Original subtitles

NASA's revolutionary Juno probe

is on a daring voyage to Jupiter.

Its goal... to reveal the the deepest mysteries

of our solar system.

Everything we see in the solar system today

is affected by Jupiter somehow in the past or now,

all the asteroids, all the planets,

the moons, the comets, everything.

So in many ways, Juno is actually giving us a view

into the history of our planetary system,

even the history of Earth.

Juno's mission is risky.

Jupiter could eat the spacecraft like that.

But by diving perilously close

to this monstrous world,

Juno could change everything we know about our solar system.

If you want to know what's happening,

you got to get up close and personal.

captions paid for by discovery communications

Independence day, 2016...

Juno arrives at Jupiter

and gets to work.

The probe angles its high-resolution camera

towards this stormy world.

Juno's snaps do not disappoint.

The images returned from Juno are just beautiful.

Suddenly you have this magnificent mosaic

of this planet.

As a human being, I'm like, "oh, my gosh, look at this.

This is amazing. This is coming back from Jupiter."

These are the closest-ever views

of Jupiter, a world 500 million miles away.

But we didn't send Juno just to take pictures.

One of its main goals is to peer deep into Jupiter's dark heart.

One of the big questions we have about Jupiter is,

does it have a core?

And you'd think, well, of course it has a core

like every planet has a core.

The Earth has a core. Everything does.

Well, it turns out, Jupiter might not.

Knowing what lies at a planet's core

allows scientists to wind back the clock billions of years

to the formation of the planets.

If Juno can reveal what lies deep within Jupiter,

it could change our understanding

of how the gas giant formed.

If Juno finds a solid core, it could mean

Jupiter first formed as a rocky planet like earth

then kept growing,

but if Juno finds no core,

it could mean that Jupiter skipped the rocky stage

and formed straight from a cloud of gas.

Answering this question could shine a light

on other mysteries, too.

If we can figure out how Jupiter formed,

we can figure out the rest of the story of the solar system.

So how do you probe down into the interior of a planet

when all you can really see are the very tops of the clouds?

Well, incredibly, you can use gravity.

As Juno orbits Jupiter,

it can sense in its orbit

tiny little variations

in the gravitational pull of Jupiter.

As Juno speeds around Jupiter,

gravitational spikes tug on the craft.

Turns out, some parts of Jupiter are denser than others.

If Jupiter were some solid ball, then as Juno passes by it,

as it passes very close above its cloud tops,

the orbit, the trajectory would be very smooth,

but in fact, if Jupiter has layers,

or places where there is more mass

and places where there's less, then it's gonna pull on Juno

a little bit differently.

Passing over areas of concentrated mass

gives Juno a speed boost.

So what they do is, the engineers back on earth

can basically just say,

"how fast is it moving right now?

How about now? How about now?"

And you build up a map of where the mass is in Jupiter

underneath the spacecraft as it passes around.

Juno's instruments begin to map out

the heart of gas giant,

revealing the mysterious core for the first time.

What Juno found was this amorphous mass,

a fuzzy thing in the center of Jupiter.

It's not as solid as we expected

if it were just a metal and rock core,

but there is something there.

In the center of the planet,

Juno detects hydrogen and rocky material

dissolved and blended together.

It's a type of planetary core we've never seen before.

Astronomers describe it as fuzzy.

We thought we were gonna find an avocado.

Instead, we found a bowl of chili.

It's a hydrogen fluid chili con carne.

So none of our models of the interior of Jupiter

turned out to be correct.

That means we have to go back to the drawing board.

One theory is that Jupiter

didn't form from rocks or gas

but from tiny pebbles less than an inch wide strewn

across the early solar system 4.6 billion years ago.

These pebbles came together.

They accreted to form a massive object

that was the sort of seed, the core of Jupiter.

The swarm of pebbles

clumped together to form one giant core

20 times the mass of Earth,

but these pebbles can't sustain this growing planet for long.

Eventually, we need to make a jump

from those centimeter-size particles

up to really large things, like 100-kilometer planetesimals,

to really kick-start growth of a planet.

As Jupiter grows, its appetite becomes insatiable.

The cores of other would-be planets are drawn in

by its immense pull and absorb on impact,

causing Jupiter's core to transform.

Huge chunks of incoming rock are mixed up with gas

and the pebbles that originally built the core.

We think that core material that might've been there is actually

dissolved and mixed in with the rest of the planet.

This mix of rock, gas, and pebbles

leaves the core in a strange state

somewhere between solid and liquid

or, in other words, fuzzy.

Once Jupiter's core reaches a critical mass,

its gravity pulls in all nearby hydrogen gas,

building the Jovian atmosphere

and leaving the fuzzy core

trapped beneath thousands of miles of thick clouds.

And that is what formed Jupiter as we know and love it today.

Juno's discovery of Jupiter's fuzzy core

could rewrite the book on

Jupiter's early years, but Juno is just getting started.

We haven't even scratched the surface

of the number of mysteries there are.

There's more to Jupiter than meets the eye

as Juno's instruments begin to reveal a darker side

to this giant world.

Jupiter's environment is one of the most vicious

in the solar system, and that's because

of its incredibly strong magnetic field.

And Juno is caught right in the middle of it.

The gas giant Jupiter

holds clues to the mysteries of our solar system,

and in 2011,

NASA launched a billion-dollar mission to uncover them.

Three, two, one, ignition.

And liftoff of the Atlas V

with Juno on a trek to Jupiter.

To reach its target,

Juno embarks on a five-year journey.

Sending any spacecraft to another planet

is gonna be tough, but sending one to Jupiter

is really pushing things pretty hard.

Juno weaves through the solar system

with extreme precision.

The craft battles violent temperature changes

and navigates carefully through the asteroid belt.

If there's a fleck of dust in your path

and that thing slams into your spacecraft,

it could do significant damage.

1.7 billion miles into its mission,

Juno finally nears its target,

but the probe is hurtling towards Jupiter

at 165,000 miles an hour.

Juno is moving really fast.

It's one of the fastest spacecraft ever.

You need to go fast enough to get there, but then you need

to be slow enough to be captured by the gravity of the planet.

You need to get it just right.

Entering orbit around

Jupiter is the trickiest part of the mission.

Get it wrong and Juno could slam into the planet

or drift out into deep space.

To successfully get Juno to enter a stable orbit around

Jupiter as almost the same as, say,

shooting a basketball from London

and having it on the land on the front of the rim in New York

and just sitting there balanced.

I could do it, but can NASA do it with Juno?

NASA has a neat game plan.

Juno performs a backflip in space

and fires its thruster towards Jupiter.

Everything is going smoothly.

We're continuing to burn and change our velocity.

The rocket burns for 35 nail-biting minutes,

reducing the craft's speed by 1,200 miles an hour.

Finally, the probe achieves orbit around Jupiter.

Right on July 4th during the fireworks

we just got into orbit.

In many ways, we're firing a rocket motor.

I mean, it is fireworks.

Safe in orbit,

Juno turns its instruments to the planet

for a crucial part of the mission...

investigating Jupiter's magnetic field.

Deep below the stormy surface, liquid metallic hydrogen

flows endlessly around the planet,

producing a huge magnetic field.

This magnetosphere stretches over 600 million miles

beyond the planet, reaching all the way to Saturn.

If your eyes could actually see Jupiter's magnetosphere

and you tried to look at it while standing on earth,

it would look about as big in the sky as the moon.

And within this magnetic field,

Juno faces an invisible threat.

Jupiter has an enormous magnetic field.

It is so enormous in terms of space,

but also in terms of power.

High-energy particles from the Sun

are funneled into deadly radiation belts

guided by the giant planet's magnetic field.

The magnetic field traps charged particles coming from the Sun

and circulates them around that system

and just bombards anything in the vicinity,

including our fragile little spacecraft.

Closer to the planet,

radiation levels are up to 30 times greater

than they were inside the reactor core room

during the Chernobyl disaster.

This is radiation.

This is bad news.

These particles, they would hit you.

They would rupture your DNA, rupture your cell structures,

and you would die.

This blistering radiation is bad news

for the spacecraft as well.

The charged particles threaten to destroy electronic

and navigational systems, but Juno has armored up.

It's not some delicate, beautiful, gossamer thing

that you are sending to orbit Jupiter.

It's more like a tank.

You have to protect this thing or else

it's not going to last very long at all.

We've got a couple hundred pounds of titanium

on the spacecraft just trying to shield us

from what Jupiter might throw at us,

so it is in a sense we're like an armored tank going into war.

Lightweight titanium is tough.

Juno's 1/2-inch-thick shielding blocks 99%

of Jupiter's vicious radiation.

But even at this reduced rate,

Juno can't survive the bombardment for long,

so the craft sets itself on a unique orbit

around the gas giant.

It actually has a very long orbit

where it spends most of its time far away,

and then every once in a while dives in and goes,

"oh, hot, hot, hot, hot. I zoomed in too much,"

and then goes safely away to communicate and process

and then back in again.

Juno takes a mighty gamble

diving deep into these radiation belts

to achieve one of its key objectives...

mapping Jupiter's giant magnetic field,

and as Juno swoops around the planet,

it reveals something scientists have never seen before.

When you look at the Earth,

we have a fairly simple magnetic field.

It's like a giant bar magnet with a north

and south magnetic pole.

Well, Jupiter has that as well.

This is called a dipolar field.

It's got two poles, but it also has a third pole.

Juno's magnetic field maps

show a north and south pole

and a bizarre magnetic disturbance at the equator.

And it's like Jupiter just sprouted a third arm,

and that's kind of mysterious.

On magnetic field maps,

north poles show up red and south poles blue,

so scientists are calling this second south pole

the great blue spot.

Everyone knows about the Great Red Spot,

but Jupiter now has a great blue spot as well.

This magnetic disturbance reflects

Jupiter's stormy interior.

You have these fast-moving winds blowing on the magnetic field,

and they're actually shearing it apart

and moving the field around.

It's not necessarily a storm,

although it could be.

It maybe is better to think of it as a magnetic storm.

Turbulence inside Jupiter could be

twisting up the magnetic field to drive the great blue spot

and the deadly radiation belts that Juno must navigate through.

Unlike earth, Jupiter is not really a solid mass

for the most part, so all of its clouds and gases

are moving at slightly different rates,

and that actually makes the magnetic field

that's generated very variable and highly changing.

For us to have a variable magnetic field

like Jupiter does,

the entire earth would have to be molten.

We really don't want that to happen.

With each orbit, Juno unravels more mysteries

of this giant planet, but Jupiter's deepest secret

could shine a light on our own origins.

If we want to understand the Earth

and our place in the solar system,

Juno has found that a lot of those mysteries

are locked up there in Jupiter.

The Juno spacecraft

is uncovering the secrets of Jupiter

from its swirling cloud tops to its dark heart,

but Juno's discoveries go beyond the gas giant itself.

They could also solve mysteries surrounding our own planet.

Jupiter is the key

to the formation of the solar system,

which means it's the key to understanding

how the Earth formed.

Juno is actually giving us a view

into the history of our planetary system,

even the history of earth.

4.6 billion years ago,

a cloud of hydrogen gas and cosmic dust collapses,

sparking nuclear fusion.

From the resulting chaos,

one star, four rocky worlds,

and four gassy giants are born

and form our solar system.

There's these distinct zones of the solar system...

rocky and metallic in the inner part,

gaseous and water-rich in the outer part,

and even without thinking about that too hard,

it kind of makes sense because in close to the Sun,

it's warmer.

Out farther away from the Sun, it's cooler.

But the Earth breaks the mold.

Our planet has far more water than theories predict.

The Earth formed in a part of the solar system that,

well, you'd think normally should be probably pretty dry

because it was pretty close to the Sun.

Our planet is just 150 million miles from the Sun,

putting us inside what scientists call the snow line.

Inside this line, the Sun is powerful enough

to evaporate water during a planet's formation.

Inside the snow line, the temperatures are high,

and there's a lot of energy from the Sun nearby.

Too close to the Sun,

those gaseous and ice-rich materials just can't exist.

They're evaporate away by the heat of the Sun.

Our watery world should be a dry rock in space.

Understanding how water got to the Earth is so important

because it wouldn't be there in the very, very beginning.

But Jupiter could hold the answer to this mystery.

To solve the riddle of earth's water,

Juno aims to discover where our Jupiter was born.

Understanding how and where

and when Jupiter formed is critical

because it has really dominated

the entire evolution of the solar system.

It's the biggest planet by far.

It's the biggest thing out there that's moving everything around.

Any water in the early solar system

could've been moved around by Jupiter's mighty gravity,

so if Juno can trace the history of this giant planet,

that could explain why we find H2O where it's least expected.

We know that planets can move closer to the Sun

and farther out while they're forming

and even after they form,

so how do we figure out where Jupiter formed?

The key is how much water is

locked up inside Jupiter.

If we can understand how Jupiter built a relationship with water,

we can understand how water got distributed

all throughout the solar system, including here on earth.

If Juno can measure the water content of Jupiter,

it will solve a 20-year-old mystery.

December 1995...

NASA's Galileo probe begins a fatal dive

into Jupiter's atmosphere.

When it did, it was able to measure the atmosphere around it

and detect water, and the thing is... it didn't.

It didn't find any, and that's weird.

Everything was bone-dry, so why in the world

did Jupiter's atmosphere look dry?

If the results from the Galileo probe are correct,

then 4.6 billion years ago,

Jupiter formed closer to the Sun,

but that's not the whole story.

20 years later, NASA sends Juno to get a second opinion.

Juno is an orbiter, and so it is loaded with instruments

and detectors to look down on Jupiter

and try to figure out everything that's going on.

Juno doesn't have to risk

its life to hunt for water.

The craft peers through Jupiter's thick clouds

using a microwave radiometer to detect H2O from a safe distance.

Using these microwaves,

Juno builds up a global map of Jupiter's water.

What Juno has found is, yeah,

there's plenty of water in Jupiter,

it's just that Galileo happened to hit a dry spot,

but in fact, if it had come in almost anywhere else,

it would've seen plenty of water.

Juno's findings may give a clue

to where Jupiter originally formed.

It seems apparent now that Jupiter

didn't form in its present location.

The leading theory is that

Jupiter formed just beyond the snow line,

the boundary between the dry inner solar system

and the wet outer solar system.

But we find Jupiter is twice as far away from the Sun

as where that original snow line would've been,

so this is telling us something interesting.

Jupiter may have wandered from

its original position,

causing unimaginable chaos.

As Jupiter moved around, things got hit

and knocked out of the solar system.

It essentially scatters everything in its path.

It's the biggest player. It's the biggest planet.

Everything moves for it.

As Jupiter bulldozes toward the outer solar system,

it slings ice-rich asteroids

and comets in towards the Sun and towards the Earth.

Jupiter would literally in some sense

have snowplowed into the inner solar system

a whole wave of water-rich planetesimals

that would've delivered much of our Earth's oceans.

Juno has helped answer why our Earth is habitable

despite being so close to the Sun.

So it was worth going all that distance,

sending Juno all the way out there to get that closer look.

Juno continues to explore

Jupiter's mysteries and its famous features.

There is nothing more iconic about Jupiter

than the Great Red Spot.

And Juno reveals that this 300-year-old cyclone

may soon vanish.

Our solar system plays host

to some epic natural wonders...

the ice geysers of Enceladus,

the giant rings of Saturn,

the martian mega volcano Olympus Mons,

but in July of 2017,

NASA's Juno probe skims the surface of Jupiter

and photographs the most famous natural wonder...

a fierce, hurricane-like storm

that's been raging for hundreds of years.

When you think of Jupiter,

one of the most visually stunning

and most iconic features of the atmosphere

is that Great Red Spot.

There is nothing like Jupiter's red spot

in our entire solar system.

As Juno soars over the Great Red Spot,

it looks down onto a storm over 10,000 miles across.

This is the most extreme storm.

The winds are blowing continuously

at 400 miles an hour.

On earth, the most powerful category 5 hurricanes

can unleash almost total destruction,

but these are less than half as powerful

as the storm on Jupiter.

The Great Red Spot is the greatest hurricane

that you've ever imagined.

But that's not all.

Juno's microwave radiometer allows scientists to see through

Jupiter's cloud layers for the first time.

Juno has instrumentation that's able to look underneath,

so one of the things we did was we looked

at how deep are the roots.

Juno peers down into the eye

of this monstrous storm.

It spots temperature changes far below the surface

that follow the storm's iconic shape,

tracing the roots of the Great Red Spot

deep into the Jovian atmosphere.

They found out that it goes down over

200 miles deep into the atmosphere.

There's nothing like that on Earth.

The greatest cyclones of our own planet

can reach heights of around 10 miles,

but Jupiter's Great Red Spot is over 20 times taller.

I think that really brings into perspective

the massive scale of this planet.

Jupiter's vast, turbulent atmosphere

hosts the deepest storm mankind has ever seen,

and Juno's discoveries get scientists wondering.

Could the Great Red Spot help explain

another of Jupiter's mysteries,

the planet's surprisingly warm atmosphere?

Jupiter looks out in our outer solar system

where everything is very cold.

The Sun is very dim when you get that far away.

Jupiter is five times farther from the Sun than we are,

so it's only getting 4%

of the amount of energy from the Sun that we do.

But there's something heating up

the atmosphere of Jupiter.

There are parts of it that are many times warmer

than we could explain with sunlight.

The question is, of course, where is that energy

coming from?

Juno swoops in for another pass on Jupiter,

turning its high-resolution cameras

on the raging storm below.

The storm unleashes vicious turbulence

into the surrounding atmosphere,

giving scientists the clue they need

to explain the planet's high temperature.

The Great Red Spot is a giant hurricane

that's powered by heat deep in the core of Jupiter,

but it has such violent and chaotic motion,

it's mixing up the atmosphere around it.

The thunderstorms on Jupiter are gonna be generating

booming thunder just the same way

that they do here on the Earth.

Thunderclouds send sound waves

rippling through the storm.

A sound wave is a wave of pressure,

of compression where air molecules

or water molecules get compacted.

They get squeezed together,

and when you squeeze something together,

they're a lot closer together

and they're gonna get pretty hot.

These sounds waves shoot up

500 miles above the storm

where they break, converting sound energy into heat.

These sound waves, they crash together,

creating a tremendous amount of energy

and heating the gases around them.

Jupiter's great red spot has helped heat

the Jovian atmosphere for hundreds of years,

but new images suggest that this may be about to change.

Jupiter's red spot is so big,

I mean, it's bigger than earth by a long shot.

It seems like it would be an incredibly stable thing.

It's just there and it's always been there and always will be.

Recently, we've seen it changing.

When NASA's Voyager space probe visited

Jupiter in 1979,

it observed a storm twice the diameter of Earth.

In 2017, Juno's images show the Great Red Spot

has lost a third of its width, but that's not all.

Despite the storm shrinking, it's actually getting taller.

The Great Red Spot is being stretched and forced

into Jupiter's upper atmosphere.

The storms in the Great Red Spot,

it's kind of like the clay on a potter's wheel,

where as you bring your hands closer together

to draw the clay in, the closer your hands are,

the taller the pottery becomes, and similarly, for the storm,

as it becomes smaller at the base,

it raises taller toward the upper atmosphere.

It's getting taller, and we see storms

do the same thing on earth, and when it does that,

the wind shear will actually take the top of the storm off

and drag it apart, and so we'll be watching it

very intently over the next few years

to see if that's what happens on Jupiter as well.

It may be only a matter of time

before Jupiter's high-altitude winds

tear this iconic storm to shreds.

The most famous storm of the solar system

may soon disappear,

but Juno reveals other storms

hidden in the strangest of places.

The storm in the Great Red Spot is one,

but not the only, giant storm that's happening on Jupiter.

NASA's Juno probe has traveled billions of miles

across the solar system

to reveal the mysteries of gas giant Jupiter,

but there's one part of Jupiter

that has remained hidden until now.

Before Juno, our view of Jupiter was very limited.

We'd never actually flown over the poles.

It's something that's very hard to do on Jupiter.

We don't have other missions that have done this.

In August of 2016, Juno's flight plan takes

the spacecraft into unknown territory to reveal

Jupiter's mysterious polar regions for the first time.

Well, and the first time we looked at the pole,

it didn't look anything like the Jupiter we knew.

We never would've guessed that was Jupiter

if somebody had shown that to us.

Juno's camera reveals a strange blue expanse

that puzzles scientists.

The electronic color

could be due to chemical changes in the clouds

brought on by a lack of sunlight,

but what Juno spots inside the blue clouds

is even stranger...

giant central cyclones spin around each pole at 200 miles

an hour, with these cyclones

surrounded by eight stormy vortices in the north

and five in the south.

There are these weird cyclones, gigantic swirls,

vortices of gas swirling around Jupiter's poles,

and they're clearly forming patterns.

It's hard to get a sense of scale here.

Now the north polar central cyclone,

that one right at the pole, that's 2,500 miles across.

That is almost as big as the continental United States.

What is going on there?

This is nothing like what we see on earth.

On earth, our weather is driven by heat from the Sun

that hits our planet at the equator

and flows across the surface.

Powerful cyclones form over tropical waters

and move around the planet,

but the polar regions receive less energy from the Sun,

so cyclones can't form at the poles.

We see that if you're at the equator,

it's warmer and it's stormier.

If you're at the poles,

where the Sun is slightly harder to see, that activity goes away.

But the weather on Jupiter

couldn't be more different.

We see lightning and convective thunderstorms

at the poles of Jupiter but not at the equator,

and that's sort of the opposite of what we see on the Earth.

The question is, what's driving Jupiter's storms?

Jupiter is five times further

away from the Sun than the Earth

and receives only a fraction of the Sun's energy.

Unlike earth, Jupiter's polar regions

seem to be where the action is.

Something is driving the planet's weird weather,

and Juno's scans of the giant planet's thermal emissions

suggests it could be Jupiter itself.

We can actually see the internal heat of Jupiter

coming right up through,

and so Jupiter will look very bright in areas

where we can see that heat.

Juno detects searing heat

beneath Jupiter's cloud bands.

Jupiter has so much material, so much mass,

so much gravity that the interior is incredibly dense

and very, very hot.

At the core, it's probably at many thousands of degrees hotter

than the surface of the Sun.

This fiery inferno buried in Jupiter's dark heart

is a relic from its birth billions of years ago.

The violent collisions that formed the planet

left its core seething hot,

a heat that remains to this day,

buried under thousands of miles of insulating gas.

As the heat slowly leaks outward,

Jupiter's fast-rotating atmosphere

creates vicious cyclones and thunderstorms.

And that's what's really driving most of the weather.

It's not the Sun. It's Jupiter itself.

And as Juno soars over the planet,

it reveals another weather mystery.

The craft detects bursts of radio waves

spiking up to four times a second...

the telltale sign of ferocious lightning strikes.

Clouds are moving around in the atmosphere

and building up electric charge

and causing bolts of lightning to form,

and we've actually seen this with the Juno spacecraft.

These are mega storms orders of magnitude bigger

than here on Earth.

And Juno finds there's more to these thunderclouds

than just flashes of light...

giant icy hailstones of water and ammonia,

the chemical which gives Jupiter's clouds

their orange color.

High up in Jupiter's atmosphere,

the ammonia is mixing with the water,

and it becomes a liquid ball

that starts to collect ice around it,

and it will fall like hail does deep into Jupiter's atmosphere.

On earth, hail falls to the ground and melts,

but on Jupiter, there is no ground.

And it gets lifted in the atmosphere

because of an updraft and then more ice,

and it builds bigger, and then it falls down,

and then it gets carried back up,

and so hail is often many layers being built.

These ice balls grow layer by layer as they soar up

and down the atmosphere.

If they formed in storms here on earth,

they'd cause some serious damage.

So if you were buzzing around Jupiter

and you were near where these storms were,

you might get hit by hail coming up or going down.

This is one of the most violent, energetic atmospheres

in the entire solar system.

Juno is revealing the secrets

that Jupiter has hidden for decades,

including the mystery of Jupiter's northern lights.

When Juno studied the lights

coming from the aurora on Jupiter,

it found that something really weird is going on.

On earth, dazzling auroras light up the skies

as charged particles from the Sun

interact with atoms high in the atmosphere.

Deep in the outer solar system, Jupiter is too far from the Sun

for strong auroras to form in this way,

but high above the giant planet's poles,

Juno spots a seemingly impossible light show.

The auroras of Jupiter are tremendously larger

than the ones that we find here on Earth.

In fact, the auroral rings near the poles

are bigger than our planet itself.

Jupiter's auroras emit

primarily ultraviolet and X-ray light,

so you can't see it with the naked human eye,

but if you could see them and you were at Jupiter,

that would be an amazing light show

because those auroras are strong.

These glowing displays are

evidence of charged particles

slamming into Jupiter's atmosphere.

But if they're not coming from the Sun,

where are they coming from?

Hunting for an answer, Juno snaps an image

of Jupiter's southern lights

with its ultraviolet imaging spectrometer.

Inside the aurora, it glimpses something strange.

When Juno studied the lights

coming from the aurora on Jupiter,

it found that they were even stronger than expected,

and in fact, when you look at

Jupiter's poles in wavelengths that our eyes can't see,

for example, ultraviolet, you see a hot spot.

This hot spot marks the point

where huge concentrations of charged particles

strike Jupiter's atmosphere.

Tracing their trajectory reveals the culprit

of Jupiter's dazzling light shows...

the volcanoes of Jupiter's moons.

Jupiter's moon, Io has hundreds of active volcanoes

spewing out materials way out into space,

and many of those get trapped by the magnetic field of Jupiter.

Io's volcanoes fire out jets of charged particles,

which are swept by the giant planet's magnetic field.

It's funneling those particles down

and slamming into specific spots in Jupiter's atmosphere.

But Io isn't the only moon responsible

for Jupiter's polar light show.

If we go further out, Europa, Ganymede,

Callisto, those are more icy.

They don't necessarily have volcanoes.

These icy moons twist up

Jupiter's magnetic field in their own way.

Some of these moons have magnetic fields that interact

with Jupiter's magnetic field,

and that actually intensifies the aurora display on Jupiter.

Jupiter's moons work together

to energize the greatest auroras in the solar system,

but in these beautiful displays

is a stark reminder of the danger Juno faces.

When you look at these pictures of the aurora on Jupiter,

and you think, oh, that's beautiful.

Wouldn't it be great to see that in person?

The answer is no, no, it wouldn't

because they will kill you.

What's causing these displays are subatomic particles

accelerated to tremendously high speeds

by the magnetic fields involved.

The radiation around Jupiter is lethal

and not just for humans.

The lifetime of the Juno mission is very limited

by the extreme conditions it has to survive in.

We think that in the future,

a lot of the instruments will be so irradiated,

they won't really work anymore.

When Juno's titanium armor finally fails,

Jupiter's deadly radiation will damage the craft beyond repair,

so the team plan to go out with a bang,

thrusting Juno into Jupiter's atmosphere,

where the craft will be torn to pieces.

Eventually, it'll be drawn down into Jupiter's depths

and become a part of the planet itself.

But before then,

Juno has many more mysteries to unlock.

We'll answer some questions, and we'll raise some more.

That's what I expect

and we'll get some fantastic images.

Every single thing has turned out to be a surprise.

There are so many things that Juno has opened our eyes to that

I can't imagine having not sent it.

So we're in for at least a year

more of the most profound surprises about Jupiter.

What we're learning, what we're unlocking,

not just about Jupiter,

but the formation of the solar system

and potential formation of life itself

here on earth,

it's mind-blowing.

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