else,

wrongly believing that the snow and ice

would crush the remaining debris

and safely entomb the toxic material forever.

They left a lot of waste at camp century.

They left behind huge caches of fuel.

They left behind buildings full of pcbs

and other construction materials.

And they left behind all the coolant water

from the nuclear reactor.

It's all still there.

So if and when camp century ever melts out,

all those wastes that were left behind,

all those toxins,

will find their way through rivers and streams

out to the coast where people live.

♪♪

narrator: Scientists continue to monitor

the temperatures of the snow and ice,

hoping to predict how the ice sheet

will behave over the next century.

At this point, it's anyone's guess.

♪♪

♪♪

hidden away in the border between russia and mongolia

is the valley of the river uyuk.

The vast landscape is frozen solid for most of the year.

It's called permafrost.

But for a short time every summer,

the top layer melts just enough to reveal a priceless discovery.

♪♪

below the surface,

german and russian archeologists

unearth an elaborate ancient tomb of a scythian ruler,

and there, they find the remains

of dozens of sacrificial victims.

When you stand back and look at it,

it defies belief.

O'keefe: One after another after another.

Can you imagine stumbling across so many bodies?

♪♪

bellinger: Even when you appreciate the value

of an archeological find like this,

you can't help but think that this is a gruesome way to die.

♪♪

narrator: Archeologists discover signs

consistent with ritual sacrifice.

A number of the bodies have pickax wounds to the skull,

indicating a quick, relatively humane death.

I've seen evidence of ritual sacrifice before,

but it's unusual to see anything on this scale.

♪♪

bellinger: There were 30 bodies,

which was in itself extraordinary,

but your focus immediately zeroes in on a single individual

whose state was frankly bizarre.

Rose: His injuries are inexplicable.

They just don't fit with the others,

so it raises all kinds of questions.

♪♪

narrator: It's clear to archeologists

that most of the victims in this vast tomb

were killed in the same manner --

all but one.

Why are his injuries so different from the others?

To be honest, it looked like he had been tortured.

He had a slash at the base of his neck...

A grotesque hole in his right cheek below his eye...

And this massive crack

running down the right side of his skull.

♪♪

it's like, who did this guy piss off?

Bellinger: It's clear that this man suffered

a great deal before he died.

What did he do to justify such a brutal death?

♪♪

narrator: The scythians were fierce, nomadic horsemen

who ruled an empire stretching from the black sea

across siberia to the borders of china

from 900 to 200 b.C.

They had no written language,

but legends about them spread far and wide.

♪♪

rose: Herodotus, who was a greek historian at that time,

described the scythians

as a brutal and ruthless race of warriors

who committed a slew of atrocities,

which is a bit rich coming from the ancient greeks.

♪♪

o'keefe: Apparently, they used to scalp their enemies,

making cloaks of their skin.

Then they gilded the insides of their skulls with gold

and used them as drinking cups.

♪♪

rose: But the truly macabre ritual the scythians practiced

had to be their death ceremony.

♪♪

billson: When a king or a military leader died,

he was buried with everything he might need in the afterlife,

including his gold, horses, his warriors, wives, and servants.

♪♪

the whole lot of them went with him to the tomb

whether they liked it or not.

♪♪

picture this -- you're perfectly healthy,

but you've just been told it's time for you to die

because your king keeled over from prostate cancer.

♪♪

o'keefe: Based on the writings of herodotus,

all of the other people in the tomb

would have been strangled.

It may sound horrific now to us,

but at the time,

it was a relatively quick and painless way to die.

♪♪

bellinger: You have to wonder

how much those who were sacrificed knew in advance.

Narrator: Did they go willingly to their fate?

Or did they fight back and try to escape?

♪♪

you can't look at an ancient ritual like this

through modern eyes.

♪♪

the scythians belief in the afterlife

must have been so strong

that they had absolute faith their lives wouldn't really end.

They would simply continue on into another realm.

Maybe they even looked forward to the next stage of existence.

Maybe they believed this was an honorable way to die.

♪♪

narrator: If all the people in this tomb

had been mercifully sacrificed

as part of an ancient scythian death ritual,

why are the injuries to one individual

so markedly different?

♪♪

narrator: Hidden under the icy permafrost for centuries,

anthropologists discover

a spectacular ancient scythian tomb.

But it's not gold and treasure they're most intrigued by,

it's the remains of dozens of sacrificial victims.

And among them, one individual stands out.

All of the other victims were killed

in the same humane manner --

all but one, who looks like he might have been tortured.

What killed this man?

And why was his fate different from all the others?

♪♪

scientists examine the wound at the back of his head

as a possible cause of death.

♪♪

rose: If you look closely at the shape of the wound,

you can see that it's made a little groove in the bone

in the shape of a "v,"

so it could have been made by a large knife or a sword.

And given what we know about this culture,

it probably happened in battle.

♪♪

this was a pretty significant blow to the head,

but did that kill him?

♪♪

narrator: Scientists run the bones through a ct scanner.

They look closely at the edges of the wound.

Billson: Here you can see signs of healing.

New bone had time to grow before this man died.

Narrator: That means this was an old injury

and not the cause of death.

So scientists then turn their attention

to the hole in his cheek.

Rose: The hole itself was generally pretty clean,

which indicates it was made by a projectile object

rather than blunt force.

♪♪

narrator: But what kind of flying object

would create a hole like this?

It looked like he took a triple-barbed arrow to the face.

♪♪

it shattered the bone below his right eye

and then lodged firmly into his cheek.

♪♪

the pain would have been unbearable.

Narrator: Then they see some thin cuts on the bone

unrelated to the arrow's puncture.

♪♪

again, we see this "v" shape --

dozens of them.

♪♪

rose: The whole unfortunate series of events

probably happened on the battlefield.

The warrior takes an arrow to the face.

Maybe his horse takes a few, as well.

He falls to the ground.

His comrades ride up, trying to help.

They're thinking,

"we've got to get that arrow out of his face."

so what do they do?

They try and hack it out with a small knife.

♪♪

o'keefe: They literally tried to cut or saw the arrowhead

out of his cheekbone repeatedly

using a small blade.

Hence the multiple "v" shaped scars.

Can you imagine?

♪♪

bellinger: If he was even still conscious at this point,

you've got to imagine he was ready to just give it up.

♪♪

the scythians may have been skilled in a lot of things,

but medicine -- that wasn't one of them.

♪♪

rose: So his friends go to get the battlefield medic,

and at this point, you're probably thinking,

how could this situation get any worse?

♪♪

narrator: Along the skull,

experts see a single major fracture

running from the hole up the right side of the skull.

♪♪

they conclude it could only have been made by one thing.

[ clanking ]

in one last vain attempt at saving the warrior's life,

the battlefield medic must have picked up a chisel

and hammered it into the cheekbone,

trying to break the arrow free.

Instead, it cracked his skull.

Narrator: They conclude this is what killed him.

So why was he buried in this tomb,

along with all of these sacrificial victims?

He must have been regarded as such a hero on the battlefield

that he was given the highest honor --

to ride with his king into the afterlife.

♪♪

♪♪

♪♪

narrator: On one of the highest mountains of the andes,

on the border of argentina and chile,

lies an unusual glacier --

the tupungato rock glacier,

whose icy core is buried a meter beneath its rocky surface.

♪♪

it's here that a gruesome and perplexing

discovery is made.

♪♪

human remains.

♪♪

can you imagine how it must have felt to stumble on that?

♪♪

o'keefe: Was it one person?

Two?

Three?

Your thoughts are just racing.

Narrator: Who did these bones belong to,

and how did they end up here?

It's just horrific.

There's still nail polish on the fingernails.

Bellinger: Was this an accident?

You're just trying to wrap your head around

what could have happened here.

Narrator: After the bones were discovered,

the argentinean army mounted a two-week expedition

to the remote glacier to investigate.

Not far from the human remains, they found an object

that could solve one of the most enduring aviation mysteries

of all time --

a battered airplane engine.

A 1945 rolls-royce merlin.

Several planes use the rolls-royce merlin engine,

one of the most famous being the lancaster bomber.

[ engine whirring ]

so you start connecting the dots --

mid-1940s, the andes, lancaster.

The only known lancaster

to go missing in the andes during that time

was a plane called stardust.

Narrator: The serial number on the wreckage confirms it.

After disappearing from the face of the earth over 70 years ago,

the long lost airliner has been found.

♪♪

[ wind whistling ]

bellinger: The strange thing is,

the last time anyone heard from stardust,

they were about to land in santiago.

They were just a few miles away from the airport.

Narrator: But the tupungato glacier,

where the wreckage is found,

is over 50 miles to the east.

How does this engine end up 50 miles away

in the middle of the andes?

[ wind whistling ]

narrator: The wreckage of an airliner

that vanished off the face of the earth 51 years ago

suddenly reappears on one of the highest mountains of the andes,

far from where the crew said they were when they disappeared.

Is there a sinister reason behind this mystery?

Researchers explore the plane's final hours looking for clues.

On August 2, 1947,

a british civilian version of the wartime lancaster bomber

took off from buenos aires

on a scheduled flight to santiago.

Flight cs59 was carrying five crew members

and six high-profile international passengers.

At the helm was the captain reginald cook,

a distinguished world war ii pilot,

along with his first and second officers,

also boasting extensive combat experience.

Bellinger: These guys weren't rookies.

They were seasoned combat veterans,

used to flying in all kinds of weather

in the most stressful environment there is -- battle.

So what happened?

Narrator: According to the accident report,

the last message ever transmitted

from the crew of the stardust was in morse code,

announcing their e.T.A. At the airport in four minutes.

But that wasn't the strange part of the message.

It was how they signed off that caused the confusion.

[ morse code beeping ]

"stendec"?

What does "stendec" mean?

Narrator: The radio operator had no idea,

so she asked the crew to repeat the message,

which they did --

two more times in rapid succession.

After that...

Radio silence.

♪♪

somara: Could it have been some sort of code?

If you look closely at the letters

that form the word "stendec,"

it's actually an anagram -- "descent."

maybe the crew were just having a little fun

after a long flight.

O'keefe: A crew with this level of experience

wouldn't be playing around,

especially when you're responsible for people's lives.

Standard operating procedures are drilled into pilots

for years before they even make their first flight.

And if they break form,

they could lose their license.

It just isn't done.

♪♪

narrator: Some believe that the crew

might have been attempting

to spell the name of the aircraft.

Bellinger: If you look at the morse code for "stendec,"

and compare it to "stardust,"

there are some similarities.

But why would the operator randomly tap out

the name of the aircraft

and get it wrong three times in a row?

Not only that, but if he was trying to identify the aircraft

to the air traffic control,

he would have used the numeric code on the flight,

not the name of the aircraft.

Again, it doesn't conform to aviation protocol.

[ morse code beeping ]

narrator: Another possibility is that with a tiny adjustment

of the dashes and spaces,

it spells the words "e.T.A. Late."

but why would the radio operator message

that they were late when they just informed them

that they would be landing in four minutes?

O'keefe: There's no rational answer

to why they transmitted the word "stendec."

so what if the crew weren't rational at the time?

Narrator: The lancaster wasn't pressurized,

which meant that each individual on the plane

had their own oxygen supply.

What if that supply got cut off,

rendering the crew susceptible to hypoxia?

Bellinger: Stardust had been cruising at an altitude

of 24,000 feet the day they went missing.

The air that high is very thin,

meaning there's not enough oxygen in it

to keep a person functioning for very long.

Narrator: If there isn't enough oxygen circulating in your blood,

your organs start to fail.

Hypoxia can come on within very few minutes --

can't breathe, you start to sweat, your muscles seize up,

and you can become euphoric or delusional.

Narrator: Was hypoxia the reason the crew announced

they were four minutes from landing at the airport?

Were they actually still in the andes,

but suffering from delusions?

O'keefe: After the plane disappeared in 1947,

an intensive five-day search of the entire mountain range

along the flight path yielded no results.

If stardust had crashed in the andes,

they would have found the wreckage back then.

♪♪

narrator: Investigators turn their attention

to the passengers on the flight,

looking for clues.

The passenger list could be ripped

from some of the greatest spy novels.

Narrator: On board the fateful flight

were three brits, a german woman,

a palestinian, and a swede.

Bellinger: The palestinian was a businessman,

wealthy enough to have a large diamond

sewn into his suit jacket.

The german was returning to chile

with the ashes of her dead husband.

And the brit was a king's messenger

carrying critical diplomatic correspondence.

I mean, where do you begin?

Narrator: Diplomatic relations

between great britain and argentina were tense in 1947.

O'keefe: The two countries were fighting over territory in the antarctic.

Could it be that someone didn't want the king's messenger

to deliver those diplomatic documents?

[ suspenseful music plays ]

[ wind whistling ]

narrator: 51 years after it vanished without a trace,

the wreckage of a british airliner called stardust

magically reappeared in the middle of the andes,

50 miles to the northeast

of where the crew said they were when they disappeared.

Could this have been a hijacking gone wrong?

Subsequent searches uncovered more fragmented pieces

of the fuselage on the crash site,

including a largely intact propeller

and a piece of the wing.

Somara: Gps logging shows that the debris field

covers just one square mile, which is too small for a bomb.

But one thing is becoming obvious.

Every piece of the wreckage is crushed and crumbled,

which can only mean one thing --

the crash was the result of a massive high-speed impact,

and it happened right there on mount tupungato.

Narrator: Why then did the crew message

that they had cleared the mountains

and were minutes from the santiago airport?

It's easy to forget that in 1947, there were no computers

to tell you where you are, where you were,

and what time you're going to get to where you're going.

Navigation was done by pen and paper.

It was something they called "dead reckoning."

bellinger: Dead reckoning is a way of determining

where you are using time, speed, and direction,

all in relation to a fixed starting point.

Somara: But the formula only works if the estimations are correct.

If you miscalculate, it could have devastating consequences.

Narrator: So what could have caused captain reginald cook

and his all-star crew to make a major miscalculation

in either time or speed or direction?

Somara: You're racking your brain,

trying to figure out what could have gone wrong.

It's a routine flight with an extremely experienced crew.

And then you have this "aha" moment.

O'keefe: If you look at the weather report

on the day of stardust's disappearance,

it was pretty bad.

That's why the crew decided to fly above the weather.

So they ascended to 24,000 feet, which put them out of sight

of the mountains and the ground below.

Irving: The lancaster was one of very few planes in existence

that could fly that high.

So little was known about the weather systems

at that altitude.

[ wind whistling ]

narrator: At 24,000 feet, they would have encountered

a meteorological phenomena called a jet stream,

a fast-moving air current that circulates high above the earth.

Jet stream winds can blow up to 275 miles an hour.

They're really strong.

And if you're heading into one, they can really slow you down.

If the stardust was flying into the jet stream,

they might not have known it.

They must have slowed down so much

that their dead reckoning calculations

were completely off.

O'keefe: When they radioed santiago,

announcing that they were four minutes away

from landing at the airport,

in actuality, they hadn't even cleared the mountains.

So when they started their descent,

they were on a collision course with the glacier.

♪♪

somara: With the cloud cover,

by the time they would have seen the mountain,

it would have been too late.

Narrator: So why didn't the argentinean army

find the wreckage back in 1947 when they searched the andes?

There's only one probable explanation.

When the stardust crashed into the mountain,

the vibration likely caused an avalanche...

Which buried the wreck under tons of snow,

and the glacier just swallowed it up.

Narrator: Over the years, the glacier inched its way

down the mountain.

When it got to the lower altitudes, it melted,

revealing the wreckage.

90% of the wreckage is still inside the glacier,

but with enough time,

we should eventually see the rest of the plane.

Narrator: But as far as what "stendec" means,

it's a mystery that will likely remain buried forever.

[ dramatic music plays ]

♪♪

in the remote reaches of northwest greenland,

buried under a massive glacier

lies a secret that's been hidden for thousands of years.

The greenland ice sheet is a massive blanket of snow and ice

covering nearly the entire island of greenland.

Narrator: But even against this immense backdrop,

the hiawatha glacier dominates the landscape.

It's comprised of millions of tons of snow and ice.

The hiawatha glacier is over 3,000 feet deep in certain places,

but until recently, very little was known

about the landscape that existed below it.

♪♪

narrator: In 2016, using ice-penetrating radar,

scientists make a startling discovery --

a massive depression under the glacier

that measures more than 19 miles across.

♪♪

the edge of the ice sheet

follows the contours of the crater below it.

♪♪

macferrin: It's actually amazing it's remained hidden for so long.

It's right in front of your eyes.

Narrator: The shape of the depression is almost perfectly round.

Could it have been caused by an asteroid of massive proportions?

♪♪

[ wind whistling ]

♪♪

narrator: An enormous crater has been discovered

underneath the hiawatha glacier in greenland.

Scientists are exploring

whether it could have been caused by an asteroid.

And if that's true, it could change our understanding of life

on this planet.

About 13,000 years ago, all the large ice age mammals

were wiped out in one fell swoop.

Why is it that so many big mammals,

including the wooly mammoth,

disappear from the fossil record

at about the same time?

Narrator: One theory is that an enormous asteroid smashed into the earth,

causing widespread death and destruction.

It's called the younger dryas impact theory,

but until now, there's been no proof.

Macferrin: Younger dryas has been a controversial concept

in climatology and geology for a long time,

simply because they never found a crater

that would fit the theory -- until now.

[ dramatic music plays ]

♪♪

narrator: Scientists set about trying to see if the depression

could, in fact, have been caused by an asteroid.

First, they have to analyze the ground underneath.

♪♪

macferrin: Nasa's ice-penetrating radar is unique,

because it's specifically designed to map

the bedrock underneath the ice.

It gives us an idea of what the ground looks like.

In this particular case,

underneath the ice, there's all sorts of bumps and peaks

that, combined with the shape of the crater,

points towards what would be characteristic

of an asteroid strike.

Narrator: But scientists need more evidence

to corroborate their theory.

They look to the melted water

running off the glacier for clues.

And they find an unusual rock formation --

shocked quartz, which looks like stained glass.

Irving: Quartz is one of the most common minerals

in the crust of the earth.

But shocked quartz can only be created

with intense heat and pressure.

Narrator: There are only two events

powerful enough to create shocked quartz --

nuclear explosions and asteroid strikes.

♪♪

the presence of shocked quartz at this site

is completely consistent

with something like an asteroid strike happening there.

Narrator: But if this was an asteroid strike,

would it have been big enough to kill off

all the large ice age mammals on the planet?

♪♪

macferrin: The hiawatha crater is 19 miles wide.

It would take a hunk of iron

nearly a mile thick to cause something like this.

♪♪

an asteroid that size would have been three times

brighter than the sun at midday.

♪♪

irving: When something that big hits the earth

going more than 40,000 miles per hour,

it's going to make a spectacular hole.

[ dramatic music plays ]

♪♪

poinar: The energy released by the impact

is greater than 700 one megaton nuclear bombs.

♪♪

landscapes would have been completely altered,

water would have been diverted,

and animals would have been burned and buried alive.

[ fire crackles ]

even if you avoid the initial strike,

you only have a few seconds before the fireball hits.

Narrator: The impact instantly evaporates ice

and showers flaming rock debris

as far away as north america and europe.

Irving: So if you imagine you're on a beach in california

and there's dust and rocks raining down

and they're coming all the way from greenland...

...There's nowhere to run, everything's on fire,

it would have felt like armageddon.

♪♪

it's not certain, but it's conceivable

that an impact this large would be enough

to extinct multiple species around the world.

♪♪

narrator: But did it hit the earth at the right time?

Scientists haven't been able to accurately date the crater yet.

Irving: At this point, it's just a theory.

We need to do more research. But now we have a new suspect.

The discovery of this crater is extremely tantalizing.

The next step would be to send an expedition

to drill beneath the ice

to see if the crater can be dated more accurately.

Narrator: Until then, the secret remains hidden in the ice.

♪♪