Original subtitles

CHRIS: From on board the spaceship, you can see the world has a secret.

At dawn or at dusk, where the shadows are lining up just the right way,

you're at just the right place in time to see an asteroid crater.

Where a bullet from the universe left a perpetual hole in the smooth surface of our planet.

There are a billion years worth of impacts.

Huge asteroids have smashed into the world, and turned it into an enveloped fire.

Uninhabitable to almost all life on the surface.

The world will get hit again.

It's just a matter of when.

So, what should we do as a species?

Should we just, like the dinosaurs, look up and die?

The reasons the dinosaurs are extinct is they didn't have a space program.

We do.

We have the capability to perhaps escape the Earth.

NARRATOR: Escaping Earth?

Leaving home is hard at the best of time.

Imagine how hard it would be if you were never coming back.

Not just back to your home town, but your home planet.

WILL: A one-way ticket away from everywhere, everything and everyone you know and need.

NARRATOR: 8 astronauts with over 1,000 days in space between then,

can tell us how being up there helped them to understand

why we are going to have to make a choice.

MIKE: Faced with extinction of life on Earth.

Our best chance of survival is to build another colony somewhere else.

LELAND: Having a base on Mars, a base on the moon or in other places,

is important to keep our civilization going.

CHRIS: It's really kinda up to us how long we wanna survive as a species.

NARRATOR: Can we really cut the cord with the planet that made us?

And face the physical extremes and mental torment of space?

WILL: Theanswers are right here on earth.

In some pretty unexpected places.

NARRATOR: Like multi-million-year-old blood.

Mutant bugs.

And humans that had left the land behind.

CHRIS: It is not going to be easy to get ourselves safely away from the Earth

and onto another planet.

People will die.

This maybe what saves us.

WILL: It's decision time on The Rock.

Escape or extinction?

NARRATOR: Earth's been through some big changes.

Ice ages have come and gone...

Volcanoes have blanketed the world in ash.

And all of this could happen again.

In fact, sooner or later, it's going to.

So, if we knew a huge asteroid was bearing down...

Or a giant eruption was about to suffocate the planet...

We'd feel a lot better if we had a Plan B.

CHRIS: To put a human base on another planet, it will involve risk.

It pushes our technology right to the very edge of our capability.

But the benefit is for the whole species.

CAPT. BOWEN: So today, what we're going out there to do is intercept the eclipse.

Really experience the full eclipse since it happens so rarely.

Fly and chase the moon.

You can't do it every day.

At 15 is rated almost up to mach 2.5.

So, our goal is approximately three minutes of time in the shadow.

NARRATOR: Alright, let me break that down.

Luckily, my dad was in the Air Force, so I can do this.

These guys are going to try something they've never done before.

Something that shows how hard it is to go from 1 planet to another.

Everything in our galaxy is moving.

During an eclipse, when the moon slides across the sun...

Its shadow speeds over the air at 1700 miles per hour.

But it's easy to forget that we're moving too.

Our planet spins at 1,000 miles per hour.

To stay in the moon's shadow, the planes have to fly faster than earth spins.

CAPT. BOWEN: 3 3 units, mark ready, ready now.

This is definitely the ultimate intercept.

Chasing the fastest object that we could chase.

If we can do this, we can intercept anything.

Keep it tight, the eclipse is coming.

PILOT: Here comes the shadow out in front of us now.

CAPT. BOWEN: Alright stand by for.

OK.

PILOT: That's pretty cool.

CAPT. BOWEN: 20 seconds.

It's almost like you're in outer space.

As a kid, you know, you always think about astronauts and travelling

to space and circling the moon.

But I never thought of how fast the moon was travelling.

OK 5:30 into the eclipse.

Here comes the daylight.

And it's daytime.

CHRIS: If you're in an aeroplane and trying to chase that shadow,

that's really just a little hint of how hard it is to launch a rocket ship and go intercept

the moon or go all the way out to Mars where everything is moving.

And the Earth isn't just rotating.

It's moving through space at almost 70,000 miles an hour.

While Mars is moving at over 50,000 miles an hour.

It's like grabbing a gun and trying to hit a bullet with a bullet.

We've sent probes to Mars and to Jupiter and to Saturn.

But probes are machines.

Getting people there?

That's a whole other level of difficult.

So before we make that commitment and fire those engines,

we really wanna be sure we know what we're doing.

The natural human reaction to the unknown is fear.

But the greatest antidote for fear is preparation.

Part of the reason I love flight is how it makes me feel.

It pushes me a little bit closer to the limit of my capabilities.

Especially when you're flying an older plane.

Just barely give it a couple of these.

You have to focus, you have to constantly thing about what are the things that are gonna try

and kill me.

Try and predict what the dangers are going to be.

And then try and get ready for those.

Pull her out.

Yeah.

Here we go.

Permanently leaving the earth.

Turning our tail to the planet and firing the engines to go somewhere else,

that is still right on the edge of impossible.

But in 1902, flying was impossible.

But after the Wright Brothers, it was something we knew how to do.

Summer of '69, impossible to walk on the moon.

And then 12 people put their grey, dusty footprints into the surface of the moon.

So I think we'll go from a space station to the moon and eventually onto Mars.

Because it's a necessary thing for the survival of our species.

NARRATOR: They call it a Goldilocks planet.

A world that's not too hot and not too cold.

Just like Earth.

WILL: Until we find it, we're looking at the next best thing.

Life on Mars.

But even if we have the technology to leave our home, do we have the biology?

NARRATOR: Nothing good lasts forever.

Earth is no different.

WILL: If we want to outlast our home, we need to franchise.

Set up an outlet on another planet.

NARRATOR: When we leave earth, we leave behind more than a rock.

Earth is a living planet.

An interconnected web of life.

We are part of it and it is part of us.

WILL: So when we go, what comes and what stays.

CHRIS: One of the final stages of preparation for my third space flight

to fly a Russian spaceship, was wiping my entire body with rubbing alcohol.

To try and get rid of as many bacteria as possible.

You don't want the spaceship to become unhealthy for the people living there.

But bacteria have been colonizing the planet for billions of years.

And they're pretty good at getting everywhere.

To spot them we have to use something else that's survived for a long time.

Horseshoe crabs were alive 200 Million years before the dinosaurs.

And yet, they've turned out to be surprisingly useful in space.

Their immune system is primitive but effective.

So we make use of their incredible blue blood.

When cells in their blood come into contact with bacteria, they instantly release enzymes.

And these enzymes can be used to detect bacteria at less than one part per trillion.

That's like detecting one grain of sugar in an Olympic size swimming pool.

So we can use a tiny spec of horseshoe crab blood to spot contamination.

It's easy to think of the bacteria on my body as some foreign matter that I would like

to get rid of.

But if you look at us under a microscope, we're crawling with life.

There are more bacterial cells in our body than there are human cells.

An entire universe inside me.

The more we study the human microbiome, all of the little microbes that live within us,

and especially when we start thinking about leaving earth, the more we realize,

the bacteria aren't stowaways, they're crew.

And we're going to have to bring some of them with us, when we go to another planet.

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DR. KERR: How far are they, ahead, do you think?

MALE CREW: I would say absolute minimum of two, probably at least three miles.

NARRATOR: We are searching for the world's biggest creature.

The blue whale.

Most species on the planet are totally dependant on their microbiomes to survive.

It's amazing how similar whales and humans are.

Even though we walk on the land and they swim in the abyss,

the same biological mechanisms are in play here.

The reality is, it's very difficult to collect data on whales.

Imagine if an elephant disappeared under the Serengeti and came up five miles away.

MALE CREW: Whale's right over here at ten o'clock.

NARRATOR: Every time a whale exhales, it's throwing up this biological treasure trove.

DR. KERR: Starting engines, clear.

NARRATOR: So how can you collect biological data in a non-invasive manner?

The answer is, snot bot.

DRONE OPERATOR: 30 plus feet, you're just going off for visual?

MALE CREW: Yeah, you're in good shape.

DR. KERR: And I see the whale now. DRONE OPERATOR: OK.

You're right to 16 feet, 16.

14.

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DR. KERR: Alright. She's dived. No words, lovely dive.

Might not have liked that head on approach, but there's no way to know.

As excited as we are with this tool, you've gotta be at the right place at the right time.

OK, so the whale's been doing 9-minute dives.

Let's launch the drone at 8 minutes and then we're ready when it comes up.

Hopefully we'll get the second blow.

DRONE OPERATOR: Looking good, right on track. That's 14 feet.

DR. KERR: They're exchanging a lung full of air, probably bigger than a VW

in one or two seconds.

It's incredible.

DRONE OPERATOR: Staying with it. DR. KERR: What's my height?

DRONE OPERATOR: You're at 14.

DR. KERR: Whale's looking really calm.

Moving very slowly.

Bingo.

Good job team, good job.

Alright, you guys ready for landing, bring her in.

And this is gonna be a snotty dish.

We know bacteria in the stomach of whales is necessary for digestion,

but we're starting to see that the microbiome in the lungs plays a key role

in fighting infection. Just like it does in humans.

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NARRATOR: There's a world of bacteria outside us and a world of bacteria inside us.

WILL: And nobody knows what will happen when those two worlds are pulled apart.

But we know one thing that we can't take with us.

And it's something that keep us all grounded.

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JONATHAN: The feeling in the platform is full of emotion, is fear, pressure, tension.

It's something that you love to do.

Even when you know that you can kill yourself.

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You have only 2.9 seconds. Anything can go wrong.

If you did a mistake in the air...

That's it, it's over.

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CHRIS: We are all intimately familiar with gravity.

The huge mass of the world pulls us down.

We call it 1 G, that's how the world pulls on us.

But we're the only species that has found a way to cheat that.

Perhaps the most magic moment in an astronaut's life is when the rocket ship has done its job.

You are at the right height, you're at the right speed, the engine's shut off.

You're in space and for the first time in your life, you're weightless.

You feel like something is magically pulling you towards the ceiling.

It's just fun to be weightless. And leaves a smile on your face.

You wanna play with it.

You wanna play with your food, you wanna do a thousand somersaults.

You wanna get into a big part so the space station so you could push off the wall

and fly across like superman.

But even as you feel super human, you quickly start to realize just how much

the human body needs gravity.

With gravity, I can tell which way up is.

The weight of my body as I sit down, the weight of lifting my arms.

All of those things constantly tell me which way is up.

But as soon as your weightless...

all that's gone.

And it makes you nauseous.

MIKE: I was feeling terrible when I first got to space.

And I thought to myself, is this really fun?

When you wanna throw up, really nothing's fun.

I did puke on my first day in space.

MAE: When you're on Earth, gravity is pulling all the fluids in your body down.

When you're up in space, there's a major fluid shift.

It feels like you've been standing on your head for about three hours.

CHRIS: Gravity defines how big our heart has to be and what the configuration

of our cardiovascular system looks like.

The whole design of the human body, the skeleton underneath it, the strength of the muscles,

it's really shaped by the gravity of the Earth.

We don't really think about it, but we're constantly weight lifting on Earth.

Holding our head up, holding our body up, fighting gravity.

Without gravity, your muscles and your bones start to waste away.

We have machines that, that we push against and lift against and elastics that hold us

on the treadmill.

Sort of gravity simulations.

But even with the best exercise equipment we've invented so far, I lost about eight percent

of the bone density across my hips and my upper femur.

My skeleton started to waste away.

What do the effects of weightlessness mean for interplanetary exploration?

With that long time in weightlessness have degraded our bodies enough that

we'd be useless when we get there?

We're working on it, but we definitely haven't solved all those problems yet.

WILL: Astronauts.

Their heads swell and they throw up a lot.

You don't see that in the movies.

The truth is, we are a part of this planet.

It is baked into our bones.

Down here we're nurtured and protected.

But when we go, we'll be going it alone.

ooner or later we are going to have to get off plane.

Plan B.

WILL: But the second we step outside the safety of our home, we are exposed.

CHRIS: Our sun is constantly spewing out radiation.

And occasionally there's a huge solar flare, where a big mass ejection

that could threaten life on Earth.

The Earth is protected by a magnetic field in the atmosphere.

And that force field helps deflect the deadly radiation.

And it keeps it from driving right through and hitting our bodies.

On board the International Space Station, we are much more vulnerable.

If the scientists on earth have seen one of these huge storms from the sun coming towards us,

we go to the parts of the space station that have the best protection from the storm

of radiation that's about to pour past.

You're subject to not just the sun's radiation, but all of the radiation of the universe.

A strange thing sometimes happens.

You see a flash of light out of the darkness.

A reminder that you're not in Kansas anymore.

When a star out in our galaxy dies in an enormous explosion that we call a supernova,

it releases a huge amount of energy.

Cosmic rays racing across the universe at essentially the speed of light,

186,000 miles a second.

So fast that those little radiation particles come by Pluto and make it all the way

to the earth in just five hours.

And if you're above the earth's atmosphere,

there is nothing to stop them slamming into your body.

Most of them you're unaware of.

But sometimes one of these little cosmic rays goes through your optic nerve.

And because of the way our vision is designed, it actually reacts like a flash of light.

And what you're actually seeing is radiation going through you.

JEFF: I'd be lying there in my sleeping bag and zap, zap, zap.

One of the best light shows I've ever seen but at the same time, I knew that that meant

that my head was getting zapped by charged particles.

JERRY: And it can be a show stopper, it can be a bombardment of radiation than not only,

you know, increases your chances of cancer down the line.

But literally gives you radiation sickness on the way.

If you're gonna spend weeks or months or years on a space ship,

you have to start considering that this causes mutations.

It overwhelms your body's ability to repair itself.

NARRATOR: So, on our trip to colonize the stars, we know we'll get seriously zapped.

We need to prepare for that.

We can start in a place where the Geiger counter clicks like it would

in a deep space mission.

PROF. MOUSSEAU: Despite the fact that this is a dangerous place,

Chernobyl provides this unique opportunity to examine what happens to the evolutionary

process when you kick it with a little extra mutation.

NARRATOR: Back in '86, I was a senior in high school.

And I remember the nuclear meltdown that caused 400 times more fallout

than the first atomic bomb.

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When the reactor exploded, it was kind of like a volcano erupting.

With radioactive metals being ejected into the atmosphere.

That landed on the ground in a haphazard way, so there are these hot spots.

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You come into this landscape that was once thriving with happy people doing their thing.

It gives you an eerie feeling.

You really have to look around and see what's being affected.

Many of the spiderwebs that were draped alongside some of the houses in the villages

were extremely unusual.

Some of the webs end up looking extraordinarily messy.

They were very irregular. They had big holes in them.

The spiders were having a problem spinning a normal web.

It's not just behavior that's changing.

Some of the creatures are even starting to look different.

And firebugs are pretty hard to miss. f you look at it straight on,

you'll see what looks like an African face mask.

Two big eyes, a nose and a chi.

And because of the symmetry, it makes it very easy to detect deviations.

One of my colleagues picked one up and said, "Look, Tim, it's a mutant."

This one bug was missing one of the eye spots.

So, we starting collecting as many bugs as we could find.

Bugs with really unusual color patterns were only found in these areas of high radiation.

This is more serious than changing your spots.

Mutations can kill you.

Humans in space have a big problem.

WILL: So, mission cancelled? Oh, not so fast.

There might be a fix.

NARRATOR: One of the more striking, unexpected observations

is that some species appear to have adapted.

Some of the bacteria where there have been thousands of generations since the accident

are becoming more radiation resistant.

As a species, humans are interested in expanding our horizons.

Moving into space, moving to other planets.

If we can develop a better understanding of the defenses used by organisms,

that maybe useful in doping ways to protect humans.

Both here on this rock...

As well as in outer space.

A traveler to Mars has to survive 9 months in space and a 30-Million-mile journey.

WILL: But once they get there, they'll face their biggest challenge of all.

And this time, it's personal.

CHRIS: One of my favorite things so see from space is a pace that you know.

You know, somewhere you grew up.

The town you were born in.

Or where you got married or where you went on vacation.

It's a delight to have a memory, like a present unwrapping itself.

The further you get from earth, one of the significant problems is,

how do we mental the mental health of the crew when you're so isolated from the rest of humanity?

NICOLE: We don't really know how difficult it's gonna be for humans to leave Earth.

I mean, we're a part of earth.

JERRY: There you are just removed from mankind and that distance, being off the planet,

you feel a disconnect.

And I'd say, you know, I'm sort of in a prison.

You know, I didn't do anything wrong for sure, but I am in a prison.

CHRIS: If I were the commander, heading to Mars, I would have a talk with the crew and say,

"Earth is now behind us. We are now Martians."

NARRATOR: Have they really been living in this 1,000 square foot done for over 130 days?

After surpassing the halfway point in the mission, I'm feeling utter disbelief.

With the nature of an isolated and confined environment, we are effectively trapped.

HI-SEAS stands for the Hawaii Space Exploration Analogue and Simulation.

We want to know how to keep people safe and happy in space.

Can they stay friends, not go crazy?

Work well together for the two to three years it will take to go to the Red Planet

and back again.

DR. DUNN: Contact.

Testing, one, two, three.

ASTRONAUT: Go with the exit protocol now.

NARRATOR: You begin to think about how harsh it is to live on Mars, all the technology,

all the trouble you have to go through just to go for a walk.

One of the greatest challenges to space travel isn't technical at all.

It's the human vulnerability.

You don't see the ocean, you don't see palm trees.

And you just see this black and red lava.

It doesn't have the different gravity, the real harsh danger of Mars.

But it does have the confinement.

And it has the isolation from your family and friends.

I was surprised by how much the stress affected not just how I felt, but how I performed.

Being away from your family can be tough, even for a week or two.

Life on Mars is an entirely different kind of separation.

You're a pioneer.

You're never going to see home again.

Everything you'll ever own, you brought with you.

The rest? You'll have to use what you find.

Luckily, that's something humans are pretty good at.

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CHRIS: We're already using simulated Martian dust to figure out how to build a settlement,

somewhere besides our planet.

So, we're definitely taking the first step.

NARRATOR: Even if we survive the journey, and make the place feel like home,

we still might not save our species.

WILL: Because just by being there, we might turn into something else.

CHRIS: Life tends to naturally settle where the conditions are best for it.

And from orbit, you can actually see where we have chosen to live.

Those patterns of human habitation repeat themselves.

Some parts of the world are so desirable that there's not enough land to support everybody

who wants to live there.

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We've taken nature and modified it to make the earth more habitable for more human beings.

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We don't really think about it, but we've significantly terraformed earth.

The farmer's fields, the terraces, the dams we've put up.

And when we go somewhere else, we're going to inevitably have to do the same thing.

But at the same time, we are influenced by the environment around us.

That shapes us.

Your body is constantly changing itself and adapting to best perform in the environment

that you put it into.

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NARRATOR: The Bajau live in a world of water.

Their kids swim before they walk.

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No need for goggles or oxygen tanks, their bodies have learned to do without them.

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The differences go deeper.

As children, the lenses in their eyes adapt so their underwater vision is twice as sharp as ours.

Pretty handy when you're hunting.

In the short term, humans can adjust.

In the long term...

We evolve.

Maybe there is a Goldilocks planet out there, another Eart.

If so, we'll be spending lifetimes getting there.

WILL: What might happen to generations born in space?

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CHRIS: One of the ways to test that is to take life forms from Earth that have a very rapid

life cycle and take them up to the space station and see how they develop.

Jellyfish have small sensors, like hairs.

And that lets them know about gravity and which way's up.

Sort of like the balance system we have in our inner ear.

When we took jellyfish to the space station, they did not develop normally.

When they came back to Earth, the ones born in space couldn't tell which way was up.

It's a sobering thought, getting to a new home might change us in ways we can't predict.

I'm confident that no matter what is thrown at us during this incredible journey,

we'll find a way to survive.

But there is a cost.

What we think of as us, can only exist here.

We will no longer be earthlings when we get there.

We will be become aliens.

NARRATOR: Sometimes you can only really see something from a distance.

WILL: No one ever got homesick staying at home.

NARRATOR: Earth has been our constant companion.

WILL: There when the first cell flickered to life, here now as we turn to the stars.

She's in our bones.

And in our guts and in our minds.

NARRATOR: We may one day ventue out from our strange rock.

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WILL: But we'll never get the Rock out of us.

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NARRATOR: Next time.

How our paradise planet was made by life.

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