All language subtitles for Kingdom Of Saturn Cassinis Epic Quest (2017)_en

She has traveled nearly

four billion kilometers.

Delivered a probe to the
surface of a toxic moon.

And produced science nine years longer

than originally planned.

She discovered flowing liquids
where none were expected.

Phantasmagorical structures
on a planet's icy rings.

A weirdly breathing magnetosphere.

And a possible abode of life.

On a tiny world with a
startling atmosphere.

Now, after 20 years in
space, controllers have sent

the Cassini spacecraft
into a daring spiral

to end her remarkable journey.

Streaking along Saturn's upper atmosphere

at more than 124,000 kilometers per hour,

Cassini streams data and
images back to Earth,

until heat and turbulence tear her apart.

Three, two, one.

And liftoff of the Cassini spacecraft

on a billion mile trek to Saturn.

On the evening
of October 15th, 1997,

a powerful Titan 4B booster leaves

launch complex 40 at the
Kennedy Space Center.

All systems go.

The product of two decades

of intense collaboration between NASA

and the European Space Agency,

in particular the Italian Space Agency.

And the
solid rocket boosters

have been jettisoned.

Some on Earth
have protested this moment.

They fear that if the launch
fails, Cassini's nuclear

electric generator will
spread radioactive plutonium.

No nukes in
space, no nukes in space.

As she glides
outward on a nearly seven-year

transit to Saturn, scientists organize

their investigations based
on past probes' findings.

Their questions nest within one another,

like the giant planet's concentric rings.

Does Saturn have a solid surface?

Or do its clouds thicken
down to extreme densities,

perhaps creating exotic forms of matter?

Like metallic hydrogen.

Is there a rocky core?

Why are the rings so bright?

How old are they?

What's going on beneath the
thick orange clouds of Titan,

Saturn's largest moon?

How are Saturn's moons and rings related?

What will this giant planet tell us

about the evolution of
solar systems, and of life?

At its distance of nearly a
billion and half kilometers

from the sun, Saturn's orbit
lasts 29.5 Earth years.

Over the past Saturn year,

Earth has added some 2.5 billion people.

Average life expectancy rose
from age 64 to almost 72.

The internet has exploded.

It now has almost four billion users,

with the half the world's
population now online.

In the time of Cassini,
our world has been consumed

with new ways of communicating,

connecting,

working,

living,

and seeing each other.

Saturn is the Roman name for Chronos,

the Greek God of time,
who ate his children

in a fit of jealousy.

In myth, as in the ever-changing universe,

time is the devourer of all things.

To catch up with Saturn,
mission planners have sent

Cassini on a series of fly-bys,

each time hitching a ride
on the planet's gravity

to speed her on her way.

Pioneer 11 flew by Saturn in 1979.

Voyager One in 1980.

And Voyager Two in 1981.

Cassini will become the
first craft to orbit Saturn,

captured by Saturn's
gravity on June 30th, 2004.

Cassini's prime mission
was to be four years,

but she will remain healthy far longer.

Her assignments will be extended twice,

an additional two-year equinox mission,

and a seven-year solstice mission.

Yet Cassini's entire exploration

will span less than half a Saturn year.

From late winter

through early summer.

The Saturn system lies 9.5
astronomical units from the sun.

That's nearly 10 times
farther out than Earth.

The whole grand clockworks speeds along

at 34,821 kilometers every hour,

more than 10 times faster than
a bullet fired from a gun.

The planet spins fast,
rotating about its axis

once every 10 hours and 39 minutes.

So while a year on Saturn
lasts only Earth 11,000 days,

it's about 24,500 Saturn days.

Made up mostly of hydrogen and helium,

Saturn is the least
dense of all the planets.

It's often said, if you could
find a bathtub big enough,

Saturn would float.

That's not quite accurate,
but its density is lower

than that of the liquid
water in Earth's oceans.

And it's big.

You could pour 764 Earths
into the volume of Saturn.

This mission is officially
named Cassini-Huygens,

honoring two remarkable men
of 17th-century science.

The French-Italian
Giovanni Domenico Cassini,

also known as Jean Dominique Cassini,

and the Dutch Christiaan Huygens.

Key players in the scientific revolution,

they collaborated and competed
throughout their lives.

In the process, transforming
astrology into astrophysics.

As director of the Paris Observatory,

Cassini built and refined
long-tube refractor telescopes.

But Huygens found a way to
remove the cumbersome tube,

inventing the so-called air telescope,

and its better engineered eyepiece.

In 1665, Cassini co-discovered
Jupiter's great red spot,

and used it to time the
big planet's rotation.

Huygens, applying Galileo's ideas,

invented the pendulum clock

and developed a balanced spring watch,

both pivotal innovations
in the study of space time.

Cassini published maps of
surface markings on Mars,

though Huygens had
actually seen them first.

And Huygens pegged the
length of the Martian day

at 24 and one-half hours,

just seven minutes shy of the
correct figure we use today.

By getting parallax observations
of Mars, Cassini was

the first to estimate the
size of our solar system.

And Cassini used Galileo's
method of measuring time

by watching eclipses of Jupiter's moons

to lay out lines of longitude on Earth.

Endeavoring to perfect the
geometry of optical lenses,

Huygens developed the
wave theory of light,

setting the stage for
today's quantum mechanics.

Cassini explained the
so-called zodiacal light,

seen by astronomers as
the reflection of sunlight

off dust in the plane of the solar system.

Toward the end of his
life, Huygens determined

liquid water to be a
key factor in searching

for extraterrestrial life,
a quest now undertaken

by the Cassini spacecraft
and its Huygens probe.

We've known Saturn as the
ringed planet since 1655,

when Cristiaan Huygens
explained what Galileo

had seen 45 years earlier.

But if you were standing
on most of Saturn's moons,

you would have a hard time
actually seeing the rings.

Because most moons ride in the ring plane,

you could only view them edge on.

From the right, watch tiny Prometheus,

just 86 kilometers across,
pass behind big Tethys,

1,062 kilometers side.

Little Pandora scoots
through from left to right.

Here, medium sized Mimas,
traveling 14 kilometers

per second, glides in
front of the larger Rhea,

at eight kilometers per second.

When Cassini launched,

18 moons were known to orbit Saturn,

and 13 more were suspected.

By the end of Cassini's mission,

astronomers will confirm 53,

with another nine marked as conditional.

Only one of them is huge.

Titan.

In 1655, Christiaan Huygens
was the first to observe Titan.

Giovanni Domenico Cassini
discerned Iapetus in 1671,

Rhea in 1672,

Dione in 1684,

and Tethys in 1684.

The skywatching siblings
William and Caroline Herschel

found Mimas and Enceladus in 1789.

In 1848, Hyperion was spotted

by the father-son team of
William and George Bond

in the U.S. and William
Lassell in the U.K.

Phoebe was the first moon to be discovered

through photography, by
the American astronomer

William Henry Pickering in 1898.

Some of Saturn's moons are
probably captured objects,

particularly those in
retrograde orbits like Phoebe.

They orbit backwards, in
the opposite direction

from the rotation of the planet.

Each Saturnian moon is a unique jewel

in the majestic planet's
elaborate necklace.

Before Cassini, no one suspected Enceladus

to be anything other than a
dead ball of rock and ice.

But scientific sleuthing led
to a remarkable discovery.

Enceladus is about 482
kilometers in diameter.

It would fit neatly between
Los Angeles and San Francisco.

The first good closeup,
taken by Voyager Two in 1981,

showed the globe was remarkably bright

and free of craters.

In fact, Enceladus is the
whitest body in the solar system.

The first hints of a more complex story

come from Cassini's magnetometer.

The moon's magnetic signature

looks more like that of a comet.

Field lines are bent around
Enceladus' south pole.

A closer fly-by shows
the southern polar region

has been recently resurfaced.

Cassini's infrared
spectrometer indicates the area

is about 100 degrees warmer
than the rest of the moon.

And that heat signature
aligns with four prominent

tiger stripes appearing across
the moon's southern terrain.

They turn out to be fissures,

cracks in the icy surface.

Each about 150 kilometers long
and about one kilometer wide.

Scientists name them Alexandria,

Cairo, Baghdad and Damascus.

From each, jets of water
vapor and water ice

shoot out into space.

Cassini eventually locates
more than 100 of these geysers.

Mission planners arrange more fly-bys

and in October of 2015,
navigate within 50 kilometers

of Enceladus' South Pole,
and right through the jets,

giving the instruments a
chance to taste and smell them.

It's mostly water ice.

There's also some ammonia,
methane and carbon dioxide,

key compounds associated with life.

And hydrogen gas, which
microbes, if there are any,

could be using as a source of energy.

Some of the particles are
salty, like frozen sea spray,

flavored by sodium and potassium.

The science team imagines
that a large subsurface ocean

lies beneath the icy crust.

As it sloshes around, carbon
dioxide makes it fizzy,

like bottled soda.

When it finds a path to lower pressure,

through the cracks of the tiger stripes,

it sprays out into space like
champagne when the cork pops.

Most of these salty
water particles fall back

to the ground as snow,
decorating and repairing

the surface of Enceladus.

But some escape Enceladus' weak gravity.

So Enceladus rides a misty
ring of its own creation.

Were the moon to shut off its water jets,

this e-ring would dissipate completely

within a few hundred years.

Tracking and modeling icy
tendrils made by interacting

geyser jets lets researchers calculate

how much mass Enceladus is
pumping into Saturn's rings.

Enceladus orbits in resonance
with the moon Dione.

Their dance is thought to
heat their rocky cores.

It's likely that Dione too
has a subsurface ocean.

Dione's big crater, Creusa,

paints bright rays at least 500 kilometers

across the moon's surface,
giving researchers

a marker of geologic time.

Craters younger than
Creusa disturb the rays.

Older ones underlie them.

Water is pulled down into
the hot cores of these moons,

reemerging as steam through the sea floor.

We know this because Cassini has detected

tiny silicate particles

that can only form in boiling water.

In Earth's oceans, hydrothermal
vents, called black smokers

and white smokers, are oases for life.

The churning hot water provides energy

and sets nutrient
particles swirling around.

Is the same thing happening
beneath the ice crystal crusts

of Saturn's snow globe moons?

To find out, future missions
must look for amino acids,

fatty, acids, long carbon chain molecules,

and perhaps microorganisms
hitchhiking on the ice crystals,

blasted far from the
undersurface ocean depths.

Many astrobiologists
are fascinated by Titan,

because it is very cold,

about minus 180 celsius, yet it is wet.

If anything lives on or inside Titan,

it is almost surely not
related to life on Earth.

Titan is about the same diameter and mass

as the planet Mercury.

And Titan's surface
gravity is about the same

as Earth's moon, but
unlike Mercury or the moon,

Titan has a thick atmosphere,
even thicker than Earth's.

And scientists don't yet know why.

It's the second-largest
moon in the solar system.

At 5,150 kilometers in diameter,

only Jupiter's Ganymede is wider.

Titan is so much larger than
the rest of Saturn's moons,

it may have formed from the collision

of several of its siblings.

By mission's end, Cassini will have flown

by Titan 127 times.

Each pass gives the craft

a gravitational acceleration equivalent

to almost 1,000 kilos of extra fuel.

When the two Voyagers sailed
past in 1980 and 1981,

they saw only this orange,
smog-enshrouded globe.

American and European
scientists were so intrigued,

they began sketching out what would become

the Cassini-Huygens mission.

23 years later, an international team

commands the release of the Huygens probe,

to land on Titan.

January 14th, 2005.

The European-built Huygens probe

aero brakes into Titan's
atmosphere with its heat shield,

deploys a parachute

and floats down

for over two and a half hours

through a nitrogen-laden atmosphere.

Its camera reveals an eerie landscape.

Huygens lands softly in a
slushy bank of frozen methane,

along the shoreline of a hydrocarbon lake.

Huygens continues transmitting
data for another half-hour

after landing, sending back
images of rounded pebbles

probably made of hard frozen water ice.

Humanity has placed its
imprint on yet another world.

The flowing liquid on Titan is methane,

which acts there as water does on Earth.

In the range of Titan's temperatures,

methane can exist in all three states,

solid, liquid and gas.

It is not impossible that a form of life

could be evolving on this moon,

feeding on the constant
rain of hydrocarbons,

a true second Genesis,

completely separate from
our earthly tree of life.

Since Voyager first glimpsed Titan,

researchers have speculated
that liquid ocenas

grace its surface.

But dense orange smog
has withheld the truth.

This haze collects when
the sun's ultraviolet light

breaks up methane in the high atmosphere,

forming long molecular
chains that grow large enough

to fall from the sky.

These methane byproducts form snow drifts

into a huge network of dunes
around Titan's equator.

Cassini's camera was outfitted
with near-infrared filters

to peer through the orange fog
to verify bodies of liquid.

Images come back of relatively flat areas,

but are they truly oceans?

Or perhaps just methane slush?

Or thick tar?

The answer comes from Cassini's visible

infrared-mapping spectrometer.

It catches a specular reflection,

a bright spot of sunlight bouncing off

a clearly liquid surface.

With Cassini's radar, flat surfaces,

lakes and seas, appear dark,

unless they are ruffled by waves.

Titan indeed has oceans, ponds and pools

of liquid hydrocarbons,
ethane, methane and propane.

Strangely, they form
mostly in Titan's northern

hemisphere, near the pole.

Saturn's eccentric orbit is to blame.

Northern summer is warmer than
southern summer on Saturn,

but because of the way Titan is tipped,

its southern summer is more severe,

so all the southern
liquid methane evaporates

and rains out in the north.

Over time, the whole system flips.

In 15,000 years, Titan's lakes will all

be in the Southern Hemisphere.

This one, named Ligeia Mare, is larger

than Lake Superior on Earth.

It's probably 150 meters deep in spots.

Mysterious, frothy islands appear,

bubbling up from under the surface.

Titan holds a store of hydrocarbons

about 10 times larger than all Earth's

petroleum and natural
gas reserves combined.

Hovering 300 kilometers
over Titan's South Pole,

a huge persistent toxic
cloud of frozen hydrogen

cyanide rotates ominously.

This vortex seems to develop when Titan's

Southern Hemisphere
enters its autumn season.

Titan thrusts its methane up into space

at a frightening rate.

The atmospheric supply can't last longer

than about 20 million years.

Something must be
replenishing it, but what?

Cassini's radar spots the answer.

Mountains, some up to a kilometer tall.

These may be cryovolcanos.

Some could be active
today, spewing methane

from within the moon.

Cassini's radio science tools show Titan's

whole body flexing in
response to Saturn's gravity.

That makes it warm enough
inside to melt ice.

Unlike the subsurface oceans of Enceladus,

with its rocky ocean floors, Titan's ocean

is probably sandwiched
between layers of water ice.

So if there's an underground marine layer,

it may be sealed off
from the hot chemistry

of geothermal vents and any
chance of nurturing life forms.

Even after Cassini-Huygens,
we still don't know

how old Titan is, where it came from,

or how long it's had an active atmosphere.

Clues point to a cataclysmic
event in the Saturn system,

perhaps 100 million years ago,

that either created Titan
from smaller bodies,

or energized a barren, frozen Titan

into an active system.

Possibly like the primitive Earth.

To find out, we'll have to go back,

float longer through the haze,

sail the hydrocarbon seas

and soar through the nitrogen skies

of Titan.

To Galileo in 1610, the ringed planet

appeared as three stars,
with two small ones

touching one large,
prompting Galileo to declare

that Saturn must have ears.

But in 1655, using more advanced optics,

Christiaan Huygens unmasked the apparition

as a flat ring circling
a spherical planet.

20 years later, Giovanni Domenico Cassini

discerned that it was not
one ring, but several,

with gaps between them.

The widest gap was later
named the Cassini Division.

We now know that it's
4,800 kilometers wide

and far from empty.

In 1859, Scottish mathematician
James Clark Maxwell

showed that the rings are not solid discs

but composed of many smaller granules.

Each tiny fleck, pebble and boulder

revolves around the
planet in its own orbit,

jockeying for position
among trillions of others.

Though all are flying several
kilometers per second,

they jostle one another only very gently.

The concentric rings are given letters.

A through G, in their order of discovery.

Material riding close
into Saturn's cloud tops

in the D ring whips around
Saturn in about four hours.

But particles in the distance F ring

take at least four times longer.

It wasn't until the Cassini's
inspection that we learned

just how flat the rings are.

Incredibly, they are only
10 meters thick on average.

From top to bottom, only about as tall

as a three-story building.

These rings are 30 million
times wider than they are high.

And ring material can ripple up and down,

crafting temporary corrugations.

Many intricate wave patterns can be seen

across the broad ring plane.

Each one is conjured by
a specific gravitational

resonance with a Saturnian moon.

Though the basic physics of
the ring system is simple,

it's mostly the product
of gravity and collisions,

the intricate structure of the rings

is hard to mathematically model,

even after 13 years of
Cassini observations.

The pressure of sunlight,
and forces from Saturn's

magnetic field, can push or pull smaller,

less massive ring particles around.

The mission team flies a
series of special orbits

that put the rings
between Cassini and Earth.

By beaming radio signals of
three different wavelengths

through the ring material,
researchers build up

a color map of particle sizes.

Red areas hold more big particles.

Blue regions contain
mostly smaller grains.

Radio waves, shown in the
bottom half of this image,

reveal finer structure than
photos taken in visible light.

Most particles are
small, from tiny crystals

smaller than a dust
grain, up to pebble sized.

Less common are ice
rocks and large boulders,

up to the size of houses.

A few are the size of mountains.

Moons in the act of
forming, or falling apart.

Grabbing an average size
ring particle would feel

something like closing your hand around

a thick layer of very cold whipped cream

to find a glob of solid
ice cream deep inside.

The packing of particles
varies between rings.

Very little light gets through the B ring

of crowded snowballs.

An astronaut would have
to dig her way through it.

The A ring is less congested.

And the G ring is very
diffuse, like fog or smoke.

The Cassini mission
confirms the rings are made

of almost pure water ice.

But tiny quantities of
simple organic compounds

tint and shade them.

The astronomer Carl Sagan called

these colorful chemicals
tholins, Greek for muddy.

Crossing Saturn's dark side,

Cassini's camera picks up the true colors

and intricate complexity of
the ring plane's variations.

Subtle gravitational effects
fashioned by the many moons

sculpt the ring material.

Small moons, this one's named
Pan, orbit within the rings.

They seem to sweep clear
their lanes of travel.

The moon Mimas, gravitationally
combing the ring's

particles, causes the
large Cassini Division.

Other rings are herded
into form by so-called

shepherd moons, like
Prometheus and Pandora.

Tiny Daphnis, just
eight kilometers across,

pushes a wave of ring material

like the bow wave of a boat on a lake.

Daphnis bobs up and down
like a merry-go-round horse,

gravitationally pulling
particles into dune-like

mounds three kilometers tall.

It has plowed a 35-kilometer-wide
furrow in the ring field,

called the Keeler Division.

The larger Pan forges the
325-kilometer Encke Gap

in Saturn's A ring, giving it a wavy edge.

And Pan's gravity inspires
a spiral wake of particles.

Based on that gap, researchers
predicted Pan's existence

in the late 19th century,
long before it was first seen.

But no on anticipated
Pan's remarkable shape.

And it's not unique.

The slightly wider moon Atlas
has a similar structure.

Both wear skirts of gravitationally
attracted icy crystals.

Certain small satellites
on eccentric orbits

repeatedly crash through the F ring,

leaving behind sets of disruptive splashes

as evidence of their passing.

Other minuscule moonlets,
too small to be seen,

fashion propellor-shaped resonant waves

in the snowy rings falling around Saturn.

The ever-evolving complexity
of these ring circles

moves like a musical score,

playing in silence.

Once every 14 years, the ring plane lies

exactly edge on to the sun.

Cassini was present for one such equinox.

In essence, the sunlight on the rings

has been switched off, and they cast

no shadows on Saturn.

They are only visible
because Saturn reflects

some light on them,

here digitally multiplied many times.

Only the F ring, which is slightly tilted

from the others, catches any sunlight.

But because the rings are so thin,

any tall structure within them

throws its shadow onto the ring plane.

Thus, in the outermost edge of the B ring,

a surprise appears.

Hundreds of long shadows
mark a field of icy spikes.

Geometry dictates these points must range

up to a kilometer or so in height.

Like icebergs growing in a
sea of mostly empty space,

these thorn-like clumps may be molded

by the invisible fingers

of a gravitational resonance
with one of the moons.

Or they may be drawn out
by static electricity

inspired by Saturn's magnetic field.

Some of Saturn's rings
are constantly morphing,

while others are stoically
consistent year after year.

How old are these bright, icy rings?

They may have formed in
the last 100 million years,

when icy moons or comets collided

or were torn apart by Saturn's gravity.

Or they might be as old as Saturn,

the leftover debris of
the solar system's birth.

Cassini may yet find the true answer.

Looking down at Saturn's North Pole,

Cassini gets a spectacular
view of the globe's jet stream.

Some resonance of the wind
energies banks the stream

into a six-sided shape, the hexagon.

Apparently, an eastward-flowing
shallow jet stream

is bumped by occasional storms.

The jet reacts by settling into the most

stable geometric shape, six roughly sides.

This polar monsoon is about
32,000 kilometers wide.

You could fit two and
a half Earths into it.

Its winds blow faster the
closer they get to the pole.

Up to 540 kilometers per hour.

Why kill Cassini in a
ball of atmospheric fire?

The international scientific
community has agreed

to avoid any possibility of contaminating

Saturn's moons, especially
Enceladus and Titan.

Cassini is warm inside,
essentially room temperature.

Any microbes that found
their way in during assembly

could have easily survived.

And Cassini's RTG will
remain hot for decades.

If she was allowed to
accidentally crash on Enceladus,

Cassini might easily melt her way down

through the ice into
the underground ocean.

Back in 2009, studies had
showed Cassini had enough fuel

to go beyond Saturn to
explore the ice giants

Uranus or Neptune.

She could have been sent back to Jupiter.

Or outward to visit a
population of comet-like

asteroids known as the Centaurs.

But to get all the science
possible from the Saturn system,

Cassini would have to die here.

That led trajectory designers at JPL

to develop a jewel of orbital dynamics,

the Solstice Mission.

The plan optimizes
repeated fly-bys of Titan.

The route features high orbits to look

at the poles and the rings.

Long loops to map the
planet's magnetic fields.

Flattened equatorial
orbits to check out moons.

And ending at the peak of northern summer

to mirror Cassini's
arrival in southern summer.

Between the two, scientists
can infer the full cycle

of Saturn's seasons.

The science based on Cassini's data

will go on for decades.

Nudging Cassini's speed by
just eight meters per second

is enough to begin her death spiral.

The craft makes repeated
dives between the innermost

ring material and the roiling atmosphere.

These maneuvers would have
been far too dangerous

to contemplate when Cassini was designed.

Along the way, the
spacecraft maps fluctuations

in Saturn's gravity and magnetic fields.

And samples icy particles
flowing in from its rings.

Until the very end,
Cassini beams science data

and images directly to Earth.

Finally, on September 15th, 2017,

as the Cassini spacecraft
streaks along Saturn's clouds,

its high-gain antenna
shifts away from Earth.

The signal fades.

And she is gone.