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Finding Life Beyond Earth -

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(generated from captions) NARRATOR: Is Earth the only planet
of its kind in the universe?

Or is there somewhere else
like this out there?

Is there life beyond Earth?

The search for alien life
is one of humankind's

greatest technological challenges...

..and scientists are seeking
new ways to find answers.

We're pushing the boundary of
information of where life can exist,

past the Earth and out
into the solar system.

Leading the search
are sophisticated telescopes

that scan the sky.

And an armada of robotic probes,

exploring the outer reaches
of our solar system.

All revealing the planets,
moons, asteroids,

and comets like never before.

We can go places and see things

that there's no other way
we could have ever seen.

The search reveals evidence
of strange and unexpected worlds.

Places with lakes, storms...

..and rain.

Violent places driven by
powerful forces deep underground.

Worlds that may have hidden oceans

hundreds of millions of miles
from the heat of the sun.

The pace of discovery,
just in the last couple of years,

is just mind-boggling.

New missions are helping
to unlock the mysteries

of what makes a planet habitable,

raising the question of whether
the building blocks of life

are more prevalent
than previously imagined,

not just in our own solar system,
but possibly throughout our galaxy.

We now have,
for the first time in human history,

definite planets, out there among
the stars, that remind us of home.

Finding life beyond Earth.

After a seven-year,
two-billion-mile voyage,

the spacecraft 'Cassini'
enters orbit around Saturn.

'Cassini' heads towards the largest
of Saturn's 62 moons...

..Titan.

Bigger than the planet Mercury,

Titan is hidden
by a thick orange haze.

No-one has ever seen its surface.

But a small probe named 'Huygens',
released by 'Cassini',

is about to change everything.

This mission will challenge
long-held notions

of where life could exist
beyond Earth.

These are the actual images
'Huygens' takes

as it breaks through
the clouds and haze.

Titan is a land of mountains
and valleys,

a place that looks
surprisingly like Earth.

Then images reveal
something no-one expects.

The surface is littered
with smooth rocks,

the type normally found
in riverbeds on Earth.

MAN: My response was shock.

We look out on the surface
and we see what looks like a desert,

and at the same time, the data
from the probe told us that

the ground around the site was wet.

Hundreds of miles overhead,
'Cassini's radar sweeps the surface.

The images show a landscape

covered with what appear to be
hundreds of lakes.

This one covers an area
of 6,000 square miles,

about the size of Lake Ontario,
one of the Great Lakes.

It's a surprising discovery.

It's the only world
other than the Earth

that has a liquid on its surface.

But what exactly is this liquid?

Titan is -290 degrees Fahrenheit.

If it's water,
it should be frozen solid.

Then one of 'Cassini's instruments
analyses the infra-red light

reflected off the lakes.

The readings are consistent,
not with water,

but with liquid methane and ethane,

substances that, on Earth,
are volatile, flammable gases.

The data from 'Cassini' are
so detailed, scientists can imagine

what it would be like to stand
on this cold, distant world.

MCKAY: Standing on
the surface of Titan,

you see Saturn
just sitting there in the sky.

Big, huge stationary object, almost
like a door to another dimension.

Here we see lakes,
lakes of liquid methane,

and in the horizon we see mountains.

These are mountains made of ice,
made of water ice,

frozen so hard
that it acts like rocks.

And the features that we see in them

are carved by the liquid methane
that's forming these lakes.

Looking across the horizon on Titan,
you might see a thunderstorm

or a range of thunderstorms
coming at you.

We see rain coming down.

It's not drops
like we're familiar with on Earth.

This is methane, instead of water.

It falls much more slowly,
due to the low gravity,

and the drops are bigger.

So, what are the implications
of finding a liquid

flowing on Titan's surface
for scientists like Chris McKay?

Liquids seem to be the key to life,

so maybe there's life
in that liquid on Titan,

little things
swimming in liquid methane,

being quite happy
at these low, cold temperatures.

There is no evidence
that living things like microbes

exist in these lakes.

But if such evidence
were found here,

it would fundamentally change
perceptions about life beyond Earth.

If life could evolve on worlds

as drastically different
as the Earth and Titan,

then perhaps life could evolve
in many other ways,

on many different worlds.

NASA's Director of Planetary Science
is Jim Green.

One of the questions
that we all wanna know,

I think, deep down inside is,
"Are we alone?"

I mean, that's really fundamental.

Jim is at the forefront
of a global effort to understand

whether the conditions for life
exist beyond our planet.

We're pushing the boundary of
information of where life can exist,

past the Earth
and out into the solar system.

So, where in our solar system
could life potentially exist?

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Heading out from the sun,
the first planet is Mercury.

It's an extremely
hostile environment.

In March 2011, NASA's 'Messenger'
probe becomes the first spacecraft

to orbit this small ball
of rock and iron.

These are some of the first images
sent back.

Three times closer to the sun
than Earth is,

Mercury bakes in 800-degree heat
on its side facing the sun,

while on the night side,
temperatures plummet to -290.

Mercury is the ultimate
desert world.

Life of any kind here
seems unlikely.

Mercury's closest neighbour, Venus,
is almost as hostile.

Though nearly twice as far
from the sun,

temperatures here
exceed 880 degrees.

Decades of observations
have revealed a planet

shrouded in carbon dioxide
and toxic clouds of sulphuric acid.

These radar images reveal
thousands of ancient volcanoes

on a surface hot enough
to melt lead.

And with an atmospheric pressure

that is 90 times greater
than on Earth...

..it is hard to imagine that
anything could live down here.

But based on chemical analysis
of the atmosphere,

scientists believe that water
once flowed on Venus's surface.

If life ever did exist here,
evidence has yet to be found.

So, what is it about Earth,
the third planet out from the sun,

that makes life possible?

The answer lies in
three key ingredients.

First, all life is made up
of organic molecules

consisting of carbon,

in compounds that include nitrogen,
hydrogen and oxygen, among others.

Although organic molecules
aren't alive themselves,

they are the basic building blocks
of every living organism.

Life also needs a liquid,
like water.

In water,
the basic organic molecules can mix,

interact and become more complex.

The last ingredient is an
energy source, like the sun,

to power the chemical reactions
that drive all life,

from the smallest microbe...

..to us.

When these three ingredients came
together billions of years ago,

life found a way to take hold.

And today persists,

even in the most extreme
environments, like here.

This is the Mojave Desert, Nevada.

It is one of the hottest,
driest places on our planet.

This part of the desert
is particularly interesting to me,

because it's the driest part.

There's an axis of dryness here.

Go either east or west,
it becomes wetter.

Surprisingly, even here,
with only a foot of rainfall a year,

all three ingredients for life
are present.

The rocks provide just enough shade

to prevent water
from evaporating completely.

Underneath the white rocks,
we can find the most amazing thing.

We see this layer of green -
this is bacteria.

The rock provides a little shelter.

It's a little wetter
and a little nicer

living under the rock
than it is in the soil around it.

In addition,
the white rocks are translucent.

Hold them up to the sun
and see light coming through.

These organisms
are photosynthesising

here in the desert,
where nothing else will grow,

so they're living in a miniature
little greenhouse.

This place shows that,

even in some of Earth's
most extreme environments,

under the right conditions,
life has a chance.

For scientists like Chris McKay,
the question is,

is Earth the only planet with
the essential conditions for life?

One way to know is to investigate
how planets like ours

formed to have these ingredients
in the first place.

That story starts
4.6 billion years ago

with the birth of our solar system.

As a vast cloud of dust and gas
collapses in on itself,

pressures increase,

temperatures at the centre
rise to millions of degrees...

..until energy from the early sun
blasts away some of the cloud.

This lights up
the young solar system,

revealing the beginnings of planets.

The mystery has always been
how did this spinning cloud of dust

become the massive planets
we see today?

MAN: How does one go
from microscopic grains,

to golf ball-sized things?

And how do golf ball-sized things
go from there to 10m-sized things?

And how do those go
to planetary embryos?

There's a lot of steps
we don't quite understand.

Many scientists believe the answers
are hidden in asteroids...

..the oldest rocks
in the solar system,

leftover debris
from its earliest days.

In 2003, the Japanese probe
'Hayabusa'

sets out on an audacious mission.

The goal - to land on an asteroid,
collect samples of dust

and then return them to Earth.

The target is asteroid Itokawa...

..a third of a mile long,

and speeding through space
at 56,000 miles per hour.

Landing on it

would be like trying
to hit a speeding bullet

with another speeding bullet.

SCOTT: 'Hayabusa' in Japanese
means 'falcon'.

And the idea was to do like
a falcon grabs a rabbit, swoop down,

sort of just touch the surface,
get your sample and go.

In 2005, 180 million miles from
Earth, 'Hayabusa' makes contact.

It stays just long enough
to grab a sample.

It will take five years

before 'Hayabusa'
returns asteroid dust to Earth.

But in the meantime,
using lasers on board,

'Hayabusa' takes measurements
of Itokawa's size and mass.

These allow scientists to determine
the asteroid's internal structure.

What they discover
could be a blueprint

for how planets like Earth
first formed.

SCOTT: It's not one solid
lump of rock.

But, in fact, it consists of a pile
of smaller rocks of many sizes,

all the way from houses
down to dust grains.

If we could see inside
asteroid Itokawa,

this is what it would look like -

a loose mixture
of smaller asteroids

that are held together by gravity.

SCOTT: Maybe 40% of
the internal volume of the asteroid

is empty space.

You probably could just take
your hand and just go like this

and just push it down
into the asteroid.

Is this the first step in building
rocky planets like Earth?

MAN: Asteroids are just not
lumps of rock.

These are the basic
parts or building blocks of planets.

Over hundreds of thousands of years,

asteroids like Itokawa
continue to collide,

growing bigger and hotter.

As their gravity increases,
they attract even more asteroids,

until, eventually, as temperatures
rise, they become spheres of rock,

with hot molten cores -
protoplanets.

Computer simulations suggest

that within 10 million years
of the solar system's birth,

up to 100 protoplanets, ranging
in size from our moon to Mars,

were orbiting close to the sun.

So why does the solar system
look so different today?

This is proto-Earth,
4.5 billion years ago.

Planetary geologist Stephen Mojzsis

believes this world was very
different from the one we see today.

Looking at the surface here,

this landscape is dominated by lava,

black and blasted by impacts.

Underfoot,
we find mostly basaltic rock.

It is the frozen product
of molten rock.

These planetary surfaces
weren't molten, boiling cauldrons.

But instead, for most of their early
histories, they were solid and cool.

The atmosphere is thick
with carbon dioxide

and laced with sulfuric acid, the
result of intense volcanic activity.

The embryonic Earth

would have an atmosphere
denser than the one we have,

and a sky yellow and red
and thoroughly unbreathable to us.

How does this toxic
and inhospitable world

eventually become
the Earth we know today?

Ironically, it will take
a cataclysmic event

to create a planet
capable of harbouring life.

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A protoplanet the size of Mars
slams into early Earth.

The collision is so violent
it melts the surface,

creates an even larger planet,

and blasts molten rock
back into space

that will coalesce
and eventually form our moon.

Earth isn't the only planet that
gets transformed by giant impacts.

Over tens of millions of years,

all the protoplanets of the early
solar system repeatedly collide,

becoming larger bodies
with each impact

in a destructive game
of planetary billiards.

This process eventually formed
the four rocky planets seen today...

..Mercury...

..Venus...

..Earth...

and Mars.

WOMAN: And so the final planets
that we have today

are really the ones
that won the competition,

in that some planets
were literally destroyed

or thrown out of the solar system

and others survived
to be here today.

Sarah Stewart
is a planetary scientist.

She's trying to determine how these
impacts created a habitable world.

There's some magic set of conditions
that has to occur in a solar system

to give you an Earth-like planet.

Figuring out what happens

when a massive planet
the size of Mars hits Earth,

is no small feat.

It requires smashing things together
at extremely high velocities.

We want to simulate what happens

when materials strike the Earth
at very high speeds.

What we can do in the lab is study
little pieces of the process

and, using the information
we gather from many experiments,

we build computer models that try
and re-create the whole event.

This requires
a special piece of hardware -

a 20-foot cannon
that uses an explosive charge

to fire projectiles
at up to 6,000 miles per hour.

At the other end
is a pressure chamber

and the target,
representing a planet like Earth,

wired up with precision sensors.

We have a 40-millimetre gun

that launches 100-gram bullets
into rocks or ices.

And we study what happens

as that shock wave
travels through the material.

The gun is set to fire.

Each test measures the temperatures
and shock waves

generated in different materials

when they are slammed
into each other.

The results are fed into
computer models

of the final stages
of a planet's formation.

SARAH: Over the past few years,

we've realised how important
the last giant impact is

to the final state of a planet.

That last impact could fundamentally
change major parts of the planet.

And that could lead to something
that's Earth-like

or something
that's more Mercury-like.

Sarah's work,
though not yet conclusive,

suggests that giant impacts
could play a role

in producing water
on a planet's surface.

Her results indicate
the collisions were so violent

they could heat rock
to 2,700 degrees,

hot enough to release water trapped
deep beneath the surfaces as steam.

Sarah believes
this may have happened

during Earth's
final catastrophic collision.

In its aftermath,
as the raging hot planet cools

over millions of years...

..this steam condenses

and falls as rain...

..covering the surface
with seas and oceans.

If this hypothesis is correct,

then several million years
after forming,

Earth has two of the three
ingredients needed for life -

water and energy from the sun.

But what about organic molecules,

the chemical building blocks
of life?

How did they get to Earth?

Some scientists believe

the answer may lie in the furthest
reaches of the solar system...

..beyond Jupiter,

Saturn,

Uranus

and even Neptune.

Here, 3 billion miles from the sun,

is a vast ring of comets and other
debris called the Kuiper Belt.

Like asteroids, comets are remnants
from the dawn of the solar system.

But as well as rock,
they are also made of ices

that only freeze
this far from the sun.

Astrobiologist Danny Glavin
and his team

think comets are the key
to understanding

how the final ingredients
necessary for life arrived on Earth.

The reason that comets
are so important to study

is that they really are
windows back in time.

These things formed
4.5 billion years ago,

before the Earth even formed.

And so we're looking
at the chemistry in these objects

that was frozen in time.

But analysing
actual comet material,

when the closest sample
is more than 3 billion miles away,

is a major challenge.

Fortunately, icy comets
occasionally fly in closer to Earth.

As they approach the sun,
comets warm up,

and the ice starts to vaporise,

spitting out tiny particles of ice
and dust.

DANNY: So when you're looking
at a comet in the sky,

what you're actually seeing
is predominantly the tail.

You don't see that tiny,
rocky ice nucleus

because it's being dominated by
the sublimation of ices and rocks.

So you see that long tail
and the solar wind,

which is just dragging it
for millions of miles behind.

MISSION CONTROL: Zero. And lift-off
of the 'Stardust' spacecraft.

A Delta II rocket
blasts into space.

On board is the probe 'Stardust'.

Gone through mach 1. Vehicle looks
very good, burning nicely.

The aim - to meet up with a comet

speeding through space
at nearly 60,000 miles per hour,

then fly through the ice and dust
and bring some of it back to Earth.

240 million miles from Earth,

'Stardust' approaches the comet
named Wild 2.

It heads to the heart of the comet,

and takes these images
of its solid icy nucleus.

The surface is broken and jagged.

And shooting out of it
are jets of dust and ice particles.

Astronomer John Spencer

is an expert on objects
from the outer solar system.

MAN: The cometary surface
is pretty treacherous.

We have crazy spires that may be
several hundred feet high.

We have overhangs.

We have upturned layers

where the surface really seems
to have been torn apart.

This is a very, very bizarre
landscape.

We have a surface
that is mostly black.

But scattered around within that
we have fresh ice.

We see a mostly black sky because
the atmosphere is almost negligible.

That black sky is punctuated

by these geyser-like jets
of ice particles

that are shooting up
at supersonic velocities.

These icy geysers
bombard 'Stardust'.

These particles hit
at almost 14,000 miles per hour,

six times faster
than a speeding bullet.

'Stardust' survives intact.

And on January 15, 2006,
the samples return to Earth.

DANNY: The samples fell down
on Utah, and boom,

we had the first
comet sample materials.

And there were astrobiologists
all over the Earth

that were kind of screaming inside,

because we knew
this was our first chance

to actually analyse comet material.

Inside, scientists discover
over 1,000 grains of comet dust.

Glavin and his team analyse
this material for three years.

Then they make
an incredible discovery.

In the dust from the comet

are traces of the organic molecule
glycine,

an integral part of living things.

Probably frozen into the comet
when it formed,

glycine consists of simple elements

found in the cloud of gas and dust
that gave birth to our solar system.

Now, glycine is an amino acid,

it's one of the building blocks
for life.

These make life go.
They make up proteins and enzymes.

They catalyse
all the reactions in our bodies.

They're fundamental to life.

Without these
we could not exist at all.

All life on Earth,

from these bacteria to us,
uses amino acids.

Glycine is special because it's the
most common of the 20 amino acids

needed to make proteins,
part of the very fabric of life.

The discovery means

that comets could have been
one source of the organic materials

necessary for life on Earth.

We've proved that in fact
comets could have delivered

the raw ingredients of life
to the early Earth.

But what could cause comets

to fly in from the furthest edges of
the solar system, slam into Earth,

and deliver these organic compounds?

The clues to one possible process
lie back out in the Kuiper Belt,

the disk of icy objects
that orbits the sun

at the edge of our solar system.

MAN: We expected,
when we found the Kuiper Belt,

that we would just see objects in
nice circular orbits about the sun.

But observations reveal

that the Kuiper Belt objects
are not orbiting as predicted.

Out here, it's chaotic.

When we look at the Kuiper Belt,

we see something that looks
like somebody took the solar system,

picked it up and shook it real hard.

And that's what started us thinking

that something really strange
has happened there.

Levison theorises
that the reason for this mayhem

likely is connected with the two
largest planets in the solar system.

Jupiter is so big, it could swallow
more than 1,300 Earths.

And Saturn, with its vast rings
of ice, is 95 times Earth's mass.

With their enormous size comes
an enormous gravitational pull.

Everything that we see is a result
of what Jupiter and Saturn did.

Levison wonders
if the chaos of the Kuiper Belt

could have resulted
from a planet smashing into it.

To find out, he runs
a number of computer simulations.

One model creates the conditions in
the Kuiper Belt that we see today.

3.9 billion years ago,
as Jupiter circled the sun twice,

Saturn made one complete orbit.

Each time these orbits coincided,

there was a powerful
gravitational surge

that pushed Saturn's orbit
further from the sun

and destabilised the orbits
of the two outermost planets,

Uranus and Neptune.

Jupiter and Saturn
sort of tugged each other,

and that drove the orbits of Uranus
and Neptune absolutely nuts.

Uranus and Neptune
are sent careening outwards

towards the Kuiper Belt.

Comets ranging in size from a mile
across to objects the size of Pluto

are blasted out of their orbits
by the planetary invasion.

The disc went kapooley!

Think of it as sort of
a bowling ball hitting bowling pins.

These things got scattered
all over the place.

The end result is
a 100-million-year period

when comets, kicked out into the
solar system by Uranus and Neptune,

smash into anything in their path.

It's a period scientists call
"the late heavy bombardment".

Earth doesn't escape.

HAL LEVISON: This was so violent
that probably every square inch

of the surface of the Earth was
hit by a comet during this time.

This is one theory
that might explain

how massive amounts
of organic molecules,

the building blocks of life,

made their way to Earth.

Possible evidence
of the late heavy bombardment

can be seen on the surface
of other planets and moons

in the solar system -
impact craters.

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Literally the seeds of life,
the amino acids,

would have been delivered
to all the planets and their moons

in our solar system.

So if life's building blocks
were delivered by comets

throughout the solar system,

could life also have sprung up
on worlds other than Earth?

It is unlikely that living organisms
exist today on Venus or Mercury,

as space probes have found
no evidence on these planets

of the other vital ingredient
life needs - liquid water.

But what about Mars?

Organic compounds
have yet to be found here,

but scientists
are searching the planet

for the other preconditions of life.

There have been many
missions to Mars

and nearly all suggest that water
once flowed on the surface.

These detailed images
from satellites orbiting Mars

reveal vast canyons
blasted out by epic floods

and valleys carved by raging rivers.

But the evidence indicates that
all this water

disappeared from the surface
billions of years ago,

as Mars cooled down
and lost its atmosphere.

But on May 25, 2008,

a spacecraft called 'Phoenix'
touches down near Mars' north pole.

Digging a few inches down,

it exposes a white material
that vaporises after a few days.

Soil analysis reveals
it is water ice.

We landed 68 degrees north.

Poof, just a few centimetres below
the ground there was a layer of ice.

Satellites analyse radar waves
bouncing back from both polar caps.

They reveal that beneath a layer
of frozen carbon dioxide

there is a lot of water ice.

If it all melted,

it would cover the whole planet
in an ocean more than 80 feet deep.

JIM GREEN: When we look at Mars,

and we see the reservoirs
of water there,

it's completely surprised us
in terms of the amount of water

and how much water
is actually trapped underground.

The same satellites orbiting Mars
are discovering that

buried ice is also widespread
beneath the desert floors.

MCKAY: When we look at Mars,

we see what looks like
a desert world, with no water,

but, in fact,
Mars has lots of water.

It's ice - Mars is an ice cube
covered with a layer of dirt.

But this doesn't mean that
finding life here is imminent.

Ice doesn't melt the same way
on Mars as it does on Earth.

The atmospheric pressure here
is 150 times lower than ours.

It's impossible for water to exist
as a liquid at the surface.

MCKAY: Ice on Mars
behaves like dry ice does on Earth.

A piece of dry ice on Earth

goes directly from
the solid ice to vapour.

It doesn't form a liquid.
That's why we call it dry ice.

On Mars, the pressure is so low
that water ice does the same thing.

No liquid water
on the surface of Mars today

means that vital chemical reactions
cannot take place.

It seems impossible
that life could exist there.

But could it exist
in the buried ice itself?

An expedition to one of
the coldest places on Earth

is looking to answer
that question.

These are the dry valleys
of the Antarctic,

one of the world's
most extreme deserts.

Here, beneath a layer of dry dirt,
is buried ice, similar to Mars.

If life can exist here,
could it exist on Mars too?

MCKAY: We're doing,
in the Antarctic,

exactly what we want to do on Mars.

We drill down into this Mars-like
soil, we collect Mars-like ice,

and what we look for what we hope
are Mars-like micro-organisms.

At the point
where the dirt meets the ice,

the team discovers
a thin film of liquid water.

And when they look at the samples
under a microscope...

..to their surprise,
there is something moving.

We're finding, at the ice, there
is life, which is quite remarkable.

Micro-organisms thrive
in this thin film of water,

but only for a short time.

They spend most of the year
frozen and dormant,

and they're only active
for a few weeks each summer,

when temperatures get warm.

On Mars,

summer temperatures at the equator
can reach 70 degrees.

Could the buried ice melt here

and create conditions similar
to those found in the Antarctic?

MCKAY: We may be able to find
conditions where the ice

is close enough to the surface,

close enough to the equator,
that even under today's conditions,

there's a small chance
of liquid water and life.

If probes were to find
liquid water on Mars,

it would be
an extraordinary discovery.

But water alone does not equal life.

There is a better match today

between conditions that we know
can support life on Earth

and conditions that
we know either exist or once existed

on other planets
within our solar system.

But that still begs the question,

what conditions are required for
life to emerge in the first place?

How does this process of genesis,

life emerging from non-living
material, take place?

Are the conditions that once
existed on Mars adequate for that?

We don't know. We simply don't know.

So how could scientists find out

if life is possible
below Mars' surface?

One recent discovery, still
open to debate, provides a clue.

Measuring wavelengths of infra-red
light, a NASA telescope on Earth

detects something mysterious
in Mars' atmosphere.

Evidence of methane gas.

It's an intriguing find.

Some methane gas on Earth is
produced by geological activity,

like mud volcanoes,

but most of the methane
found in our atmosphere

is a waste product
generated by micro-organisms.

Methane has a very interesting
connection to life in many ways.

It could be a product of life,

it could be something that life
has made, evidence of life.

JIM GREEN: Well,
the discovery of methane

was really
one of the fabulous discoveries

just in the last several years.

New observations
by the Keck telescopes

suggest that certain areas on Mars

are releasing thousands of tons
of methane gas every year.

So, where is the methane
coming from?

It's seasonal.

We seem to have more methane emitted
during the summer season on Mars

than we do at any other time.

There is not enough data yet
to tell scientists

what is producing the methane,
but whatever the source,

it's a tantalising clue that could
change our understanding of Mars.

Methane could be biological,
which would be amazing,

or it would indicate that there's

some geological process
making methane,

which would also be amazing,

because that would indicate
that Mars is an active world.

To find out, NASA is going back
to the Red Planet.

This time, one of its key missions
is to search for organic molecules,

the building blocks of life.

If we were to find
organic molecules on Mars

and confirm that they're
actually from Mars

and not something
we brought along - wow!

That would be spectacular.

If found, it might mean that all
three ingredients for life are here,

opening the possibility
that life could take hold.

Of course, we're all human, right?
And we want certain things.

Nobody wants us to be alone, right?

But it's important in science
to maintain an open mind.

To find organic molecules,

NASA is launching a Mars rover
the size of a compact car...

..named...'Curiosity'.

'Curiosity' will be our first
great chance, I believe,

to look for life on Mars.

'Curiosity' holds the most advanced
set of science instruments

yet sent to the planet.

It will zap, grind
and bake Martian rocks,

and use spectroscopic analysis
to reveal

if the samples contain any of
the chemical ingredients for life.

It is not just a geologist,
it's an astrobiologist.

It can look at rocks
and everything else around it

in ways that we've never looked
at the material before.

Even with an advanced
set of instruments,

finding organic molecules
will still be a challenge.

SQUYRES: It's gonna be
a tricky problem.

There are lots of processes
that can destroy organic molecules.

Radiation from space
can destroy them,

oxidising compounds in the Martian
atmosphere can destroy them.

So you're looking for organic
molecules that have somehow been

protected from the Martian
environment for a while.

And the bar is set even higher,

because 'Curiosity' will search
for specific organic compounds

that are the product
of living things...

..evidence that life
once existed here.

That's what Jennifer Eigenbrode's
experiment is designed to uncover.

Organic molecules tell a story
about where they came from

and what happened to them,

and that's the story that I'm trying
to uncover in Mars rocks.

JIM GREEN: That experiment may very
well change our impression of Mars

as a lifeless body,
and change it to harbouring life.

If 'Curiosity' turns up any evidence
that life once existed on Mars,

it will have enormous implications.

If right here,
in our own little solar system,

life started twice, then it would
say that life is just everywhere.

'Curiosity' and other missions
may one day reveal

if life once existed on places like
Mars, and if it still exists today.

But even if scientists
ultimately conclude

that there is no life
on the planets closest to Earth,

it doesn't mean it's not out there.

Beyond Mars are other worlds
waiting to be explored.

The distant moons that orbit
the giant planets Jupiter...

..and Saturn.

Moons just as strange
as the orange-shrouded Titan.

One pockmarked
with hundreds of volcanoes.

Others glistening with ice
and covered in mysterious lines.

And one tiny moon
etched with deep fissures.

JIM GREEN: We're now finding,

when we look at these giant planets
and their moons,

that they are almost like
mini solar systems in themselves.

Probes are making discoveries
on these moons

that are changing our understanding
of where life can exist.

They're finding evidence
of new sources of energy.

Hidden oceans of liquid water...

..and organic molecules
blasting into space.

And far beyond these worlds,

scientists are exploring entire new
solar systems around other stars.

MARCY: Surely billions,

hundreds of billions of the
Earth-like planets out there

have the conditions
suitable for life.

As scientists race to explore
these distant places

with more and more
advanced technologies,

they are finding that
the conditions for life

are not exclusive to Earth

and that the natural forces
set in motion here

might be active elsewhere
in our galaxy and beyond.

Supertext Captions by
Red Bee Media Australia
Captions copyright SBS 2012

(METAL DETECTOR BLEEPS)

(SPEAKS INDISTINCTLY)

Morning, guys.

WOMAN: Good morning.
Good morning.

I'll go directly to you by the 7th.

Mm-hm.

And then we are out of there.

Uh, what have they called so far?

Jared?

MAN: (ON TV) Right now,
we have a major projection,

a major projection to make
in the state of Maryland.

Congressman Ben Cardin, the
Democrat, we project will be elected

the next United States senator
from the state of Maryland,

succeeding Paul Sarbanes...

No, that's good.
Did you call them all?

No, I'm going to make calls now.

Do they have a count
on the House seats yet?

WOMAN: Not many.
They haven't called many of them.

That's the only one
that's a pick-up.

Though, Yarmuth in Louisville
is up with, uh... (CHUCKLES)

That's what I'm talking about.
..96% in.

But they haven't called it yet.

My goal is every candidate
I campaigned for, I want to win.

Every single one.

Hey, congratulations, Madam Speaker!

We're...

Well, listen, we're...
we're so proud of you.

You're making history,

and let's figure out how
I can be helpful going forward.

Alright. Bye-bye.

WOMAN: We keep asking you,
"Are you ready to run?"

Are you ready to serve as president?

You know, the, uh... I haven't
had time to catch my breath.

This, I think,
will be the first week

where I haven't taken off my shoes
at the airport security terminal.

So, I'm going to step back,
take a look at what's going on,

and, you know,
really do some soul-searching

in terms of how I can be
most useful to the country.

I haven't had time to do that yet.

At this point, with 84.5 in.

Whew! You don't get
a lot tighter than that.

Nope.

I love elections.

(CHUCKLES) It's so much fun.

It's even more fun
when you're not on the ballot.

(PEOPLE CONVERSE BUSILY)

MAN: My name is Ronnie,
calling from the Barack Obama
campaign here in Des Moines,

and just wanted to try
to get acquainted

with people in the community.

I'm going to be working in that area
through the caucuses in January.

Oh, you do a caucus?
Well, that's great.

Have you decided
who you'll be supporting?

Not yet? Well, you're right,
it is awfully early.

Well, Alvin, is there any particular
issue that you care about?

Something that stands out
in your mind?

RONNIE: Just...basically
trying to get out there,
meeting with activists,

let them know that we're here
and we like to talk to them.

You know, people want to see him,

but don't necessarily know
a lot about him.

He is the biggest and best tool
we have

in terms of drawing people in
to get interested.

I think that's half the battle.

How are you?
What's going on, brother?

Having fun? (LAUGHS)
Huh?

Been a couple of crazy days, huh?
I like this.

You like it? Good.
Yeah, I do.

Linda, I can't wait for...
to see you on the 30th,

and let's...let's just
stay in touch.

Stay hi to...say hi
to your husband and son for me.

Alright. Bye-bye.

Unsupervised...
I may want to...

Sorry, after this next, uh...
these next two calls,

are we going
straight to the farm thing?

MAN: Yes.
OK. I...

We're gonna do the remaining
press calls in the car.

I just want a second
to change out of...

This is not...the best outfit for...
Yes, sir.

I hear you.
..rural America.

We've got overalls.
I'm not gonna wear overalls...

And a horse.
(LAUGHS)

Is...that going to be a problem?

A horse, I wouldn't mind, actually.
That sounds kind of cool.

So I just want to check in

and find out, you know, what
we need to do to earn your support,

'cause I think, once I get you,
that puts us over the top.

Then I've got Iowa at that point.

I...you know, I...I...
I understand completely.

But, you know, the one thing
I will say is that...um...

..we want to make sure that
anybody who is supporting us,

that, you know, this is all part
of a single team.

I'm fascinated by Obama.

Here's a man who's been in town,
Washington, for two years?

As near as I can tell,
hasn't done a thing.

Apparently, there's
no performance criteria

in the process of selecting
somebody to be president.

Nobody asks the question,
"What has he in fact ever done?"

WOMAN: What do you think
of Barack Obama?

I think he's a cool guy. I don't
know much about him, to be honest.

I have no clue who that is.
You don't?

I have no clue who that is.

Wait. Is he African American?
Yeah.

OK. It'd be really cool if he
was our next president, then.

(CHANTS) # I got a 'O'
You got a 'bama'

# O! O!
CROWD: # Bama! Bama!

# I got a 'O'
You got a 'bama'

# O! O!
# Bama! Bama!

# I got a 'O'
You got a 'bama'

# O! O!
# Bama! Bama!

# O! O!
# Bama! Bama! #

I haven't done this...since, um...
I campaigned for Bobby Kennedy

back in the mid-'60s, '68.

And there just hasn't been anybody
that's been exciting enough.

CROWD: (CHANTS) # I-O-W-A
Barack Obama all the way!

# I-O-W-A
Barack Obama all the way!

# I-O-W-A
Barack Obama all the way! #

WOMAN: Do you think this country
is ready to elect the first
African American president?

No. No.
MAN: Sure.

Not even Colin Powell?
He would get elected.

That's a different story. He's
smart enough to know not to run.

WOMAN: Right now, I have to say
that I'm looking at Edwards.

I would like to see Richardson.

WOMAN: I don't like
any of the candidates.

I don't think any of them
are the right people.

I think Hillary's
been around too long.

She doesn't stand
for anything anymore.

Obama's wonderful, but he's just
a little too young and untried.

Of course, after Bush, anybody can
be president. I can be president.

You know, it's for good reason.

If you think about it, the odds
of me standing here are very slim.

I wasn't born into money,
I wasn't born into fame.

I didn't have a famous
family member. I...

You know, my father left
when I was two years old.

I was raised by a single mom
and by my grandparents.

And so they...they gave me love

and they gave me an education

and they gave me hope.

MAN: I met Barack Obama in 1992.

He was an extraordinary guy.

He was thoughtful, he was funny,
and he was obviously well motivated.

In 2002, I heard

that he was considering a race
in 2004 for the Senate,

and I felt like

if you could elect Barack Obama
to the United States Senate

that you would be doing something

that you could be proud of
for the rest of your life.

She was the manager
for my first campaign.

Yes, I was.

Carol Holliwell,
from the west side of Chicago.

Right on. (LAUGHS)