Original subtitles

The Earth, home to millions of species.

But what might live... beyond?

Astronomers have discovered thousands of planets

outside our solar system.

They believe there are trillions more.

If life exists on only a fraction of them,

then the universe must be... alive.

All living things have the same needs.

To feed...

reproduce...

and evolve.

By applying the laws of life on Earth

to the rest of the universe...

it's possible to imagine

what could live...

on alien worlds.

Being an astronomer, it's sort of like being a human conversation piece.

There's two questions you always get. The first is "What's inside a black hole?"

And the second, which is the one people are really interested in,

is "What about life elsewhere in the universe?"

And then, you know, almost always, we come down to this place.

Area 51 is a secret U.S. Air Force base.

Its existence was only officially recognized in 2013.

So, what really goes on back there?

Well... nobody knows.

Of course, some people think they know.

The believers, the... the conspiracy theorists,

they think that that's where all the alien bodies are.

All the dead aliens in the crashed spaceships are taken somewhere back there

and they're held in refrigerators or "defructinators,"

or whatever technology you need for an alien body.

And, you know, that's essentially where all the secrets

that we're not allowed to know about are being kept.

This is footage supposedly showing an alien body

being examined at Area 51.

But the video is a hoax...

perpetuating the idea that aliens are among us.

The reason why most ufology sounds like a science-fiction story is,

it is a science fiction story.

But, you know, in spite of the silliness of ufology,

I do believe that there is other life in the universe.

And, as a scientist, um, I... I... I'm taken to that belief,

because I really believe that's where the numbers now are leading us.

A couple of years ago, a colleague and I

tried to take all the amazing data that we now have,

and we wrote down an equation

that allowed us to calculate

the total number of planets out there that might have civilizations on them.

Essentially, what we found was that there were ten billion...

trillion...

planets out there...

in the right place where life, and possibly, civilizations could form.

Every one of those planets is essentially an experiment.

And for none of them, other than ours, to turn out with a civilization...

that's pushing it quite a bit.

If alien civilizations are statistically so likely,

why haven't astronomers found any sign of them?

Where is everyone?

Think about it this way.

Out there in the Pacific Ocean, there's 187 million billion gallons of water.

Now, if I take this bucket here and throw it over...

and then haul up,

see what's in it...

All righty. What do we see?

Nothing.

Should I take the fact that I don't see any life in my bucket

to tell me that there's no life in the Pacific Ocean?

Well, that would be crazy, right? There's all kinds of life out there.

There are sea otters, and whales, and octopuses, and jellyfishes,

and God only knows what's out there.

They're just not in this bucket.

That's why this is a perfect metaphor

for the search for extraterrestrial intelligence.

Every time we look at an individual star,

that's like dropping a bucket in the ocean.

We're going to have to look at a lot of stars,

and we're gonna have to search through a lot of data...

until we find the clue that leads us to another civilization.

What sort of alien civilizations might exist in the vastness of space?

Imagine a planet nine billion years old,

twice as old as Earth.

Old enough that a truly advanced intelligence could evolve.

This is Terra.

It was once a fertile world.

Now, it is barren.

But life can still thrive here...

in artificial domes.

Plants convert sunlight into glucose energy...

which feeds the inhabitants of Terra.

Each box contains the brain matter of a super-intelligent being.

Over time, they've evolved not to need their bodies.

They exist only as neural tissue.

They never age. They never die.

They're monitored and maintained by robots.

Each is an individual.

But they're connected to think as one.

A hive mind.

This is a hyper-advanced civilization.

On Earth, humans are the only species to have created any form of civilization.

Why haven't other intelligent creatures done the same thing?

The octopus is as close to an alien intelligence

as exists on our planet.

Octopuses belong to a group called cephalopods.

And they have evolved down a completely different pathway.

The octopus has separate nervous systems in each of its arms.

So, each arm contains about 14 million neurons.

And each arm can make independent decisions.

So the octopus can be said to have, essentially, nine separate brains.

I kind of wanna reach out and touch him.

Lego toys are quite hard to get apart.

But we're curious to see if he's gonna be able to open them.

Octopuses are clearly smart.

But being smart isn't enough to form a civilization.

The key is cooperation...

sharing ideas...

passing down knowledge from one generation to the next.

Our culture is constantly improving.

We keep building on each other's inventions.

All right.

Take this taxi, for example.

Wheels were invented more than five-and-a-half thousand years ago.

Iron has been smelted more than four-and-a-half thousand years ago.

Vulcanized rubber has been used for tires since about 180 years.

So, all of these inventions were necessary

to actually build something as complicated as this car.

An octopus, by comparison, has to pretty much figure out everything for himself.

There is no improving and building on previous solutions.

And that's pretty limiting, even if you have nine brains.

Civilizations are like living organisms...

with millions of connected parts.

It's this connectivity

that allows them to grow.

But the civilization on Terra is in peril.

Its star is double the age of our own sun.

And as stars get older, they burn bigger and brighter.

Eventually, the planet Terra will be incinerated.

So an escape plan is underway...

to colonize another planet in the same solar system...

further from the star than Terra.

There's ice on this world, but no atmosphere.

It needs to be manufactured.

This is engineering on a planetary scale.

Giant machines melt the ice caps

to release vapor and gas...

generating enough atmosphere to warm the planet.

Such a massive project requires a massive amount of energy...

delivered directly from the aging star.

The ability to harness energy is the bedrock of civilization itself.

Part of what I do is to try and predict the future.

And you can look back in history and get a lot of ideas from there,

but there are underlying trends we can use to some extent to see what's to come,

like life expectancy, wealth, population size.

And one of the most revealing is the amount of energy that civilizations use.

The more energy a civilization can access,

the more powerful it becomes.

That's the secret of progress...

from the Stone Age until today.

So, unleashing the heat and energy in charcoal

allowed us to get temperatures hot enough to smelt metals

to make tools and weapons.

Later on, of course, we harnessed fossil fuels like coal and gas,

allowing the creation of vehicles that could hurtle us across the world

at much higher speed than we ever had before.

But the greatest source of energy is, of course, our star.

The Noor Power Station is the largest solar complex of its kind in the world.

Half a million mirrors at the edge of the Sahara Desert.

The ones over here are heliostats,

and they track the sun as it moves through the sky

and focus all its energy down on that tower.

And that energy goes out into the world

and powers modern civilization.

More and more of our transport,

our lighting, our agriculture.

Very relevant for here, air conditioning.

Basically, everything that keeps us safe,

working and entertained comes from electricity.

And more and more of that electricity

is coming from solar power plants like this.

But humans use only a tiny fraction of all the energy available from the sun.

So, 430 quintillion joules of the sun's energy fall on the Earth every hour.

For comparison, that's very roughly 2,000 Hiroshima bombs every second.

A lot of energy. How much do we use?

Well, humanity uses 410 quintillion joules... in a year.

So, in a year, we fail to use

all the energy that the sun sends us in a single hour.

Imagine if we could capture all that energy

and use it to power our civilization.

What miracles could we accomplish?

What places could we explore with all that?

According to astrophysicists,

any truly advanced civilization will be able to harness all its energy...

directly from the stars.

By this measure, the civilization on Terra is supremely advanced.

It has built solar panels in space,

near to its star...

for maximum effect.

But as the star becomes bigger and brighter...

it also becomes more volatile.

A solar flare.

Sooner or later, this will be the destiny of Terra itself...

to be swept away by the power of its sun.

The solution is to colonize the new planet as quickly as possible.

There are no life forms here.

All the work is done by machines.

They're able to think for themselves and make their own decisions.

They are artificially intelligent.

If humans are to form colonies in space,

the groundwork will be done in the same way...

using robots.

And those robots will be designed

by people like Philip Metzger.

He has spent his whole life in and around the space program.

My father used to work in this building,

and he helped build the Saturn V rockets

that were large enough to take humans to the moon.

Apollo 11, this is the launch operations manager.

The launch team wishes you good luck and Godspeed.

Ah, thank you very much. Know it will be a good one.

I'll never forget the Apollo 11 flight.

I was seven years old.

I was across the river during the launch, watching it.

There were helicopters flying around.

People had come from all over the world,

coming to watch the moon launch.

It was electric.

Astronauts report it feels good. 20 seconds and counting.

T minus 15 seconds, guidance is internal.

Twelve, eleven,

ten, nine...

Ignition sequence starts.

six... five... four...

three... two... one...

zero.

Liftoff!

We have a liftoff.

As it climbed into the sky, you could see that long, beautiful flame

shimmering across the water.

We got skirts-up?

Roger, we confirm skirts-up.

So, I grew up wanting to be a rocket scientist, my entire life.

Philip became a NASA scientist.

But rather than sticking at rocket design,

he moved into robotics.

If we ever really want to do anything fabulous in space,

we need robots.

RASSOR is designed to work in tough planetary environments.

It can climb over rocks.

If it gets stuck, it can get itself unstuck.

If it flips upside down, it can flip itself over.

In any situation, it can get itself out of trouble.

The simplest thing that we could mine on a planet is the regolith,

the dirt that covers the planetary surface.

You can extract metal from the regolith.

You can also make ceramics that are used for insulating electrical systems.

And you can make rocket fuel.

But mining does take intelligence.

You have to know where to drive, where to cut.

You've gotta keep from getting lost, get yourself unstuck.

So it's going to take a clever machine like RASSOR

to be able to start industry in space.

The Holy Grail of robotics is self-replication...

a machine that can make copies of itself.

This is a spare wheel for RASSOR.

A robot part made by a robot for another robot, using space materials.

But this is an early example of how we're evolving the robots

toward a fully closed ecology of robots that can self-reproduce in space.

Once you've got self-reproducing robots, everywhere is a place you can go.

I don't think there are any limits.

Without input from any life form,

the robots are re-engineering a planet...

making it ready for colonization.

Now, it's time to abandon Terra.

Each of the domes has been designed for this moment...

to get into orbit.

From here, they will travel to their new home.

The domes have their own life-support systems.

But they're helpless

against a high-energy burst of solar radiation.

Nothing is evolved to survive in the vacuum of space.

This is as true for aliens as it is for humans.

Michael Foale knows all about the dangers of space travel.

In 1997, he was a guest American astronaut on the Russian Mir space station...

during the first collision in space.

There was, uh, an attempt by the Russian commander, Vasily,

and his crewmate to control a cargo ship that weighed seven tons,

and dock it without the radar,

without speed, without distance measurements...

Dock it to our space station.

I felt the station...

I didn't "felt" it, I saw the station move all around me and I heard a thud.

And at that point I thought, "Mm... This could be it, you know, where I die."

Uh, 'cause I'm looking at all these bolts

and I was just waiting for those bolts to part,

and to, kind of, rip open and just see the vacuum of space.

And then, all the fans, all the lights,

all the computers failed and went silent.

And now we're in a completely silent station

that's getting cold.

We've lost power.

Pressure is at 602.

And then my ears started to pop.

I knew we were depressurizing,

and that basically, air was leaving the space station,

and we only had 23 minutes left to live,

if we stayed there and we didn't stop the leak.

I started helping Sasha pull these cables out.

Huge cables I thought would have taken us hours to undo,

we did them in six minutes.

And we'd take this cap and we'd put it in and it sucks in, and it goes... "pew."

And at that point, we've stopped the leak.

And it was there in front of the window, looking at the galaxy...

I said...

"Well, I know it's been a really bad day, but this is an amazingly beautiful view."

You're kind of sensing, trying to sense all of the, uh...

The presence in the... in the universe.

In total, Michael Foale went into space on six missions.

Oops, more hair going away.

But every second spent off-world

increased his dose of radiation.

We're exposed to radiation on Earth,

but once you go into orbit,

now you're exposed to thousands of times more radiation.

And that radiation now is damaging our DNA much faster,

and the repair mechanisms that we evolved to have

are not able to cope with it.

When I came back from my space flights,

they found I had, like, four percent of my white blood cells had DNA mutations.

Most of those mutated cells get killed by other white blood cells in your body,

but, some of them, unfortunately, don't die.

They reproduce and mutate and become cancers.

That is a fundamental risk for astronauts.

And if we imagine going out to stars,

it could be that, out of a hundred ships, only one of them makes it.

Long-distance space travel will always be risky...

even for intelligent aliens.

There's no protection against a sudden blast of stellar radiation.

But for those that make it to the end of the journey,

this is their reward...

a new Terra.

Rather than adapting to a different world,

they have created a copy of their old world.

Such are the benefits of an advanced civilization.

But how long will the good times last?

The star keeps growing, bigger and brighter...

spitting out more radiation.

Eventually, it will render the new planet as lifeless as Terra.

And then they'll need to relocate again,

to another planet, further from the star.

This is the advantage of being mobile.

It's possible to transit from world to world,

making and remaking home.

Perhaps there's an alien civilization already headed for Earth.

If so, should we hide from them,

or make ourselves known?

Okay. Um...

Let me... Let me end by saying...

Let me close by telling you why we should begin transmitting

and why we should begin right now.

Doug Vakoch wants to open up a dialogue with potential aliens

by sending them radio messages.

But first, he needs to persuade astronomers on Earth

that it's a good idea.

This is where it all started.

The biggest radio telescope Earth had ever seen.

There's something about being here,

the awesomeness, the scale of the place.

This is where, in 1974, we sent humanity's first message into space.

It starts by these pulses that count out the numbers from one through ten.

Then after we've shown extraterrestrials how we count,

we use those numbers to describe

some of the chemical elements essential to life on Earth.

And then after that...

what we look like,

how many humans there are,

how tall we are.

Then after that, a representation of our solar system.

And then it ends with a representation of this telescope itself,

where the message came from.

The pulses of the Arecibo message

could be arranged into a pictogram

to inform intelligent aliens about life on Earth.

But it was a one-time event,

aimed at a star cluster 25,000 light-years away.

If we'd been sending messages to nearby stars

at the same time we sent out the Arecibo message,

we could be getting responses today from any of thousands of stars.

But we haven't, and so we're in the dark.

The biggest reason we haven't sent more messages is because we're afraid.

Because the blockbuster science-fiction films

show aliens coming to Earth and annihilating us...

and so that's what we think would really happen.

I think the... the most prominent challenge is the concern that some people have

that transmitting intentional messages, uh, will lead to an alien invasion.

And I think the easiest response to that is,

our planet has been giving off evidence of life for two billion years.

So, if there are any really paranoid aliens out there

who want to annihilate any competition,

they've had a long time to come here, and I haven't seen 'em.

Rather than sending an occasional message into space,

Doug's plan is to transmit thousands of them...

when the Arecibo telescope is on downtime.

With radio astronomy, you can do it any time of the day.

But... I like to do it at night.

Caffeine is essential for astronomers. Um...

A lot of late nights in the observations and we have to stay sharp.

Once a month, Arecibo does a survey of recently discovered asteroids.

Quite often there's a gap, maybe an hour,

where the transmitter is transmitting off into space at no particular place.

What I'm proposing is that Arecibo should use those gaps in the schedule

to target nearby stars with a message,

in case there are any extraterrestrials in orbit around that star.

Each month, we could be targeting about 50 stars

that may support intelligent life.

And for me, it's a no-brainer. I think we should be doing it.

I think of this in terms of what's sometimes called

"joining the galactic club."

And what I find so strange about that analogy is that no one ever talks about,

um, paying our dues or even submitting an application.

And that's what messaging extraterrestrial intelligence does.

It may just be our way of making first contact.

Thanks.

Thank you very much to Doug for this interesting presentation.

When we reach out to other stars, when we send them our messages,

in the best-case scenario, we get a reply back in 10 or 20 years.

But realistically, it could take thousands of years.

So this is something that we're doing,

not for ourselves, but for our children, for our grandchildren.

And even for the aliens.

Eight, seven, six,

five, four, three,

two, one.

Mission liftoff.

Switching down range.

In 2018, the latest planet-hunting telescope went into orbit.

It is finding evidence of new worlds

across the night sky.

Astronomers think it's only a matter of time

before some alien life forms are discovered.

Among them, perhaps, intelligent beings.

One day, we will know for sure.

Until then, we can only guess at who or what is out there.