Original subtitles

The sun is the center of our solar system.

The earth is completely dependent on its energy.

We could not live without it.

But, in the future, the sun will change.

One day, its benevolent influence will turn

against the planets that it has nurtured

for so long.

944 is N.A.

The astronauts who went to the moon,

thought that they would be the first in a long line

of travelers in space.

But in fact, there have been no more.

The last man to set foot on another world

was Captain Gene Cernan.

The moon is bland.

It's gray in shades, and other than the color

you have brought there yourself, the only

color you see out there is the earth.

The multi-color blues of the ocean and whites

of the snow and the clouds.

And the earth itself is three dimensional,

and it moves through this blackness with logic

and with purpose and with beauty

beyond comprehension.

For the first time ever, you're beginning

to see the earth

as a planet, when you never saw it that way before.

It's spiritually different to be able to see

the earth evolve, see something that is very

strange and yet very familiar.

And it's something I guess I didn't expect to see.

And as you head out to the moon, that earth grows smaller.

Very, very quickly at first, until the point does come

when you can literally block out all humanity.

Your identity with reality is something

no bigger than the size of your thumb.

Since the moon missions, no spacecraft

or probe had been far enough away to capture a view

of our planet from a greater distance.

Until Voyager.

The unmanned Voyager spacecraft were launched in 1977.

They left our solar system and headed for

interstellar space.

On their way, they have sent back photograph

after photograph of the planets in beautiful detail.

But there was one more picture

that just had to be taken.

An image which provided a unique

perspective of our earth.

The idea to me that Voyager was gonna be

in a location that no other spacecraft had been

before, equipped with sophisticated instrumentation

so that it could turn around and take a picture

of all the planets in the solar system and I thought

that this would be a riveting collections of images.

You know, a first.

Voyager scientist Carl Sagan had long

campaigned for the spacecraft to be turned around.

But the risk of sun damage to the cameras was

seen as too great.

At first, Carolyn Porco met with the same response.

And they said, "Well, there's really no scientific

justification for this.", and I couldn't argue with

that because there wasn't.

The planets were gonna be just pinpoints.

They were gonna be just pixels.

They couldn't see it.

But as Voyager came to the very end

of its mission, there was nothing to lose,

and on Valentine's Day, 1990, 13 years after

leaving earth, Voyager turned its cameras back

towards the now-distant planets.

The spacecraft was 3.7 billion miles away.

Each signal took five and a half hours to

reach the earth.

No single image could capture the entire

solar system and the mosaic of pictures

stretched six meters across.

The planets could barely be made out.

Mars and Pluto were too small to be recorded,

and Mercury was lost in the glare of the sun.

And I took my hand and swiped the glossy print

trying to remove the dust off it, okay, and it

turned out that one of those specks of dust

was the image of earth.

It was that small.

These were not tremendously beautiful

glorious images, I mean, we knew they wouldn't be.

That wasn't the point.

The portrait of the planets that

has now been taken,

is, it seems to me, in the same tradition

as the extraordinary color photographs of the

whole earth taken by the Apollo astronauts

on their way to the moon.

This looks like more than a dot, but it is

in fact, less than a pixel.

In this color picture you can see that it is

slightly blue, and

this is where we live.

On a blue dot.

I talk about standing on the moon and looking

at the earth and describing it as humanity,

my identity with humanity.

I mean, think about moving outside of our solar system.

And seeing it as the Voyager saw it.

But that's what we've now done.

We came to know the solar system.

We came to know it's history.

We came to know how it's configured.

And we're starting to piece together how it

possibly came about, basically because of

the Voyager mission.

The Voyager mission gave us a perspective

on things that we just didn't have before.

But what Voyager showed was just one moment in time,

a snapshot.

All the planets will change and evolve in

different ways before the end of their lifetime.

One thing we are certain will change

are the rings of Saturn.

In a hundred million years,

the rings won't be there any longer.

They will be worn away by the bombardment of

meteorites, little bit by little and that

material basically gets lost to the Saturn system

or else it ends up spiraling in and being

consumed by Saturn.

To me, the whole solar system will be

completely reconfigured.

You wouldn't recognize it.

In one billion years at Neptune,

the moon, Triton, will spiral inwards towards its

planet gradually getting closer and closer

until the moon is ripped apart.

Out of this destruction will come something

even more spectacular.

Close in to Neptune is a

collection of satellites, and if you took those

satellites and bashed them all up at the same time,

the material would spread out to form a ring

system that would look pretty much like Saturn's

rings, so we might, while losing Saturn's rings

we might have, in the future, another beautiful

supernatural-looking ring system around Neptune,

which wouldn't be too bad a swap.

Whatever the solar system will look like,

the most important question for its future

is what will happen to our sun?

The sun's fate will determine ours,

but how will it change?

The answers lie in the moon rocks gathered

by the Apollo astronauts.

You got some left in there?

I got some small ones and some big ones.

Don't fill it too full.

We took some of the rocks and brought

'em in the spacecraft with us.

We when we would get out of our suits and we'd

examine the rocks with our bare hands,

the dust would literally penetrate into

the pores of our skin and beneath our nails.

I mean, just way down in.

It was weeks and weeks before, when I got back,

before that load of dust ever grew out with my

nails and was de-penetrated, if you will,

from my skin.

For billions of years, constantly

bombarded by solar particles, the moon gives

a unique insight into our sun.

Its rocks act like a sponge, quietly absorbing

the particles and so keeping a record of the sun's activity.

The Apollo astronauts removed the rocks buried

beneath the lunar dust and brought them home.

The rocks show how the sun's energies fluctuate over time.

They reveal it has been much more active in the past.

The sun is aging, and we too are part of that aging process.

I think thinking about the planets

and the sun and the solar system as a family of

objects and wondering what's their long-term future?

I think it's a sobering process because we tend

to think of the earth as forever.

The eternal sea, we call it.

But yet, when we start looking at the planets in the

solar system, we realize that they're not eternal.

The earth is in some sense, halfway though its

lifetime, its expected lifetime.

We are living on a middle-aged planet.

The earth is middle-aged because the

sun is middle-aged, and as the sun gets older,

it will start to work against us.

Since it's creation, it has been getting 10% hotter

every billion years.

In one billion years' time, it will have become so

hot that it will begin to destroy life on earth.

Plants and animals will find it hard to cope with

the rapidly forming levels of carbon dioxide.

Our time on earth could be limited by this

changing solar system.

If we were to come back on our solar

system in a billion years, it's still a place where

you can find liquid water and go for a swim.

Earth is still the planet of choice, I think,

in a billion years.

Maybe two billion years or three billion years,

it's now starting to become a hothouse here.

The oceans might start warming up and evaporating

into the atmosphere, creating a runaway greenhouse.

The earth would be like Venus, very thick

atmosphere trapping in a lot of heat.

Then, as the sun gets even brighter,

the earth might eventually just vaporize.

We can see the gradual steps in the earth becoming

less and less desirable as a place to live.

There will reach a point where earth is no longer

habitable, so, ultimately, we have to find another

place to live.

5-4-3-2-1

We have ignition and we have

liftoff on NASA's Mars Climate Orbiter as we

continue to explore the mysteries of the Red Planet.

Oh, we've always imagined life on Mars, and yet

when we got there to look for life, we didn't find any,

and it was all the more puzzling because there was

everything that life would need in terms of the elements.

But the key ingredient for life on Mars,

liquid water, is missing.

We now know that water once flowed in abundance

on the planet.

The many channels in its surface were created by the

action of seas and rivers, but as the planet cooled

over millions of years, water turned to ice and

became trapped below the surface.

If we assume that there is water tied up

in the polar caps and as the sun gets much brighter than

it is now, and the surface temperature of Mars gets

above the melting point, then the polar caps are just

gonna turn into oceans and Mars will, once again,

have a water-rich environment and that could trigger

a release of large amounts of CO2 very quickly,

once you cross the freezing point.

Mars may have its second re-awakening

and could be suitable for life, and that would occur

when the sun was two or three times brighter than

it is today.

Springs will emerge through the pores

of the planet surface.

The desert-like surface could again have the

possibility of life.

And as the water vapor rises, the planet will rebuild

its atmosphere and once again be shrouded in white

cloud, like the earth.

As the sun gets brighter, well, it could

be too much of a good thing from Mars' point of view,

if you go from being too cold to being too hot.

Mars is probably not a long-term place for home,

but if you think about it, there's no place that's

gonna be suitable for life forever.

It's just a question of how long.

How long do we wanna have the rent on this planet

or that planet?

Earth, we've been lucky, we've had several billion

years, Mars we may have half a billion years, but

still, a place to live for half a billion years

is a good place.

As the sun warms the moons of the distant

planets that perhaps will be the best hope for life

in the future solar system, Jupiter's moon, Europa

already looks the most likely candidate.

Far below it's dense and inhospitable layers

of ice, some form of primitive life may, even now, exist.

Dr. David Black is chairman of the NASA Origins Program,

a project designed to search for the signs of life in space.

The moon Europa is very very intriguing, it appears.

It's an ice covered planet, but some of the features

that we see on the surface suggest that, in fact,

there's a liquid ocean below that.

How extensive, we don't know that yet, that's one of

things that we'll try and explore in the future.

We know that deep down in our own ocean,

where there's no sunlight to speak of, we've seen signs of

life near these deep-sea vents, the smokers,

as they're called.

So, it's possible that there's an analogous situation

going on on Europa even as we speak.

There may be very primitive forms of life there.

In the future, Europa will warm up, and

its icy surface will start to melt.

It could become a watery world

where life might just survive.

I'm not sure that this means it's a

vacation spot in the future, but it's at least a place

where we might see life at a very very primitive stage

another place in the solar system.

The Cassini-Huygens Mission left Earth

in October, 1997 on a seven year journey

to Saturn and its moon, Titan.

As the sun continues to heat up, this little moon

might also develop life.

It's the only other planetary object

that looks like our own earth.

It's the only other object that we know of that has

an atmosphere of nitrogen, and also, we know that there

is an organic chemistry taking place inside this

atmosphere and we have the creation of all those

molecules that we find on earth.

The only thing that is lacking is a little bit

of temperature, little bit of heat,

and a little bit of oxygen.

Along the beach here is where the

Huygens probe will land.

The question is, will it be able to see the oceans?

In Paris, Athena Coustenis and Chris McKay

are studying some of the latest telescope images of Titan.

Right now, it's very cold, but it has all the ingredients

to being a very nice place to live.

In some sense, it's like a pie frozen in the freezer,

and when the sun gets more bright, it would warm up and

bake and have a nice water-rich environment with a

nitrogen atmosphere and we know today that there's

rich organic chemistry occurring in the haze in Titan's

atmosphere, that organic chemistry could, in fact,

be the seeds for life so even if life from earth doesn't

migrate to Titan, Titan could initiate life of its own

when the sun becomes bright enough to cook that pie.

Titan is covered entirely by thick cloud deck,

and it does not allow you to look down to the surface.

So we have been very frustrated.

For years, we have been trying to get a glimpse of

the surface of Titan and nothing would come out.

The tiny European space agency probe,

Huygens, will parachute through the thick Titan

atmosphere and descend to the surface below.

To me, the most interesting question

that Huygens will answer is,

"What is the nature of the surface?

What is that material that it slams into or

splashes into?

Is is liquid hydrocarbons that have accumulated

over billions of years, literally a sea of natural gas,

or is it solid ice or solid CO2 or is it something

that we're not even expecting at all?"

No matter how earth-like it becomes,

eventually, even life on Titan will become impossible.

Like the earth, it, too, will finally be uninhabitable.

Ultimately, there is no hope for survival within

our solar system.

The sun is on the path to destruction

and nothing can stop it.

This fact was first discovered by Father Angelo Secchi,

a Vatican astronomer.

In 1868, he peered through his telescope as he had done

many nights before.

He gazed up at a dying star far above the earth.

It was Gamma Canes Venatici, 400 light-years away.

He was using a new technique to analyze starlight,

spectroscopy.

The light was split into colors using a prism,

and the chemical composition of the star could

be determined from the patterns of color.

Secchi had recorded blue stars and yellow stars

in the past, but that night, he added a new star

to his list.

A red star.

Secchi started to catify them and give them names.

The red star, called Superba, the arrogant star,

because its spectrum is very very different.

The real reason it looks very different is

because it was cooler, and it was big and luminous

and it is what we now know as a red giant star.

This was one of the most significant

of all Secchi's discoveries,

but its secrets were not to be revealed for

another fifty years.

Cambridge astrophysicist Douglas Gough is a leading

solar scientist.

In the 1950's, he was inspired to work on stars

after studying under Sir Fred Hoyle, one of the

century's greatest cosmological thinkers.

Fred Hoyle is one of the leaders of the

revolution that has overtaken astronomy.

His views are often controversial, as he strives

to understand the very origin of our universe.

Internationally famous, he commutes regularly

between Cambridge and California.

Fred Hoyle, the man who coined the

phrase "Big Bang", was one of the first people

to realize what was going to happen to our sun.

He had a really broad vision of

how everything in physics fitted together,

and I found that very very inspiring.

He picked out the most important things that

needed to be understood, to get the whole story

right, and then pursued them with vigor and enthusiasm.

During WWII, Fred Hoyle devoted his spare

time to developing theories on the evolution of stars,

and on the destiny of one star in particular.

Ours.

It was known that red giants existed,

but one of the things that Fred

contributed to was understanding that

these are towards the end of the life of a star.

In those days, there were no computers,

and so, therefore, he really had to use his brain and think.

He started to understand why stars became red giants.

Our sun was destined to become a red giant

from the moment it was born.

Created in a blinding flash, every star has a finite

supply of fuel to take it into old age.

Fred Hoyle discovered that a red giant is

a star about to run out of fuel.

He realized, too, that this limited the sun's future.

Stars are like people.

They're born, they live and they die and part of the

way a star dies is that it becomes a red giant.

So, something like the sun, for example, will swell

after another roughly five billion years is our best

guess, nothing that I'm going to worry about.

It will swell up to a size perhaps as large as

where the earth is in its orbit.

When the sun becomes a red giant, it puffs up,

becomes enormous,

very distended, whereas the core shrinks,

and it's tiny, it's like a pea in a swimming pool.

A red swimming pool because the star is red, and

it gets very turbulent, lots of motion, and the sun

will expand 50, 100 times its current size.

The sun will engulf Mercury and Venus, probably.

It probably won't get as far as the earth, we're not

100% sure of that, but it will get a good fraction

of the way to the earth, so it will fill the sky, almost.

It'll be this enormous big, red object in the sky.

The process of burning hydrogen in the

sun's core will eventually come to an end.

But hydrogen trapped in its outer layers beyond

the core will cause a final burst of energy out

into the solar system.

As the sun expands, the earth will start to vaporize.

Its surface will disappear in the intense heat.

It'll be rather like a cube of ice in a glass

of boiling water, so the outside will start to melt

as the ice would, I mean, evaporate as far as the

earth is concerned, but the inside may survive.

It depends on how big the sun gets.

Maybe it won't completely engulf the orbit of

the earth, but nonetheless, we will be fried for

sure, so if we have any inclination to save ourselves

we better high-tail it outta here before then.

As the giant red sun gradually cools,

material from it will disperse into space, leaving

behind its tiny core, a white dwarf star.

Ultimately, it will fade into darkness

and our solar system will fade with it.

What planets are left will still be orbiting around it,

the inner planets will have gone,

and, they will be orbiting around something which is

just as heavy, but which is very small and very

dim, so everything will be black and cold,

and it will be night all the time.

As our sun dies, there's gonna be

other stars and suns that are born.

I would expect that by that time we would have

been smart enough and moved far enough into the future

to hitch a ride on another star out there

and find another planet.

When we go to a dark place, anywhere here on earth,

the desert somewhere and we look up and we say,

"My golly, look at all the stars, I didn't know there

were that many stars."

You realize how many suns and

how many planets and how many stars are out there

that we know so little about because think of all the

ones we can't see.

A handful of sand contains one million grains.

One thousand handfuls make one billion.

There are 100 billion individual stars within

our galaxy and there are at least 50 billion galaxies

in the universe.

There are more stars in the universe than there are grains

of sand on every beach on earth.

One of the things we learn in astronomy is that

almost all young stars have discs associated with them.

Now, we believe these discs are the precursors,

the things out of which planets are formed.

How many of these discs of dust

actually go on to form planets is unknown.

But now, astronomers are setting out to hunt

for planets around distant stars.

The detection of extrasolar planets,

or planets around other stars,

is difficult because the first

idea is only to look and see if we can see planet,

and this simple idea is not so efficient because

of contrast of light between the star and the planet

is so huge.

It's about one billion, so it's absolutely impossible,

at least at the present time to directly detect and

take a picture of a planet.

Planet hunter Michel Mayor and

his colleague Didier Queloz have been trying

to find planets around distant stars.

Every few months, they take the long drive from

their base in Geneva to a little-known

observatory in Saint-Michel, Haute-Provence,

with no chance of ever seeing a planet directly

from earth.

The two of them developed a way of looking

for planets indirectly by looking at the motion of stars.

A wobble in the star would indicate the presence

of a planet, it's gravity tugging against the

star's orbit.

The planet is turning around the star, in fact, the

star itself is turning also a little bit and if the

planet is doing a very big orbit,

the motion of the star

will be extremely small, so this is, the idea is,

to look for this wobble.

[{Voiceover] In December, 1994, they discovered a star

whose wobble could only have been caused by something

like a planet, but whatever was causing this wobble

was stranger than anything they had imagined, and was

orbiting the star very quickly, going right round

in a matter of days.

We detect something completely crazy which was planet

of the size of Jupiter, but which had a period of five

days, less than five days, it means very close to the star.

And nobody was expecting this, even us.

They were extremely cautious about

revealing their discovery.

It was not the first time that such an extraordinary

claim had been made.

There were half a dozen or so claims of the detection

of the first planet ever around a star.

All turned out to be bunk, in short, and various

people contributed to the de-bunking of these planets,

but because of this rather sordid history of planet

detections that proved to be false, there was an

extraordinary burden placed on the Swiss team to

be extra careful.

Before they could double-check their

data, the star, 51 Pegasus, disappeared below the horizon.

They had to wait a frustrating six months to

observe it again.

We had to be sure that this was real, and we had to

work a lot to be convinced that the only explanation

for this phenomena was a planet.

The Swiss team had discovered the first

world outside our solar system.

But a planet with such a fast orbit could easily

be observed by another team.

They had to keep it secret until they were

ready to announce the discovery.

We were joking on this secret,

and my son,

he was 17 years old at the time, say,

"Oh, I know the number."

because he was measuring with us during the

night, he was

clever enough just to see that every

light we were measuring was the same star and we have

a long discussion with Didier if we have to kill him

to keep the secret.

Others had been looking for extrasolar

planets since the early 1980's.

At the Lick Observatory in San Francisco,

Geoff Marcy was planet hunting.

When the discovery of 51 Pegasus was announced,

he took a closer look at his data and realized

he'd long since found what he was looking for.

We were developing our technique for looking for

wobbles of stars and not actually analyzing our data,

and we only found out a couple of months later that

among the 107 stars that we had been monitoring,

two of them leapt out immediately as having

planets and in the successive few months, four more

stars leapt out as having planets.

So, by April of '96, we had discovered six planets

around other stars in rapid succession.

Geoff Marcy's team have continued to

discover new planets.

Well, the pace of discovery is frenetic is all I can say.

We're discovering about a planet every month.

I expect that to continue for the next few years,

and I think the next few years will find that we've

scoured the galactic neighborhood for all of the

big planets there are to be found.

Planet hunters have now uncovered

over 100 planets outside our solar system.

But these newfound planets are very different

from anything that was expected.

It was thought impossible for a giant planet

to exist close to its star.

They should only form far out in the coldest

ice-bound regions of a solar system.

The image we had, a formation of planets, was

very much based on one system.

Ours.

And so, we thought we had understood the process

by just looking at one system.

Now here it comes and they are totally different.

This is all a system that looks different.

These are strange planetary worlds.

So strange that some scientists have questioned

whether they are really planets at all.

Some argue that until we've actually seen them

directly, we cannot be absolutely sure.

Others remain convinced.

The chances that this is not a planet are so remote

that nobody believes it.

It would be an incredible thing, it would even be

more incredible to have something that mimics so

closely the presence of a planet than having a

planet itself.

The easiest interpretation at this stage, and in fact,

the only one I think is that if it walks like a duck

and it quacks like a duck, what we've found are ducks.

And I think that's the best argument that we've, in fact,

found planets around other stars.

But how much can be found out about

these other worlds?

With Michel Mayor, Athena Coustenis is looking at

the new data from 51 Pegasus.

She has developed a new technique that identifies

the chemical makeup of the star's planet,

something previously thought impossible to

measure from such a distance.

Three years ago, we have absolutely no idea that

we can have access to the chemistry of a planet, so

it's sometimes, science is exciting.

The idea we had was to use the star itself

to push forward its planet and tell us something about

what its planet's made of.

They cannot see the planet itself, but

they can see changes in the lights from the star.

The interaction between the wind of the star and

the atmosphere of the planet create big tail flowing

away from the planet and if the light of star goes

through this tail, you have access to the chemistry

of the planet.

By analyzing the changing spectrum of

light from the star, they hope to find out exactly

what the atmosphere of the planet is made of.

Of course, if we manage to detect an atmosphere,

it's definite proof that this is a planet.

However, the future for planet hunting

will lie not in ground based observations,

but in space missions.

200 miles above us, the Hubble Space Telescope

is providing a unique insight into deepest space.

Among the thousands of galaxies that Hubble has

photographed, there must be a myriad of other planets.

But to see even the planets in our own galaxy,

The Milky Way, we need a vast telescope in space.

Probably the most important telescope in the line

of telescopes that we're thinking about for the Origins

program is a device that we call "The Planet Finder".

This is a fairly large telescope that will probably

be what scientists call an interferometer.

It's really more than one telescope.

It'd be made up of four or five small telescopes

that will mimic a very large telescope.

Telescopes like Planet Finder

will allow us to see extrasolar planets for

the first time, bringing the unseen into sharp focus.

The Planet Finder will provide us not with a picture

in the sense that we're used to seeing from

satellites in orbit around the earth, we won't

get that kind of a picture.

What we will get is

a dot is about all we'll get in

terms of the image, but the signal that comes from

that dot will be the key thing for the scientists.

Rock 'n roll Atlantis.

But what can a dot of light tell us

about another planet far away in the universe?

Before the probe Galileo headed for Jupiter, it

looked down on Earth to see if life could be

detected from space.

What Galileo showed us was that, in fact, these

molecular signatures that we think are indicative

of life on the planet were really there and you

could separate them out so it gave us some confidence

that by looking for similar signatures when we look

at the atmospheres of other planets, that we could

maybe infer from those signatures

that life was there, as well.

The signs of life as we know it are

universal, the combinations of chemicals on earth

could be repeated on any planet, and all of these

chemicals can be identified from a distance.

And we'll be looking for things like signs of

water in the atmosphere, carbon dioxide, which would

indicate that it's got a substantial atmosphere.

Ozone, which says that there's oxygen in the atmosphere.

And all these taken together, each one tells you

something about the likelihood that the planet is

either inhabited or may be habitable.

If you can find methane, especially with oxygen in

the atmosphere, it's a slam-dunk, as we say in

America in basketball, that you can conclude that

life is on that planet.

Somewhere in a solar system, many now

believe that the combination of these elements will

almost certainly mean life.

If you hand a biochemist a planet with a rocky

surface with a temperature that's not too cold so

that the water is frozen into ice and not so hot that

the water is evaporated into steam, but a temperature

that, in the words of Goldilocks, is just right for the

liquid form of water, it will pool into lakes and

rivers and streams and of course, oceans, and the

biochemists are unanimous that the laws of chemistry

will take over.

You'll end up with complicated organic molecules

that we, in fact, would call life.

But we've yet to find a planet that

falls within this "Goldilocks" zone and is rocky

and small enough to be suitable for life.

A planet like the earth.

I would be happy to find an earth-like planet

even if it's cold or far away or close by or too hot

or anything.

I'd like to see that these exist, as well, because

if I find one of those, I can be sure that there are

others elsewhere that might be more suitable for life.

So, I think the major question is to see one, then

we'll start being picky and wanting them at the

right temperature.

Like Voyager looking back at our family

of planets, telescopes in space may one day allow us

to look at distant worlds.

The earth is a very insignificant, at least in a

cosmic sense, very significant to us, but in a cosmic

sense it's that pale blue dot as Carl Sagan has said

off in the distance.

And in many ways, much of what the Origins program

is about is a search for yet another example of the

pale blue dot.

Some 500 years ago, Copernicus, in effect, removed

the earth from the center of the universe.

We have since had great observations that show

that the sun itself is nothing special, neither is

our galaxy, but the thing that remains is that we've only

have evidence from one example of life and that's

the life that's on this planet.

We are so obsessed with finding other life forms

and understanding how life originated, it's like life

needs to seek out itself.

That's manifest in our thinking.

Almost certainly, any expedition we mount to

another solar system will be to a solar system that

looks like it's going to be most like our own.

It's not beyond the stretch of imagination

to think of sending a probe, an automated probe...

Imagine that your sitting at a control room 50 or 60

years in the future after this probe was launched, and

suddenly there's this signal that comes back and you're

not quite sure where it is and you scratch the computer

archives and by the way, this probe is actually one we

sent to Beta Hydrae 50 years ago, and now it's

telling us what that remarkable place is like.

I think that would be very exciting.

It was curiosity about what lay

beyond our atmosphere that drove us into space.

But the further we venture in our search for new

worlds, the more we are struck by the special

beauty of own planet.

Our tiny Earth, remains for us, the most

inspiring place in the universe.