The northern lights on Jupiter are the most
spectacular in our solar system.
They're stunning.
And they're bigger than our entire planet.
They produce incredibly powerful flares
that reach terawatts of power.
That's more energy than you'd need to briefly
supply all of human civilisation.
What causes them?
Why do they seem to pulse like clockwork?
To truly unlock Jupiter's mysteries
we needed a way to get closer to it than ever before.
Jupiter is the most extreme environment
NASA's ever visited.
To send a spacecraft there is a little bit insane.
We had to build an armoured tank to go there.
Juno arrived in Jupiter's orbit in 2016.
As it got closer, the auroras on Jupiter
became so dramatic and active
that astronomers said it was like
Jupiter was putting on a fireworks display
for Juno's arrival.
Which seems apt given the
sheer scale of the spacecraft.
Behind me is the Juno spacecraft.
Basically life-size, it's an enormous spacecraft
close to 70 feet in diameter
as it spins around and cartwheels through space.
This is one of the largest spacecraft ever made.
Juno showed us more than we'd ever seen of
Jupiter's auroras as they rippled over the
planet's poles.
The northern lights on Earth
are caused by solar winds entering our
atmosphere and interacting with the planet's
magnetic field.
Jupiter's magnetic field,
also known as the magnetosphere,
is 20 thousand times stronger
than the one here on Earth.
It extends all the way back to Saturn and
perhaps further.
And it's the biggest
structure in the Solar System
next to the Sun's magnetosphere.
That's one of the reasons Jupiter's auroras
are so huge.
These gigantic magnetic tentacles capture
particles from across the solar system,
thrusting them towards the planet's poles,
creating this epic light show that never dies.
But this is only part of the story.
As well as photographing Jupiter's dazzling displays
Juno also began mapping Jupiter's core.
And that's when things got interesting.
Jupiter is a gas giant.
It is full of loads of gas,
especially hydrogen and helium,
and when hydrogen is under extreme pressure,
it acts in a really weird way.
It becomes liquid metal.
Liquid metal!
Like at the core of Jupiter is
an ocean of liquid metallic hydrogen.
And using some of Juno's findings,
physicists in California tried to recreate this
extraordinary phenomenon bubbling away deep
inside Jupiter's core.
So basically, we are creating a little planet
interior inside our laboratory.
Marius Millot and his team at the
National Ignition Facility
conducted a pretty crazy experiment.
They fired lasers at a tiny target
which imitates the core of Jupiter.
The lasers simulate the unfathomable
pressures going on inside.
So this is the target that we put inside this
target chamber.
We fill a little portion inside this cone here
with liquid hydrogen.
About 20 millionth of a gram.
And then we shine 80 laser beams from the top
and 80 laser beams from the bottom.
So the the power that we put in the lasers when we
shine the laser onto the target, is about
500 times the power that is used for the
entire United States at a given moment.
T minus five, four, three, two, one, shot.
Through the laser blast, the team observed
this surreal change that takes place in the
core of Jupiter.
At this time, the pressure got so high that
the light is now reflecting off the shiny
surface of the hydrogen.
Hydrogen transform from being transparent
to opaque and then becomes a metal
like a shiny metal.
If we were to go deep inside Jupiter,
we would see a deep ocean of fluid, shiny metal.
And just like that, the planet completely
messed with what's possible with the elements.
It throws out the rule book.
On Jupiter this metallic hydrogen makes up to
potentially 50% of the planet's mass,
and it's this huge liquid metal ocean
that accounts for Jupiter's gigantic magnetic field.
But that's not all.
It also causes charged particles to
leak out at its extremities,
and it's this that causes the breathtaking auroras
that outshine all the others in the Solar System.
So Jupiter's core is the main source of the auroras,
but its moons also wanted to get in on the act.
Particularly one of the strangest
moons in the Solar System, Io.
This moon is the most volcanically active in
the Solar System.
Its spectacular volcanoes
spew plumes up to three hundred miles into
the atmosphere, adding extra fuel to
Jupiter's light show.
So we see Jupiter in the middle, but around
Jupiter, we see the moons.
Io, Europa, Ganymede, Callisto.
The gases that come from Io become trapped in the
magnetic field, and they become accelerated to
very high energies.
These trapped charged particles get dragged
towards Jupiter's poles by its
all-encompassing magnetosphere.
Energetic charged particles come in, bombard
the atmosphere, make it glow, and then we're
seeing this glow in the atmosphere of Jupiter.
So the combination of the gigantic
magnetosphere, its super-charged liquid
metal core and unique moons create these
breathtaking aurorae.
But astrophysicists were still puzzled by one thing.
Why do these aurora light up and flash in
semi-regular patterns, pulsing in this
extremely bizarre way?
It took a team at UCL to crack the case.
In the time they watched the auroras
they found that they pulsed every 27 minutes.
By closely analysing the data sent back from Juno
and the European Space Agency telescope
XMM-Newton
they came to the conclusion that
periodic vibrations crashed across the
magnetosphere, causing waves of plasma to
send heavy ion particles surfing across the
magnetic field toward Jupiter.
But the mystery isn't over.
Just what causes these vibrations?
What determines the pattern of these pulses?
And why does Jupiter randomly decide on these
rhythmic regular intervals?
This is just the beginning of our
learning about Jupiter's auroras.
And that's just the start of a wider search.
There were more like them across the galaxy
waiting to be explored.