All language subtitles for Nova S46E14 The Planets Jupiter.DVDRip.en.PBS

♪♪

Half a billion miles
from the sun...

♪♪

The giant of the planets...

It's very violent

and it's very intimidating.

♪♪

Jupiter.

Of all the worlds
in the solar system...

It's the biggest planet.

It sort of pushed
a lot of the planets around.

It's the bully
of the solar system.

♪♪

Jupiter's immense size

gives it incredible influence.

Jupiter is the most powerful
gravitational object,

second to the sun.

And while Jupiter is at a safe
distance from Earth today,

in the past,
it drew much closer.

Four-and-a-half billion years
ago,

it embarked on a rampage
across the solar system,

leaving a trail of destruction
in its wake.

We can think of
the asteroid belt

as a planetary graveyard.

Jupiter transformed
the destiny of the planets,

and could even have changed
the course of life on Earth.

♪♪

It is the most influential
planet of our cosmic home.

♪♪

"The Planets: Jupiter."

Right now, on "NOVA."

♪♪

♪ They'll say
no one can see us ♪

♪ That we're estranged
and all alone ♪

♪ They believe
nothing can reach us ♪

♪ And pull us out
of the boundless gloom ♪

♪ They're wrong ♪

♪ They're wrong ♪

♪♪

Beyond the edge
of the inner solar system

and the desolate wasteland
of the asteroid belt...

is the gas giant Jupiter.

Its serene marbled appearance

disguises a planet in turmoil,

where violent storms rage
through clouds

more than a thousand miles deep.

When we look at Jupiter,

we find one of the most
amazing places we've seen

in the solar system.

♪♪

It's very mysterious.

It's covered by clouds

that hide what's underneath.

But Jupiter is a planet
as influential

as it is beautiful.

Jupiter is by far
the biggest planet.

Its mass is greater than
300 times that of the Earth.

So it is the most powerful
gravitational object,

second to the sun.

Four-and-a-half billion years
ago,

Jupiter's gravity
had devastating consequences

for the worlds around it.

Jupiter had this
incredible effect that helped

to shape the solar system
overall.

♪♪

Clearing material
from the inner solar system,

Jupiter transformed
the destiny of the planets...

Including our own.

♪♪

You're looking
at the crime scene...

The structure of the
solar system, what it is today...

And trying to piece together
what happened

four billion years ago.

♪♪

It is an amazingly intriguing
problem.

Jupiter is a world
with a dark past.

And you don't have to look far

to see the evidence.

♪♪

In the northern Arizona desert,

this is Barringer Crater.

♪♪

It was formed 50,000 years ago,

when an iron-nickel asteroid
150 feet across

hit Earth
at 27,000 miles per hour...

♪♪

An asteroid that was likely
thrown in our direction

by Jupiter.

♪♪

So what is it that enables
Jupiter to influence the Earth

from so far away?

♪♪

And how did it grow
to such dominance?

Only by seeing Jupiter close up

could we begin
to answer those questions.

♪♪

♪♪

In 1972,

Pioneer 10
becomes the first spacecraft

to cross the asteroid belt.

Before Pioneer,
we really had no idea

whether or not
a spacecraft would be able

to survive all the hazards
of a trip like that.

The images brought back to us
really blew our minds

in terms of what we could see
of Jupiter.

To have the incredible detail

about the dynamics
of the atmosphere

really was new and different
to us.

Now the world wants to know,
"What have we learned?"

During its brief fly-by,

Pioneer observes Jupiter
for four days...

♪♪

Proving that missions
to the outer solar system

are possible.

We have ignition

and we have lift-off
of the Titan-Centaur,

carrying the first
of two Voyager spacecraft

to extend man's senses
farther into the solar system

than ever before.

♪♪

The Voyager spacecraft see
Jupiter's Earth-sized red spot

in unprecedented detail...

♪♪

Discover the planet's rings,

and capture
the first detailed images

of Jupiter's moons.

♪♪

It wasn't until Voyager

went up-close and personal,

and took amazing pictures
of the moons,

that we really began to get
a sense of just how complex

and the variety

of the worlds around Jupiter.

♪♪

The icy surfaces of Europa,
so different, so dynamic.

The volcanos on Io,

Ganymede all broken up,

and then Callisto
was just this big icy surface

covered in impact craters.

♪♪

We now know the giant planet
has more than 79 moons.

Jupiter is a world so large,
its immense gravity

has assembled a solar system
in miniature.

So how did it grow
to such incredible size?

T-minus ten,

nine, eight, seven...

In 2011, the Juno spacecraft
launches from Cape Canaveral.

Ignition,

and lift-off of the Atlas V
with Juno,

on a trek to Jupiter.

Its mission:

to uncover the secrets
of Jupiter's formation.

♪♪

When we launched
the Juno spacecraft

away from the Earth
out towards Jupiter,

we didn't have enough speed
to get away

out of the gravity of the sun.

So, we actually
had to come back to Earth,

get a gravity assist from Earth,
and then go out to Jupiter.

♪♪

After traveling for five years,

on July 4, 2016,

the spacecraft finally arrives.

It's an incredible moment
for the science team.

You see all these swirls,

you see all sorts of
spots coming up.

You see all these vortices.

You see dramatic storm systems
interacting.

♪♪

It's mind-blowingly beautiful
pictures

that this little camera
has been taking.

♪♪

JunoCam was able to see
the Great Red Spot

from up close.

We can see height to the clouds,

we can see features
that look like storms.

Maybe it's hailing or snowing
ammonia.

On Jupiter.

♪♪

And the most startling thing
that we saw

from JunoCam's imagery

was that the poles of Jupiter
are actually blue.

Juno's objective

is to look as close at Jupiter
and as deep inside

as we possibly can

to understand as best as we can,
what is it made of?

What is its
interior structure like?

Because the answers
to those questions

help to tell us where and how
Jupiter might have formed.

♪♪

By analyzing the planet's

magnetic and gravitational
fields,

Juno is able to look deep
into Jupiter's interior.

And what we found is that
there is a lot of mass inside.

That mass
is the core of the planet

around which the hydrogen
was pulled in

in those early stages
of solar system formation.

By discovering
the planet's core,

Juno is helping us

to reconstruct
Jupiter's first moments...

A story that begins very early
in the solar system's history.

♪♪

Nearly five billion years ago,

a distant exploding star

sends a shockwave
across the galaxy...

♪♪

Causing the cloud
of gas and dust

that would become
our solar system

to collapse,

forming the sun.

♪♪

Farther out,

Jupiter's core
is already beginning to grow,

gathering in vast clouds of gas.

♪♪

After 50 million years,

the sun's nuclear furnace
ignites...

♪♪

The light of its first dawn

revealing Jupiter.

While the terrestrial worlds
are little more than rubble,

Jupiter is fully formed,

allowing it to shape everything
that follows.

So when it comes
to setting the stage,

setting the structure of how the
solar system is going to evolve,

Jupiter plays the biggest role.

It is the most influential
planet of our cosmic home.

♪♪

Over the next 100 million years,

the four rocky planets
of the inner solar system

form in their
familiar positions:

Mercury...

Venus...

Earth...

then Mars.

And while this layout
is familiar to us,

it might be extremely rare.

♪♪

The more we've looked around,
the more we've found

that the typical solar system
is unlike that of our own.

♪♪

Our sun is just one of around
300 billion stars in our galaxy.

And almost every one
of those stars

is likely home
to its own system of planets.

When we look out
into the rest of our galaxy,

we're starting to discover
worlds around other stars,

we call them exo-planets.

♪♪

The planets that we're seeing,

they're not all
Earth-like objects,

they're not all big objects
like Jupiter.

The vast majority of them
have sizes and masses

that are similar
to Uranus and Neptune.

♪♪

In most other systems,

the region of space
where our planet orbits

is empty.

Instead, close to the star,

we see "Super Earths,"

vast rocky planets
between two and ten times

more massive than Earth.

But these worlds are thought

to have thick, suffocating
atmospheres

that render them inhospitable
to life as we know it.

So what is it

that makes our system
so different?

Some sequence of events
must have happened

that made our solar system
special.

♪♪

As we've explored the planets,

we discovered strange anomalies

that hint
at a catastrophic upheaval

that shaped the solar system.

Our missions to Venus

found that it once had
far more water

than you'd expect for a planet
so close to the sun,

just as Earth has today.

The spacecraft we've sent
to Mars...

touched down on a world
that is, curiously,

just half the size of her
sister planets Earth and Venus.

But it was in the region
of space closest to Jupiter

that our probes discovered
the most astonishing evidence.

The asteroid belt actually holds

a remarkable amount
of information

about the solar system's
dynamic and dramatic evolution.

The asteroid belt sits
in between Mars and Jupiter,

and it separates
the inner solar system

from the outer solar system.

People think
that the asteroid belt

is very densely packed,

but the asteroids there

are actually
very widely separated.

They're spread
over this huge volume.

So, if you stand
on top of one asteroid,

you won't be able
to see another one.

It's nothing
like what you would imagine

in science fiction.

When we send spacecraft
outward into the solar system

through the asteroid belt,

we double-check that there's
not going to be

a large asteroid in the way,

but we really don't need to make
any kind of course correction,

because the asteroid belt
is largely empty space.

♪♪

But it hasn't always
been like this.

It's thought the asteroid belt
once contained enough material

to build a planet
the size of Mars.

So why is it so empty today?

Five, four, three, two...
main engine start... one, zero,

and lift-off of the
Delta Il rocket with Dawn,

using ion propulsion

to reach the catalysts
of our solar system.

♪♪

♪♪

Dawn's mission is to investigate

the two largest asteroids
in the asteroid belt...

Vesta and Ceres.

After a year in orbit
around Vesta...

in March 2015...

Dawn makes its final approach
on Ceres,

a body that makes up
over a third of the mass

of the entire belt.

It was really exciting

because an object that had been
sort of grainy and mysterious

was suddenly there,
revealed before us,

ready for exploration.

♪♪

On approach,

the first images
Dawn sends back to Earth

reveal something unexpected.

As Ceres came into view,

we would see these amazing
bright spots on the surface,

pockmarking it here and there,

nothing like
we'd ever seen before.

And the most outstanding ones
were found in Occator Crater.

Occator Crater

is one of the larger
but younger craters on Ceres.

The most intriguing thing,
though,

is what we see in the center,
which is a central pit

and then a bright dome

of, of this intriguing
super-bright material.

Now the mission team's challenge
is to identify

what the mysterious substance
actually is.

With the instruments
on the Dawn mission,

we're looking
at the chemical fingerprints

of the bright materials,

and actually, we see
that they're salts.

All of this points to the fact

that there were once brines,
salty waters,

that rose
near the surface of Ceres

to create these deposits.

Dawn goes on to discover
over 300 bright spots...

clues to Ceres' former life.

♪♪

If we were to peel away
the dark surface of Ceres,

what we'd find underneath
is a mixture of rock and ice.

Ceres is not just
the largest asteroid;

it's a dwarf planet
in its, in its own right.

It's spherical and it has
differentiated into layers.

We know from Dawn data
that there is an ice-rich layer

on the outer,
comprising the outer crust,

tens of kilometers thick.

♪♪

But it hasn't always
been this way.

Ceres is frozen today,
but early in its history,

radioactive elements
in its interior

would have provided heat
that melted the liquid water

that's currently ice.

And so we think that,

during the early portions
of Ceres' history,

it had a global ocean.

♪♪

In infancy,
Ceres was well on its way

to becoming
a fully-fledged world.

The water that now lies frozen
within its interior

was once liquid.

Protected beneath
a thin layer of ice,

ancient Ceres is covered
by a deep salt-water ocean.

But then, something happens
to cut its development short.

♪♪

As the young Jupiter
circles the sun,

it clears a path
through the gas cloud

that envelops
the early solar system.

But that process causes it
to do something alarming.

♪♪

Jupiter begins
to spiral inwards...

plowing straight through
the region of space

that would become
the asteroid belt.

♪♪

When the young Jupiter moves

through the primordial
asteroid belt,

things get scattered around,

things get
gravitationally deflected,

and as a consequence of all of
this gravitational interaction,

more than 99% of the
original mass that was there

is basically now gone.

The asteroid belt
has been disrupted over time

by the movement
of the giant planets,

and this has acted to throw
material from the asteroid belt

out of the asteroid belt,
into the outer solar system.

These proto-planetary cores,
like Ceres,

were never able to graduate
to full-fledged planets

because there was just
not enough material

in the orbital neighborhood.

♪♪

When Jupiter passed through
the primordial asteroid belt,

it starved Ceres of material,
halting its growth.

And the dwarf planet
was condemned to spend eternity

as a cold, barren rock.

But Ceres isn't the only world
in our solar system

whose development was cut short.

Mars would share a similar fate.

♪♪

After marauding

through what would become
the asteroid belt...

Jupiter enters
the region of space

where Mars is forming...

♪♪

Continuing its journey
spiraling towards the sun.

♪♪

As Jupiter bulldozes inwards...

its immense gravity
scatters material

in all directions.

♪♪

Some is sent careening
into the sun...

♪♪

And some is thrown out
into interstellar space.

It is because

of the gravitational clearing
of this neighborhood

by Jupiter

that Mars was unable to grow

to more than ten percent
of that of the Earth.

This is why Mars is small.

And by clearing material
out of the inner solar system,

the giant planet may also have
prevented the formation

of the Super-Earths we see
in other systems.

And if it had continued
moving inward,

our planet, too,
might never have formed.

♪♪

But then, just as it looks

like Jupiter will sweep
everything away,

the giant planet
stops in its tracks.

Because in the far reaches
of the outer solar system,

another planet is forming...

the solar system's
second gas giant...

Saturn.

And its arrival
changes everything.

As Jupiter moved inwards,
Saturn moved inwards,

and caught up
to Jupiter's orbit.

When this happened,
the two locked into

a special configuration known as
a mean motion resonance.

This is where the planets begin
to interact gravitationally

in a very coherent manner.

And now, locked as a unit,
the two reversed

their migration course
and moved back out.

Saturn caused Jupiter
to retreat...

♪♪

Leaving behind
just enough material

from which the inner planets
could form...

Mercury...

Venus...

♪♪

And our home.

Earth is in exactly
the right location

to provide the environment
for life to develop.

So if Jupiter had moved
around even more,

who knows, maybe life
never would have developed

in this solar system
as we know it.

♪♪

And as its voyage
across the solar system

draws to a close,

Jupiter helps to provide
our living world

with its most precious
ingredient.

♪♪

Today, two-thirds of our
planet's surface

is covered by ocean.

More than 320 million
cubic miles of water...

each drop teeming with life.

♪♪

One of the big questions
about the evolution

of our solar system is,

how did we get water here
on this planet?

EDGARD RIVERA-VALENTíN:
We think that the inner planets

didn't naturally form
with a lot of water.

Water is primarily
in the outer solar system.

But if you end up having

Jupiter and Saturn
moving outwards, then that

is able to suddenly deliver
more water

into the inner solar system.

Locked in a gravitational dance
with Saturn,

Jupiter moves back
through the asteroid belt.

And as it does so, water-rich
material is flung inward,

where it is incorporated into
the growing terrestrial worlds.

So the movement
of the giant planets

have actually played
an important role,

in the delivery of water

to the inner solar system.

♪♪

In a sense,
it is Jupiter's outwards motion

through the asteroid belt
that we have to thank

for the delivery of water

to surface of the Earth.

The Earth would be
quite a different planet

if not for Jupiter's
primordial dance.

♪♪

Today, Jupiter has settled into
a regular orbit,

back beyond the far edge
of the asteroid belt...

its days of marauding through
the solar system at an end.

But its gravity
remains a constant threat.

And nowhere
is that more apparent

than on the closest
of Jupiter's large moons.

♪♪

Io is the most volcanic world
in the solar system.

If you were to send a spacecraft
to Io and take a picture,

you would see hundreds of
volcanoes erupting at one time.

Active volcanoes,

lava spewing out...
Hot, hot, hot lava.

The biggest lava lake on Io
is Loki Patera.

♪♪

At more than 120 miles
in diameter,

it's a million times the area
of any lava lake on Earth...

its surface constantly churned
by waves of molten rock.

♪♪

But Io is the same size
as our moon.

So why isn't it just as cold
and dead?

Jupiter is a massive planet.

It's 318 times
the mass of the Earth.

And this poor little moon
has to orbit near this giant,

and meanwhile the other moons
are in an orbital resonance

with it and they keep tugging it
out of a circular orbit.

♪♪

When things are in resonances,

that means they're meeting
each other up at the same point

in space constantly

so that means that
there's a constant tug coming in

from all of these moons.

♪♪

This tugging creates friction.

And this friction becomes heat,

very much in the same way

as if you were to rub your hands
together on a cold day,

that friction would create heat.

And this is what we call
tidal heating.

When you take a moon like Io

and you stretch it this way
and then let it relax

and stretch it this way
and let it relax,

the friction inside is
constantly heating up the rock

until you reach
the melting point.

♪♪

This process raises
the temperature in Io's interior

to more than 2,000 degrees
Fahrenheit...

creating its lava lakes...

and powering immense
volcanic plumes...

that rise up to 200 miles
from the moon's surface

and out into space.

♪♪

Because of Jupiter's great size,

the gravitational field
that drives Io's volcanism

extends far beyond its moons...

Even as far as Earth...

♪♪

Where there's evidence
it's done far more

than create
the occasional crater.

Preserved in the
limestone layers

along this stretch of river are
several thousand dinosaur tracks

dating back
to the Jurassic period

some 150 million years ago.

Etched into the banks
of the Purgatoire River

are the final traces
of a lost world.

Some of these tracks are from
a large herbivorous dinosaur,

a sauropod,

big hind footfalls
moving through the area,

and right near those

are three-toed prints
of a meat-eating animal...

Something like allosaurus...

And all of those tracks
being together tell a story,

and the easiest story
that one might imagine

is that of a predator pursuing
prey on this ancient lake shore.

♪♪

But today,
the dinosaurs are gone.

The course of evolution
was dramatically changed,

and it's likely Jupiter
was responsible.

♪♪

Jupiter has been
profoundly implicated

in periodic extinctions
of life on Earth.

And, indeed, it's quite likely
that the asteroid

which wiped out the dinosaurs
almost 70 million years ago

was launched
from the asteroid belt

by Jupiter's gravitational
influence.

People often think
of the asteroid belt

as this unstructured, unchanging
population of debris,

but as you can see here,
there's quite a bit of structure

to the asteroid belt.

In green, what we have are
the so-called Trojan asteroids.

Objects that occupy
the same orbit as Jupiter.

In red, what we have
are the Hilda asteroids.

They form this triangular shape

because of the resonance
that they're in with Jupiter.

The asteroid belt as a whole is
kind of dancing

to Jupiter's tune.

But it is a delicate balance

that can change at any time.

Because Jupiter exerts

such tight control

over the long-term changes
of asteroid orbits,

if an asteroid comes off its
well-defined orbital track,

so to speak,
then Jupiter will just

fling it out of the
asteroid belt

and potentially
even send it towards the Earth.

Dislodged from its orbit
by Jupiter's gravity,

an asteroid six miles across

tumbles out of
the asteroid belt.

♪♪

It is now on a collision course
with Earth.

♪♪

♪♪

When it strikes,

the impact generates
a fireball so hot,

anything within a 600-mile
radius dies instantly.

♪♪

The impact throws some
300 billion tons of sulfur

up into the atmosphere.

♪♪

And during the "nuclear winter"
that follows,

75% of species,
plant and animal,

are wiped from the face
of the Earth,

including the largest creatures
ever to walk on its surface.

By driving
the dinosaurs to extinction,

Jupiter cleared the way for us
to inherit the planet.

And although it still

occasionally flings asteroids
our way...

Jupiter also protects us.

For objects heading toward Earth

from the far reaches
of the solar system,

the giant planet's immense
gravity acts as a shield.

Around 100 years ago,

a lump of rock and ice
2.5 miles across

is hurtling toward
the inner solar system.

But Jupiter stands in its way.

Five, four, three, two, one.

We have ignition and lift-off
of Atlantis

and the Galileo spacecraft
bound for Jupiter.

♪♪

70 years later,

a mission launches
that will witness

just how effective a shield
Jupiter can be.

♪♪

On board the space shuttle
Atlantis,

the Galileo orbiter.

♪♪

Three years
after Galileo launches,

Comet Shoemaker-Levy 9 has been
captured by Jupiter's gravity.

And now, locked in the
giant planet's deadly embrace,

tidal forces begin
to tear the comet apart.

♪♪

Its journey into the inner
solar system cut short,

what happens next
presents the Galileo scientists

with a unique opportunity.

So everyone was observing it
and they realized two things.

One is that it had just passed
very close to Jupiter

and probably had gotten
pulled apart by Jupiter's tides,

and the other was that it was
going to crash into Jupiter

two years later.

The discovery that a comet
was about to hit Jupiter

was a huge surprise

and very exciting.

After crossing
the inner solar system,

Galileo is approaching the spot

where it will witness
the comet's final moments.

We knew Galileo would be able

to see the flashes directly.

We knew that the impacts
were going to occur

on the night side
and that Galileo was going

to be able to see 'em.

♪♪

On July 16, Galileo sees the
first fragments of the comet

enter Jupiter's
southern hemisphere.

At 60 kilometers per second,
the fragments

really heated the atmosphere
red hot,

almost to the temperatures
of the sun.

And the pieces hit the planet
one after the other.

♪♪

Pieces of Comet Shoemaker-Levy 9

strike Jupiter over the course
of six days.

They looked like big flashes
on Jupiter.

The pictures of the impact

were fantastic.

♪♪

These powerful pulses of light,

captured from
150 million miles away,

are the only time we have
ever witnessed a comet strike.

The most destructive impact

releases energy equivalent to
six million megatons of TNT...

leaving behind a giant
dark cloud 7,500 miles across.

By capturing objects and
incinerating them on impact,

Jupiter protects us from bodies

that might otherwise
threaten Earth.

Galileo would go on to study
Jupiter for another eight years.

The spacecraft will orbit
Jupiter at least 11 times,

making a close flyby of one
of the Galilean satellites

on each orbit.

♪♪

As the probe samples
the Jovian atmosphere,

scientific results will be
relayed to the orbiter.

Galileo records 400 mile per
hour winds in Jupiter's clouds.

And measures lightning strikes

many times more powerful
than those on Earth.

The spacecraft will sweep
within 200 kilometers

of the surface of Europa,

yielding high resolution images.

Galileo's Europa encounters
will give us our first

detailed look at this moon's
mysteriously fractured surface.

♪♪

Galileo's images confirm Europa
is an ice moon.

Analysis of its magnetic field

reveals Europa's cracked surface

floats above an ocean
60 miles deep

which contains more water
than all the oceans on Earth.

Then, on September 21, 2003,

Galileo meets the same fate

as the comet
that had greeted its arrival.

At the end of the mission,

the spacecraft was low on fuel

and it had suffered
a lot of radiation damage

and we had to dispose of it.

♪♪

And the best way to do that
is to send it into the planet

so it burns up.

♪♪

You don't want the spacecraft
to hit one of the moons,

especially a moon like Europa,

that may have life.

Because the spacecraft may be
carrying life from Earth.

♪♪

When you have to say goodbye,

it's a sad moment.

♪♪

But on the other hand,
you can look back and say

what a successful life
the spacecraft had.

And I think that's the way
we all felt.

♪♪

Jupiter,

the oldest and largest
of the planets,

is the giant
of our solar system.

♪♪

In youth, it went on a rampage.

♪♪

For some young planets,
that spelled disaster.

But for others,
like our own world,

it cleared the way
for their formation.

♪♪

And so Earth...
And all of humanity...

Owe Jupiter a great debt.

But the fate of the dinosaurs
is a reminder

that it's a debt that could be
recalled at any time.

Solar system evolution
is never really done,

and the orbits of the planets

are just not going
to stay stable.

Over million-year time scales,

the orbits of the planets
are quite predictable.

Over much longer time scales,
however,

they act in a
fundamentally chaotic manner.

Which means the story of Jupiter

may have one final twist.

Among our calculations

of long-term evolution
of the solar system,

we find that about
1% of the time

Mercury's orbit can become
exceedingly elliptical

as a result of gravitational
interactions with Jupiter.

This would have
dire consequences

for the inner solar system.

Mercury could be thrown
into the sun,

flung out into
interstellar space,

or even set on a collision
course with Earth.

In every one of these
situations, however,

the orbits of the other planets,
Earth included, get messed up.

So, the solar system,
the inner solar system,

becomes an unlivable place

if this occurs.

♪♪

And so Jupiter,

the giant that shaped
the birth of our world,

might one day bring about
its demise.

♪♪