Original subtitles

(instrumental music)

Downloaded from YTS.MX

Official YIFY movies site: YTS.MX

NARRATOR: 140 million miles from Earth.

Our planetary neighbor and our greatest mystery...

Mars.

For centuries we've gazed at it in wonder.

But it's always remained out of our reach...

until now.

Today a pioneering spacecraft

is bringing the planet dramatically closer.

Pixel by pixel, it's beaming Mars back to us...

as we've never seen it before.

Now using these images,

we can do something remarkable.

And take you on a journey no human being

has ever been on before.

A single circuit of this world

from dawn to dusk.

Exploring its most spectacular...

and surprising features.

(rumbling)

On a mission to unlock its deepest secrets.

And we join the quest to answer the biggest question of all.

Is there life on Mars?

(beeping)

Our journey begins at a vast black spot,

one thousand miles wide.

This is where humanity's dream of Mars first began.

It's called Syrtis Major.

Hidden in this intriguing landscape is a mysterious feature,

that first made us hope that Mars could be Earth's sister.

Another planet teaming with life.

DERRICK: It's almost unthinkable that just 100 years ago,

people actually thought that there was civilizations on Mars

and if there was a civilization there,

what was the civilization like?

Did they have commerce? Did they have language?

Could we communicate with them?

Was there any chance for space travel so that we could connect with them?

NARRATOR: Here in Flagstaff, Arizona, in 1894,

a Mars obsessed astronomer built a state of the art telescope,

to study the red planet in more detail than ever before.

What Percival Lowell saw would shock the world.

On the surface of the planet,

he made out patterns, structures, movement.

Mars appeared to be alive.

DERRICK: He looked at Mars every opportunity he had

and he kept records of what he saw.

Here are three of Percival Lowell's globes.

He's detailed out the regions of vegetation.

He also seemed to observe the change in the vegetation

over time and over seasons.

He's included vast networks of canals,

bringing water from the melting polar caps

down to the drier, dying regions of the planet,

providing water for the civilizations that he imagined that lived there.

NARRATOR: In the years after Lowell's discovery,

Mars fever gripped our planet.

(rumbling)

We imagined alien oceans,

exotic landscapes and bustling cities.

Even Martians staring back at us.

(roaring)

But we didn't get a chance to find out if we were right,

until 1964.

MAN (over radio): Three, two, one, zero.

All engines running, lift off.

Roger, one, three seconds.

MAN 2 (over radio): We're on our way.

NARRATOR: Mariner 4 was NASA's first successful mission

to the red planet.

At last a chance to study Mars up close.

There was pressure. There was definite pressure.

We were inventing stuff every step of the way.

It was exciting.

But you're working hard, had guys working 50, 60 hours a week.

This was the 60's, the dawn of the space age.

And it just fired our imagination about you know, what could be there?

Who could be there?

AMY: Mariner 4 was a huge deal,

because we'd never really seen the surface of Mars,

all we had was people looking at Mars with a telescope

and drawing what they saw.

The public was expecting to see these

lush civilizations built by Martians.

I was 13 and I actually can remember

watching the 6:00 news and this was broadcast nationwide.

NARRATOR: Nervously, the world waited to see

the first ever close-up image of Mars.

(indistinct conversation)

MAN (over PA): Picture number one is coming in.

JOHN: We didn't know what it was gonna look like.

It took eight hours to get one picture back.

We had these little tape recorders that would just

print one line of numbers after another,

and each pixel was represented by one number

on this little strip chart.

So we got the idea of, why didn't we just take that

and color those numbers appropriately.

NARRATOR: As the data came back, a picture emerged.

MICHIO: It did not show a tropical environment

with cities and gleaming skyscrapers.

No.

No canals, no oceans, no rivers.

No vegetation, no forests.

We didn't see any cities,

we didn't see any Martians walking around at all.

Mariner 4 was a historical bummer.

(indistinct conversation)

What amazed me was,

when the first pictures came back,

the first thing you noticed is that it's dominated with craters.

I never heard anybody predict that.

I did never hear anybody in the science community saying,

"Well, when we get there,

it's gonna look a lot like the moon.

There's gonna be craters."

No, there was never any of that.

NARRATOR: For all our dreams of a living Mars,

we seem to have found a dead, deserted world.

How had we got it so wrong?

Today we can see the answer.

Circling above the planet's surface, a new electronic eye.

This is NASA's Mars Reconnaissance Orbiter.

On board, HiRISE--

the most powerful camera we have ever sent to another world.

It's capturing Mars in unprecedented spectacular detail.

The HiRISE camera is a game-changer.

It gives us the illusion,

the feeling of flying over Mars in a helicopter.

The way you look out and almost touch the landscape.

Think about it-- One pixel, one dot on the HiRISE photograph

is the size of a basketball.

NARRATOR: HiRISE is showing us that Mars is much more than a barren desert.

It's revealing a world beyond our wildest imagination.

JAMES: This is just not beautiful, it is magnificent.

AMY: They look like abstract paintings.

DAVID: The planet comes alive

and you see this vibrancy and this-- this motion.

TANYA: The beautiful color palette of this planet,

that we've always just thought of as this red rock.

DAVID: But once you can see things in that detail,

it's like, whoa, I got a new prescription for my glasses

and all of a sudden I can see the world, (stammers) only it's the world of Mars.

NARRATOR: Using HiRISE data, we can now show you for the first time

what Syrtis Major really looks like.

This is a view no human has ever seen.

Over 100 foot tall,

stretching for 100 miles.

These are the Nili Patera sand dunes.

When Percival Lowell looked towards here,

he thought he saw life.

Today with HiRISE's powerful gaze,

we can see how he got Mars so wrong.

(electronic beep)

The dunes move in the Martian wind.

On a global scale,

sand can be seen being blown around Mars' surface.

The size of shape of regions like Syrtis Major

ebb and flow.

DERRICK: Percival Lowell could see these large shaded regions

that seemed to grow and change over time.

Maybe even seasonally, very much like we see vegetation

changing with seasons here on Earth.

He was actually observing dust storms and shifting sands

on the surface of Mars.

NARRATOR: But was Lowell completely wrong?

For years, humanity thought so.

But now using HiRISE imagery,

we can glimpse something extraordinary.

A Mars that may once have been much more like his vision.

It's a story that begins at our next destination.

(beeping)

3,200 miles southwest of Syrtis Major,

is a window into Mars' deepest past...

Noachis Terra.

Noah's Land.

At first glance,

this looks like another dead landscape,

but it holds an astonishing clue to a very different world.

A world with a real chance of life.

This is one of the most ancient places on Mars.

Noachis Terra is absolutely filled with craters.

AMY: Some are huge, the size of a city or an entire state.

Some of them are five or ten meters across, very small.

We can also see that some craters have been

overprinted with other craters.

MICHIO: Simply by counting and analyzing these craters

on Noachis Terra,

we think it dates back almost four billion years.

NARRATOR: Now we can build these craters from real data.

Each is formed by a single meteorite impact,

that punched through rocks, billions of years old.

They are holes punched through time.

These craters are like opening doors into the geology of Mars,

we can use it to dig down through the various layers

and we can see almost every kind of Mars there was.

NARRATOR: These craters are 140 million miles away.

So their secrets might seem beyond our grasp,

but incredibly they can be unlocked.

By a rock found on Earth.

NARRATOR: This is a rock worth 200 times more than gold.

A rare and revealing treasure.

JAY: There's so many objects in this world that you can have.

You can have diamonds, you could have gold,

you could have houses, cars

and they really don't do anything for me.

And this is NWA 8-4-5-5.

This is NWA 10-608.

This is NWA 8-6-8-7, it's called a troctolite.

And I liked it 'cause it was shaped like a star. (laughs)

Meteorites are like my babies.

Sometime around May of 2011,

I had a friend in Morocco, he was a dealer.

(camera clicking)

He showed me a picture of this black rock found in the desert

that looked unlike anything either of us ever seen.

Then I said, "You know what, I think it's a meteorite."

It's called Black Beauty, NWA 70-34.

And I loved when I got it in my hands,

because the skin of it is so different.

And so I knew that it was special.

CARL: In this safe I have unknown meteorites,

they are things that I'm working on currently.

This is from the meteor crater.

This is a Lake Murray meteorite.

This is an iron meteorite that fell in Odessa, Texas.

One day I received a shipment from Jay

and I looked at this very unusual

dark black specimen--

Black Beauty.

The first thing that I thought was,

this looks so black and shiny, it can't be real.

He told me he thought it had shoe shine polish or that

they polished it up and he really never saw anything like it.

And I said, "Hey, would you look at it, but don't cut into it."

And so I went over to the lab next door

and put it on a diamond saw

and sliced off the first piece of it.

(saw whirring)

I saw immediately that it wasn't something that had been faked--

That it was actually something quite remarkable.

The analyses were suggestive of a Martian origin.

And it took about a year collaborating with other scientists

to assemble enough evidence that no one could argue with it.

JAY: It is mind boggling to me,

that I can hold a piece of Mars.

(beeping)

NARRATOR: The story of how this Martian rock ended up on Earth

is a remarkable one.

Mars' craters are the clue.

A violent meteorite strike,

punched deep into the planet's surface.

Fusing together ancient rocks,

to form Black Beauty.

Like shrapnel, it was launched into space.

And for millions of years, it wandered the solar system,

until it felt the tug of another planet's gravity.

Safe on Earth,

the secret for Mars' craters could be revealed.

CARL: What we have here is a section of Black Beauty

and from those grains, we're able to determine

a snapshot of geologic time and the geologic history of Mars.

NARRATOR: Hidden in the layers of rock,

Carl discovered something incredible.

CARL: We were astonished because out of Black Beauty was coming

a huge amount of water.

Black Beauty was soaked with Martian water

and remnants of that are still in there.

NARRATOR: So could water really have flowed on this dusty world?

Black Beauty only gives us a tiny, tantalizing hint.

To discover how big a part water played on ancient Mars...

we've had to send probes to the planet itself.

And that's proved a formidable challenge.

(beeping)

As we leave Noachis Terra behind,

and begin the next leg of our journey,

something strange sparkles in the Martian dust.

Mars is kind of a graveyard of spacecraft.

In fact, there's something called the Mars jinx.

Mars has its own plans for whether this is gonna go well, or not.

NARRATOR: The quest to find water and perhaps even life on Mars,

comes at a high cost.

More than half of the 45 missions sent to Mars ended in failure.

AMY: The Soviet Union was the first to start sending missions to Mars

in 1960 and they all failed.

Mars 2, Mars 3, the Mars Zond missions, the Cosmos missions,

the Phobos missions.

The Brits have tried, Europe has tried.

NASA's Mars climate orbiter burned up in the atmosphere,

because of a mix up between metric and imperial units.

(whirring)

It takes so long to get one of these missions

to go from a concept to actual hardware that you fly.

This is somebody's entire career and to see it just pfft.

You're going 13,000 miles an hour

and you have seven minutes to get down to zero miles an hour

and hit the surface gently.

There's enough energy and motion

that it can melt or vaporize the entire spacecraft.

(rumbling)

NAGIN: You can do everything right

and you can still have a bad day on Mars.

NARRATOR: Even if you can make it through the atmosphere...

(explosion)

...landing is a whole new challenge.

ABIGAIL: It's nerve-racking

but, man, does it make it so exhilarating when it works.

NARRATOR: And some really do work.

One that made it to the surface,

became arguably the most successful mission ever.

Thanks to a mysterious alien force.

(beeping)

NARRATOR: The longest running rover that has ever explored Mars

can be found at our next destination.

The sandy plains of Meridiani Planum.

Still sitting here today is the lifeless shell

of NASA's Opportunity rover.

Expected to operate for 90 days,

it lasted 14 and a half years,

making a discovery that transformed our understanding of Mars.

And the key to its marathon mission was a mysterious force,

that leaves these strange patterns in the sand.

(beeping)

MAN (over radio): Three, two, main engines start,

zero and lift off of the Delta Rocket with Opportunity.

NARRATOR: Opportunity's mission was to hunt for evidence

of ancient water on Mars.

But first, it had to land where so many others had failed.

CALLAS: Landing on Mars is very difficult.

And so in those tense moments, either during the launch phase

or you know, the arrival and entry descent into landing,

you're on the edge of your seat,

waiting to hear word on whether you are successful

or whether it's a failure.

(instrumental music playing)

NARRATOR: To protect their rover,

the engineers came up with a plan as bizarre

as it was audacious.

MAN (over radio): Suspected retro rock and ignition on my mark.

Mark.

NARRATOR: Shock absorbers...

MAN (over radio): At this point in time, we should be on the ground.

NARRATOR: Space style.

CALLAS: When you think about half a billion-dollar spacecraft

inside this gigantic beach ball

bouncing around on the surface of Mars,

it goes into the category of "what were they thinking?"

(instrumental music playing)

NARRATOR: Opportunity was safe on the ground.

Now it began using its state of the art camera...

(cheering)

...to capture the most detailed images of the Martian surface ever seen.

JAMES: When we landed and we saw the first view

it's like, seeing King Tut's tomb.

There's the story we've been waiting for.

I remember crying and saying, "This is exploration."

Opportunity is turning our camera back on this tiny little shallow crater

and looking at the deflated airbags.

ABIGAIL: Opportunity was able to leave the pad

and become a real rover.

NARRATOR: Opportunity showed us icy clouds

dancing across an alien sky.

Even the other worldly setting of our shared sun.

Opportunity's discoveries were truly breathtaking.

Everyone wanted to see more.

But the clock was ticking.

CALLAS: I knew then end would come at some point.

It's much like you have an aging parent.

Maybe they're in good health.

But you know that they're not gonna last forever.

Every day was precious.

We thought we had a finite amount of time to get our job done.

And it comes down to the fact that the rovers are solar powered.

We knew that Mars is a dusty place

and that the dust falls out of the atmosphere.

So we figured the rovers would have enough time to last

90 days before the solar rays were so dusty

that they couldn't generate enough energy.

But Mars and the rovers proved us wrong.

(wind howling)

NARRATOR: The Martian dust did make Opportunity's battery levels run down.

But then they would miraculously bounce back up.

The rovers engineers were perplexed.

But some astonishing images would provide the answer.

NARRATOR: As the Martian dust settled on NASA's solar powered rover,

the engineers were puzzled at how it kept going.

Then the received some extraordinary images.

We have actually a series of time lapse photographs

of the plains of Mars,

in which we captured a series of dust devils moving across.

And we think it's something like that

that cleaned the dust off the rover.

NARRATOR: As these dust devils move across the landscape,

spiraling up to twelve miles into the sky,

they leave tell tail tracks behind them.

The mysterious patterns that we can see with HiRISE.

Incredibly it was Martian weather

that allowed Opportunity to explore Mars for so long.

But in July 2018, a global dust storm hit the planet.

CALLAS: The skies were so dark that you couldn't see the sun.

The rover got too cold and something broke inside.

We never heard from the rover again.

It's sad. It's emotional.

But to have fourteen and a half years was such a gift.

NARRATOR: Over its mission Opportunity sent back over

200,000 images.

Revealing a Mars we had never seen before

and confirming something extraordinary.

DERRICK: We can clearly see these wonderful layers of rock.

Sedimentary layers are always laid down in water.

NINA: We call these Blueberries because when we first saw them

we thought they looked like blueberries in a muffin.

DAVID: They were formed out of haematite.

They seem to be telling us of a time when there was

highly acidic water flowing through and over the ground of Mars.

NINA: This is a vein of the mineral, gypsum.

Has a lot of calcium and Sulphur in it.

And it only forms by evaporating water.

It's a mineral that has water chemically bound inside.

This was the smoking gun. We have it.

Water was here and we found it.

NARRATOR: The Black beauty meteorite revealed moisture

in an ancient Martian rock.

And Opportunity showed there were once pools of water

on the planet's surface.

Our next stop is one of the most intriguing features on the planet.

It will reveal just how different ancient Mars must have been.

(beeping)

1,600 miles from the final resting place

of NASA's Opportunity Rover,

is a chasm so huge that it's visible from space...

Nirgal Vallis.

A clue to Mars' former life etched into the rock.

DAVID: It's about 300 miles long.

It's narrower on one end and wider on the other.

We can see these long channels, like a tree,

all connected to a single trunk.

MELISSA: And these patterns they seem to start out of nowhere.

And then they get deeper and deeper as they go along.

And they connect together.

NINA: As planetary geologists we're studying the surface of the planet.

Like detectives trying to understand the history of a planet.

And how it came to be the way that it is today.

NARRATOR: Only one substance has the power to change

entire landscapes in this dramatic way.

KRISTEN: Water has a huge effect.

Chemically it slowly dissolves different components of the rock.

But geomorphically it can just do tons of work.

Water can move rock in incredibly fast ways.

And actually shift entire landscapes.

It leaves a print so you can see these beautiful canyons

carved out by rivers.

NARRATOR: Nirgal Vallis reveals that ancient Mars

was awash with water.

MELISSA: We're not talking about just a trickle of water.

We're talking about full rivers.

Full to their banks, flowing water.

There were oceans.

There were clouds in the sky.

There were rain storms.

There were floods across the surface.

MELISSA: We're talking huge volumes of water

and a whole cycle of water.

Precipitation.

Maybe snowfall on the tops of mountains.

(beeping)

NARRATOR: To cut Nirgal Vallis into the landscape,

would have taken a raging torrent.

A river one and a half times the size of the Nile.

Carrying 4,800 cubic meters of water

every second.

DERRICK: You know Percival Lowell might not have been

that wrong after all.

Although he might have been off by four billion years or so.

But it looks like Mars is a much more intriguing planet

than ever through before.

NARRATOR: But if Mars once looked like this,

where did all the water go?

(beeping)

NARRATOR: Eight hundred miles west of Nirgal Vallis

lie a pair of colossal features

the most spectacular on the planet.

They helped solve the mystery of Mars' missing water.

The first, a gigantic cut

running a fifth of the way around the entire plant...

Valles Marineris.

MICHIO: It is about the size of the United States of America.

It would extend from Los Angeles all the way out to New York City.

It's six miles deep.

It's 150 miles wide.

If you stood on one end you couldn't see the other end

because the planet itself would curve away from you.

It's just incomprehensible how big this thing is.

It's the longest canyon in the solar system.

It's the big daddy.

NARRATOR: Just over the horizon a feature so enormous

it looks unreal...

Olympus Mons.

ADAM: It's the biggest mountain in our solar system.

It's hard not to go there. Right? That's pretty cool.

It rises literally out of the atmosphere.

DERRICK: This volcano was two and a half times as tall as Mount Everest.

JAMES: Rising nearly 90,000 feet above its base.

DERRICK: Since the gravity on Mars is just one third that of Earth,

there's much less gravitational force holding things down.

And this is why Olympus Mons dwarfs anything on the Earth.

NINA: If you were to look at Olympus Mons from the side,

just you know if you were flying past Mars,

you could actually see the bump

above the curvature of the planet.

That's how big it is.

NARRATOR: Both Olympus Mons and Valles Marineris

are giant relics of an epic chapter in Mars' history.

They hold the story of how Mars once lived.

And why it died.

(beeping)

In Mars' infancy, raging volcanoes...

ejected a staggering billion, billion tons

of molten rock from its interior.

This lava formed a vast plateau

that stretched over 3,000 miles.

The colossal mass of this new rock

put huge stress on the surrounding crust.

Literally tearing the planet apart.

Valles Marineris was born.

But with the violence of early Mars...

...came creation.

MELISSA: When volcano's erupted on ancient Mars

they released all sorts of gases that made up the Martian atmosphere.

DAVID: Carbon dioxide.

Sulphur dioxide.

Methane. Water vapor.

This contributes to creating a thicker atmosphere.

And once you have a thicker atmosphere

then you can have water existing on a surface.

MELISSA: There has to be enough atmospheric pressure

to keep water in a liquid state.

Otherwise water goes directly from a solid as ice,

into a vapor.

Having enough atmospheric pressure

is crucial to having running water on a surface.

NARRATOR: But Mars' atmosphere wasn't to last.

And the story of how it disappeared

holds a terrible warning for us on Earth.

Our planet is protected by a force field.

It extends 40,000 miles into space.

But it's generated,

at Earth's very core.

DERRICK: It's really kinda terrifying if you think about it.

We stand on a very thin skin that encloses

essentially a molten ball of iron.

NINA: This ball of iron that is moving

at a slightly different rate than the rest of the Earth.

It's kind of sloshing around in there.

That creates a magnetic field.

That extends tens of thousands of miles out into space.

NARRATOR: The Aurora in our night sky

is much more than a pretty light show.

You are perceiving directly Earth's magnetic field.

It's a manifestation of this magnetic field.

DERRICK: Charged particles from the sun

travel through the solar system at supersonic speeds,

impacting the atmosphere of the Earth.

If we didn't have the magnetic field to deflect those around the Earth,

it would just slowly strip away

all the pieces of our atmosphere over time.

GRUNSFELD: The atmosphere, you know,

is just this tiny thin blue line.

Barely big enough to see.

And everything that lives on Earth

is dependent on that thin blue line.

It really makes you think how fragile our existence is.

NARRATOR: In the deep past

an Aurora also danced across Martian skies.

But Mars couldn't hold on to its precious force field.

About four billion years ago,

a terrible chain reaction began.

NARRATOR: Just like Earth, ancient Mars' magnetic shield

protected its atmosphere

and allowed water to exist on its surface.

But it wasn't to last.

MELISSA: The smaller you are the faster you lose heat.

It's simple physics.

DAVID: Think of if you take a bunch a bunch of potatoes

out of the oven.

The tiny little mini potatoes will cool off very quickly.

And the large ones will take much longer.

Mars being half the size of Earth,

lost its heat faster than Earth has lost its heat.

As the planet cools the churning and the interior

starts to slow down and stop.

NARRATOR: Mars started to die from the inside out.

The protective force field began to falter.

The solar winds stripped away the atmosphere.

Volcanoes fell silent.

Gases no longer replenished the skies.

The planet's water evaporated into space...

killing Mars.

(beeping)

Today there are only two places on Mars' surface

where water can still be found.

They're the next stops on our journey.

The planet's most spectacular and alien landscapes.

Its poles.

Mars has two polar caps

and each has their own distinct personality.

The Mars North Pole is like this beautiful

hockey puck of ice about the size of Greenland.

It's 600 miles wide and 1.2 miles deep.

TANYA: The northern polar cap of Mars

has these amazing dune fields.

And these striking cliffs that skirt along the outside.

We've even spotted avalanches in progress.

NARRATOR: At the other end of the planet,

the landscapes are even more breathtaking.

The south polar cap is over two miles thick.

That's a lot of ice.

MELISSA: The polar cap forms these incredible

swirling patterns in whites and oranges and reds.

It reminds me of orange sherbet or a dreamsicle.

TANYA: There are these bizarre kaleidoscopic patterns.

JAMES: Areas where some of the landscape has disappeared,

the holes.

Other places where it's built up as rings.

It almost defies words.

It's Ansell Adam-esqe but not terrestrial.

NARRATOR: Some volatile force must have shaped this

fantastical terrain.

But it can't be the water.

It's so cold here that it remains eternally frozen...

like concrete.

So what is it?

The answer lies at the edge of the ice cap.

And its revealed by HiRISE.

NINA: We can see here that these are really

strange little starburst features that radiate out from the center.

And so for obvious reasons we call them spiders.

NINA: It turns out that Mars has seasons

just like the Earth does.

So as winter approaches in the southern hemisphere of Mars,

the temperature basically plummets.

We get things like frost and snow. But with a difference.

This isn't water snow.

It's actually snow made out of carbon dioxide or dry ice.

It's alien yeah.

I mean we don't see anything like that on Earth.

NARRATOR: For the duration of winter

temperatures never climb above minus 190 degrees Fahrenheit.

The entire polar region,

water ice cap, and surrounding planes

is covered in a thick layer of dry ice.

But as the spring comes,

things start getting a little bit interesting.

As the sun returns the dry ice begins to melt.

But it doesn't form a liquid.

It actually goes straight to gas.

So you start building up pressure because you're making more gas,

but trapping it inside of this ice layer.

And so you're building up, building up, building up pressure

until that one point where the pressure just increases so much

that it just explodes.

And that aftermath of that explosion are these dark streaks

that we see on HiRISE images.

NARRATOR: Carved into the surface by exploding jets of carbon dioxide,

each one of these strange spider formations

took 10,000 years to form.

And it's the same force, carbon dioxide,

changing from gas to dry ice to gas

that makes Mars' poles

so beautiful and bizarre.

They're both completely alien landscapes.

And it's quintessential Mars.

It's alien Mars.

NARRATOR: Exploding poles.

Scarred frozen planes.

A planet stripped of its atmosphere

and blasted by solar winds.

The idea that Mars could ever support life might seem hopeless.

But we now know that billions of years ago,

when the first life forms appeared on Earth,

the two planets were much more alike.

And if life emerged on our world,

why not here?

(beeping)

NARRATOR: As afternoon turns to evening,

we head towards the Marian Equator.

To a place where since 2012,

NASA has been on an audacious mission.

In Gale Crater right now,

a high-tech Rover is hunting for the very ingredients of life.

-MAN (indistinct over PA) - (cheering)

ASHWIN: The night that we landed

I saw my engineering colleagues across the room,

jump up and down in their chairs.

And you know some of them begin to cry.

And for me of course, I felt all those same emotions.

But then it, all of a sudden it hit me that now there gonna

give us the car keys and it's really up to us as scientists

to fulfill the promise of the whole mission.

NARRATOR: Three and a half billion years ago

Gale Crater was filled with water.

Today it's a dried-up lake bed.

But it conceals clues

to just how habitable Mars might have once been.

Combing its surface is a one ton mobile science lab.

The only Rover at work on Mars today...

NASA's Curiosity.

DIANA: Curiosity's an incredible rover.

It is an SUV size, laser beam eye robot

that is going around Mars, trying to figure out

if there was the environment to sustain life at some point.

When I describe it that way it just sounds like

I am talking about science fiction.

MELISSA: Curiosity is a huge beast of a rover.

Six-wheel drive, stands seven feet tall.

She's powered by plutonium that gives her a quantum energy source.

She can run for years.

Dust storms that kill rovers don't touch Curiosity.

GRUNSFELD: Curiosity is so big

that we can see it with HiRISE in great detail.

We can see the body, we can see the wheels,

we can see the wheel tracks.

NARRATOR: Alongside its serious science kit,

Curiosity has no fewer than 17 cameras.

It can even take selfies.

ASHWIN: We designed these rovers

to act like our human surrogates on Mars.

They have eyes that are about six feet off the ground

and they take color pictures that have the same wavelengths as our human eyes.

All this is designed to put a human virtual presence on Mars.

NARRATOR: Using half a million images taken by Curiosity and Mars' orbiter's

NASA has rebuilt Gale Crater...

on earth.

DAWN: I feel like I have been on the surface of Mars.

The images and the topography

fills your mind and you get lost in this virtual world.

It's just so interesting to actually use data

to transport yourself into another environment,

onto another planet.

NARRATOR: But this isn't just for fun.

Curiosity is far more than a mobile camera.

Dawn uses the virtual world...

to choose the most promising places for the rover

to deploy its high-tech toolkit.

At its heart Curiosity is a chemical laboratory

that we've landed on the surface of Mars.

She's got a laser ablation spectrometer,

which is a laser to zap rocks.

You know, we can drive round and say, wow,

that looks interesting, 'zu', 'pu', what's in there?

And what that allows us to do is to see what Mars is made of.

DAWN: Curiosity is designed to take the powder and heat it up

and then it smells the chemicals that--that come off

and those chemicals will say something about what's inside the sample.

It doesn't tell us everything we want

to know but it gives us some really nice clues.

NARRATOR: In 2014, Curiosity astonished the world

with the biggest breakthrough yet,

in our search for extra-terrestrial life.

What we found was organic molecules in mud stones.

NARRATOR: Organic molecules are complex molecules containing carbon,

the ingredients that make up all life on earth.

JAMES: Those molecules are clues.

We can't quite decipher exactly where they came from

but they're so hopeful that there could be

part of the record of what might have been ancient life on Mars.

The biggest overall find is that Mars was a habitable planet

and we didn't know that before Curiosity went there.

NARRATOR: Water on the surface,

organic molecules in the rocks.

For at least a billion years Mars had everything

life needs to get started

and yet the final proof remains just out of reach.

ASHWIN: What we have not found is that life ever took hold,

ever made use those great conditions that Mars provided.

NARRATOR: So strong is our desire to find that life on another planet

that we have overreached before.

The experts are saying tonight

that they have, quote,

"reasonable evidence of past life on the planet Mars."

NARRATOR: In 1996,

NASA shocked the world.

Inside a meteorite from Mars, found in Antarctica,

they discovered bacteria shaped structures.

While the evidence may be

just microscopic and perhaps millions of years old,

today they displayed the rock that has rolled back years of findings

and has made science fiction a reality.

NARRATOR: The whole world was asking,

was this really life from Mars?

If this discovery is confirmed

it will surely be one of the most stunning insights into our universe

that science has ever uncovered.

NARRATOR: But the dream soon began to fracture.

People started interrogating and then doubting.

It was so hard to prove the morphology,

the shape of what we thought we were seeing

was actually made by life.

AMY: This isn't something obvious like digging up a dinosaur skull.

This is a microscopic bacteria billions of years old.

We don't know what this is.

NARRATOR: The strangest puzzle was the size of the shapes in the rock,

smaller than any life ever recorded on earth,

smaller than life could ever exist

or so we thought.

(intense music playing)

NARRATOR: Today, one scientist's work

is making us rethink the search for life on Mars.

(intense music playing)

This is Dalol, Ethiopia,

one of the most hostile places on earth.

Here, volcanic forces

create conditions very similar to those on ancient Mars...

and that attracts astrobiologists

like Felipe Gómez Gómez.

FELIPE: There is a heavy smell in the air.

The water coming out from the chimneys

can be higher than one hundred degree Celsius.

Salinity, it's practically saturated in salt.

The water pH

is more acidic than a car battery.

Early Mars was quite similar to this kind of environment.

MAN 2: You don't want to put your hands into that.

No, it would be burned.

Yeah, I know.

NARRATOR: Inside these samples,

Felipe has uncovered something no one was expecting.

(speaking in native language)

(speaking in native language)

These are microbes?

Yup. The bacteria.

These were found in Dallol, in the pools of Dallol.

Wow.

Living inside the salt, interacting with the salt.

Multiplying themselves and colonizing

this really extreme environment.

So you are telling me these things are alive?

They are not fossils of bacteria?

Exactly, they are bacteria and they are alive.

They are growing.

NARRATOR: The very things that make this environment

so dangerous to us

make it perfect

for primitive lifeforms to get started.

So they eat the salt?

They eat the salt.

They are able to take the energy, the power supply from the minerals.

NARRATOR: But the breakthrough

isn't just that bacteria exist, it's also their size.

They are twenty times smaller than the regular bacteria.

It's nanobacteria.

NARRATOR: The bacteria are about the same size

as the mysterious shapes found in the Antarctica meteorite.

This extreme environment is like Mars was four billion years ago

at a very early age of Mars.

And if there is life here, who knows that probably

could be possible to find similar life on Mars.

(speaking in native language)

NARRATOR: The discoveries of extreme life on earth

have reignited our hope...

of finding life on Mars

and that's exactly what NASA's next mission will attempt to do--

Dig for alien fossils.

(beeping)

2,400 miles west of Gale Crater

is the site targeted for the search.

It will make Mars 2020 NASA's toughest mission yet.

Jezero Crater is a rugged, cracked landscape,

with jagged channels carved through the rock.

Scientists now know this is the fossilized remains

of a giant river delta.

On ancient Mars

this would have been the perfect place for life to thrive

and Jezero also has the perfect conditions

to preserve fossils of it to this day.

MAN: Over time, sediment builds up, layer after layer.

WOMAN: Any life forms present or organic molecules

would have been concentrated in those layers of mud.

It's a layer cake of stories in the record of the rocks.

DAVID: Buried treasure that's been sitting there,

waiting all these billions of years now

for us to go and dig it up and see what's there.

NARRATOR: But the best place for hunt for life

is the toughest place to land

and in February 2021

that's exactly what NASA will attempt to do.

NAGIN: Of course, if it was entirely up to the engineers

we would pick a completely flat place with no rocks

and no winds and the scientists would immediately say,

well that's super boring.

ADAM: This mission, it's a big deal.

It's the most ambitious mission we've ever attempted,

so for 2020 we will take the rover and put it in places

that would be unthinkable for Curiosity

or the airbag landings of history.

NARRATOR: Unlike on previous missions,

this landing site will be full of rover killing hazards.

But NASA has a new trick up its sleeve.

NARRATOR: Every mission to Mars has faced one huge problem.

It takes 20 minutes to get a signal back to earth.

So engineers can't guide the spacecraft from their control room.

But Mars 2020 will have a super power.

It will be able to navigate itself.

ADAM: For Mars 2020 we took the landing system

that we'd used on Curiosity and we added a very important feature,

an ability to tell where it is on Mars.

NARRATOR: For this mission,

the engineers from NASA's jet propulsion laboratory

have harnessed the power of HiRISE.

They have used its images to build a map of the landing site

in incredible detail.

We've used HiRISE to help us understand the dangers

that the terrain might provide.

NARRATOR: Mars 2020

will compare the map with what it sees on the ground.

Then it will zero in on its target.

Retro rockets will guide this $2.5 billion rover

safely to the surface.

(whirring)

Once on the ground Mars 2020 will carry out its simple

but awe-inspiring task,

to burrow into the planet's surface,

searching for fossils of Martian life.

DIANA: Is there life or was there life on the surface of Mars?

It can't get more fundamental than that.

I can't imagine a Mars that wasn't alive in some way.

If Mars 2020 can answer that question

I think that we can drop the mic at JPL and just walk out of the lab

because we had just answered the most fundamental question of human history.

NARRATOR: As these robot pioneers hunt for life on Mars,

we are laying the groundwork for the next great challenge--

sending human pioneers to join them.

BRIDENSTEIN (over PA): The moon is the proving ground,

Mars is the horizon goal.

WOMAN (over radio): We have ignition of

NASA's space launch system solid rocket motor,

powering us on our journey to Mars.

NARRATOR: Engineers are racing to develop the technology.

ELON (over PA): Do you want the future

where we become a space faring civilization

and are out there among the stars

or one where we are forever confined to earth?

Space exploration, a tough but not impossible thing.

NARRATOR: The first humans who will set foot on Mars

are already among us.

MAN: We intend to send her to Mars one day, folks.

NARRATOR: But this mission will be together than anything

we've ever attempted.

There are two giant hurdles.

First, you have to get there.

There's really no shortage of challenges

when it comes to getting humans to Mars, (stammers) not on Mars,

just to Mars.

ADAM: The navigation is hard.

A little bit off and you will burn up because

you're coming in too steep and then come in too shallow

you'll skip off into the solar system

and orbit the sun forever and be dead.

LUJENDRA: It takes about seven months to get to Mars.

Once you get on Mars you have to be there for two more years

before you can take the return flight back to earth.

WOMAN: You're going to have a kind of cabin fever

that's--that's unprecedented.

NARRATOR: When you finally arrive on the planet

you have to survive in terrifying conditions.

Unbreathable air,

extreme cold, toxic dust.

And an unseen danger that even spacesuits offer

little protect against.

Deadly radiation.

It seems an impossible problem.

But the planet also offers a solution.

(beeping)

NARRATOR: Just 350 miles west of Jezero Crater,

where Mars 2020 will hunt for alien life,

we return to Syrtis Major,

where we first thought we saw it.

And here, where our journey began,

we find the key to living on Mars... ourselves.

DAVID: Every once in a while, we come across one of these

sort of strange snaky, snake like forms.

And this is in terrain that's incredibly flat,

highly cratered.

We're pretty sure these features are lava tubes.

NINA: Lava tubes form near volcanoes

as lava is flowing out through fractures.

TANYA: And eventually that kinda drains out

and it leaves these caverns behind.

ABIGAIL: Sometimes we can see holes punch through these features

and these are dark holes

and when you look down you just see darkness.

NARRATOR: No human invention has yet cracked the radiation problem.

But these underground wonders might just be our salvation.

Deep in the mountains of northern Spain

a team of scientists is exploring how we might survive

in Mars' lethal environment.

JOSÉ: I believe what we're going to do on Mars

will be incredible.

But it is not easy.

We evolved on planet Earth

and our biology is accustomed to this planet.

CARMEN: If you would live on Mars for longer time,

even wearing the spacesuit,

the radiation would definitely be deadly.

We need to go underground and obviously

the deeper we are

the more protection we will have from radiation.

Some of these caves are really, really long.

They could be several kilometers long,

so we could go deeper and deeper and create a habitat for us to live.

NARRATOR: Here, in its own version of a Martian lava tube,

the team can find out what this subterranean life

might be like.

You lose track of time really because

you don't have any day or night.

You're in a confined environment,

in an extreme environment,

which makes it very challenging.

We need to be independent in every way,

not just psychologically independent

but in terms of food, materials, resources, energy.

This would be our home on planet Mars

and we need to create an environment for us to survive and to thrive.

NARRATOR: Lava tubes will provide a readymade shelter

for the first intrepid pioneers.

And experts believe

they could also be sites for longer term settlements.

Some may even be large enough to fit whole cities inside.

JOSÉ: We live between the last human single planetary generation

and the first multi planetary generation.

Once we colonize Mars we will change history,

we will change the future.

NARRATOR: And it may be, in these lava tubes,

that the quest that has driven our interest in Mars for centuries

finally comes to an end.

Those same conditions that will keep us safe underground

might, for billions of years,

have kept something else safe too,

living Martian life.

DAVID: Because of the tremendous radiation bathing the surface

any lifeforms that are there today

are gonna be buried under the surface.

This is a whole new place for us to explore on Mars

and, in particular, it's one of those places

that seems like it could be a really good habitat

for any extant Martian life, should it exist.

NARRATOR: Our day on Mars is coming to a close.

The sun is setting over the dunes of Syrtis Major.

Once this place made us dream of an earth like world,

but our journey has revealed Mars' story to be

more astonishing than anything we could have imagined.

And now, at last, it's almost within our reach.

NINA: Mars is like my second home.

I would love to go visit.

It is magnificent.

(explosion)

ADAM: I used to dream about being the first person to climb Olympus Mons,

the biggest mountain in the solar system,

plant the flag on top.

DERRICK: Mars makes us redefine who we are

and what are connection is to the universe.

JAMES: Would I go? Of course, in a heartbeat.