Original subtitles

♪

NARRATOR: Planet Earth.

Our home.

We are part of an astounding interdependent ecosystem

coating its surface,

containing a dizzying variety of animals and plants.

Life is amazing.

But it seems incredible that life exists at all.

Extreme forces dominate the cosmos.

[explosion]

It could not appear more hostile

to the existence and survival of fragile organisms.

Planet Earth has long seemed a unique oasis

in a violent barren universe.

But groundbreaking science is now challenging this view.

DR. DRAKE: How, when and where

life might have arisen in the universe,

it's probably the most important questions

that modern science can hope to address.

NARRATOR: Scientists are revealing

the incredible alchemy of starlight.

DR. SANDFORD: The UV photons can come in

and break a molecule in half.

NARRATOR: They are uncovering explosive secrets

about the origins of life on Earth.

DR. SUTHERLAND: We were literally gobsmacked

at the results we got.

NARRATOR: And they are detecting telltale traces of life

on other planets.

DR. MCKAY: That's big, that's huge.

I don't see why life wouldn't have started on Mars.

NARRATOR: And as new technology

brings the skies above into ever-sharper focus,

the conclusions are mind-blowing.

DR. BATALHA: When I go out at night and look at the sky,

I don't see those pinpoints of lights as stars.

I see them as planetary systems.

NARRATOR: Many scientists now believe we are not alone.

DR. MCKAY: Earth, and life on Earth, is not unique.

All the clues are pointing in that direction.

[birdsong]

♪

NARRATOR: Life is astounding.

Inside every cell of every plant and every creature

lies a staggeringly complex world

sustained by intricate organic molecules.

DR. MCKAY: The simplest cell on Earth

is the most complicated thing we can imagine.

All sorts of molecular machines working together, processing

information, processing matter, processing energy,

all to ensure the survival and the reproduction

of this little, tiny organism.

NARRATOR: How such complex structures ever came

into existence has long been one of Earth's greatest mysteries.

But 21st century science

has started to look beyond our planet for answers

and come to some incredible conclusions.

DR. DRAKE: The rest of the universe is actually central

to the whole question of the origin and evolution

of life on Earth.

Without the rest of the universe, we wouldn't be here.

NARRATOR: It starts with the universe's building blocks --

atoms.

All giant organic molecules, like DNA, contain countless

atoms in intricate formations, mostly the big four --

hydrogen, oxygen, carbon and nitrogen --

with a sprinkling of heavier elements.

But where do the atoms originate?

And how did they come to form these structures?

It turns out that to uncover the secrets of life

we must track the evolution of the cosmos itself.

13.8 billion years ago,

the universe begins with the Big Bang.

Within a second it cools enough for particles to form.

And within a few hundred thousand years

these particles combine, forming the first simple atoms --

hydrogen and helium.

These ancient atoms are the foundations of everything.

At this early stage of the universe's evolution,

the ingredients do not yet exist

to make even the most basic molecules of life.

And as space expands, these atoms are in danger

of dissipating into the void.

But already they feel the force of gravity.

Under its influence,

everything that matters will come together.

DR. BATALHA: Gravity is a fundamental driver

for the creation of structure in the universe.

The universe was a relatively uniform volume

of hydrogen and helium that was rapidly cooling

because of the expansion.

But the devil's in the details.

There were regions that were slightly over-dense.

And where you had those over-dense regions,

gravity was able to kick in and create

even more over-dense regions

that led to all the structuring complexity

that we observe in the visible universe today.

NARRATOR: Over a few hundred thousand years,

gravity creates spiraling regions so dense

their temperatures begin to rapidly increase.

The swirling gases form huge discs

far larger than our solar system.

Temperatures in their centers surpass 100 million degrees.

And suddenly the first stars are born.

From this moment on, primordial stars appear in the billions

and cast the first light on the universe.

But they will also transform it.

Through a quirk of nature,

stars will generate all the raw materials of life.

DR. BATALHA: Stars are interesting.

They behave in interesting ways,

but they're actually quite simple structurally.

It's a ball of plasma that's balanced by gravity pushing in

and gas pressure pushing out.

♪

NARRATOR: Stars stave off collapse

through the power of nuclear fusion.

Simply put, extreme gravitational pressure in

the core forces hydrogen atoms to fuse into heavier helium,

releasing tremendous energy.

DR. DRAKE: The starlight that we see essentially comes

from Einstein's famous equation -- E=mc2.

Well, the mass of the products of that nuclear fusion

is a little bit less than the mass

of the products that went into it.

And so we have a little bit of mass left over.

And this leftover mass can be converted into energy.

NARRATOR: The energy keeps the star from collapsing,

allowing fusion to continue.

This process now creates all the missing ingredients of life.

DR. DRAKE: Stars are essentially the cauldrons of the universe

where the elements are made.

♪

NARRATOR: Inside the helium cores of massive stars,

totally new elements are now forged.

For the first time, huge quantities

of oxygen, carbon and nitrogen are fused into existence.

DR. BATALHA: Lo and behold, that's exactly the stuff

that our own human bodies are made out of.

We are literally made of star stuff.

NARRATOR: The most massive stars continue to create

heavier and heavier elements.

But fusion engines don't last forever,

and all stars come to an end.

The biggest with a bang.

DR. BATALHA: Because you don't have any more energy,

there's nothing to support the star.

It's gonna collapse and then detonate.

[explosion]

NARRATOR: 13 billion years ago,

the death of the first generation of massive stars

spreads new atomic elements into the void.

The universe reaches a crucial threshold.

For the first time it contains everything necessary

for life to form.

Ancient hydrogen has now been joined

by huge quantities of oxygen, carbon and nitrogen,

alongside trace amounts of the heavier elements.

And astronomers have discovered that almost immediately

they start along the path to life.

DR. OÖBERG: After you had this first generation of stars,

you enter into a universe that's full of chemistry.

You have suddenly a chemical universe

which you did not have before.

NARRATOR: By analyzing the light

reflected by interstellar dust clouds,

astrochemists can determine their composition.

Over the decades, as their observations

became more precise, they made an astonishing discovery.

The universe is filled with water.

DR. OÖBERG: Water, this really important molecule

here on Earth, is one of the most abundant molecules

that we find in space.

NARRATOR: In the immensity of the void,

individual atoms rarely interact.

But the dust grains of heavier elements,

formed from the debris of exploded stars,

turn out to be a form of galactic flypaper.

DR. OÖBERG: We had realized that where these molecules form

is on the surfaces of these tiny, little dust grains.

These are little interstellar catalysts.

NARRATOR: Given the opportunity, oxygen bonds with hydrogen.

These two most abundant reactive elements

form huge amounts of water.

Carbon and nitrogen join them, and simple gases,

including ammonia and methane, are added to the mix.

The dust cloud chemistry appears unremarkable.

But new discoveries suggest it is the basis

of everything biological.

Because in the heart of these clouds, gravity ensures

that a second generation of stars is taking shape.

The first generation made the elements.

The second will kick-start the chemistry of Life.

♪

NARRATOR: Ten billion years ago,

a second generation of stars began forming

in the hearts of element-rich dust clouds.

Today, experiments reveal their presence

may have coated the surrounding dust

with the building blocks of life.

[radio chatter]

In cutting-edge facilities, astrochemists are recreating

the extreme conditions of outer space.

Dr. Scott Sandford leads a team

at NASA Ames Research Laboratory.

DR. SANDFORD: We're trying to make a little piece of space

right here in the laboratory so we can study what happens

in those kinds of environments.

At the South Pole in the middle of the winter

I think you get down to temperatures

that are something like minus 60 or 70 degrees centigrade

or something.

We're like 200 degrees below that.

And ten degrees above absolute zero.

NARRATOR: Sandford's ice cold experiment

is designed to shed light on a mystery --

how simple molecules in space became more complex.

Because astrochemists have discovered

the universe's second generation of stars

kick-started chemistry.

Stars generate visible light but also ultraviolet light,

at the high end of the electromagnetic spectrum.

DR. DRAKE: The ultraviolet light

is essentially like visible light

except it's more energetic.

It can do things that visible light can't do.

NARRATOR: Sandford and his team create their own UV light,

which they focus onto a super-cooled film of molecules,

simulating the surface of dusty grains found in outer space.

They have discovered that the UV light

creates a chaotic burst of chemical activity.

DR. SANDFORD: The UV photons can have enough energy

that can come in and break a molecule in half.

♪

NARRATOR: Bombarded by the UV rays,

the simple molecules split into reactive fragments

that recombine into more complex structures.

Because by chance, the abundant carbon atoms

want to form multiple bonds.

DR. MCKAY: Carbon naturally forms

more and more complex molecules.

It naturally brings in nitrogen and oxygen atoms.

So carbon is the master chemist.

NARRATOR: Carbon-based molecules form the basis of all biology.

And in recent decades astronomers have detected traces

of crucial biological molecules known as amino acids

in the dust and debris of outer space.

But they could be just the tip of the iceberg.

Sandford's simulations have produced

an incredible array of organic molecules

including those found in DNA itself.

With these simple building blocks

all of life can be constructed.

DR. MCKAY: Think of like a Lego kit,

little tiny blocks that kids play with,

and you stack them together.

That's what biology does -- makes wonderful structures

out of the simplest blocks.

NARRATOR: Evidence that life's building blocks

may be commonplace in the universe

has led a new generation of scientists

to question the uniqueness of life on Earth.

DR. SANDFORD: The universe seems to be sort of hardwired

to produce abundant amounts

of very complex organic molecules.

DR. OÖBERG: It really does seem like the universe

is set up to produce a rich chemistry,

to produce the kind of organic molecules

that we think are so important for life.

NARRATOR: But the hostile environment of outer space

is no place to stick the building blocks together.

♪

DR. OÖBERG: Starlight is absolutely fundamental

to create chemical complexity.

But it's really a double-edged sword.

So it can promote both creation of molecules,

but it can also destroy them.

NARRATOR: The high-energy radiation emitted by stars

continually devastates the very molecules it helped form.

The irradiated environment of space

is too unstable for the chemistry of life to continue.

But beginning 10 billion years ago,

as clouds settled around newborn stars,

out of the swirling dust new sanctuaries would start to form.

♪

NARRATOR: Powerful telescopes are transforming

our knowledge of young star systems.

DR. OÖBERG: We have a new set of eyes in the sky.

We have the ALMA telescope down in Chile,

which is this amazing array of 66 telescopes

that's working in unison.

NARRATOR: The ALMA array has a magnification

ten times that of previous telescopes.

Its extraordinary definition

allows us to witness how young star systems

evolve over time.

One such young star is TW Hydrae,

lying 175 light years away from Earth.

ALMA's power means we can actually see

the star's disc of dust

and how it is marked by circular grooves.

Astronomers believe they know what generates them.

From the moment a disc forms,

dust grains are aggregating into larger particles,

which gravity draws together.

In a few million years some massive accretions

of dust and ice absorb everything in their orbits,

clearing paths through the dust.

We call them planets.

In the cold outer zone of the disc, gas and ice giants form.

Like Jupiter and Saturn in our solar system,

their cores are molded from icy dust,

and they are smothered in the hydrogen and helium

they draw in from the surrounding disc.

They are hostile places.

But closer to the hot star,

where its rays have cooked the dust

and blown away the surrounding gas,

another type of planet can form from the remaining debris.

We call them rocky planets.

Freed from the smothering gases of the disc,

rocky planets can form their own atmospheres.

From gases leached from their own rocks.

They can let heat down to the surface

but protect it from the worst of stellar radiation.

And if they are just the right distance from their star,

something special can happen.

[thunder]

Water can become liquid.

By chance, the universe has created the perfect environment

for a more gentle chemistry to take place.

DR. MCKAY: From the biological perspective,

why planets are so useful is because

they allow water to become liquid.

It really is that simple.

Planets allow for liquid water.

Liquid water allows for life.

NARRATOR: But mysteries remain.

How could oceans of water reach the surface?

And how could chemistry become biology?

[thunder]

NARRATOR: Four billion years ago,

our solar system was in its infancy.

But something was happening on a rocky planet close to the sun.

The Earth was becoming a water world.

This crucial change would make the planet

a rare sanctuary for life.

DR. OÖBERG: Liquid water is absolutely crucial for life.

It is amazing the number of elements and molecules

that can become dissolved and therefore react

to form more complex molecules.

NARRATOR: The Earth's orbit lies in

what scientists refer to as "The Goldilocks Zone,"

a distance from our sun where the temperature is just right

for liquid water to pool on the surface.

But there is a mystery.

Some believe Goldilocks planets

should lack the resources to fill their own oceans.

DR. OÖBERG: The problem with forming in the Goldilocks Zone

is that you're forming too close to the star

to form from icy grains.

And that means that you form dry.

We see an Earth that has large amounts of water on the surface.

So the question is where did all that water come from?

NARRATOR: The answer may lie in the heavens.

Then, as now, the solar system was filled

with asteroids and comets, formed alongside the planets

from the same icy grains of dust.

But it's believed that four billion years ago

the solar system was unstable.

Some gas giants migrated in their orbits,

the gravitational pull disturbing

millions of these projectiles,

hurling some towards the Earth.

These icy rocks could have delivered

more than enough water to fill the oceans.

DR. OÖBERG: Having an early instability

in your planetary system

and planets moving around stirring things up

might be very important

to deliver water to otherwise dry, rocky planets.

And I think from a chemistry point of view,

what's really interesting about that

is that the water did not come alone.

NARRATOR: Buried in their ice were organic molecules,

the building blocks of life.

When organic molecules encountered liquid water,

miracles could happen.

♪

NARRATOR: High in the mountains of Chile lies El Tatio,

a volcanic geyser field.

Dr. Maria Eugenia Farias is an expert in this unique ecosystem.

DR. FARIAS: Tatio is a beautiful place,

but also it is like a time machine.

This is a very important place

to study the early Earth conditions.

Because here we are over 4,000 meters over the sea level.

Here there is a lot of UV radiation

and we have these geysers

produced because of volcanic activity.

Those are similar conditions to the early Earth.

♪

NARRATOR: Four billion years ago

the surface of the young Earth

was alive with volcanic activity.

Organic molecules of carbon, hydrogen, nitrogen and oxygen

mix with traces of phosphorus, sulphur and other minerals

bled from the hot rocks.

This inhospitable cocktail of chemistry

is ready to transform the universe.

DR. FARIAS: In places like this, chemistry became biology.

NARRATOR: But just how it happened remains a mystery.

DR. MCKAY: We understand life from biology looking down.

And we understand life from chemistry looking up.

But we haven't yet got those two ends to meet.

There's still a gap in the middle

called "the origin of life."

NARRATOR: Cambridge, England.

♪

In the laboratories of the Medical Research Council,

Dr. John Sutherland leads a team

dedicated to closing that gap.

DR. SUTHERLAND: Life must come from chemistry.

It must be possible to produce life from chemistry.

And we should be able to recreate that process

in a laboratory.

NARRATOR: Scientists like Dr. Sutherland

believe that the secret to the origin of life and its evolution

lies with a certain fragile, flexible,

self-replicating molecule called ribonucleic acid, or RNA.

DR. SUTHERLAND: DNA bears all the hallmarks of being

the product of evolution, its ancestor being RNA.

And RNA looks to us like the product of chemistry.

NARRATOR: The large RNA molecule naturally self-assembles

from much simpler molecular rungs.

But for years, Sutherland's team has tried to determine

how an ancient prebiotic chemical soup could

naturally generate RNA rungs from even simpler molecules.

Finding the correct balance of chemical ingredients,

temperatures and radiation levels

remains a challenge.

But Sutherland believes that at the heart of the key reactions

lies one molecule, hydrogen cyanide.

DR. SUTHERLAND: Hydrogen cyanide has certain

chemical properties which are highly conducive

to produce more complex structures.

NARRATOR: The problem is that to form enough hydrogen cyanide

requires a huge burst of energy,

equivalent to an endless lightening storm.

This has long been thought unrealistic.

But the team has recently discovered the answer

may lie beyond the clouds,

in another gift from outer space.

♪

NARRATOR: In their search for the origins of life on Earth,

some scientists now believe

vital chemical reactions on the surface

may have been triggered by meteor strikes

that were common events four billion years ago.

[explosion]

New experiments have demonstrated

that when the largest meteors vaporize on impact,

the incredible temperatures generate

a high-energy chemistry,

creating huge quantities of a key reactive molecule,

hydrogen cyanide.

At the same time, the impact crater

forms the perfect hydrothermal volcanic environment

for organic chemistry.

♪

When John Sutherland's team in England

recently simulated this chemical scenario,

the ingredients spontaneously produced

many key molecules they had been struggling to form.

DR. SUTHERLAND: We were literally gobsmacked

at the results we got.

It could be that life starts

as a result of really aggressive events

taking place in the early solar system history.

These incessant impacts were actually giving rise

to a very, very interesting chemistry

that would ultimately give rise

to the molecules required for life and life itself.

NARRATOR: It looked like they might have hit upon the process

that had generated the first RNA molecules.

The evidence is compelling, but the proof remains elusive.

What we do know is that at some stage

between 4 billion and 3.5 five billion years ago,

single-celled organisms, the simplest form of life,

evolved from the chemical soup and gained a foothold.

Successive generations became

increasingly robust and adaptive.

The volcanic streams at El Tatio are

some of the most inhospitable environments on the planet.

But even here these simple forms of life can thrive.

DR. FARIAS: I love bacteria; they are amazing.

They are so simple, and this is their main advantage.

Because if you are simple you can adapt quickly

and you can live in these extreme environments.

You can see yellow, green, pink.

All are surviving at high temperature, high UV radiation.

And in fact they are making stones.

Just in the same way they did 3.5 billions of years ago.

NARRATOR: Over time, the mineral excretions

from mats of bacteria

can form distinctive stony structures -- stromatolites.

3.7-billion-year-old fossilized stromatolites

are the earliest records of life on Earth.

But microbe-made structures

may also have left a record of life on Mars.

♪

For over a decade NASA's Mars rovers

have been exploring the Red Planet.

New observations have noted remarkable similarities

between El Tatio's geyser field stromatolites

and rock formations photographed by the Mars Spirit Rover.

These appear to support the idea that four billion years ago

there were two living planets in our solar system.

DR. MCKAY: I don't see why life wouldn't have started on Mars.

Early Earth, early Mars are very similar.

And they're similar during the time

when we know life first appears on Earth.

The most important feature of Earth

is that it has liquid water.

The most clear evidence we have of early Mars

is that it had liquid water.

So whatever you fancy is necessary

for the origin of life on Earth,

Mars would have had the same environments.

NARRATOR: But today, Mars is cold and dry.

Water predominantly exists in the poles as ice.

So what happened to her oceans?

A clue lies in her atmosphere.

It's 100 times thinner than that of Earth.

DR. MCKAY: The thickness of the atmosphere is like a switch.

If it falls below a certain level,

water will not stay as liquid. It will just boil.

NARRATOR: Something destroyed the atmosphere of Mars.

Many believe the culprit was the sun.

Alongside light and heat, our star

radiates invisible waves of sub-atomic charged particles

capable of immense destruction.

We call this the solar wind.

DR. DRAKE: The solar wind is essentially

the very outer atmosphere of the sun

that's just flung out into space

with energy generated from magnetic fields.

It is going from 500 kilometers a second

to 1,000 kilometers a second.

When it impacts a planet,

that's gonna have some erosion power

on the planetary atmosphere.

NARRATOR: Four billion years ago,

even as Mars's oceans were taking hold,

the particles of the solar wind

were smashing into the gasses of her atmosphere.

Over half a billion years they scoured it away.

And the planet's oceans evaporated into space.

This poses a big question.

How did life on Earth survive?

NARRATOR: Like all stars in the universe

our sun continually sprays out

a stellar wind of charged particles.

Billions of years ago its constant scouring

destroyed the atmosphere of Mars,

ending any chance of life developing on its surface.

Which poses the question,

how did life on Earth survive its onslaught?

♪

The island of Svalbard, high in the Arctic Circle.

Dr. Lisa Baddeley is heading to the office.

DR. BADDELEY: We are about 1,000 kilometers south

of the North Pole.

It can get quite difficult sometimes

when it's minus 40 degrees.

And then sometimes you can get a complete white-out.

So I have to rely completely on the GPS unit.

NARRATOR: Lisa braves the conditions

because this is the best location

to study a unique spectacle

visible from just a few points on Earth.

DR. BADDELEY: And here we are.

NARRATOR: She's here to witness a battle

between our planet and our star.

DR. BADDELEY: Well, you may notice that

we've got the domes and the cameras all pointing upwards.

So we're here to study a very unique phenomenon

that we see in the sky overhead.

NARRATOR: In the high atmosphere above, the conflict plays out

24 hours a day, 365 days a year.

The core of the Earth is molten iron.

As the core rotates,

it generates a powerful magnetic field.

This creates a protective bubble,

diverting the charged particles of the solar wind

away from the atmosphere.

The battle is continuous.

But the protective effect is weakest near the poles,

and some particles shoot through

to impact atoms in the atmosphere,

creating one of the greatest shows on Earth.

The aurora borealis.

DR. BADDELEY: When the whole sky is lit up

green and red and dancing,

you can stay out there for hours without realizing.

It's an amazing thing to see.

You can see how dynamic it is.

And you can also see little paths.

And that is actually the Earth's magnetic field lines.

And these particles

are traveling down these magnetic field lines

and into the atmosphere.

NARRATOR: What they hit and what energy they have

determines the color of the light produced.

It's beautiful, but scientists believe

that an aurora all over the planet

would eventually bring an end to life on Earth.

Mars's dramatic decline

shows just how vital this shield can be.

DR. MCKAY: Early in its history Mars did have a magnetic field.

We know that from observations on the ground and from orbit.

It was protected, then it lost its protection.

NARRATOR: Many believe that Mars' failure

to retain her watery environment was the result of her size.

DR. MCKAY: Mars is ten times less massive than the Earth;

it's a small guy.

As a result of that, it cannot maintain

the active convective molten core that Earth has.

All of Mars's troubles really trace back

to the fact that it's too small.

DR. DRAKE: The example of Mars is very instructive.

So life-sustaining environments on planets

are not necessarily forever;

they're not necessarily for billions of years.

They may only last a few hundred million years.

Life on certain planets could be a very transient phenomenon.

♪

NARRATOR: But if a planet does stay stable,

the life it nurtures can transform its environment,

which is useful.

Because initially life was forced to stay small.

DR. MCKAY: When we talk about life on Earth,

we usually mean trees and animals and birds

and the things that we can see.

But, in fact, that's just minor detail.

Life on Earth is microorganisms.

NARRATOR: For nearly three billion years

single-celled microorganisms were the only life on Earth.

They stayed simple because they lacked a source of energy

that would allow them to grow more structurally complex.

But by chance, a species of bacteria evolved

that would change the game.

Its descendants still populate

the lakes of the Atacama Desert in Chile.

DR. FARIAS: This mat, it's made of bacterias.

Each layer has a color

and it means a different bacterial community.

If we keep on taking away we will find this green layer.

NARRATOR: These are cyanobacteria.

As a byproduct of their life cycle they produce oxygen.

DR. FARIAS: You can see here these bubbles are oxygen.

NARRATOR: 2.5 billion years ago,

the cyanobacteria became so abundant

they began to fill the air with oxygen.

The Great Oxygenation Event had profound consequences.

Free oxygen would be the energy supply

that allowed life to grow

into complex multicellular organisms.

♪

With access to oxygen

life went from building rocks

to building skyscrapers.

DR. MCKAY: We wouldn't be here

if those little green microorganisms

hadn't produced all this pollution

and contaminated the planet irreversibly with oxygen.

We now rely on it.

We call it fresh air.

NARRATOR: Mankind has come a long way.

But ever since we first looked up

we have searched for signs in the stars that we are not alone.

Now, 21st century technology allows us to take that search

to the next level.

The quest for life in our solar system has already begun.

Today, probes scour Mars.

And soon, NASA may send others further.

DR. OÖBERG: There are a couple of moons

in the outer solar system

that have liquid water and they have organics.

And I see no reason why they shouldn't have life on them

if that is all that is needed for life to originate.

DR. MCKAY: Enceladus in particular,

moon of Saturn with a geyser of organic-rich water coming out,

we can just fly through it and search for evidence of life.

I wanna do that.

We're gonna look for the molecular skyscrapers.

These molecules of design that are built by life

and that will be preserved even after the organisms are dead.

We'll find them in the soils on Mars,

we'll find them in the ice in Europa,

we'll find them in the plume of Enceladus.

And they will tell us that there was life here.

[rocket engines roar]

NARRATOR: But if it turns out that life

requires a planet like our own with surface water,

we need to look further afield.

The Kepler Space Telescope was launched in 2009.

It aimed to determine if any planets orbited nearby stars.

Incredibly, it detected them almost everywhere it looked.

We now believe that in our galaxy,

one in five stars hosts a potentially habitable planet.

DR. BATALHA: The field of exoplanet research

has transformed completely.

When I go out at night and look at the sky,

I don't see those pinpoints of lights as stars,

I see them as planetary systems.

Kepler has fundamentally changed

the way I perceive the universe.

NARRATOR: The challenge in the coming decades

is to discover signs of life on these alien worlds.

A new generation of ground- and space-based telescopes

is set to transform the search.

DR. OÖBERG: The next big exciting telescope to come along

is the James Webb Space Telescope, or JWST.

This telescope will be able to look very close to the star

and really see what the chemistry looks like

right where rocky planets are forming.

NARRATOR: On Earth, one of the most ambitious projects

is the Giant Magellan Telescope.

DR. DRAKE: The Giant Magellan Telescope

should be able to look at the atmospheres of nearby planets.

And this is crucial for searching

both for signs of life, for signs of oxygenation

that we think is the signpost for life,

but also to determine whether planets are actually habitable.

NARRATOR: Breakthroughs in many fields of science

mean there is new confidence in the quest

for extraterrestrial life.

DR. DRAKE: The fact that we're now finding

planets around most stars

and the fact that we're now seeing that chemical processes

that build up organic molecules in space

seem to be quite common,

all this seems to be pointing toward the direction

that life is maybe much more common in the universe

than we may have previously thought.

DR. MCKAY: Earth and life on Earth is not unique.

All the clues are pointing in that direction.

DR. OÖBERG: If all that's needed is

a rocky planet and water and organics,

life should be abundant in the universe.