Original subtitles

MAN: T minus 40 seconds. Everything looks good for launch.

NARRATOR: No planet beats Saturn for jaw-dropping beauty.

WOMAN: Saturn is the most photogenic planet in all the solar system.

Some of the pictures are to die for.

NARRATOR: But the postcards only tell part of the story.

MAN: Beauty's only skin deep.

It really is roiling and seething inside.

NARRATOR: Soar above the planet with its six-sided storms

for ringside action.

WOMAN: | could just imagine

what it might be like to like hold a ring particle in my hand.

NARRATOR: Even more mystery surrounds the impressive fountains of Enceladus,

where the secrets of life might spring from the moon's salty geysers.

MAN: This is the little moon that has it all.

And the samples are coming out in space,

there's a big sign there:

Free Samples: Take One.

NARRATOR: Then drop by the big orange moon Titan

and descend beneath its smoggy veil.

MAN: It would be one of the seven wonders of the solar system.

NARRATOR: Take to Titanian skies for a magical mystery tour.

MAN: The balloon just allows extraordinary possibilities for exploring Titan.

NARRATOR: Drift over propane lakes, flammable sand dunes and methane streams.

MAN: You could actually stand next to a babbling brook of liquid methane.

| sometimes wonder, what would that sound like?

NARRATOR: But nothing is as it seems here.

MAN: If you put your hand on a lava flow on Titan,

you wouldn't burn your hand, you would freeze it.

NARRATOR: All this and more, and only a billion miles from home.

Ready to take off?

There has never been a better time

to venture where no human has gone before...

to follow in the footsteps of our robot pioneers

and explore the planets of our solar system.

WOMAN: Houston now controlling.

NEIL ARMSTRONG: That's one small step for man...

NARRATOR: Imagine boarding a flight to Saturn.

What would you need to know before traveling?

The best ringside vantage points?

The must-see moons?

Think of this as your personal guide

to the splendor of the Saturnian system.

MAN: Oh, man, that's incredible!

NARRATOR: A wandering spot of light twice as far as Jupiter

and four times further than the asteroid belt.

Although it's a billion miles from home,

Saturn has always commanded our attention.

CAROLYN PORCO: Saturn is the most phenomenologically rich planetary system

that we have in our solar system

because of its rings and planet and magnetosphere

and an enormous collection of very diverse moons.

It has it all.

| mean, even just taking the rings as an example,

in Saturn's rings we find examples of the other rings around Jupiter,

around Uranus and Neptune,

we find them in Saturn's rings.

If you wanted to ask fundamental questions

about the solar system in general,

Saturn would be the place you would go.

MAN: And liftoff of the Cassini spacecraft on a billion-mile trip to Saturn!

NARRATOR: When the Cassini-Huygens spacecraft took off in 1997

for a close encounter with Saturn

it was packed with essential items for long adventure in deep space:

a power generator, extra fuel, a good antenna, and a moon probe.

Imaging team leader Carolyn Porco

made sure it took along a pretty good camera, too.

PORCO: He's actually made quite a task for himself.

NARRATOR: After all, this destination is the pin-up boy of the solar system.

Saturn might be the second largest planet in the solar system,

but like gas giant neighbor Jupiter,

it's a triumph of show over substance.

KEVIN BAINES: Saturn's, first of all, a big giant gas ball.

Actually it's a big giant ball of fluid,

and the outer parts of it are gases, atmospheres.

But as you go deeper it gets hotter and hotter

and also gets more pressurized,

and so as you get down deep enough you start getting sort of fluid effects.

NARRATOR: Saturn is a big boy,

but pound for pound, a cosmic lightweight.

It's big enough to swallow 765 Earths,

but as the least dense planet, it would float on water.

Like Jupiter, this is a world with nowhere to stand.

With no solid surface, it's hard to measure how long a day is,

though the cloud tops go around about every 11 hours.

But it's what's up above, not down below,

that will draw the crowds to Saturn.

TORRENCE JOHNSON: It's just hard to imagine anything more beautiful

than the ring system.

They're the first thing that any kid with a telescope wants to look at.

NARRATOR: Spotting these rings from a backyard telescope is a treat.

In an instant they can all but disappear

when Saturn tilts toward the sun.

JOHNSON: The overwhelming thing

that you as a space tourist would be struck by

is how incredibly thin they are.

PORCO: They are no thicker

than about one or two stories in a modern-day building.

NARRATOR: Interested in seeing for yourself?

Strap in, space travelers, it's quite a ride.

After seven years and a billion miles of space,

the Cassini-Huygens spacecraft faces its greatest challenge

on June 30, 2004:

to go into orbit.

First it had to maneuver through an obstacle course of rings.

TODD BARBER: The hopes and dreams of thousands of scientists and engineers

are resting on the next few moments.

We'd been to Saturn twice before with Voyager 1 and Voyager 2 spacecraft,

but rather than these quick Kodak moments

we wanted to take a nice, long, leisurely look at the Saturnian system.

The only way to do that was to slow down

and let Saturn's gravity capture us into orbit.

MAN: Current speed of the Cassini spacecraft,

50,000 miles an hour

and increasing as Saturn's gravity draws us in.

NARRATOR: Cassini presses on,

aiming for the gap between the outer F and G rings,

hopefully clear of orbital debris.

ROBERT MITCHELL: We turned the main high-gain antenna in the direction

the craft would see the ring particles coming toward it,

so that it would act as a shield.

NARRATOR: You are listening to the actual recording

of tiny particles hitting the spacecraft as it crosses the plane of the rings.

[crackling]

WOMAN: Let's go ahead and switch Canberra over to V zero.

NARRATOR: So far, so good.

But as Cassini disappears into radio silence behind Saturn,

everything rests on the spacecraft firing its engine perfectly

and slowing down.

It's a nail-biting wait at Mission Control.

WOMAN: Go ahead, com.

MAN: The Doppler has flattened out.

[applause]

NARRATOR: As Cassini emerges proudly from Saturn's shadow,

it turns to cross the ring plane again.

BARBER: To any potential inhabitants of the Saturnian system,

your eyes are not deceiving you tonight.

There is a 32nd moon gracing your night skies,

and that is the Cassini-Huygens spacecraft.

NARRATOR: With Saturn's 62 known moons,

Cassini finds itself in good company,

with out-of-this-world photo opportunities

to make even a seasoned professional gasp.

PORCO: Saturn is the most photogenic planet in all the solar system,

so | just, it, you know, | mean, you couldn't get luckier than me, right?

The ones that give me shivers are Saturn with the rings

where Saturn is a crescent.

We're looking down on the rings from above

and there's a moon in the background.

They are just artistic compositions.

You know, here | am leading a team of scientists.

Our duty, our job is to take images, and we have this fantastic target.

| kind of have this feeling like I'm the, you know,

standing on the bridge looking out the window, you know.

| have a very strong feeling of being at the forefront,

being out there exploring myself.

That's the thrill of it for me.

NARRATOR: The view from Cassini's bridge exceeds anything seen before.

LINDA SPILKER: Lo and behold, as we got close enough

it looked like the rings dissolved into all of these individual ringlets,

looking a lot like grooves on a phonograph record

for people who remember phonograph records,

and it was just very exciting

to try and figure out what could be causing that structure.

What looked like rather featureless rings in a telescope

now had thousands of features in them.

PORCO: | was surprised at how surprised | was

at the clarity of the images

because | thought to myself, well, for Pete's sake, you know,

I've been thinking about this for years, for 14 years I've been thinking about this,

I've been planning these images for a decade or whatever it was,

you'd think | would have, you know, anticipated,

well, we're going to have this kind of resolution,

it's going to look like this, and | just hadn't.

NARRATOR: For the first time, vivid details of Saturn's rings are revealed,

beckoning us to stare in wonder for a closer inspection.

Every tour itinerary has one main attraction.

With Saturn, you just can't miss the rings.

As imaging team leader for Cassini, Carolyn Porco has had a ringside seat.

PORCO: The rings consist of just countless particles,

and they range from big boulders the size of small apartment buildings

all the way down to the finest, finest dust particle

and everything in between,

and they're all orbiting like crazy around Saturn

at 20 to 40,000 miles per hour,

but it's like traffic on a highway.

Everybody can be going 90 miles an hour,

but relative to each other they're going very slowly.

If you could put a spacecraft there,

you could manage to move at the same speed,

then the speed wouldn't be that dangerous at all.

SPILKER: You can think of rush hour on a Friday night,

you know, on the freeway,

that the B ring has a lot of traffic and a lot of particles,

whereas you go to the A ring, it's a little bit better.

The C ring is more like being out in the country;

you aren't going to see ring particles too often.

NARRATOR: Possibly the remnants of a failed moon,

the ring particles have been flattened by gravitational forces

into a super thin disc nearly 200,000 miles across.

Edge to edge, that's almost the distance from the Earth to the Moon.

PORCO: | have in fact imagined myself orbiting Saturn,

hovering over the rings, it's hard not to.

SPILKER: | could just imagine what it might be like

to like hold a ring particle in my hand and see what does it look like.

Is it like a fluffy snowball if | start to pull it apart?

What's it like on the inside?

So you can think of each of the rings, A, B, C, D, like different beaches,

and so you'd want to collect samples from each of those rings.

NARRATOR: And the icy grains on these Saturnian beaches

are washed by passing traffic.

SPILKER: When a moon comes by, it creates a wake,

just like a motorboat creates a wake that goes behind it.

And | kind of imagine the ring particles

doing an intricate cosmic dance around the planet,

and you can almost picture like little ballet dancers

each with their own orbits and paths

and sometimes colliding and encountering and sometimes not.

NARRATOR: Deeper secrets of this cosmic ballet are revealed,

courtesy of a seasonal trick of the light.

Once every 15 Earth years,

as Saturn makes its slow trip around the sun,

summer swaps hemispheres.

In 2009, Cassini was in a perfect position to witness equinox on Saturn.

PORCO: The Sun at exact equinox

will be shining exactly edge on to the rings.

But a little bit before and a little bit after

the sun will be low to the rings just like the sun is now low over London.

Any vertical protuberances, either up or down below the rings

will cast very long shadows.

And we have in fact found that the rings aren't completely flat.

There are places where the ring particles in fact form these structures

that soar a mile or two or three above the plane of the rings.

For the first time in 400 years

we now know that the rings are three-dimensional.

NARRATOR: Enormous and enormously complicated,

the rings also form a major part of Saturn's amazing weather machine.

Upon arrival, you might be slightly disappointed

that the cloudy face of Saturn looks a little plain.

But the planet beneath the rings is wild at heart.

Saturn's apparently peaceful appearance

is due to a haze of high-level ammonia in the upper atmosphere.

By looking deep into Saturn in the infrared,

using the planet's own internal heat as a light source,

Cassini has revealed the planet's true nature.

BAINES: The winds on Saturn vary dramatically

from the equator to the pole.

In fact at the equator, we have huge winds.

We're getting close to 900 miles an hour now,

near the speed of sound in that planet.

ANDY INGERSOLL: The winds are stronger at Saturn than they are on Jupiter,

and that's a surprise because the two planets

are rather similar in terms of basic composition.

They're both gas giants,

and yet Saturn has less sunlight to power the winds

and the winds are stronger.

NARRATOR: Try explaining the six-sided vortex at the north pole!

INGERSOLL: Saturn has a hexagon.

It's some kind of a wave, but it's a permanent wave.

It's been there since Voyager discovered it back in 1980,

so this is just one more example of how atmospheric features,

which are basically nothing but gas,

they last forever on these giant planets.

NARRATOR: There is another permanent storm at the south pole;

not quite as strange, but gigantic in size.

At 5,000 miles across, you could almost fit the whole Earth inside.

INGERSOLL: The south pole has something that looks very much like a hurricane eye

except the clouds are five times the height of the eye wall

around a terrestrial hurricane.

BAINES: So it's kind of a window into the depths of Saturn

showing us just how dynamic the planet really is.

and it's sort of kind of neat.

NARRATOR: And at the bottom of this window,

storms within the storm.

Adding their own level of complexity to the weather forecasts of this alien planet

are the rings.

For half a Saturnian year

the rings block the light in the northern hemisphere,

and the other half of the year it's blocked in the southern hemisphere.

INGERSOLL: We are interested in studying seasonal changes on Saturn

because of this extreme effect of the rings.

Already we know that the sky was blue

when the northern hemisphere came out of the rings' shadow,

and it's now turned sort of pinkish, yellowish, hazy color

because somehow smog developed in the atmosphere of Saturn

once the sun started shining.

Probably not too different from smog in Earth atmosphere,

organic compounds or something.

NARRATOR: For a planetary weatherman like Andy Ingersoll, Saturn has it all.

INGERSOLL: If | had an airplane that could fly in Saturn's atmosphere,

| think it would be a wonderful sight

to be surrounded by rings.

It wouldn't get dark at night.

There's more light on the night side of Saturn from the rings

than there is from the full moon on Earth,

so you could certainly read a newspaper

on the night side of Saturn.

NARRATOR: There'd be no shortage of strange stories to read by ring shine

in the Saturn Express.

And a lot of breaking galactic news,

for Saturn is far from the only show in town.

Shiny, white Enceladus.

A bright ball hiding within Saturn's diffuse E ring,

this was a moon of little consequence until Cassini started sniffing around.

But something was fishy here.

BONNIE BURATTI: It was first found by the magnetometer team.

They saw this hint of something in the magnetic field of Saturn

wasn't just right,

it was being kind of deflected to the side.

SPILKER: It was like unraveling a puzzle.

And so the magnetometer team said let's go closer.

As we got closer, we watched as a star went through

and noticed the change in brightness.

Something is going on.

PORCO: We could see even from a distance

there seemed to be this material coming off the south pole,

and it was so dramatic and so unusual

that we thought, well, it might be a camera artifact.

NARRATOR: Enceladus is tiny, just 300 miles across.

Too small for any kind of dramatic geology.

BURATTI: If you look at Enceladus, it kind of looks like it's covered in snow.

It's very bright, it's as bright as freshly fallen snow.

PORCO: Everywhere you look there's fractures.

There are mountain ranges and there are deep chasms,

and when we finally looked at the south pole,

that's when it just became apparent,

that's where all the activity's going on.

NARRATOR: The team found something extraordinary.

Row after row of enormous geysers shooting water and ice crystals

out into space from the snowy white surface.

SPILKER: And so it was like a giant detective story,

piece by piece putting the evidence together

until finally you get back that really great picture, the smoking gun,

showing the geysers actually coming out from the south pole of Enceladus.

JOHNSON: Water and water ice are spewing out of giant cracks,

from a region about the size of Southern California

that's apparently just basically a big geothermal field.

You can think of it that way.

NARRATOR: It doesn't look much like California from orbit,

just cool, as you'd expect an icy moon this far from the sun to be.

But that's the mystery of Enceladus.

PORCO: | mean, the bloody thing is hot.

The south pole's hot.

OK, it's like it's as crazy as saying

the north pole of the Earth is hotter than the equator.

NARRATOR: The best indications so far suggest the source of the water

lies in a subterranean ocean or sea,

hidden beneath the icy crust under the south pole,

warmed by tidal heating.

BOB BROWN: It's been a mystery because Enceladus is so small.

It's not supposed to have that much heat.

We think that heat source underground melts water,

and that melted water,

which might be mixed with some ammonia and other things

to lower its melting point,

then works its way out of the ground and spews up into space.

CHRIS McKAY: Here is the surprise entry in the search for life.

This little moon that you'd expect to be pretty dead and dull,

and coming out of the south pole of it is a jet of water-ice.

All the things you need for life are there.

There's an energy source, there's a water source,

there's an organic material source, there's a nitrogen source,

check, check, check, all the requirements for life.

This is the little moon that has it all.

And the samples are coming out in space,

there's a big sign there:

Free Samples: Take One.

We just fly through and grab it on our way.

PORCO: | think it is the go-to place in our solar system right now

for investigating issues of astrobiological importance.

It wins out the game over Mars, over Europa, over Titan even

simply because of accessibility.

It's accessible.

If these jets are deriving from liquid water, then they're there for the sampling.

NARRATOR: The Cassini team has been flying the spacecraft

at heights as low as 15 miles on its way to the plumes.

Unbelievable precision flying for a remotely controlled robot

that was never designed for such a feat, a billion miles from Earth.

McKAY: From Cassini we learn that there's methane in the plume,

nitrogen in the plume, ammonia in the plume,

organic molecules in the plume, it's a real soup.

We're seeing a soup of organics

being spewed out into space, where it's freezing.

You can almost go there and jar it,

put it in a can and sell it on Earth as organic nutrient soup.

NARRATOR: On Earth, geysers and hot springs

are home to bacteria

with pedigrees dating back to the beginning of life.

They can also be breathtaking,

but nothing on Earth matches the Saturnian "Cold Faithful."

JOHNSON: Sitting there at the south pole of Enceladus

and taking a look at Saturn,

while you're sitting there watching this eruption going on,

would be beautiful.

PORCO: It wouldn't be a dangerous thing.

You would see these towering, towering dramatic fountains of just icy particles.

You would never see them stop

because some of them actually extend

tens of thousands of kilometers into the space above the south pole,

and in fact into orbit around Saturn.

This is how the E ring of Saturn is formed.

NARRATOR: Cassini has solved the mystery

of how at least one of Saturn's rings formed.

And this may help solve the bigger mystery of life beyond Earth.

Larger than Mercury or Pluto,

Saturn's Titan is the only other world apart from the Earth and Venus

to have both solid ground and a thick atmosphere.

RALPH LORENZ: Titan, if it weren't in orbit around another planet,

we'd have really no hesitation in calling it a planet in its own right.

MITCHELL: We knew going that Titan was going to be exciting.

Titan was a mystery hidden inside this hazy, smoggy atmosphere.

NARRATOR: Cassini confirmed that Titan is shrouded in thick orange smog.

Laboratory experiments have shown this could be the result

of 4.5 billion years of sunlight

reacting with the thick nitrogen and methane atmosphere.

Cassini's camera could only see partly through the haze:

the patches of light and dark looked like continents and oceans.

PORCO: The picture we had of Titan before we got there

was that it was going to be dark and eerie and cold.

And as dark as twilight is on the Earth even at high noon,

and you could be standing on a body the size of the Mediterranean

brimming with paint thinner.

NARRATOR: For over seven years, the European Huygens probe

rode piggyback on the American Cassini spacecraft.

On Christmas Day 2004, it was sent on its way.

Planet Earth never attempted to land on such a distant world before.

With the Huygens probe on final approach to Titan,

operations switched to European mission control.

LORENZ: The probe hurtled into Titan's atmosphere

at 6 kilometers a second.

The atmosphere would have been glowing violet

around the probe as it decelerated.

NARRATOR: Once on a parachute, the probe descended for the first 80 miles,

seeing nothing but smog and haze.

LORENZ: As we got closer to the surface, down at about 30 kilometers,

the surface features started to peek through the haze.

Progressively this landscape emerged

of these bright hills cut by these small, dark channels

that showed there had been rain there at some time in the past.

NARRATOR: The signal was taking over an hour to reach Earth.

No doubt Huygens was sending postcards from the edge.

JONATHAN LUNINE: There were just 20 of us

in the office area where the pictures were delivered.

It was dark in Germany, it was the winter,

it really felt like we were out there

gazing at this alien world that was just at our doorstep.

NARRATOR: The probe drifted further,

snapping these remarkable images all the way down.

LORENZ: We all kind of saw,

you know, a back yard in Arizona or the French Riviera,

wherever it was you were from,

you kind of saw some aspect of Titan that looked familiar.

PORCO: They were everything that our images from orbit were not.

Because you could see a dendritic drainage pattern

that looked like a river system

just like a river system would appear on the Earth.

Boy, that was heady,

that was like, ooh, it was like Jules Verne come true.

It was just spectacular.

MAN: Wow! Rocks!

WOMAN: Yes, yes, yes, yes!

Look, look, look!

MAN: We've just earned all of our paychecks.

NARRATOR: Huygens landed on Titan.

It sent back these few hundred pictures

until the batteries died and the probe froze solid.

LORENZ: The probe landed with a thud, on basically a stream bed,

an area littered with rounded cobbles,

that showed that these little rocks or ice particles

had been tumbled around in a stream

at some point in the past.

LUNINE: The whole thing just was very chilling,

not in the sense of temperature

but just in the sense of what we were looking at.

It was very, very alien.

BROWN: It's not a place where you want to just jump out there

in your shoes and socks and shorts and t-shirts.

It's roughly 200 degrees Fahrenheit colder than dry ice.

NARRATOR: With a surface temperature this low, nothing is what it seems on Titan.

McKAY: Titan is a world with liquids.

The difference is the liquid is not water.

The liquid is methane.

Think of gasoline, it's a liquid like white gas.

JOHNSON: So you've got rivers of methane flowing on the surface.

Anybody who has looked out of an airplane window

flying over deserts and things like this

say yeah, | sort of understand what's going on, on the surface there.

LORENZ: Because it's so cold,

water behaves like rock does and methane behaves like water does,

but everything's just sort of shifted along a scale of volatility.

NARRATOR: How do you end up with a landscape

that looks so much like home on a world that's so different?

NARRATOR: Methane soaks into ice like water into the ground.

And just like on Earth, any overflow will cut its path downhill.

JOHN SPENCER: Titan would be a wonderful place to visit.

Stand next to a babbling brook of liquid methane, running by your feet.

And | sometimes wonder, what would that sound like?

JOHNSON: In fact, as we took radar pictures of other parts of Titan,

we found even wilder things.

In the northern polar areas, there are entire lakes or even seas.

It looks to all the world like you could go take a boat

and go do jet skiing or something,

right, you know, up and down these channels there.

BROWN: Titan is the only other place in the solar system

that we know liquids exist on the surface.

So here you have vast reservoirs of liquid natural gas,

and, oh, by the way, we have thrown in some ethane,

which is a slightly more complex hydrocarbon,

and, oh, by the way, there's some propane in there.

Everybody knows what propane is; you use it in your backyard barbecue.

NARRATION: Cassini's radar spied lakes as big as inland seas,

even bigger than Lake Superior.

BROWN: Imagine standing on the shoreline

of what to you looks like an ocean of liquid hydrocarbons.

That's got to be pretty special.

NARRATOR: And if you think the lakes are weird, try the volcanoes.

BROWN: We think the material that comes out of Titanian volcanoes

is a mixture of ammonia and water

which allows water to melt at a much lower temperature.

NARRATOR: This is lava on Titan:

a stinky mix of water and ammonia, molten at minus 150 degrees.

BROWN: You can build anything

from small cones to large mountains on Titan out of this stuff.

If you were a visitor and you walked up and put your hand on a lava flow,

you wouldn't burn your hand, you would freeze it.

NARRATOR: In stark contrast to the cryo-volcanoes

and wet polar lake lands,

bordering the equator are vast Titanian deserts,

covered in dunes.

LORENZ: | think it would be one of the seven wonders of the solar system.

What you'd see is almost unending sea of massive dunes.

Exactly the same size and scale of dunes that we see on Earth.

Some areas where you see nothing but dunes

for hundreds and hundreds of kilometers.

NARRATOR: The by-product of billions of years of production

from the chemical smog factory in the upper atmosphere,

the grains in Titan's dunes may literally fall from the sky.

Like a rain of flash-frozen coffee grounds,

they are swept by the wind into deep piles that cover 20% of the surface.

And like a good coffee,

these Titanian dunes are dark and rich.

LORENZ: The dunes represent a massive inventory of organic material,

hundreds of times larger than all the coal for example, on the Earth.

NARRATOR: You're not likely to be hauling this alien coal home,

but the liquid hydrocarbons lapping on Titanian shorelines

could be very useful for the return trip.

LUNINE: There's more, let's call it fossil-fuel-type energy

than we actually have known reserves on the Earth,

by a factor perhaps of ten or even a hundred.

NARRATOR: That's a lot of gas in anyone's language.

But something even more valuable might be found

among the storehouse of organic molecules.

The answer to life, the universe and everything.

BROWN: How do you go from such simple material

like carbon and hydrogen and oxygen and nitrogen,

to something which asks questions about where it came from?

That's a huge leap.

And on Titan there's a real good possibility

that some of those really difficult to understand

intermediate stages actually occurred.

It hasn't gone to completion-- at least we don't think it has--

although there are some people who think that if we go to one of Titan's lakes

we will discover Titanian bacteria

that have figured out how to metabolize liquid methane.

McKAY: That's not a liquid that we life forms on Earth like,

but maybe a life form on Titan that grew up with liquid methane

would be perfectly comfortable there

and would look at shock at the thought that organisms would live in water,

oh, my God, those things on Earth living in water.

Pity those poor Earthlings.

We live in liquid methane. Much more pleasant.

NARRATOR: Titan is the ultimate test for life in our solar system.

If life exists under these alien conditions, then you might find it anywhere.

Even before the mission is over, Cassini has left a thirst for a return trip.

Planetary explorer Jonathan Lunine and aeronautical pioneer Julian Nott

think they know the perfect way to do it:

a robotic hot air balloon.

LUNINE: So what we're flying over now is very much like the Huygens landing site.

And I'd love to see those ravines on Titan,

those steep valleys where the methane is flowing and carving out the hills,

very much like what we're seeing now.

NARRATOR: The dream is to return to Titan

and drop a robotic balloon into the atmosphere.

A radioisotope generator will provide the electrical power and the waste heat

to give the balloon lift in the chilly atmosphere.

LUNINE: Titan has a dense atmosphere, it's cold, the gravity is low,

the winds are gentle, so ballooning is very easy.

JULIAN NOTT: I think this flight just makes the point so beautifully

why a balloon is a wonderful way to explore Titan.

If you're over an interesting area, it's very easy to come down,

maybe even land on the surface, lower instruments down.

LUNINE: One could cover with a robotic hot air balloon

the entire circumference of Titan in a space of perhaps six months.

NARRATOR: You shouldn't think of Titan as a place just for robots.

With a thick, protective atmosphere and plenty of frozen water,

Titan could be a more user-friendly destination for earthlings than Mars.

LUNINE: When humans do finally move out into the solar system,

and | think they will,

Titan will be seen as a somewhat distant but very attractive place to go play.

You don't need a pressure suit on Titan.

You don't have that feeling as the astronauts describe it

of trying to work with a beach ball between your arms.

MAN: Man, that /s hard.

NARRATOR: Breathing from a souped-up scuba unit

and outfitted in a cross between a super ski suit and a hazmat coverall,

future Titanauts could explore with confidence.

LUNINE: You just need that thermal protection and oxygen,

and then you can go play on the surface and take a balloon ride.

It will be a place where people will want to go

to see a truly exotic and alien world.

NARRATOR: Not even a minor rip in the suit will be life-threatening.

LORENZ: | did a calculation once

of whether the small amounts of carbon monoxide in Titan's atmosphere

would kill you before the hydrogen cyanide did.

Actually, it turns out both are probably only enough to give you a headache.

But the place would probably smell like an oil refinery.

NARRATOR: Speaking of refineries, refueling for the return trip

could be as simple as pulling up to the nearest lake

to fill up your methane rocket, now under test development on Earth.

And if you reach as far as Titan, why not a side trip to Enceladus as well?

McKAY: On Enceladus we are many steps ahead of where we are

in terms of Mars or Europa.

We already know that there's organics.

We already know where they are.

We already know how to get them.

It's time to bring them back to Earth and look at them

and ask the next level of questions: Are they biological?

PORCO: It may not happen for a very long time,

but | really think that's a must-do for us in taking the next step,

and to me the question

of whether or not life has gotten started elsewhere in the solar system

is the reason why we do this, you know,

because we want, finally, ultimately, we want to come to understand

why the Earth has been the successful abode of life that it has become.

NARRATOR: Moving now into the extended extended mission,

the Cassini team met recently in London

to take stock of where they'd been and to plan the road ahead.

It was the 58th time they'd met,

and fitting that they chose

the Royal Observatory in Greenwich to celebrate.

The prime meridian here is the longitude, the mark on the ground

from which all great voyages are measured.

This is the view back to our remarkable home planet

that the first human out here can look forward to.

A distant blue dot lost in the beauty of Saturn's backlit rings.

It's a real image,

another perfect postcard from Cassini urging us into the heavens.

LUNINE: Humans have looked out from the shores of seas and oceans

and imagined great adventures.

Now think about standing on the shore of an alien sea,

and we know those shores are there, we just have to go experience it,

and that's what I'd like to do.

I'd like to go land in a balloon, step out,

pick up one of those rounded pebbles and toss it at Huygens.

BAINES: I've proposed that maybe we have to talk

about a planetary park down the road

and where should we preserve for future generations.

You know, do we want to go in and mine Titan for its methane?

Maybe we'll go mess up other places perhaps,

but Saturn is just an exquisite place, and we should probably leave that alone.

NARRATOR: With so many interesting moons in its flight path,

NASA is making plans for what to do

when Cassini's mission comes to an end around 2017.

SPILKER: We want to make sure that the spacecraft

doesn't hit one of these bodies,

and so what we're going to do is put it into the atmosphere of Saturn.

BARBER: Crash it into Saturn and burn it in a blaze of glory

after a rich 20 years of exploration in space.

MITCHELL: All the molecules that currently make up the Cassini spacecraft

would still be at Saturn, and in fact will be there forever.

NARRATOR: A fitting fiery funeral

for one of the greatest interplanetary voyagers of all time.

It might be a ball of gas and float in water,

but Saturn is a very solid destination

both for science and for viewing spectacular sights.

We've only begun to realize the riches it offers,

and only because we sent a spacecraft to stay.

It's the same story everywhere in the solar system.

You'll never know what you're missing if you never go.