(tense music)
Jupiter was cool because it's the biggest planet.
It's spinal tap.
Everything's turned up a little bit closer to 11.
Jupiter is enormous.
And everybody loves 11.
(dramatic music)
The great red spot, the drama of the poles,
and all the vortices going around.
It's got these fantastic cloud layers spinning around.
These storms raging bigger than the Earth itself.
And then the moons!
It's like a little solar system in itself.
Instead of a starred center with planets going around it.
You've got Jupiter with moons going around it.
79 moons.
Four big ones.
Io, Europa, Ganymede, and Callisto and they are huge!
Each one their own world of ice, or rock, or volcano.
It's a very violent, dangerous,
deadly place in the solar system.
(dramatic music)
You send a spacecraft to Jupiter,
you're gonna get fried really quick.
(machine whirring)
Can we send a spacecraft through that environment?
The Greeks weren't wrong to make
that thing the king of the gods.
(dramatic music)
(gentle music)
Juno was gonna be the first spacecraft
to fly over the poles of Jupiter,
and it was due to arrive on the 4th of July.
(dramatic music)
That day I had my whole family.
We were going into JPL.
I remember turning to my kids in the backseat and said,
"It might not work something bad could happen.
"NASA and the country and the world
"are taking a big risk here."
We had no idea what this polar environment was like.
We had some sense of the radiation belt.
We knew they are nasty,
really, really nasty.
(dramatic music)
Juno is an armored tank,
but it's nothing compared to Jupiter.
So we want to be really careful.
Go through quickly and get out.
And so, Juno is moving really fast.
It was coming in at about 150,000 miles an hour,
which is like going around the Earth
five times in two hours.
Not because we had this incredible prolusion system,
but because Jupiter's gravity was sucking us in.
(dramatic music)
The engineers hoped that it wasn't gonna get us completely.
We were gonna just go really close to it.
(dramatic music)
If it doesn't work, it's over.
Lights off.
(insects chirping)
Long before Juno would make its daring attempt,
scientists had begun to realize
that it was an unusual region of space.
(dramatic music)
Back in 1955, they detected bursts of radio emission
coming from Jupiter, and they didn't know what it was.
(dramatic music)
It's like a gigantic engine, and the amount of energy
that must be just bopping around that thing is amazing.
But this told us that Jupiter has a magnetic field,
and perhaps, more importantly, a very strong one.
Some planets have a dynamo inside,
which means they behave like a giant spinning magnet
surrounding them with a magnetic field.
Early on, little was known about
what these magnetic fields could do.
Then in 1958, an experiment
would begin to reveal the secret.
At the end of the 1950s,
there was a huge push in America
to have a successful satellite in orbit,
and the concept of the Explorer 1 mission was developed.
Now the scientific payload for that mission
was led by a person called James Van Allen,
who had a big interest in magnetic fields
and the particle environment
that might be above our heads in space.
(dramatic music)
One of the things that he was excited about
was really high-energy particles,
and so he proposed an instrument to be on Explorer 1,
our very first spacecraft.
So Explorer 1 had a very simple detector system
that would count particles.
It was a Geiger-Muller tube,
the kind of thing you look for radiation with.
It does the click, click, click counting for radiation.
They wanted to fly this on the rocket
to measure the radiation up in space.
The experiment was looking for cosmic rays.
Now cosmic rays are the radiation coming out
from far out in the galaxy entering our solar system.
And it went up there.
They're counting the particles, zip, zip, zip going in.
At some point though, the signals disappeared.
(machine whirring)
At certain altitudes,
particularly around about 2,000 kilometers
above the surface of the Earth,
the count rate dropped to zero.
They thought, "Ah-ha, you know what's happening.
"This is saturated.
"The number of particles are so high
"that the detector has just said I'm gonna shut down."
(dramatic music)
That realization actually led to a phenomenal discovery.
In space there are donut shaped regions around the Earth
where there are many, many electrically charged particles,
for example, electrons
and other electrically charged particles.
The radiation gets trapped into this really
lethal zone around the Earth.
They're trapped because electrically charged particles
feel a force from the magnetic field.
We had discovered that the Earth's
magnetic field creates a bubble around the planet
called a magnetosphere sphere,
that both deflects charged particles
and captures some as well.
Many of these particles of radiation
come streaming from the sun,
and this is called the solar wind.
The scientific discovery is fantastic on the one hand,
but it's also slightly worrying.
Because high-energy charged particles can pack a punch
when they interact with materials.
So let's imagine, for example, the impact on the human body.
If these particles have enough energy,
they can penetrate the skin
and start to interfere with the cells of the body.
So in an extreme case,
you might get radiation sickness if you had enough
high-energy particles coming into your body.
(dramatic music)
We have to be really careful, not just because of humans,
we don't want to be damage but also the electronics.
So can we send our spacecraft to places like Jupiter?
Will our spacecraft survive in those kind of environments?
(dramatic music)
When Van Allen discovered these incredibly
high-energy radiation belts around the Earth,
I think, people started to then look at the models
of what would be needed at Jupiter
to explain what was being observed?
All of a sudden like pieces of a puzzle,
the ideas started to come together.
The calculations started to be made,
and people were startled because Jupiter
was so much more powerful than the Earth.
I mean, our radiation belt, as severe as they are
and dangerous as they may be, are really a piece of cake
compared to Jupiter.
(gentle music)
So the first time we left Earth
to go out in the solar system
beyond the orbit of Mars, there were major concerns.
Can we send a spacecraft through that environment?
So we sent two Pioneer space rockets.
They were pretty crude
with very limited computational capabilities
and very limited power and ability to communicate.
So they would just make a few measurements,
and then send the information back to the Earth very simple.
(funky electronic music)
So when the Pioneers flew
through the magnetosphere of Jupiter,
we didn't know how big this was.
We didn't know how large the magnetic field is,
and we didn't know how it was shaped
or buffeted by the solar wind.
(dramatic music)
Pioneer 10 was due to fly past Jupiter
on the 3rd of December 1973,
and these are some of the first images it sent back.
(dramatic music)
Pioneer carried some protection,
but it probably went a little bit
closer than it should have.
But it was zipping through pretty fast.
In order to try to assess what it was like there,
I mean, it basically was carrying a Geiger counter.
I think, everybody was startled
at the amount of energy that we're talking about.
During its closest approach to Jupiter,
Pioneer 10 absorbed 1,000 times
the lethal dose of radiation for a human being.
The spacecraft is collecting
its worse radiation exposure.
Tension is even greater this time
and so is the relief. (people applauding)
R-10, R-two.
Makes it all worthwhile.
After 10 years of having to put with all these people
and 14 hours a day it's all worthwhile.
(gentle music)
And so, after the Pioneers we knew the extent
of the Jovian magnetosphere, and it is enormous.
(dramatic music)
If we could see it in the night sky
with Jupiter sitting rather far away from us,
it would still be roughly five times larger than the moon.
I always wished it could be like a light purple
traveling through the sky, and it would just be huge.
The solar wind that hits that magnetic field
shapes it like a comet and produces a long tail.
The tail stretches all the way to Saturn.
(dramatic music)
The primary purpose of those Pioneers was really to say
can we survive this lethal dose of radiation,
so then we can follow with more sophisticated
instrumentation that can do a lot of interesting science.
(lively drum music)
I was lucky to start working on Voyager
as a graduate student at MIT.
It was the first project that I worked on.
I came along just as we were about to launch the spacecraft
on its way out first to Jupiter.
I got a job as an undergraduate assistant
to the imaging team.
It was a mind blowing experience in so many ways.
We had the Voyager spacecraft down
at the Cape ready to launch.
It was the Pioneer data that made us realize
that the radiation tolerance that we had designed
into the Voyager spacecraft was not gonna be adequate
for the environment that Pioneer 10 and 11 had sensed.
It threw us into a real turmoil
of trying to recover from that.
(funky guitar music)
By the time we got to the Voyager spacecraft,
we were already so scared and intimidated by Jupiter
that we started to move away from it.
We didn't wanna get so close
because we knew if you got close,
you're probably spelling the end of the spacecraft.
So you've gotta stay away and respect this beast.
This monster it's much more powerful than we are.
Even with a quite small telescope from your backyard,
you can look up and see Jupiter on a clear night,
and you can see the belts and zones.
You can see the red spot.
(funky upbeat music)
But Voyager saw up close
and making a movie as it approached.
(funky upbeat music)
It was really like you were
on the spacecraft looking out the window.
You could see these belts and zones,
east, west winds going back and forth,
and the great red spot being caught up
in those belts and zones.
So the weather system was becoming clear.
As we flew by, we could get a real sense
of how this dynamic atmosphere was working.
(gentle music)
As we come in for a close view of Jupiter,
you'll see clouds orbiting around the planet
at different rates, with different thickness bands,
and these are called the jets.
These jets go around lines of latitude, back and forth,
some faster than the planet, some slower than the planet,
and so if you were living on the planet,
there'd be these huge sheers at different latitudes
as these fight back and forth in different directions.
Finding out what causes this wild weather
became a key scientific objective.
On Jupiter the affects of planetary rotation
are incredibly important, why?
Well, the strength of the rotational forces
depends on how fast the system rotates,
and it also depends on how big the system is,
and Jupiter's huge.
Jupiter has a diameter of a 140,000 kilometers
and it was discovered that the planets rotates
at about 40,000 kilometers per hour.
So this body is just completely flying.
If you think of the whole planet as a gyroscope,
it would be a very big, very fast gyroscope.
Those gyroscopic effects dominate
many of the dynamics we observed.
We use this demo to explain Jupiter's great red spot,
which is a really interesting phenomenon
that we've observed for over 200 years,
and we think it's existed longer than that.
It's, essentially, a massive hurricane
that's about 1.3 times the size of the Earth.
In this experiment you're looking at
a simplified analog of the surface of a gas giant.
The cloud layer it's only about
five or six centimeters deep and a meter across,
and we faked the photo chemistry with
sprayed in food coloring.
(funky upbeat music)
So Jupiter is very strongly rotating body,
but it also has a lot of strong turbulence.
The great red spot has formed
from this rapidly rotating turbulence.
Instead of having the massive turbulence
that's naturally occurring in Jupiter
by the hand of God, we just mix a little.
As a cloud of gas or liquid
moves across a rotating surface,
its path begins to curve along with the rotation.
This is called the Coriolis effect,
and it's what spins hurricanes and typhoons here on Earth.
But because Jupiter is so large and turns so fast,
its weather is far more extreme.
The affect of the Coriolis force
in the presence of turbulence
acts to generate large scale structures,
like the great red spot, and they persist.
But now what you're seeing in the tank
is the formation of these beautiful vortices.
You can see there's all these filaments connecting them.
That's what you get in rotating systems.
You naturally role things up
into large vertical structures.
(funky upbeat music)
They live a long, long time
when the system's rapidly rotating.
If the planet stopped rotating,
that organization would be gone.
(dramatic music)
The Voyager spacecraft were not
just visiting Jupiter in order to examine the planet.
The four giant Galilean moons were a key objective,
and none more so than the mysterious moon Io.
(dramatic music)
As we were coming in,
the ultraviolet instrument was saying,
"Whoa, this is bright.
"Whoa, there's a lot of gas around this environment near Io.
"You better be careful."
(dramatic music)
Voyager flew by and we saw it covered with volcanoes.
We saw gases spewing out
hundreds of kilometers up into the sky,
and so now we began to make sense what was happening.
That these volcanoes were spewing out gases
about a ton every second.
Those gases were becoming trapped in the magnetic field
to make this donut of charge particles.
They get accelerated to very high energies.
(dramatic music)
Most of them go out to fill a big volume.
Some of them go in, and as they go in,
they go to even higher energies
and form this very tight environment close to Jupiter,
this lethal radiation environment.
That inner region is very analogous
to the Van Allen belt of Earth
but many times stronger and more nasty.
The background radiation here on Earth
that we're exposed to is about a third of a rad.
At Jupiter, the radiation environment is 20 million rad.
We did know Io, Europa, Ganymede
are in these orbital residences
where Io goes around four times
for every two times and one times
that the others go around.
The orbits are elliptical,
and so when Io was close to Jupiter, it squeezes it.
When it's further away from Jupiter, the squeeze is less,
and so you're literally looking at Io going like this.
That heat has got to go somewhere.
There'd been a paper published in science magazine
that had come out the week before Voyager got there
predicting volcanoes on Io because of this tidal flexing.
(dramatic music)
But, we were not expecting what we saw with Voyager.
(machine beeping) (gentle music)
Everybody thought the Io was the cool neat one
and the others were okay.
(gentle music)
We knew there was something weird about Europa.
It was bright and maybe it had these weird markings,
but you couldn't really see them before.
(gentle music)
Then all of sudden there it is,
and this first image is appearing on the screen.
Europa has all these cracks in the ice
and these lines going across.
They're gonna be two.
Io and Europa there's a twin.
At that moment it was just like whoa.
What does that mean?
(gentle music)
As an airless body, we kind of expect
things to be bombarded all the time, so you end up
with a surface peppered with craters much like our moon.
What about the relief in the cracks?
Because the cratering rate throughout the solar system
is relatively well understood,
the fact that Europa has so few craters
is very consistent with it having a young surface,
with a surface that has been geologically resurfaced.
Carl Sagan who was there in the room
he said, "Ah, Percival Lowell was right.
"Only the canals are on Europa not Mars."
Now this is something we keep discovering
in planetary science.
We thought the moons of Jupiter would be
all dead and boring, and they're not
because there's a mysterious unknown energy sources.
(scientists chatting)
It's like, "Oh, wow, there's more going on here
"than we thought with our Earth-based assumptions."
(upbeat music)
The Voyager observations were so spectacular,
the dynamics of the atmosphere,
the different kinds of moons and what was going on.
Everybody said we gotta go back.
But this time we have to go back and stay.
With Voyager we had a couple of
very short fleeting flybys.
Like just whizzing some pictures
out your car window as you drive by,
as opposed to actually stopping,
getting out of the car and exploring.
We have to go into orbit send a probe into the atmosphere.
Find out what it's like inside.
Go past all the moons
and look at them in different directions.
(upbeat music)
Before the Voyagers had Jupiter
in their rear view mirrors,
NASA had been building a spacecraft they intended
to go into orbit around the giant planet.
The mission was called Galileo.
Galileo had a fitful start right from the very beginning
about how exactly it was going to get to Jupiter.
Galileo was scheduled to launch
in January 1982 onboard the space shuttle.
The launch date slips to '84, then '85, and then '86,
and then the whole shuttle program
suffered a terrible tragedy.
(somber music)
The spacecraft was down at the Cape.
I can remember looking out the window
of the Challenge launch.
Challenge go with throttle up.
The significance of that, of course, the loss of life
and a disruption of the whole program,
but to us was we didn't have a launch vehicle.
And so, we packed up our spacecraft
and took it back to California
trying to figure out what to do.
Not only was the launch delayed,
but after the accident,
NASA was understandably more risk averse.
The liquid hydrogen fueled rocket booster,
which was originally planned to deliver
the Galileo mission directly to Jupiter,
was no longer deemed safe enough.
It was no longer possible
to take Galileo straight up to Jupiter,
and that's where the mission designers here
pulled a rabbit out of the hat
and found the so-called VEEGA,
Venus Earth Earth Gravity Assist trajectory
that took another five years to get there.
(crowd applauding)
We have a go from main engine start.
Six, five, four, three, two, one.
We have ignition and lift off of Atlantis
and the Galileo spacecraft bound for Jupiter.
(gentle music)
(astronauts chatting)
Galileo is on its way to another world.
Fly safe.
After the first flyby,
we knew we would be far enough away from the sun
that we could actually begin to use the high-gain antenna.
(gentle music)
It was like an umbrella.
You imagine an umbrella being folded up.
Then when the time came
when the spacecraft would fire a device,
and then the antenna could unfold.
So we accentuated the motor to free the antenna
and it stuck.
(bright music)
If you imagine. (imitates machine whirring)
It stalled only partially deploying some of the antenna.
(bright flute music)
The motor doesn't reverse.
We could tell the antenna had deployed a little bit
because the spacecraft's spin wasn't quite the same.
It's like if you stick out one arm and you're spinning
you start to do this a little bit.
Well, the antenna was doing that a little bit.
So we knew it opened some.
So why didn't it open?
Well, we understand now that the reason it didn't open
was because of the combination of the fact that
the antenna had remained stowed for so long,
and the fact that it went in
from two vibrations environments.
Once when we latched this spacecraft up in California,
trucked it down the Kennedy.
Challenger didn't work.
Put it back in the truck.
Trucked it back to Pasadena.
Said, "Let's not mess with that antenna.
"It was all put together right.
"We'll just leave it the way it was."
Back to Cape again.
So it made three trips across the Cape
in a truck which was vibrating the whole time.
(bright music)
And so, we did a lot of things.
We worked on calibrating how far the antenna was open.
Could we use it the way it was,
and could we do the cold turns to free it up
and see if anything springs free?
We'd know again by seeing the spin rates change
if anything broke free.
So we spent a couple of years working on those things.
JPL never did get
the high-gain antenna to open.
Our capability at Jupiter
with an antenna that hadn't opened
was gonna be dependent upon a single low-gain antenna.
That just meant we had to transmit
a lot fewer picture over the same time.
But, overall reduction and mission return
was large but not disastrous.
(dramatic music)
The Galileo spacecraft carried along with it a probe.
It's sort of like this size.
It had a big heat shield to protect it around it.
In July 1995, we launched that probe
and sent it in the direction of Jupiter.
Now it didn't have engines,
so we weren't guiding it and saying go there.
We just sort of sent it on a trajectory towards Jupiter.
Five months later on the 7th of December 1995,
the Galileo probe was due to arrive at Jupiter.
(dramatic music)
There were no cameras onboard only censors
and a little probe that was going to have
an extremely violent introduction to Jupiter.
It was coming in at something like
a 130,000 miles an hour
because it was pulled in by the gravity of Jupiter,
and we had to slow it down.
This heat shield heated up to about three times
the temperature of the surface of the Sun.
(dramatic music)
During its maximum deceleration
the probe endured forces of 228-Gs.
Then eventually we kicked off that heat shield,
put up some parachutes,
and so as it went down,
we were able to get a sense of what it was like.
What we were expecting was three separate layers of clouds.
(dramatic music)
And we went down it was like, "Where are the clouds?
"Where are the clouds?
"We're not seeing the clouds what's going on?"
So everybody was completely confused.
Well, the hint came from the ground.
Telescopes on Earth were looking in the infrared
at Jupiter at the same time we sent the probe in.
We realized that the probe went into a hot spot
somewhere where there's very little water.
I think, we realize that our whole idea
of exploring these planets with single probes
is a little bit susceptible to going into the wrong place.
By the time the probe had got down to about 160 kilometers
something like 23 times atmospheric pressure,
it was now starting to get really hot,
and so at that point the electronics
is just not working anymore.
It stops communicating and sending signals back to Earth.
What happened to it after that?
Well, it was so hot that it basically vaporized.
But let's imagine what it will be like
if you could be a pressured capsule as you get deeper down.
(thunder rumbling)
I mean, it's either a hang glider's nightmare
or his dream depending on how risky they wanna be.
But as you went deeper and deeper,
it would get a little calmer, a little less turbulent.
The pressure would get higher and higher.
It's so hot everything's vaporous.
Eventually, you get down to material
that are almost like rock clouds,
and they're probably precipitating.
Now when you get down something like 10% of the radius,
you're now getting to the point where the pressures
are about a million times Earth's atmospheric pressure,
and the density is getting really high.
At that point hydrogen changes its phase.
It's no longer molecules,
protons and electrons connected together.
But the protons and the electrons are moving separately,
and it becomes metallic.
That is it becomes electrically conducting.
In this region you can generate a magnetic field,
what's called a dynamo.
The fluids convert some of their motional energy
into magnetic field energy, into currents.
(dramatic music)
On Earth the dynamo is very far from us.
Earth's core is halfway through the planet.
But on Jupiter you don't even go 10% of the way in,
and you've got this 60,000 kilometer radius ball
of molten metallic material.
(dramatic music)
Maybe that means it's not amazing
that you generate a huge magnetic field.
I suspect it would look like Mercury.
A glob of Mercury is what it will probably look like.
(dramatic music)
If you existed, you would be
unbelievably thin, flat out pancake.
You get to the center of Jupiter we're talking
four times the temperature of the surface of the Sun,
50 millions atmospheres pressure,
and a density that's denser than the heaviest
metals that we have on Earth.
Now the Galileo probe
had succeeded with its mission
and subsequently vaporized inside Jupiter,
the mothership had to avoid a similar fate
and insert itself safely into orbit.
In just that first pass when we were getting into orbit,
Galileo received half of its radiation dose,
like a 150 kilo rads in one shot.
Then it went out further and kind of licked its wounds.
Because of Galileo having this broken antenna,
it meant that we couldn't make all the observations
of Jupiter that we wanted, the movies and so on so forth.
We had to be selective.
Remembering that we don't wanna get
into the radiation belts too quickly,
so we tended to focus further out first.
The first really exciting thing we found
was Ganymede has its own magnetic field.
The seventh moon out
from the surface of Jupiter,
Ganymede, is a moon the size of a planet.
Larger than Mercury,
it's the biggest moon in our solar system.
The fact that Ganymede has a magnetic field,
means that it might have some ability
to protect itself from the harsh radiation of Jupiter,
a key attribute for a habitat where life might be found.
So now it starts to open up
how we think about even what's a planetary body?
These moons how different are they from other planets?
They can have their own magnetic field.
(dramatic music)
But now the Galileo spacecraft,
despite its troubles, was about to make arguably
the most important discovery in the history of space flight
at the mysterious moon that Voyager
had visited 17 years before Europa.
What we measured as we flew by
was something quite remarkable.
There were electrical currents
that were flowing inside the moon
that perturbed the magnetic field,
and we concluded that Europa has to have
a liquid ocean underneath that ice.
(dramatic music)
The reason is, ice is not very electrically conducting.
You need it to be liquified as water in a big ocean
to carry those electrical currents.
Probably has to have salt in it
to be electrically conducting
in the way that the Earth's salty ocean
is electrically conducting.
The reason why we hardly see any craters
on the surface of Europa,
is because that ocean is squirted out
and has filled them in over time.
Like Io, Europa,
which is also in an elliptical orbit
gets squeezed and relaxed every two or so days
as it goes around the planet,
is dissipating that heat by melting that ice shell.
We believe the ocean can be as thick as a 100 miles
and maybe even thicker.
At the rocky surface at the bottom of the ocean,
I know exactly what it looks like.
It looks like Io.
We call those molten volcanoes on Io,
but underneath the ocean in Europa
we would call them hydrothermal vents.
Such vents are also found here on Earth.
Those hydrothermal vents form fields.
So it's not just a single chimney.
But there's a field of chimneys, if you like,
and those fields we think on the early Earth,
and potentially on some moons,
could spread across an entire sea floor
the ones we're interested in,
and they are not black smokers,
which are kind of chimneys with black smoke
belching out of the top.
It's a different type of vent.
The hydrothermal fluid are warm, not hot, and alkaline.
They look almost deserted.
But they are chemically active.
You have this kind of porous lathering
sort of interconnected pores.
Sort of hydrogen from the vents
mixing with CO2 from the oceans,
making organic molecules.
Here you have a setting which looks an awful lot
like the way that modern cells work.
This kind of chemistry was almost certainly behind
the origin of life on Earth.
(liquid sloshing)
(gentle piano music)
When you look at Europa and you look at the cracks,
there is this brown gunky stuff
that seems to be coming from the interior.
But also could it be that there's a source of chemistry
coming from Io, in Io's volcanoes,
impacting the surface of Europa bringing sulfur,
and perhaps more importantly oxygen, into Europa,
and that material then gets carried down into the ocean,
oxidizing the environment of the ocean,
and maybe enhancing the life that maybe is there.
Maybe not, we don't know.
I think that Europa is a place where,
given what we think we know about life,
there ought to be life.
But it is the most likely place.
If you wanna go somewhere in the solar system,
to find out if there's life, that's where I'd put my money.
After the incredible discovery at Europa,
the Galileo mission found that Ganymede
also had a sub-surface ocean,
and there's was strong suspicions
that Callisto might contain an ocean as well.
We had no idea that life could exist
anywhere else in our solar system prior to this.
It was just we have life on Earth,
so to get life anywhere else you need to have planets,
and other star systems that look just like Earth.
I think, we're realizing now that there
are other places even within our solar system
that you can have these right ingredients
and have energy and these primordial ingredients
that is required to actually make something complex
out of randomness, essentially.
(dramatic music)
Galileo made a lot of incredible contributions
to our understanding the whole system
and how it interacts with each other.
What was really going on as Io spit out all this material,
Ganymede had its own magnetic feel.
Europa had an enormous ocean.
But by then we'd kind of done
what we were gonna do with Galileo.
The radiation of Jupiter
is very, very hard on electronics.
So it upset the spacecraft.
It goes into saving, stops all the sequences,
and you have to restart things.
After having its mission extended three times,
it was eventually decided in 2003
to dispose of the aging radiation damaged spacecraft
by flying it into the clouds of Jupiter.
We learned so much from Galileo.
In fact, it was really the results of Galileo
that led us to Juno.
Lift off of the Atlas V with Juno
on a trek to Jupiter.
The big question after Galileo
was did not probe just go into somewhere weird
or was the lack of water symptomatic of the entire planet?
Now this is extremely important.
In 30 minutes that it took the probe
to go into Jupiter and get this data,
every theory of solar system formation was proven wrong.
Because remember we think that gas giants formed by having
giant snowballs, say 30 times the mass of the Earth,
that pull in the hydrogen to make the gas giants.
So at the core we think there was ice.
Yet, when we went in with that probe,
we didn't see any or very little.
So what's going on?
So when Juno came along,
one of its primary objectives
was to go in and see how much water
and oxygen is in Jupiter.
We have to go back and find out.
We could send in a 100 probes.
But, that's gonna be expensive and difficult.
We thought of a cleverer way of doing it.
(dramatic music)
Juno was designed in order to make measurements
almost over the whole planet and look at the water
rather than in one spot,
and to go much deeper remotely not with a probe.
The brilliant idea was to use microwaves.
Everyone knows that microwaves are absorbed by water.
So what we want to do is fly over Jupiter
and map out the distribution of water
from the absorption of those microwaves.
But to find out what it's like deep inside,
we have to measure distribution of mass inside
that changes the gravity field in some subtle ways.
To do that we had to go into a polar orbit,
and we also had to get really close.
Now remember we've got a problem with Jupiter.
Jupiter has these radiation belts around it.
You don't really wanna take your sensitive electronics
of your spacecraft through that environment,
at least not for long.
We had to somehow get beneath the radiation belt.
If we can just thread that needle.
(dramatic music)
I was just praying with my eyes closed
that this was gonna work.
We were getting a few thousand miles above the cloud tops
when we were doing this maneuver.
Nothing had ever been that close.
Fire the engines.
Go head now.
Yeah, we see the action has started.
Copy that, that's good news for us.
(people applauding) Thirty-five minutes
they're firing away slowing down the spacecraft,
so it gets caught in Jupiter's gravity.
(dramatic music)
And when we find out spacecraft's alive, phew, big relief.
(people applauding and cheering)
Juno welcome to Jupiter.
(dramatic music)
NASA did it again.
(crowd applauding and cheering)
You know the thing that was also sobering
was we were coming back, this was our game plan.
Every orbit we were gonna have to
run through that fire with our bare feet.
Juno carried a camera called Juno cam
designed to provide pictures for the public back on Earth.
But these images were too reveal a great surprise.
Our view of Jupiter before Juno was from the equator.
So then when Juno flies over the poles and is looking down,
and there we see these vortices, all this structure,
it's just extraordinary.
(dramatic music)
The Juno cam that little camera that was just slapped on
to get some publicity photos
has turned out to be just extraordinary.
I'd love to say that I figured this out
and did it on purpose,
but really what I wanted was a great picture.
Little did we know that the poles of Jupiter
were gonna become this huge science discover by itself.
Giant polar cyclones nobody anticipated that.
With the help of the citizen scientists around the world
helping us process those images
we are seeing all sorts of little structures,
and pop up you clouds.
Nobody expected that level of detail.
(dramatic music)
When we fly in close measuring
the perturbations in Juno's motion,
we're beginning to get a sense of what it's like inside.
What we're finding is that
it's not like the textbook picture
where you have a metal rock core inside
and then a layer of hydrogen, and then a layer of gas above.
It's much fuzzier, much more mixed up,
and so, in fact, that core
is spread out to about 40% of the radius.
It's mixed in with the metallic hydrogen.
You're beginning to see that the convection system
we see on the outside extend a long way in.
They're much, much deeper.
(gentle dramatic music)
But what Juno has not yet been able to explain
is what drives the jets?
It might be that turbulence
at the surface drives these jets,
and then the jets burrow down into the depths.
(dramatic music)
But with Jupiter so much heat is coming
out of the interior of the planet,
that maybe the jets are being driven by deep motions,
and it's their surface expression
that we're seeing about the top.
There's probably something deep down
is driving a lot of motion inside of Jupiter.
We're beginning to think about that region
where hydrogen becomes metallic
that generates this strong magnetic field.
The magnetic field is probably moving things around.
Driving convection and eddies and all kinds of motion,
and so somewhere there's a balancing act.
The stuff that's coming in from the top
meets the stuff that's coming up from the bottom,
and all hell breaks lose.
What's the right answer?
We do not yet know.
Open question.
One of the great questions for me
as a scientist looking at Jupiter and studying Jupiter.
Nobody really knows for sure what makes the colors
in Jupiter's zones and belts.
We see all these oranges and reds
and beautiful yellows and browns.
Io spewing out tons of sulfur among other things
because it's volcanic.
Models sort of indicate to us that
as I radioactively change sulfur,
it can make these reddish hues,
and so Io may have had a huge effect
on the way Jupiter appears to us.
But it's producing a lot of material
that's definitely going into Jupiter,
and it may be part of the reason that Jupiter
is this incredibly beautiful object.
So in many ways the combination of Io
and its volcanoes with Jupiter's strong magnetic field,
is really at the core of an engine or a generator.
(low rumbling) (dramatic music)
(gentle music)
When we laid out the objectives of Juno,
it was to go sort of figure out the puzzles
of what it was made out of and how it formed.
Nobody really conceived of the idea that we'd go there,
and the entire structure was gonna be
different than we thought.
(gentle music)
It may be that we've been a bit naive.
That if Jupiter could throw us this many curve balls,
that our ideas of how stars worked
could be kind of wrong too.
I mean, there's even more energy,
and they're even more massive.
Astronomers have looked out and seen many stars,
right, billions, and billions.
Many of those are binary systems,
two stars going around each other.
Sometimes there's a big star and a little star.
Maybe a star that has only a tiny bit of fusion inside
like a brown dwarf.
In our case and many others we've seen
where we have a star and a planetary system,
the biggest planet does not have enough mass
to have a fusion reaction inside.
So let's think of our solar system
where we have the sun and we have Jupiter.
Jupiter is 1/1000th the volume
and 1/1000th the mass of the sun,
and so it's too small to have fusion inside.
It's a failed star.
But it's a very successful planet.
(dramatic music)
Juno continues to explore Jupiter
diving beneath the lethal radiation belt
on every daring orbit,
and each time we learn a little more about
the greatest planet in the solar system.
But we have unfinished business with some of its moons.
JUICE is the next major exploration mission
for the European space agency.
Jupiter, icy moons, explorer.
Its sole purpose is to go to Jupiter
and explore the icy moons.
The main aim is really to try and understand
what they look like below the surface,
how thick is the ice layer,
how deep is the subsurface ocean.
NASA has been funding a mission called Europa Clipper,
which will take a number of flybys of Europa
to try and get a deeper investigation
of what might be happening on the surface,
even a basic understanding of some
of the chemistry that might be there,
in preparation for investigations yet to come
getting down to the oceans.
For places like Europa, Ganymede,
getting below the ice layer is the holy grail.
Getting into that subsurface ocean
that is a whole new frontier,
and that will be a fascinating thing
if we can ever achieve that.
Well, the first challenge you have
is actually getting down through the ice.
While people have talked about drills and other such things,
we wanna reduce this 20-kilometers of ice
as much as possible,
and so we've built submersibles
that can actually navigate through tunnels and canyons
to be able to try and make their way down through perhaps
these open crevices as close to the water as possible.
Now if we can get into the water itself,
we've built a buoyant rover that goes underneath the ice
and floats so it drives on the underside of the ice
exactly at that ice water boundary on there
by turning the camera to look up at the microbes
that we might find there on the underside of the ice.
Then we've been working on deep ocean vessels
where we hope to go down to the bottom
of the ocean on Europa,
and then bring back samples to us
of what might be down at the bottom of the ocean.
JUICE doesn't launch till 2022.
It's not gonna get there until 2030.
In the mid-2020s we hope to launch Europa Clipper.
After a 67-year voyage we'll reach Jupiter itself.
(dramatic music)
Some of the people already working on it now
will have retired.
Some will probably have passed away.
What I love about it is that there's this
generational feeling to it.
By the time we get the data,
there will be another generation
of scientists looking at it.
There is an immense opportunity
for us to find the first signs of life
beyond our world in these warm, watery,
rich environments that we are just beginning
to see that we can even access.
The rovers that we're developing
and that are testing here on Earth
are only the ancestors, the far ancestors,
of what we might eventually send there.
(dramatic music)
So, perhaps one day we'll discover life
residing under the ice,
a precious habitat thriving despite
the brutal radioactive environment
in the shadow of the mightiest planet
in our solar system: Jupiter.
(dramatic music)