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Jupiter,

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A cosmic colossus
reigning over the other planets.

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Take the planet earth,
now get 1,000 of them,

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and that's the size of jupiter.

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Hidden
beneath its swirling clouds

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lie the secrets of our
solar system's foundation,

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of our planet's
violent youth...

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When the biggest thing
in the solar system

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is moving this far this fast,

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it changes everything around it.

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..and the birth of life.

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If it wasn't for jupiter,
right where i'm standing,

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there might be
gigantic meteor impact crater.

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Now, scientists are unlocking

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the giant planet's secrets
and discovering that jupiter,

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more than any other planet,
shapes our solar system's

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past, present, and future.

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Without jupiter, most certainly,

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we wouldn't be here
to talk about it.

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Jupiter

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named after the roman king
of the gods, the god of the sky,

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it looms between
the four inner rocky planets

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and the three
frozen gas giants beyond.

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It is our largest planet by far.

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Jupiter is the king
of the planets,

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and that's because it
is the biggest of the planets.

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It has a storm on it
that's actually four times

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bigger than the earth itself,

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and it's been raging
for hundreds of years.

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It has dozens of moons,
this gigantic magnetic field.

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Everything about jupiter
is just huge.

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It doesn't do anything small.

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If you were looking
at our solar system from afar,

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you'd look and you'd say,

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"our solar system
is made of the sun,

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jupiter, and assorted rubble.

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this vast planet

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contains the clues
to our solar system's formation,

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its evolution,
and its eventual death.

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jupiter
is a cosmic time capsule.

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if only we could open it.

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in the roman myth,
jupiter, the god,

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drew a veil of clouds around him
to hide his mischief,

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and that's, to some extent,

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what's happened
when we look at jupiter.

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we're seeing not the surface
of a planet,

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but the edge of a cloud.

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this shroud of gas
hides jupiter's deepest secrets.

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one of the big
mysteries of jupiter

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is what's at the very center.
what is its core?

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and this is something
that we actually don't know yet.

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but we do know that
what's happening inside jupiter

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gives the planets its power.

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if we want to know
more about what's going on

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in this king
of the planets,

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we're going to need
to be able

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to part those clouds
and peer inside.

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simple physics tells us

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its massive atmosphere
is the stuff of nightmares.

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because it's a gas giant,
the atmosphere,

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as you get deeper into it,
just gets denser and denser

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and the pressure
gets higher and higher.

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from the cloud tops
to the planet's center

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is 43,000 miles.

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that's a three-day,
nonstop journey in a jumbo jet.

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the decent would be
a hellish roller coaster ride.

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and we know this,
because we've tried.

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the galileo probe
orbited jupiter for years

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looking at the cloud tops
of the planet

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and the moons that orbit it.

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but at the end of the mission,
they decided they could do

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one more scientific experiment.

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december 7, 1995.

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nasa's galileo space craft
drops a 750-pound titanium probe

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into jupiter's atmosphere.

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it slams into the cloud tops
at over 106,000 miles an hour.

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even though jupiter looks calm
and serene from a distance,

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as you get closer,

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you realize
that there are ferocious winds,

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there are lightning storms,

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and there are pressures
that would crush any instrument.

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the planet is 1,000 times
the mass of the earth,

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and that means as you go inward,

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the pressures and densities
become very large.

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the probe sensors
reveal that hydrogen

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makes up 90%
of jupiter's atmosphere.

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temperatures soar
to over 300 degrees.

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winds rage at 400 miles an hour.

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it's hotter and more turbulent
than scientists ever imagined.

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58 minutes after
entering jupiter's atmosphere,

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and just 95 miles down,
the probe...

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vaporizes,

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leaving most of jupiter's
secrets beyond our reach.

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we can't reach
the planet's center,

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but at the national ignition
facility outside san francisco,

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scientists can recreate
conditions deep inside jupiter.

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there are a lot
of other facilities

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where we can generate, say,

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states that are found
at the center of the earth

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or some of the other
terrestrial planets,

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but this is the only place

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you can recreate
the deepest interior of jupiter.

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the team takes hydrogen,

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the most common element
in jupiter,

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and freezes it,
increasing its density.

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then, they fire up
the world's largest laser.

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multiple laser beams race
through a series

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of amplification chambers,

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intensifying
by a quadrillion times,

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until, perfectly synchronized,
the beams converge.

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for 20 billionths of a second,

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the laser bombards the hydrogen
with 1,000 times more energy

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than the entire united states
uses at any given moment.

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it turns out that at
those very extreme pressures,

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a hundred million atmospheres
of pressures,

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chemistry
is just completely different.

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instead of really distorting
the chemical bond,

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now, you're distorting
how the atom itself behaves.

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matter behaves
in a fundamentally different way

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than we experience it here
on earth.

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the atoms break down,

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transforming the hydrogen gas
into a liquid --

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a liquid metal concentrated
deep inside the planet.

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essentially, you would have

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this very dense structure,

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and it perhaps would look
like this massive ball

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of mercury
at the center of jupiter.

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under immense pressure,

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the liquid hydrogen emits energy
as heat,

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pushing temperatures at the edge
of this metallic sphere

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up to 11,000 degrees.

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what lies inside
remains a mystery.

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there could be
a little rocky planet

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underneath all of that gas
and all of that liquid.

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it could be more of a ball
of super compressed ice.

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there probably is something
solid down there.

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it's the processes
happening inside jupiter

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that give the planet
its power --

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power to shape the solar system
since its earliest days.

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apart from the sun,

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jupiter is the biggest influence
in the solar system.

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but this monster is shrinking.

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is jupiter losing its power?

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a thousand times
more massive than the earth,

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jupiter could swallow
all the other planets

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in the solar system twice
and still have room for more.

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but this giant
is getting smaller.

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gravity is still bringing

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all of the gases
and liquids together.

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and that heats up
the interior of jupiter.

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this heat rises up
to jupiter's surface

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and escapes into space.

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the planet cools and shrinks,

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making the gas giant
a third smaller today

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than when it first formed.

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as the planet cools,

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the shrinking slows from
an inch a year in its infancy

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to just a few fractions
of an inch today.

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and scientists calculate
it could continue shrinking

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for 1,000 billion years.

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even then, it will always be
the solar system's

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biggest, most powerful planet.

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jupiter is shrinking too slowly
for us to see,

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but we can see the effect
of this rising heat.

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this is actually one
of the reasons jupiter

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has the spectacular weather --

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all of those beautiful bands
of clouds.

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on earth, the sun's heat
drives our weather.

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switch off the sun,
and our weather would stop.

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but jupiter's weather
would keep on going.

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its weather doesn't come
from the sun.

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it comes from deep
inside the planet itself.

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heat rises up
through the boiling soup of gas,

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churning its cocktail
of volatile chemicals,

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creating jupiter's spectacular
swirling clouds.

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and the whole time,
the giant planet spins.

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at 29,000 miles an hour,

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jupiter rotates
faster than any other planet

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in our solar system.

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jupiter rotates on its axis
about once every nine hours,

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compared to a 24-hour day
for us.

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so, huge, super-heated clouds
from the interior

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get smeared out by the rotation,

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and we have the beautiful cloud
tops of jupiter.

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this marriage of heat
and motion spawns a monster.

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jupiter's red spot
is a gigantic cyclone,

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larger than the size
of the earth,

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and has been rotating stably
with winds in excess

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of 250 miles per hour
for over three centuries.

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imagine a storm
that lasts for 300 years.

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on earth, cyclones
die when they hit land,

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but jupiter has no land
to stop its storms,

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almost unlimited heat
to fuel them

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and a rapid rotation.

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jupiter is basically stoking

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the fires of the great red spot.

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we're used to storms growing
and then going away on earth,

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but if they're spinning
the right way,

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because jupiter is so big
and spinning so quickly,

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they feed into each other,
and it keeps the storm alive.

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long after the other planets
freeze and die,

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jupiter will
still be pumping out heat,

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driving its monster storms,

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thanks to its immense size.

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and the secret of its size

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lies in the infancy
of the solar system.

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just over 4.5 billion years ago,

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in the disk
of dust and gas leftover

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from the sun's formation,
the first planet forms.

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jupiter began to form early on
and began to gobble up

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water, frozen comets, meteors,
and grow.

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when you imagine
a litter of animals,

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one of them usually wins.

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and the one that wins is the one

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that begins to eat the most
first.

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the same thing happened
with jupiter, in some sense.

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jupiter forms at the right time

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and in the right place --
just inside the frost line,

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the point 325 million miles
from the sun

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where water vapor turns to ice.

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close to the sun,

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rocky planets
cannot grow very big.

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a little bit
bigger than the earth,

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and the planet falls apart.

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further out, however,

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ice is a glue
that can hold rock together.

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and so you have
massive rocky ice planets

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big enough to capture hydrogen
gas and become a gas giant.

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close to the sun,

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gas is too hot and energetic
to stick to anything.

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out here,
gas is cold and sluggish.

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so, when gravity pulls gas
towards jupiter's core,

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it sticks,

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and jupiter balloons.

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and as it grew,
its gravity grew,

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and therefore, its ability
to gobble up more increased.

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so it was the lucky winner

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by starting early
and eating often.

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the planet
eats everything in its reach

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until it becomes the giant
we see today.

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but 4.5 billion years ago,
jupiter is in the wrong place.

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it's spiraling towards the sun
and a fiery death.

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the biggest planet
with the biggest influence,

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jupiter is unique
in our solar system,

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but not in our galaxy.

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00:13:50,017 --> 00:13:53,721
october 1995,
scientists discover

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the first planet
beyond our solar system.

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51 light-years from earth,

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51 pegasi b
is a giant gas planet,

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similar to jupiter
in every way except one.

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00:14:09,836 --> 00:14:13,073
the first exoplanet found
orbiting a star like the sun

252
00:14:13,074 --> 00:14:14,607
was a huge surprise.

253
00:14:14,608 --> 00:14:16,142
it was called a hot jupiter

254
00:14:16,143 --> 00:14:18,545
because it's something
roughly the size of jupiter,

255
00:14:18,546 --> 00:14:21,548
but it was tremendously close in
to its star,

256
00:14:21,549 --> 00:14:23,917
much closer, even,
than mercury is to the sun.

257
00:14:23,918 --> 00:14:25,954
since that first discovery,

258
00:14:25,955 --> 00:14:29,590
astronomers have identified
hundreds of gas giants

259
00:14:29,591 --> 00:14:31,893
outside our solar system.

260
00:14:31,894 --> 00:14:36,764
many orbit extremely close
to their parent star.

261
00:14:36,765 --> 00:14:41,670
the planet wasp-33 b,
378 light-years away,

262
00:14:41,671 --> 00:14:44,505
orbits so close to its star

263
00:14:44,506 --> 00:14:49,844
that its surface
is a scorching 5,800 degrees.

264
00:14:49,845 --> 00:14:53,648
it's the hottest planet
ever observed in the universe.

265
00:14:53,649 --> 00:14:56,284
now, we know that planets
like that can't form there.

266
00:14:56,285 --> 00:14:58,888
it's just too hot to be able
to coalesce from all the gas.

267
00:14:58,889 --> 00:15:03,058
these hot jupiters
must have formed farther out.

268
00:15:03,059 --> 00:15:05,059
how do you get
a jupiter-like planet

269
00:15:05,060 --> 00:15:06,562
that close to a star?

270
00:15:06,563 --> 00:15:09,664
somehow, you need to be able
to build a big planet

271
00:15:09,665 --> 00:15:11,332
and then move it in.

272
00:15:11,333 --> 00:15:13,269
and this had us asking
all kinds of questions.

273
00:15:13,270 --> 00:15:15,804
if we see it going
on elsewhere in the universe,

274
00:15:15,805 --> 00:15:17,841
is that how our own solar system
worked, too?

275
00:15:17,842 --> 00:15:19,408
so now, when we look at jupiter,

276
00:15:19,409 --> 00:15:21,611
we think, all right,"
that's where it is today,

277
00:15:21,612 --> 00:15:23,712
"but it doesn't mean
it's always been there.

278
00:15:23,713 --> 00:15:25,380
it could have moved"
all over the place,

279
00:15:25,381 --> 00:15:27,082
"and it just ended up
where it is --

280
00:15:27,083 --> 00:15:28,318
where we find it today."

281
00:15:28,319 --> 00:15:30,819
The question is how?

282
00:15:30,820 --> 00:15:34,456
How did this giant planet
end up where it is today?

283
00:15:34,457 --> 00:15:37,893
And what effect
did a migrating jupiter

284
00:15:37,894 --> 00:15:39,163
have on the other planets?

285
00:15:39,164 --> 00:15:43,732
In 2011, walsh and his team
re-imagined the solar system.

286
00:15:43,733 --> 00:15:47,270
They set jupiter adrift,
and in the process,

287
00:15:47,271 --> 00:15:51,408
they solve one of the solar
system's greatest puzzles.

288
00:15:51,409 --> 00:15:54,443
We would build our models,
would get a venus

289
00:15:54,444 --> 00:15:57,247
right where the venus
is supposed to be,

290
00:15:57,248 --> 00:16:00,717
would get an earth right where
the earth is supposed to be.

291
00:16:00,718 --> 00:16:02,184
But where mars is today,

292
00:16:02,185 --> 00:16:05,054
we were usually getting a venus
or earth-massed planet.

293
00:16:05,055 --> 00:16:07,957
No matter what we did, no matter
how we changed the model,

294
00:16:07,958 --> 00:16:10,226
we were always getting
a really big mars.

295
00:16:10,227 --> 00:16:11,394
All of our simulation

296
00:16:11,395 --> 00:16:13,163
showed that mars,
where it is in the disk,

297
00:16:13,164 --> 00:16:15,866
should be at least ten times
the mass that it is.

298
00:16:15,867 --> 00:16:20,002
Something came in
and literally ate mars' lunch.

299
00:16:20,003 --> 00:16:23,240
And that something was jupiter.

300
00:16:23,241 --> 00:16:25,009
Four and a half billion
years ago,

301
00:16:25,010 --> 00:16:29,547
jupiter forms 325 million miles
from the sun,

302
00:16:29,548 --> 00:16:32,016
roughly a third closer
than it is today.

303
00:16:32,017 --> 00:16:33,818
The orbiting planet collides

304
00:16:33,819 --> 00:16:37,221
with the debris left over
from the sun's formation,

305
00:16:37,222 --> 00:16:40,023
and these collisions
slow it down.

306
00:16:40,024 --> 00:16:41,858
It loses momentum,

307
00:16:41,859 --> 00:16:45,829
and the sun's gravity
pulls it closer.

308
00:16:45,830 --> 00:16:47,799
Jupiter spirals inwards,

309
00:16:47,800 --> 00:16:53,471
gobbling up the raw materials
that should have made mars.

310
00:16:53,472 --> 00:16:55,405
So, seeing that result,
seeing a great solution

311
00:16:55,406 --> 00:16:59,077
to the small mars problem
was kind of the eureka moment.

312
00:16:59,078 --> 00:17:01,244
Like, well, maybe
there's a mechanism out there.

313
00:17:01,245 --> 00:17:02,681
We know that planets migrate.

314
00:17:02,682 --> 00:17:04,348
So, let's put these two things
together,

315
00:17:04,349 --> 00:17:06,651
and maybe this is going to work.

316
00:17:06,652 --> 00:17:08,853
As jupiter travels inwards,

317
00:17:08,854 --> 00:17:13,523
it bulldozes the rocky material
that lies in its path.

318
00:17:13,524 --> 00:17:16,527
On the inward migration,
there's a lot of material there.

319
00:17:16,528 --> 00:17:18,395
It actually pushes
almost all of that,

320
00:17:18,396 --> 00:17:20,531
about 80 % of it, inward.

321
00:17:20,532 --> 00:17:23,468
And when we make the movies
in a certain way,

322
00:17:23,469 --> 00:17:25,271
it really looks like a snowplow.

323
00:17:29,542 --> 00:17:31,343
The gas and dust squeeze

324
00:17:31,344 --> 00:17:34,145
into an inner disk
around the sun.

325
00:17:34,146 --> 00:17:35,381
As jupiter orbits,

326
00:17:35,382 --> 00:17:39,216
it pushes against this disk,
creating a bulge.

327
00:17:39,217 --> 00:17:43,655
The bulge races round the disk,
pulling jupiter with it.

328
00:17:44,924 --> 00:17:48,993
Jupiter accelerates and tries
to pull away from the sun.

329
00:17:48,994 --> 00:17:53,298
But the debris behind jupiter
continues pushing inwards.

330
00:17:53,299 --> 00:17:54,866
It's a cosmic stalemate,

331
00:17:54,867 --> 00:17:59,138
with the planet trapped between
the inner and outer disks.

332
00:18:02,107 --> 00:18:06,077
Then, something extraordinary
happens.

333
00:18:06,078 --> 00:18:09,248
The giant planet
changes direction.

334
00:18:09,249 --> 00:18:10,616
As we're building this model,

335
00:18:10,617 --> 00:18:13,018
we've had this vision
of jupiter coming inwards,

336
00:18:13,019 --> 00:18:14,420
turning around
and going outwards.

337
00:18:14,421 --> 00:18:16,120
And we thought of it
as a sailboat,

338
00:18:16,121 --> 00:18:18,658
kind of tacking, coming about,
turning through the wind.

339
00:18:18,659 --> 00:18:20,559
So, the name
the grand tack model,

340
00:18:20,560 --> 00:18:23,462
it actually
comes from sailing terminology.

341
00:18:23,463 --> 00:18:26,098
But jupiter is no yacht.

342
00:18:26,099 --> 00:18:29,135
It's a giant supertanker
of a planet.

343
00:18:29,136 --> 00:18:31,604
Changing its course
is going to take something

344
00:18:31,605 --> 00:18:34,241
seriously powerful.

345
00:18:34,242 --> 00:18:38,077
Enter the solar system's
second largest planet,

346
00:18:38,078 --> 00:18:39,480
saturn.

347
00:18:39,481 --> 00:18:41,615
Like jupiter before it,

348
00:18:41,616 --> 00:18:46,452
saturn has spiraled inwards,
closing in on the giant planet.

349
00:18:46,453 --> 00:18:49,691
Amazingly, there was
this wonderful interplay

350
00:18:49,692 --> 00:18:51,325
between jupiter and saturn.

351
00:18:51,326 --> 00:18:53,594
As they ate up all the material
around them,

352
00:18:53,595 --> 00:18:56,730
there was a gap
in the disk left over.

353
00:18:56,731 --> 00:18:59,534
With less material
behind jupiter and saturn,

354
00:18:59,535 --> 00:19:02,102
there's less holding the planets
in place,

355
00:19:02,103 --> 00:19:04,572
allowing the force
from the bulging disk

356
00:19:04,573 --> 00:19:06,741
to fling jupiter back out,

357
00:19:06,742 --> 00:19:10,010
with saturn hitching a ride.

358
00:19:10,011 --> 00:19:13,080
The key for stopping
jupiter's inward migration

359
00:19:13,081 --> 00:19:15,281
in the grand tack is saturn.

360
00:19:15,282 --> 00:19:19,319
Saturn growing at the right time
and at the right place

361
00:19:19,320 --> 00:19:22,423
allowed it to migrate
close to jupiter and change

362
00:19:22,424 --> 00:19:25,826
and stop
jupiter's inward migration.

363
00:19:25,827 --> 00:19:27,930
Saturn saves jupiter
from a fiery fate.

364
00:19:30,031 --> 00:19:31,666
And this grand tack

365
00:19:31,667 --> 00:19:35,704
leaves a parting gift,
the earth itself,

366
00:19:37,706 --> 00:19:40,107
because when jupiter
migrates out,

367
00:19:40,108 --> 00:19:45,247
it leaves behind the rocky
debris it bulldozed in.

368
00:19:45,248 --> 00:19:48,718
It's from this debris
that the earth forms.

369
00:19:50,253 --> 00:19:52,922
But beyond mars,
jupiter's powerful gravity

370
00:19:52,923 --> 00:19:56,892
pulls on the debris, preventing
it from sticking together,

371
00:19:56,893 --> 00:20:01,463
leaving the rubble scattered
as a band of asteroids.

372
00:20:01,464 --> 00:20:07,001
Jupiter's gravity is so strong
that it determines in some ways

373
00:20:07,002 --> 00:20:08,904
what can exist where
in the solar system

374
00:20:08,905 --> 00:20:10,708
and what can't.

375
00:20:13,344 --> 00:20:16,145
The rocky planets,

376
00:20:16,146 --> 00:20:19,048
our planet,

377
00:20:19,049 --> 00:20:20,716
and beyond mars,

378
00:20:20,717 --> 00:20:23,152
the asteroid belt,

379
00:20:23,153 --> 00:20:27,589
they all exist because
of jupiter's epic journey.

380
00:20:27,590 --> 00:20:29,125
When the biggest thing
in the solar system

381
00:20:29,126 --> 00:20:30,527
is moving this far this fast,

382
00:20:30,528 --> 00:20:32,363
it changes everything around it.

383
00:20:33,431 --> 00:20:35,967
Five million years
after it first formed,

384
00:20:35,968 --> 00:20:39,301
483 million miles from the sun,

385
00:20:39,302 --> 00:20:43,139
jupiter
reaches its present orbit.

386
00:20:43,140 --> 00:20:44,575
Its outward movement

387
00:20:44,576 --> 00:20:49,245
and the inward pull of the sun's
gravity are finally balanced,

388
00:20:49,246 --> 00:20:53,916
but this is still not the solar
system that we see today.

389
00:20:53,917 --> 00:20:55,452
The end point
of the grand tack model

390
00:20:55,453 --> 00:20:57,119
was actually
the ideal beginnings

391
00:20:57,120 --> 00:20:58,488
of what we think happened

392
00:20:58,489 --> 00:21:02,358
later on
in solar system history.

393
00:21:02,359 --> 00:21:04,094
But from this stable orbit,

394
00:21:04,095 --> 00:21:09,099
jupiter is about to trigger
a deadly domino effect

395
00:21:09,100 --> 00:21:12,603
that threatens to destroy
the infant earth.

396
00:21:23,383 --> 00:21:25,351
Four and a half
billion years ago,

397
00:21:25,352 --> 00:21:29,488
jupiter orbits
between the rocky inner planets

398
00:21:29,489 --> 00:21:32,991
and the icy outer planets.

399
00:21:32,992 --> 00:21:35,193
From this
strategic vantage point,

400
00:21:35,194 --> 00:21:38,696
the gas giant dominates
our planetary system

401
00:21:38,697 --> 00:21:40,333
and unleashes hell.

402
00:21:44,971 --> 00:21:47,740
In the early environment
of the solar system,

403
00:21:47,741 --> 00:21:50,808
where there was a lot more junk
surrounding the earth

404
00:21:50,809 --> 00:21:53,612
and in the inner solar system,
the earth was bombarded,

405
00:21:53,613 --> 00:21:57,451
as were all other objects,
at an incredible rate.

406
00:22:00,119 --> 00:22:04,123
It's an incredibly violent time
in solar system history.

407
00:22:04,124 --> 00:22:07,660
We refer to that timescale about
several hundred million years

408
00:22:07,661 --> 00:22:09,560
after the planets
actually formed

409
00:22:09,561 --> 00:22:11,365
as the late heavy bombardment.

410
00:22:18,271 --> 00:22:20,006
These were
very large-scale impacts

411
00:22:20,007 --> 00:22:22,743
and they actually do create
melt pools --

412
00:22:22,744 --> 00:22:25,777
liquid rock on the floors
of these impact craters.

413
00:22:25,778 --> 00:22:28,314
And some of those craters
can glow hot

414
00:22:28,315 --> 00:22:30,784
for tens of thousands,
hundreds of thousands of years,

415
00:22:30,785 --> 00:22:31,918
in some cases.

416
00:22:31,919 --> 00:22:33,720
If you were actually
on the earth at that time,

417
00:22:33,721 --> 00:22:35,721
there would have been
enormous balls of dust

418
00:22:35,722 --> 00:22:37,891
continuously thrown
into the atmosphere.

419
00:22:37,892 --> 00:22:39,927
The sky would be hazy, cloudy,

420
00:22:39,928 --> 00:22:42,095
and the terrain
would be mountainous

421
00:22:42,096 --> 00:22:45,098
from the rims
of craters all around, rocky,

422
00:22:45,099 --> 00:22:47,401
and a wholly unpleasant place
to be.

423
00:22:58,580 --> 00:23:02,182
Today, the scars have healed.

424
00:23:02,183 --> 00:23:06,688
Glaciers advance and retreat.

425
00:23:06,689 --> 00:23:09,123
Volcanoes erupt.

426
00:23:09,124 --> 00:23:13,126
Wind and water
erase our planet's dust.

427
00:23:13,127 --> 00:23:17,699
But the evidence
is still visible if we look up.

428
00:23:17,700 --> 00:23:18,833
Look at the moon.

429
00:23:18,834 --> 00:23:20,468
Every night,
you see the moon coming out,

430
00:23:20,469 --> 00:23:22,002
and it's pockmarked,

431
00:23:22,003 --> 00:23:23,904
because for about a billion
years

432
00:23:23,905 --> 00:23:27,475
after the solar system
was formed, there was chaos.

433
00:23:30,012 --> 00:23:33,781
In 2011,
nasa's spitzer space telescope

434
00:23:33,782 --> 00:23:38,886
reveals this kind of bombardment
around another star.

435
00:23:38,887 --> 00:23:42,857
Astronomers see a vast disk
of gas and dust

436
00:23:42,858 --> 00:23:46,729
circling a young star
called eta corvi.

437
00:23:46,730 --> 00:23:50,298
This may be evidence
of icy comets and asteroids

438
00:23:50,299 --> 00:23:53,969
swarming
into its inner solar system.

439
00:23:53,970 --> 00:23:55,470
Four billion years ago,

440
00:23:55,471 --> 00:23:58,541
the same thing was happening
in our solar system.

441
00:24:02,578 --> 00:24:05,614
There was a wave of material,
asteroids and comets,

442
00:24:05,615 --> 00:24:08,016
that swept in
from the outer solar system.

443
00:24:08,017 --> 00:24:11,287
It turns out it probably
came from jupiter and saturn,

444
00:24:11,288 --> 00:24:12,587
the outer planets.

445
00:24:12,588 --> 00:24:13,989
As they were orbiting the sun,

446
00:24:13,990 --> 00:24:16,191
they were interacting with
each other gravitationally --

447
00:24:16,192 --> 00:24:19,460
a very complicated dance.

448
00:24:19,461 --> 00:24:21,162
Jupiter goes
around the sun three times

449
00:24:21,163 --> 00:24:23,265
every two times
that saturn does.

450
00:24:23,266 --> 00:24:25,333
And so, when they
would migrate outwards,

451
00:24:25,334 --> 00:24:26,535
they'd be locked
in this resonance.

452
00:24:26,536 --> 00:24:27,835
They'd be very close
to each other.

453
00:24:27,836 --> 00:24:30,337
And at some point,
as they were moving around,

454
00:24:30,338 --> 00:24:33,307
their gravitational powers
basically combined,

455
00:24:33,308 --> 00:24:35,810
got a little bit better
at affecting the material

456
00:24:35,811 --> 00:24:38,046
around them.

457
00:24:38,047 --> 00:24:40,681
Together,
the two inner gas giants

458
00:24:40,682 --> 00:24:44,853
sling the two outer gas giants,
uranus and neptune,

459
00:24:44,854 --> 00:24:46,922
even farther out.

460
00:24:46,923 --> 00:24:50,360
Uranus and neptune swap places.

461
00:24:53,931 --> 00:24:57,133
Neptune slams
into the frozen dust and gas

462
00:24:57,134 --> 00:24:59,736
in the solar system's
outer reaches,

463
00:24:59,737 --> 00:25:03,775
scattering icy debris
far and wide.

464
00:25:05,742 --> 00:25:07,110
In the inner solar system,

465
00:25:07,111 --> 00:25:10,512
this debris
collides with the asteroid belt.

466
00:25:10,513 --> 00:25:13,982
Billions of comets
and asteroids swarm

467
00:25:13,983 --> 00:25:17,921
across the orbits of the earth,
moon, and other inner planets.

468
00:25:17,922 --> 00:25:19,757
If that had persisted,

469
00:25:19,758 --> 00:25:22,526
then life
never could have evolved.

470
00:25:22,527 --> 00:25:24,428
Only after
a few hundred million years

471
00:25:24,429 --> 00:25:26,999
was it possible
for life on earth to develop.

472
00:25:31,002 --> 00:25:35,140
But this destruction
contains the seeds of creation

473
00:25:35,141 --> 00:25:39,911
because the icy comets
deliver a precious cargo.

474
00:25:39,912 --> 00:25:42,212
Jupiter periodically disturbs

475
00:25:42,213 --> 00:25:45,083
objects in the outer solar
system, largely water objects,

476
00:25:45,084 --> 00:25:46,785
and directs
the towards the earth.

477
00:25:46,786 --> 00:25:48,720
Nowadays,
that would be a disaster,

478
00:25:48,721 --> 00:25:51,855
but in fact, if you look
at the water on earth,

479
00:25:51,856 --> 00:25:54,425
it's quite likely that almost
all of the water on earth

480
00:25:54,426 --> 00:25:57,662
that's now here came from ice
that impacted upon the earth,

481
00:25:57,663 --> 00:25:59,231
directed here by jupiter.

482
00:26:03,502 --> 00:26:07,839
Every ocean, every river,

483
00:26:07,840 --> 00:26:12,210
every drop of rain may owe
its existence to jupiter.

484
00:26:12,211 --> 00:26:17,383
The gas giant may have even
sowed the seeds of life itself.

485
00:26:17,384 --> 00:26:18,817
The chemical building blocks

486
00:26:18,818 --> 00:26:23,789
of life may have hitched a ride
to earth on-board a comet.

487
00:26:23,790 --> 00:26:28,493
Without jupiter,
life would have never started,

488
00:26:28,494 --> 00:26:31,030
and it would have
never survived.

489
00:26:33,099 --> 00:26:37,035
The main bombardment
ended 3.8 billion years ago,

490
00:26:37,036 --> 00:26:39,005
but a threat remains.

491
00:26:39,006 --> 00:26:44,143
Every day, nasa's near-earth
objects program scans the skies

492
00:26:44,144 --> 00:26:47,479
for potentially dangerous
asteroids and comets.

493
00:26:47,480 --> 00:26:52,483
So far,
they've spotted over 10,000.

494
00:26:52,484 --> 00:26:57,055
And it only takes one
to cause a catastrophe.

495
00:26:57,056 --> 00:26:58,457
Just three miles wide,

496
00:26:58,458 --> 00:27:02,827
this small comet is big enough
to wipe out life on earth.

497
00:27:02,828 --> 00:27:06,431
Luckily, jupiter is in the way.

498
00:27:06,432 --> 00:27:07,799
Jupiter acts, in a lot of ways,

499
00:27:07,800 --> 00:27:09,635
like the protector
of the inner solar system.

500
00:27:09,636 --> 00:27:11,172
By shepherding comets
in its vicinity,

501
00:27:11,173 --> 00:27:12,771
ejecting them
from the solar system,

502
00:27:12,772 --> 00:27:15,910
jupiter
helps protect the earth itself.

503
00:27:18,712 --> 00:27:21,382
In a sense, the way objects
move in a solar system

504
00:27:21,383 --> 00:27:24,351
is a little bit
like a roller derby.

505
00:27:24,352 --> 00:27:26,720
You've got all of these objects
moving around the sun

506
00:27:26,721 --> 00:27:29,088
in the same direction, going
around and around and around.

507
00:27:29,089 --> 00:27:33,226
But they have gravity, and they
can interact with each other.

508
00:27:33,227 --> 00:27:34,896
Imagine this skater in white

509
00:27:34,897 --> 00:27:40,232
is an icy comet racing in
from the outer solar system.

510
00:27:40,233 --> 00:27:44,337
The skaters in black
are the gas giants.

511
00:27:44,338 --> 00:27:47,540
The comets veer
across the planets' orbits

512
00:27:47,541 --> 00:27:51,178
until it encounters jupiter.

513
00:27:51,179 --> 00:27:54,381
Jupiter moves
faster than the comet.

514
00:27:54,382 --> 00:27:56,883
Then, the giant planet's gravity

515
00:27:56,884 --> 00:28:02,288
grabs it and gives it an assist
in a slingshot maneuver.

516
00:28:02,289 --> 00:28:05,225
The comet steals
some of jupiter's momentum,

517
00:28:05,226 --> 00:28:07,962
accelerates,
and changes direction.

518
00:28:08,463 --> 00:28:10,766
Jupiter can fling it
out of the solar system

519
00:28:10,767 --> 00:28:12,467
by giving it
that extra velocity,

520
00:28:12,468 --> 00:28:13,535
and it goes away.

521
00:28:13,536 --> 00:28:15,170
It's ejected.

522
00:28:15,171 --> 00:28:19,774
Jupiter slings objects
out and stands guard.

523
00:28:19,775 --> 00:28:23,444
Every year, 200 times
more comets and asteroids

524
00:28:23,445 --> 00:28:26,480
smash into jupiter
than the earth.

525
00:28:26,481 --> 00:28:29,351
Something had to be there
like a sheriff

526
00:28:29,352 --> 00:28:32,720
to clean out all the riffraff
and clean out all the debris,

527
00:28:32,721 --> 00:28:35,489
and that's the planet jupiter.

528
00:28:35,490 --> 00:28:38,860
If it wasn't for jupiter,
right where i'm standing,

529
00:28:38,861 --> 00:28:42,597
there might be
gigantic meteor impact crater.

530
00:28:42,598 --> 00:28:45,165
Without jupiter, most certainly,

531
00:28:45,166 --> 00:28:46,935
we wouldn't be here
to talk about it.

532
00:28:48,971 --> 00:28:52,941
Our lives depend on jupiter.

533
00:28:52,942 --> 00:28:55,476
Because of
the incredibly important role

534
00:28:55,477 --> 00:28:58,680
that jupiter's played in
the evolution of life on earth,

535
00:28:58,681 --> 00:29:00,181
when we look at exoplanets,

536
00:29:00,182 --> 00:29:02,483
when we look for life
elsewhere in the universe,

537
00:29:02,484 --> 00:29:06,020
we may not need to look just
for those habitable planets.

538
00:29:06,021 --> 00:29:08,489
We may need to look
for jupiters or objects

539
00:29:08,490 --> 00:29:12,495
like them that have saved them,
as jupiter saved us.

540
00:29:14,030 --> 00:29:18,536
Jupiter is the secret behind
our solar system's success.

541
00:29:21,704 --> 00:29:27,575
It makes life on earth possible
and helps protect that life.

542
00:29:27,576 --> 00:29:31,817
It may even nurture life,
alien life.

543
00:29:42,693 --> 00:29:44,629
Jupiter dominates
its neighborhood

544
00:29:44,630 --> 00:29:50,468
for millions of miles, looming
over at least 67 moons,

545
00:29:50,469 --> 00:29:51,603
from ganymede,

546
00:29:51,604 --> 00:29:53,871
which is larger
than the planet mercury,

547
00:29:53,872 --> 00:29:56,606
to a rock barely a mile across.

548
00:29:56,607 --> 00:29:58,809
The innermost moons
are more rocky rich.

549
00:29:58,810 --> 00:30:00,877
The outermost moons
are more ice rich.

550
00:30:00,878 --> 00:30:02,380
So, in a lot of ways,

551
00:30:02,381 --> 00:30:04,317
a little miniature solar system.

552
00:30:07,352 --> 00:30:10,287
Jupiter
is a cosmic puppet master,

553
00:30:10,288 --> 00:30:13,958
controlling
and manipulating its moons

554
00:30:13,959 --> 00:30:17,896
and perhaps making
one of them home to life.

555
00:30:17,897 --> 00:30:20,165
March 1st, 2007,

556
00:30:20,166 --> 00:30:25,604
nasa's new horizons probe
flies past io,

557
00:30:25,605 --> 00:30:29,775
a moon roughly
the same size as our own.

558
00:30:29,776 --> 00:30:31,410
Io is one
of the most interesting moons

559
00:30:31,411 --> 00:30:32,577
in the solar system,

560
00:30:32,578 --> 00:30:34,880
and not just because
it looks like a pizza.

561
00:30:34,881 --> 00:30:36,816
It's covered with volcanoes.

562
00:30:36,817 --> 00:30:38,918
In fact, these volcanoes,
one way or another,

563
00:30:38,919 --> 00:30:40,719
have been continuously erupting

564
00:30:40,720 --> 00:30:43,622
since we've been observing io
with space probes,

565
00:30:43,623 --> 00:30:45,325
for the past 20 years.

566
00:30:50,596 --> 00:30:51,797
This small moon

567
00:30:51,798 --> 00:30:55,834
is the solar system's
most volcanic body,

568
00:30:55,835 --> 00:31:00,806
with at least 400
active volcanoes.

569
00:31:00,807 --> 00:31:04,242
Together, they pump out
100 times more heat

570
00:31:04,243 --> 00:31:06,012
than volcanoes on earth.

571
00:31:07,713 --> 00:31:10,816
Io's orbit is actually slightly
eccentric around jupiter.

572
00:31:10,817 --> 00:31:12,485
Sometimes,
it's a little closer to jupiter;

573
00:31:12,486 --> 00:31:15,922
sometimes,
a little farther away.

574
00:31:15,923 --> 00:31:18,024
As the gravitational
field changes,

575
00:31:18,025 --> 00:31:20,360
io's body, the structure
of the moon itself,

576
00:31:20,361 --> 00:31:23,529
is twisted
and pulled back and forth.

577
00:31:23,530 --> 00:31:27,566
And that heat through friction,
the interior of the moon,

578
00:31:27,567 --> 00:31:29,434
that heat basically melts it,

579
00:31:29,435 --> 00:31:32,307
and that erupts through
the surface as volcanoes.

580
00:31:35,409 --> 00:31:38,478
The volcanoes on io
are really fascinating.

581
00:31:38,479 --> 00:31:40,145
They're ejecting vast quantities

582
00:31:40,146 --> 00:31:42,918
of sulfur dioxide
above the surface of io.

583
00:31:43,919 --> 00:31:46,354
It's split apart
by the ultraviolet light

584
00:31:46,355 --> 00:31:48,889
from the sun
into sulfur ions, oxygen ions,

585
00:31:48,890 --> 00:31:50,124
and those ions interact

586
00:31:50,125 --> 00:31:53,694
with the magnetic field
of the planet jupiter.

587
00:31:53,695 --> 00:31:56,564
Jupiter's magnetic field
carries chemicals

588
00:31:56,565 --> 00:32:00,669
and charged particles
away from io

589
00:32:00,670 --> 00:32:03,173
and onto its neighboring moon,
europa,

590
00:32:05,141 --> 00:32:07,942
making this distant,
frozen world

591
00:32:07,943 --> 00:32:11,146
one of our best hopes
of finding alien life.

592
00:32:13,615 --> 00:32:15,549
When we got up close
to europa with spacecraft,

593
00:32:15,550 --> 00:32:17,852
we saw it was covered
in cracks and ridges,

594
00:32:17,853 --> 00:32:19,022
which looked very much

595
00:32:19,023 --> 00:32:21,389
like the way
ice floes look here on earth.

596
00:32:21,390 --> 00:32:23,793
And it turns out
that's exactly what's going on.

597
00:32:23,794 --> 00:32:26,627
We know, because of seeing
the flexure of the ice

598
00:32:26,628 --> 00:32:29,264
and the cracks in the ice
on the surface of europa

599
00:32:29,265 --> 00:32:31,600
that there's probably
a sub-surface ocean

600
00:32:31,601 --> 00:32:34,302
deeper than the deepest
of earth's oceans there

601
00:32:34,303 --> 00:32:36,072
on that little icy moon.

602
00:32:41,743 --> 00:32:46,248
Jupiter's gravity
pushes and pulls europa,

603
00:32:46,249 --> 00:32:48,950
creating friction,

604
00:32:48,951 --> 00:32:53,823
generating heat
and melting europa from within.

605
00:32:56,090 --> 00:32:58,527
Jupiter is so far away
from the sun that it's natural

606
00:32:58,528 --> 00:33:01,062
to assume that anything
around it is frozen.

607
00:33:01,063 --> 00:33:04,399
The fact that gravity
can heat something up enough

608
00:33:04,400 --> 00:33:07,268
to produce liquid water
is profoundly important.

609
00:33:07,269 --> 00:33:10,805
All of the indications of liquid
water under the surface

610
00:33:10,806 --> 00:33:12,074
have been indirect --

611
00:33:12,075 --> 00:33:14,875
the way the surface looks,
the resurfacing of it.

612
00:33:14,876 --> 00:33:18,913
But very recently,
we got direct evidence of water

613
00:33:18,914 --> 00:33:22,350
under the surface of europa
in the form of a geyser --

614
00:33:22,351 --> 00:33:27,522
a plume of water being ejected
from the south pole of the moon.

615
00:33:27,523 --> 00:33:29,759
November 2013,

616
00:33:29,760 --> 00:33:33,029
analyzing photographs
from the hubble space telescope,

617
00:33:33,030 --> 00:33:38,767
scientists spot two giant
geysers spewing water 124 miles

618
00:33:38,768 --> 00:33:42,437
into the atmosphere
above europa's south pole.

619
00:33:42,438 --> 00:33:44,105
It's the best evidence yet

620
00:33:44,106 --> 00:33:48,576
of liquid water
beneath europa's frozen crust.

621
00:33:48,577 --> 00:33:51,814
Seeing direct evidence
of liquid water on europa

622
00:33:51,815 --> 00:33:53,582
is terribly exciting.

623
00:33:53,583 --> 00:33:57,152
Finding liquid water is very
important for finding biology.

624
00:33:57,153 --> 00:33:59,988
We don't know that wherever
there's water, there's biology,

625
00:33:59,989 --> 00:34:01,323
but we're pretty sure
that without it,

626
00:34:01,324 --> 00:34:02,860
it would be a lot tougher.

627
00:34:03,862 --> 00:34:05,095
For life to evolve,

628
00:34:05,096 --> 00:34:08,732
it needs water
and other chemicals.

629
00:34:08,733 --> 00:34:12,069
And that's where jupiter's
magnetosphere comes in,

630
00:34:12,070 --> 00:34:14,705
the network
that transports chemicals

631
00:34:14,706 --> 00:34:18,774
from volcanic moon io to europa.

632
00:34:18,775 --> 00:34:21,710
Scientists think the
magnetosphere delivers sulfur,

633
00:34:21,711 --> 00:34:24,480
carbon and other minerals,

634
00:34:24,481 --> 00:34:25,881
and that its radiation

635
00:34:25,882 --> 00:34:30,018
splits apart frozen water
molecules on europa's surface

636
00:34:30,019 --> 00:34:32,757
into hydrogen and oxygen.

637
00:34:35,293 --> 00:34:37,995
From a biology point of view,
what's important is

638
00:34:37,996 --> 00:34:40,763
that there's interesting stuff
being made on the surface,

639
00:34:40,764 --> 00:34:43,968
and if that stuff could
get carried into the ocean,

640
00:34:43,969 --> 00:34:45,570
organisms might appreciate.

641
00:34:45,838 --> 00:34:49,174
So, europa's geysers
are a major discovery.

642
00:34:49,175 --> 00:34:52,711
One of the more exciting aspects
of seeing this geyser on europa

643
00:34:52,712 --> 00:34:54,645
is it means
that the liquid ocean

644
00:34:54,646 --> 00:34:56,915
underneath the surface
has a way of getting out,

645
00:34:56,916 --> 00:34:58,883
which means maybe there's a way
of stuff

646
00:34:58,884 --> 00:35:02,520
from the surface
getting into the ocean itself.

647
00:35:02,521 --> 00:35:04,754
It could be that in this ocean,

648
00:35:04,755 --> 00:35:10,828
there's a nutrient-rich supply
of food.

649
00:35:10,829 --> 00:35:12,263
Life needs water.

650
00:35:12,264 --> 00:35:16,767
It needs food
and something else.

651
00:35:16,768 --> 00:35:18,636
You also need an energy source.

652
00:35:18,637 --> 00:35:20,272
On the earth, mostly,
that's the sun.

653
00:35:20,273 --> 00:35:22,640
It's light coming down
and warming the surface.

654
00:35:22,641 --> 00:35:24,808
On europa, though,
if you're deep in that ocean,

655
00:35:24,809 --> 00:35:26,811
it's probably pitch black.

656
00:35:29,514 --> 00:35:32,318
But life can exist
without the sun.

657
00:35:33,853 --> 00:35:35,486
If you go
to the ocean floors on earth,

658
00:35:35,487 --> 00:35:38,457
there are places where there are
vents, cracks in the crust,

659
00:35:38,458 --> 00:35:41,060
and gasses and all sorts
of noxious chemicals

660
00:35:41,061 --> 00:35:44,663
are coming up,
but there's life there.

661
00:35:44,664 --> 00:35:47,832
An ocean that there could be
this flow of nutrients

662
00:35:47,833 --> 00:35:51,470
from the sub-surface
into an oxygen-rich water

663
00:35:51,471 --> 00:35:54,439
and life living
at this boundary between them,

664
00:35:54,440 --> 00:35:56,776
that's an example
right in front of us

665
00:35:56,777 --> 00:36:00,013
of how an ecosystem
could be shaped that way.

666
00:36:00,014 --> 00:36:02,448
Life evolves
to match the conditions

667
00:36:02,449 --> 00:36:04,151
in which it finds itself.

668
00:36:04,152 --> 00:36:06,486
The conditions
under the surface of europa

669
00:36:06,487 --> 00:36:08,388
are very similar
to the conditions

670
00:36:08,389 --> 00:36:10,156
at the bottom
of the ocean here on earth.

671
00:36:10,157 --> 00:36:12,625
We may find life there,

672
00:36:12,626 --> 00:36:15,229
and if we do, it may look
quite a bit like

673
00:36:15,230 --> 00:36:17,798
life under the ocean
here on earth.

674
00:36:21,702 --> 00:36:24,537
If there is life
beneath europa's surface,

675
00:36:24,538 --> 00:36:26,440
it may outlive us all.

676
00:36:28,409 --> 00:36:32,645
This inhospitable world
could become a last refuge

677
00:36:32,646 --> 00:36:35,480
for life in the solar system,

678
00:36:35,481 --> 00:36:38,317
because 5 billion years
from now,

679
00:36:38,318 --> 00:36:41,655
the sun is destined to die.

680
00:36:53,635 --> 00:36:56,437
Jupiter,
more than any other planet,

681
00:36:56,438 --> 00:36:58,906
has left its mark
on our solar system.

682
00:36:58,907 --> 00:37:01,241
The largest planet
with the strongest gravity,

683
00:37:01,242 --> 00:37:06,046
it shaped our past
and influences our present.

684
00:37:06,047 --> 00:37:09,683
But the planet's future
hangs in the balance.

685
00:37:09,684 --> 00:37:14,089
The ultimate fate of jupiter
may rest on the fate of the sun.

686
00:37:14,090 --> 00:37:16,191
And in 4 to 5 billion years,

687
00:37:16,192 --> 00:37:19,227
the sun will expand
to become a red giant,

688
00:37:19,228 --> 00:37:23,230
perhaps eating up the earth
in the process.

689
00:37:23,231 --> 00:37:25,299
We think that the sun's
outer layers are gonna

690
00:37:25,300 --> 00:37:28,236
expand possibly
even to the orbit of mars.

691
00:37:28,237 --> 00:37:30,671
The earth is possibly
going to be engulfed

692
00:37:30,672 --> 00:37:33,442
and completely devoured
by the expanding sun.

693
00:37:33,443 --> 00:37:35,109
And when that happens,
of course,

694
00:37:35,110 --> 00:37:36,746
it's game over for earth.

695
00:37:38,181 --> 00:37:40,216
Five billion years from now,

696
00:37:40,217 --> 00:37:44,152
the inner rocky planets
will burn up.

697
00:37:44,153 --> 00:37:46,254
Will jupiter be next?

698
00:37:46,255 --> 00:37:48,758
From the perspective of somebody
orbiting around jupiter,

699
00:37:48,759 --> 00:37:51,861
the sun is going to turn
into this angry, fiery thing.

700
00:37:51,862 --> 00:37:53,162
And yet,

701
00:37:53,163 --> 00:37:57,033
jupiter itself is probably going
to be relatively safe.

702
00:37:57,034 --> 00:37:58,602
It may lose
some of its atmosphere,

703
00:37:58,603 --> 00:37:59,968
but jupiter's a big planet.

704
00:37:59,969 --> 00:38:01,337
It has plenty to spare.

705
00:38:01,338 --> 00:38:05,975
Clearly, the region of the earth
will become uninhabitable.

706
00:38:05,976 --> 00:38:08,111
But what's also equally clear is

707
00:38:08,112 --> 00:38:10,513
the regions
we now think of as remote,

708
00:38:10,514 --> 00:38:14,585
far away, frozen,
become much more attractive.

709
00:38:16,054 --> 00:38:17,555
It'll be warmer,

710
00:38:17,556 --> 00:38:19,423
so its moons
might actually warm up.

711
00:38:19,424 --> 00:38:21,091
And it has icy moons.

712
00:38:21,092 --> 00:38:24,562
Right now, they're frozen water,
but with the warm sun

713
00:38:24,563 --> 00:38:27,029
for millions or tens
of millions of years,

714
00:38:27,030 --> 00:38:28,966
they may actually liquefy.

715
00:38:28,967 --> 00:38:32,937
And europa may become basically
a gigantic water droplet,

716
00:38:32,938 --> 00:38:36,573
a self-contained ocean
orbiting jupiter.

717
00:38:36,574 --> 00:38:38,309
It's an amazing thought.

718
00:38:40,878 --> 00:38:43,647
Perhaps
europa will be life's last,

719
00:38:43,648 --> 00:38:47,116
best refuge as the sun dies.

720
00:38:47,117 --> 00:38:50,120
As the sun evolves,

721
00:38:50,121 --> 00:38:53,489
will the moons of jupiter --
could it be

722
00:38:53,490 --> 00:38:57,361
that they become
the prime places

723
00:38:57,362 --> 00:39:01,131
that we either travel to,
or perhaps,

724
00:39:01,132 --> 00:39:03,433
life once again begins?

725
00:39:03,434 --> 00:39:06,904
In our dying solar system,

726
00:39:06,905 --> 00:39:11,841
jupiter's moons
may offer a safe haven for life.

727
00:39:11,842 --> 00:39:15,012
But jupiter's time
in the sun is limited.

728
00:39:21,454 --> 00:39:24,221
After the sun undergoes
its dramatic red giant phase,

729
00:39:24,222 --> 00:39:26,823
it's going to collapse down
and end its life

730
00:39:26,824 --> 00:39:28,058
almost with a whimper.

731
00:39:28,059 --> 00:39:29,862
It will become a white dwarf.

732
00:39:33,331 --> 00:39:35,299
You wouldn't even be able
to see the sun

733
00:39:35,300 --> 00:39:37,134
from the surface of jupiter

734
00:39:37,135 --> 00:39:39,837
when the sun
undergoes its final stage

735
00:39:39,838 --> 00:39:42,305
to become a piece
of nuclear waste

736
00:39:42,306 --> 00:39:45,042
drifting in outer space.

737
00:39:45,043 --> 00:39:50,781
Jupiter and its moons
will become dark once more.

738
00:39:50,782 --> 00:39:52,716
As the sun
evolves into a white dwarf,

739
00:39:52,717 --> 00:39:56,187
jupiter will probably
go largely unaffected.

740
00:39:56,188 --> 00:39:57,990
Our solar system
and the evolution of the sun

741
00:39:57,991 --> 00:39:59,790
won't change its orbit
very much.

742
00:39:59,791 --> 00:40:02,158
And it's just gonna
keep trucking along and continue

743
00:40:02,159 --> 00:40:06,129
to orbit that old white dwarf
for billions of years.

744
00:40:06,130 --> 00:40:07,064
Jupiter will live on,

745
00:40:07,065 --> 00:40:10,802
and with it, the hope of life.

746
00:40:10,803 --> 00:40:13,204
If there's life
underneath the ice on europa

747
00:40:13,205 --> 00:40:15,941
somewhere in the ocean
beneath the surface,

748
00:40:15,942 --> 00:40:19,211
it's possible
that it could still continue,

749
00:40:19,212 --> 00:40:21,514
warmed by the tidal forces
from jupiter

750
00:40:21,515 --> 00:40:26,151
even after the sun has met
its end as a white dwarf.

751
00:40:26,152 --> 00:40:28,121
The thing is
europa is already

752
00:40:28,122 --> 00:40:29,787
a shell of ice with liquid water

753
00:40:29,788 --> 00:40:32,590
that doesn't really
need the energy from the sun.

754
00:40:32,591 --> 00:40:34,860
So, if there's life there,

755
00:40:34,861 --> 00:40:37,429
it's not gonna care
whether the sun's alive or dead.

756
00:40:37,430 --> 00:40:40,700
They actually might outlive
the sun itself.

757
00:40:40,701 --> 00:40:43,003
Five billion years from now,

758
00:40:43,004 --> 00:40:46,006
jupiter will take center stage.

759
00:40:50,044 --> 00:40:52,979
Jupiter determines
more than any other planet,

760
00:40:52,980 --> 00:40:55,182
how our solar system works,

761
00:40:55,183 --> 00:40:59,686
much as a conductor governs
the dynamics of an orchestra.

762
00:40:59,687 --> 00:41:01,621
As we unlock
the planet's secrets,

763
00:41:01,622 --> 00:41:03,322
we're discovering jupiter

764
00:41:03,323 --> 00:41:06,592
is the key
to our solar system's success.

765
00:41:06,593 --> 00:41:07,894
We're talking about a planet

766
00:41:07,895 --> 00:41:11,463
that dominates
the entire solar system,

767
00:41:11,464 --> 00:41:14,066
whose gravity
determines the very structure

768
00:41:14,067 --> 00:41:17,503
of the solar system itself,

769
00:41:17,504 --> 00:41:22,809
a planet whose evolution helped
to clean out the solar system.

770
00:41:22,810 --> 00:41:24,209
So, we see that the past

771
00:41:24,210 --> 00:41:27,515
and the future
depends on jupiter.

772
00:41:30,183 --> 00:41:31,550
Jupiter has been here

773
00:41:31,551 --> 00:41:34,487
since the solar system's
earliest days,

774
00:41:34,488 --> 00:41:39,092
and it'll be here at the end.

775
00:41:39,093 --> 00:41:44,796
Creator, protector,
nurturer, and survivor,

776
00:41:44,797 --> 00:41:48,501
jupiter shaped the solar system
that we see today

777
00:41:48,502 --> 00:41:54,542
and makes life possible
on earth and perhaps beyond.

778
00:41:54,592 --> 00:41:59,142
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