The Planets (2019–…): Season 1, Episode 3 - The Godfather: Jupiter - full transcript
Brian Cox continues his exploration of the solar system with a visit to a planet that dwarfs all the others: Jupiter.
Lift off of Messenger on Nasa's
mission to Mercury.
♪ They'll say no-one can see us
♪ That we're estranged
and all alone
♪ They believe
nothing can reach us
♪ And pull us out of
the boundless gloom
♪ They're wrong
♪ They're wrong
♪ They're wrong. ♪
Beyond the inner solar system...
past the asteroid belt...
lies Jupiter.
The largest of the planets
is a giant swirling ball of gas...
its marbled appearance generated
by violent winds
that rage through its clouds.
Jupiter is a world as strange
as it is remote.
If you fly upwards, only about
100km or so,
you reach the edge of our atmosphere
and the blackness of space.
It's really not that far.
But once you're in space,
the distance scales are sort of
incomprehensible.
I mean, Venus, the closest planet,
is over 40 million kilometres away.
Jupiter around 650 million
kilometres.
It takes our fastest spacecraft
years to get there.
So, the idea that those planets
could have any influence on us
here on Earth seems fanciful.
And, indeed, if you're talking about
your chances of meeting a handsome
stranger
or your life plans requiring a
moderate reconfiguration
about a week on Wednesday,
then you would be right.
However, if you ask more profound
questions, deeper questions like,
"Why is the Earth the way that it
is?
"Why is there life on Earth?
"Why do we exist at all?"
then it turns out that the planets,
and Jupiter in particular,
have had a profound effect.
Early in its life, the young
Jupiter went on the rampage.
The giant planet embarked
on a voyage of destruction
across the solar system...
that transformed the destiny
of the planets,
and the course of life on Earth.
Jupiter is the godfather
of the planets.
Understand it and you understand
how the solar system came to be.
On Earth, we can see glimpses
of Jupiter's power...
in the scars it's left...
on the face of the planet.
This is the famous Barringer
Meteor Crater in Arizona.
It is about a kilometre across,
170 metres from the rim to the
crater floor
and it was created about 50,000
years ago
when a meteorite, 50 metres across,
entered the Earth's atmosphere
travelling at about 13km per
second.
That means it would have taken
around, what, seven seconds
to go from the top of the atmosphere
to the ground
and it hit with such force that the
energy released
was equivalent to ten megatons of
TNT.
And that is a very large
nuclear bomb.
The meteorite that hit the Earth
here
is thought to have come from the
asteroid belt...
the ring of rocky debris
that orbits at the edge
of the inner solar system.
And it was deflected from its orbit
most likely by the gravitational
influence of Jupiter.
Jupiter is a completely different
class of planet to the Earth.
A gas giant.
A swirling ball of hydrogen
and helium so large
you could fit 1,300 Earths inside.
Jupiter can exert such a powerful
influence on the asteroids
because it's so massive.
It's about two-and-a-half times
the mass of all the other planets,
moons and asteroids in the solar
system combined.
And, therefore, it has a strong
gravitational pull.
And this means that Jupiter
exerts an influence
across the entire solar system
that's second only to the sun.
And that influenced us far
more than create the odd crater.
It can change the history
of worlds.
To understand how Jupiter rose
to such dominance,
you have to go back to a time before
the solar system even existed.
Nearly five billion years ago,
a distant exploding star sent
a shock wave across the galaxy...
causing the cloud of gas and dust
that would become our solar system
to collapse...
as the sun began to form.
But further out, something
else was growing.
After 50 million years...
the sun's nuclear furnace ignited.
The light of its first dawn...
revealing Jupiter...
the solar system's first world.
A planet born so early, it swept
up most of the material
left over from the formation of the
sun.
Because of its dominance, Jupiter
had a profound effect
on the newly forming solar system
and paved the way for our living
world to form.
This is a model of our solar system.
So, here's the sun, and then we have
the four inner rocky planets,
Mercury, Venus, Earth and Mars.
Then comes the asteroid belt,
the ring of millions of smaller
pieces of rock
orbiting around the sun.
And then the gas giants.
Jupiter, Saturn, Uranus and Neptune.
Now, this has a pleasing regular
structure about it.
All the rocky planets close to the
star
and the gas giants further out.
And we thought that this must be the
natural order of things,
the way that solar systems
have to form,
until we started to detect planets
around distant stars
and then we found that this
arrangement is not typical at all.
Our sun is just one of around
300 billion stars in our galaxy...
and almost every one of those
stars
is home to its own system of
planets.
In most other systems, the region
where our planet orbits is empty.
Instead, closer to the star, we see
super-Earths,
vast rocky planets
many times bigger than our own.
But, crucially, these worlds are
thought
to have thick toxic atmospheres,
making them completely inhospitable
to life.
And that raises a very interesting
question.
Why, then, is our solar system
the way that it is?
To answer that question,
we've sent spacecraft to every one
of the planets...
and they've uncovered strange
anomalies
that reveal our solar system's past.
Our missions to Venus found
that it once had far more water
than you'd expect for a planet
so close to the sun...
just as Earth does today.
The spacecraft we've sent to Mars
touched down on a world that is
curiously just half the size
of her sister planets Earth and
Venus.
And in the asteroid belt,
we've uncovered a graveyard
of failed worlds...
their growth mysteriously cut
short.
To cause all these anomalies,
it's thought that something
catastrophic must have happened
very early in the solar system's
history.
All the evidence suggests
that around 4.5 billion years ago,
Jupiter's orbit began to change,
triggering a period of unprecedented
violence
which completely transformed the
face of the young solar system.
And we know this because
the marauding planet
left a trail of destruction in its
wake.
Early in its life, Jupiter began
to move inwards towards the sun...
and the effects of that journey
can be seen to this day.
In between the orbits of Mars
and Jupiter...
lies the asteroid belt...
a desolate wasteland of debris
left over from the beginning
of the solar system.
Rocky bodies too small to be planets
in their own right.
In science fiction films, the
asteroid belt is often depicted
as an un-navigable
mass of tumbling rubble.
But it's not like that at all.
So much so, in fact, that modern
spacecraft engineers
can fly a spacecraft through without
making any course corrections.
The reason for that is there's not
much mass in the asteroid belt.
A sum total of all of them is only
about 4% the mass of the moon
and they're spread out in a huge
sort of ring,
out beyond the orbit of Mars.
So, it's a vast amount of space.
That means that the average distance
between any two large asteroids
is about eight times the distance
between the Earth and the moon.
So, I could stand on one of those
large asteroids
and look out into space
and my nearest neighbour would just
be a dim star in the dark.
But scattered amongst the rubble
are objects
that are far more than mere rocks.
Five, four, three,
two, main engine start, one,
zero and lift off
of the Delta II Rocket.
In 2007, Nasa's Dawn mission
was sent to explore the two largest
objects in the asteroid belt.
After a year in orbit around
the giant asteroid Vesta...
in March 2015...
Dawn made its final approach
on a body so large
it makes up almost a third of the
mass of the entire asteroid belt...
Ceres.
On arrival, the first images Dawn
sent back to Earth
contained something entirely
unexpected...
mysterious bright patches in one
of Ceres' largest craters.
Spectral analysis of the images
showed that the patches were, in
fact,
the salty residue left
behind by liquid water...
suggesting there must be large
amounts of ice
just beneath the crust.
Dawn went on to discover over 300
bright spots all over the surface.
And this means that beneath
this thin crust,
Ceres has a thick ice rich mantle
surrounding its rocky core...
evidence that the dwarf planet
is made up of multiple layers.
The interior of Ceres is like
nothing else in the asteroid belt.
The differentiation, that separation
into layers, observed by Dawn
is more characteristic of a planet
than an asteroid.
So, 4.5 billion years ago, Ceres
was well on its way
to becoming a fully-fledged world.
It's thought that's in its infancy
Ceres was very different.
The water that now lies frozen
within its interior was once liquid.
Protected beneath a thin
layer of ice...
Ceres was once covered
by a deep saltwater ocean.
Before Ceres had reached
its full potential,
a great disturbance sent shock
waves through
what would one day become the
asteroid belt
and cut its development short.
As Jupiter circled the young sun,
it started to clear a path
through the gas and dust
that shrouded the early
solar system...
but that process caused it to do
something alarming.
Gravitational interactions with the
gas made the giant planets
spiral inwards towards the sun...
ploughing straight through the
region of space
that would become the asteroid
belt...
scattering the material
from which Ceres
would otherwise have grown.
Computer simulations of the early
solar system
suggest that the asteroid belt once
contained enough material
to build a planet the size of the
Earth.
And perhaps that was Ceres's
destiny.
But when Jupiter passed through,
it scattered 99.9% of the material
away,
and Ceres's fate was sealed.
Within 100 million years, Ceres's
ocean froze
and was buried beneath its crust.
The young planet's development
cut short
before it could fulfil its promise.
But Jupiter's reign of terror was
far from over.
It would continue its journey
inwards
towards the place our planet
was beginning to form...
threatening the very existence of
Earth.
Jupiter had such an overwhelming
effect on the young solar system
because of its powerful
gravitational field...
the effects of which we can
still witness today.
Jupiter exerts its influence
across the solar system
through its gravitational field...
which is by far the most powerful
of all the planets,
because Jupiter is the most massive
of all the planets.
It's about 320 times the mass
of the Earth.
That's why it was so destructive
in the past.
And we see the power of
that gravitational field today
in its influence on the closest
of Jupiter's largest moons, Io.
Io is the most volcanic
world in the solar system.
Its surface covered with hundreds
of active volcanoes...
and lakes of molten lava.
The largest, known as Loki Patera,
is more than 200km in diameter.
A million times the area
of any lava lake on Earth.
Its surface tormented by waves
of molten rock.
Io is a vision of hell...
created by the moon's proximity
to Jupiter.
Volcanism here on Earth
is powered by the internal heat
down below the surface.
Now, much of that is residual heat
left over from the Earth's
formation
four-and-a-half billion years ago,
about half of it, and the other half
is down to radioactive decay of
elements around the Earth's core.
Now, on Io it's different.
Io's a much smaller world
and so it didn't retain
much residual heat.
So, there, the volcanoes are powered
by a different process.
It's known as tidal heating.
The energy that drives Io's
volcanism
doesn't come from heat
stored within the moon.
It's generated by gravity...
because Io orbits just 350,000km
from the tops of Jupiter's clouds.
Io orbits at about the same distance
from Jupiter
as our moon orbits the Earth.
But because Jupiter is so much more
massive,
Io goes around much more quickly.
In fact, it goes around once every
42 hours.
Now, if Io were Jupiter's only
moon,
that orbit would be circular,
but it isn't.
The next moon out - Europa - goes
round Jupiter precisely once
for every two orbits of Io...
which means that every second
orbit,
Io and Europa fall into
alignment.
It's what's known as an orbital
resonance.
That gives it a gravitational kick
and that moves Io's orbit
into an ellipse.
Now, that means that the
gravitational force's on Io
are constantly shifting and changing
and that stretches and squashes the
moon,
and heats it up - by friction.
Now, that is called tidal heating
and that is the origin of
Io's volcanoes.
This process raises the temperature
in Io's interior,
which would otherwise be frozen
solid,
to more than 1,000 degrees
Celsius...
creating its lava lakes...
and powering immense volcanic
plumes...
that rise up to 300km
from the moon's surface...
and out into space.
Io provides the solar system
with a vivid reminder...
of the giant planet's power.
Jupiter's intense gravitational
field...
is the source of Io's
volcanism today.
But we don't feel that gravitational
pull here on Earth,
because Jupiter is so far away,
but four-and-a-half billion years
ago,
Jupiter was migrating inwards
towards the inner solar system,
approaching the region where
Mars and Earth were forming.
After passing through what would
become the asteroid belt...
Jupiter entered the inner
solar system...
continuing its journey, spiralling
towards the sun.
Back then, the area where Mars
and Earth orbit today
was densely packed with gas and
rock.
But as Jupiter approached,
it wrought havoc...
scattering the rocky material
in all directions...
some sent careering into the
sun...
others thrown out
into interstellar space.
And it's this that may explain our
solar system's unusual structure.
Here's the solar system today.
The sun, the four inner rocky
planets, the asteroids and Jupiter.
And what we think may have happened
is Jupiter made it inwards
through where the asteroids
are, as far in as the orbit of Mars.
And that would have cleaned out
quite a lot of the material
in the inner solar system, leaving
less for the formation of planets.
And that's why we don't see
super-Earths in our solar system.
Those big massive rocky worlds
that we see in orbit around so many
other stars.
This also might explain
why Mars is so small.
See, if Jupiter was orbiting
in the region that Mars was forming,
there would have been much less
material here.
And that might explain why Mars
is only a tenth of the mass
of Venus and Earth.
Had Jupiter continued to move
inwards,
it would have had a similar effect
on the Earth...
meaning the world we inhabit
might never have formed.
But just as it looked as if Jupiter
would sweep everything away,
something stopped the giant
planet in its tracks...
because in the shadows of the
outer solar system,
another planet was forming.
The solar system's second gas
giant...
Saturn...
and its birth changed everything.
When a planet forms in a disk
of material around a star,
as Jupiter did in our solar system,
it tends to clear out a gap in the
disk.
Now, the material tends to fall
inwards towards the star.
It's called the accretion
and that drags the whole thing
inwards.
And that's what happened to Jupiter.
But, then, a less massive planet,
Saturn, formed further out.
It cleared out its own disk
and it too fell inwards
towards the sun,
but more quickly than Jupiter.
That meant that Saturn got
into a resonance with Jupiter.
It went round once in orbit around
the sun
for every two orbits of Jupiter
and that has the effect of cleaning
out the whole region
between the two planets.
And that has the effect,
through a series of complicated
gravitational interactions,
of slowing and stopping the in-fall
and eventually causing the two
planets to move back out again.
And that is what happened to Jupiter
and Saturn in our solar system.
Saturn caused Jupiter to retreat...
leaving behind just enough
material
from which the inner planets could
form.
Mercury.
Venus.
Mars.
And our home...
the Earth.
By preventing the formation of much
larger super-Earths,
Jupiter allowed our planet to grow.
And even as Jupiter's reign of
terror was drawing to a close,
it provided one last parting
gift to our world.
The young Earth formed in an arid
region of the inner solar system.
There was very little water
that close to the sun,
but as the Earth was forming,
Jupiter was already tacking back
outwards again into the outer solar
system
through the region that we now call
the asteroid belt,
a region populated by many icy,
water rich comets and asteroids.
And they were scattered back inwards
again,
bringing water back into the inner
solar system.
So, I think it is quite a wonderful
thought,
that Earth is a water world today
because of the motion inwards
and then back outwards again
of the massive planet Jupiter.
This idea does seem quite
contrived, almost fantastical,
but the more we learn about
the formation of solar systems,
and the more we try to model
a system like ours,
with four terrestrial, water-rich
planets close to the star
and then the gas giants further out,
the more we learn that perhaps all
these things had to happen,
these unlikely movements and
interactions between the planets,
in order to produce a system like
ours and a planet like ours.
So, places like this may
be extremely rare.
Today, Jupiter has settled
into a regular orbit
back beyond the far edge
of the asteroid belt...
its days of marauding through
the solar system at an end.
Jupiter has been established
in a stable orbit
for almost four billion years.
If I was to sit here on Earth 3.8
billion years ago
when life began and look
up into the night sky,
I would have seen it shining
there as a point of light
the same as it looks today,
distant and seemingly detached.
And it's remained that way for the
vast expanse of time it's taken
for evolution by natural selection
to transform those first populations
of organisms into all this,
to transform the Earth into an oasis
of life
in the desert of the solar system.
But Jupiter's influence over the
Earth remains to this day...
and that's because, despite its
great distance from us...
it retains a vice-like grip
over the asteroid belt.
It's easy, I think quite natural,
to think of the asteroid belt
as a single structure.
A sort of ring of rock surrounding
the sun.
But that's not
what it's like at all.
In reality, each one of those
millions and millions of pieces
of rock is following its own
individual orbits.
And this remarkable animation
is made up of ten years
of astronomical observations.
And every point you see
on this animation...
is a single asteroid,
apart from all the planets.
And so you see Earth and Mars
and Venus whizzing around the sun.
But the interesting one
is Jupiter...
orbiting just outside the asteroid
belt.
What you can see is that the
asteroid belt
dances to Jupiter's tune.
It's the conductor of the asteroid
belt, if you like.
There are complex patterns
here, but there's also structure.
And the reason for that is
the delicate interplay
between the gravitational pull
of the sun
and the gravitational force from
Jupiter.
Now, what can happen is that
perhaps because of an interaction
between two asteroids,
perhaps they collide with each
other,
or perhaps on their orbit
they line-up perfectly with Jupiter
and get an extra gravitational kick,
those asteroids can be disturbed
from this structure
and be sent
inwards to the inner solar system.
And by that mechanism, Jupiter
has a profound influence
on the planets closer to the sun.
Around 100 million years ago,
an asteroid 10km across was ejected
from the asteroid belt.
Dislodged by Jupiter's gravity,
it was set on a collision
course with the Earth.
When it struck, it generated
a fireball so hot,
anything within a 1,000km
radius would have died instantly.
The impact threw 300 billion
tonnes of sulphur
into the atmosphere.
And during the nuclear winter
that followed,
75% of all species were wiped
from the face of the Earth.
In one fell swoop,
Jupiter changed the course
of our planet's history.
There are a few places on Earth
today
where you can catch a glimpse
of lost worlds,
you can see Earth as it was millions
of years in the past
and perhaps glimpse the Earth as it
might have been.
And this is one of them.
Today, this is the Colorado Plain,
over a kilometre in altitude,
south of Denver close
to the Rocky Mountains,
but 200 million years ago,
this was at sea level.
It was an ancient lake and the
ghosts of those lost worlds,
the imprints of the past, can be
seen over there,
because there are literally
thousands of dinosaur footprints.
And here they are, the dinosaur
footprints.
I find this absolutely remarkable.
This is the footprint
of a sauropod dinosaur.
That's one of the big ones. The big
herbivores with the long necks.
This animal would have weighed
about 30 tonnes.
It was tall enough to peer
over a two-storey house.
What happened here is, probably
a herd of them, a group of them
came lumbering across this lake bed
and, then,
perhaps that same afternoon,
predators came,
maybe following the herd.
And that's these footprints here.
The allosaurus', these three-toed
footprints.
Much smaller animal, maybe
about twice the height of me,
about two tonnes, very nimble and
agile.
So, you see a whole story
played out here, frozen in time.
Today, just their traces remain...
but were it not for Jupiter...
they might still be here.
There are so many chance events,
not only throughout the history of
Earth,
but also spanning the entire history
of the universe
for 13.8 billion years, without
which we wouldn't exist.
There's an unbroken chain of life
stretching back
four billion years here on this
planet.
You interrupt or interject
at any point
and life on Earth is different.
But having said that, there are
major events that affected life.
And one of them is the asteroid
that wipes out the dinosaurs.
And, in that sense, it is certainly
true to say
that without Jupiter, we wouldn't be
here.
The godfather of the planets
paved the way for us
to inherit the Earth.
And although it occasionally
flings rocks
from the asteroid belt our way...
it also protects us...
because for objects heading
towards the Earth
from the far reaches of the solar
system,
Jupiter's gravitational
field acts as a shield.
Around a century ago, a lump
of rock and ice
4km across and weighing
17 billion tonnes...
was hurtling towards the inner
solar system...
until Jupiter intervened.
Five, four, three, two, one...
We have ignition and lift off of
Atlantis
and the Galileo Spacecraft
bound for Jupiter.
70 years later, we witnessed
just how effective a shield
Jupiter can be.
Onboard the space shuttle
Atlantis...
the Galileo orbiter.
Three years after Galileo launched,
comet Shoemaker-Levy-9 had been
captured by Jupiter's gravity.
Locked in the giant planet's
embrace...
tidal forces now began to tear
it apart.
Its journey cut short...
the comet now faced annihilation.
After crossing the inner
solar system,
Galileo passed through the asteroid
belt...
approaching the spots from where
it would witness
the comet's final moments.
On July 16th, Galileo saw the first
fragments of the comet
enter Jupiter's southern hemisphere.
Pieces of comet Shoemaker-Levy-9
struck Jupiter over the course of
six days.
It was the first time a comet strike
had ever been witnessed.
The most destructive impact released
energy
equivalent to six million megatons
of TNT...
leaving behind a giant dark
cloud 12,000km across.
By capturing objects
and incinerating them on impact...
Jupiter sweeps up bodies
from the outer solar system...
that might otherwise collide
with Earth.
Jupiter,
the oldest and largest of
the planets,
is the godfather of our
solar system.
In youth...
it went on the rampage.
For some young planets, it spelt
disaster.
But for others, like our own
world,
it cleared the way for their
formation.
And in adulthood, it created
the conditions
that allowed us to rise...
so we owe Jupiter a great debt.
But as the dinosaurs found
to their cost,
it's a debt that could be recalled
at any time.
To the naked eye,
Jupiter is one of the brightest
points of light in the night sky,
and through a small telescope, it is
a beautiful banded world.
But it feels distant, eternal,
disconnected from events
here on Earth.
But the more we've understood about
the history of the solar system,
the more we've come to understand
that that is not the case.
Jupiter has played an important
and perhaps decisive role
in the stories of all the planets,
including Earth.
So, the solar system is just that.
It's a system.
Complex, interconnected and
interdependent.
So, next time you see Jupiter,
just hold your gaze.
Maybe think for a minute, because it
is so much more than just a point
of light, or a planet, even.
It is the great sculptor
of the solar system,
the destroyer and creator of worlds.
I think people are drawn
in by Jupiter
because it's very mysterious.
It's covered by clouds that hide
what's underneath.
It's very violent.
And it's very intimidating.
It's also very beautiful.
It has all these things going on
and it's hard not to be taken in.
T-minus ten, nine, eight, seven,
six...
Such is Jupiter's mystique,
it's been a recurring
target for space exploration.
And lift off of the Atlas V with
Juno on a trek to Jupiter.
In 2011, Nasa launched its latest
mission - Juno.
When we launched the Juno spacecraft
away from the Earth out towards
Jupiter,
we didn't have enough speed to get
away out of the gravity of the sun,
so we actually had to come back
to Earth,
get a gravity assist from Earth,
and then go out to Jupiter.
After travelling for five
years, Juno finally arrived.
This is a mission that goes closer
to the planet in its orbit
than any other mission ever has.
Only a few thousand kilometres from
the cloud tops and very, very fast.
We go from pole to pole in two
hours,
slipping between the radiation belts
in the cloud tops,
getting the data as fast as we can
and getting out.
So, in every way, Juno is breaking
new ground
and that's allowed us to see things
that we couldn't have ever imagined.
Juno's mission is to explore
the planets inside and out.
And amongst the many scientific
instruments it has on board
is its camera, JunoCam.
You see all these swirls, you see
all sorts of spots coming up.
You see all these vortices, you see
dramatic storm systems interacting.
It's mind-blowingly beautiful
pictures
that this little camera
has been taking.
JunoCam was able to see
the Great Red Spot from up close.
We can see height to the clouds.
We can see features that look
like storms.
Maybe it's hailing or snowing
ammonia on Jupiter.
And the most startling thing that we
saw from JunoCam's imagery
was that the poles of Jupiter
are actually blue.
They are nothing like the orange
and white planet
that we grew up thinking about as
children.
Juno has just begun to unlock
Jupiter's secrets.
And so, at last,
the godfather of the planets
has begun to talk.
A planet that began life
as an unremarkable rocky world...
but transformed into one
of the jewels of the solar system...
where shimmering rings of ice
harbour a potential home for life.
Saturn.
Journey through our solar system
with this free poster
produced by the Open University
and discover more about its planets
and moons.
Order your free
copy by calling...
Or go to...
and follow the links
to the Open University.
Journey through our solar system
with the Open University
and discover more about its planets
and moons.
Explore this and more with our
academic experts.
Go to...
and follow the links
to the Open University.
mission to Mercury.
♪ They'll say no-one can see us
♪ That we're estranged
and all alone
♪ They believe
nothing can reach us
♪ And pull us out of
the boundless gloom
♪ They're wrong
♪ They're wrong
♪ They're wrong. ♪
Beyond the inner solar system...
past the asteroid belt...
lies Jupiter.
The largest of the planets
is a giant swirling ball of gas...
its marbled appearance generated
by violent winds
that rage through its clouds.
Jupiter is a world as strange
as it is remote.
If you fly upwards, only about
100km or so,
you reach the edge of our atmosphere
and the blackness of space.
It's really not that far.
But once you're in space,
the distance scales are sort of
incomprehensible.
I mean, Venus, the closest planet,
is over 40 million kilometres away.
Jupiter around 650 million
kilometres.
It takes our fastest spacecraft
years to get there.
So, the idea that those planets
could have any influence on us
here on Earth seems fanciful.
And, indeed, if you're talking about
your chances of meeting a handsome
stranger
or your life plans requiring a
moderate reconfiguration
about a week on Wednesday,
then you would be right.
However, if you ask more profound
questions, deeper questions like,
"Why is the Earth the way that it
is?
"Why is there life on Earth?
"Why do we exist at all?"
then it turns out that the planets,
and Jupiter in particular,
have had a profound effect.
Early in its life, the young
Jupiter went on the rampage.
The giant planet embarked
on a voyage of destruction
across the solar system...
that transformed the destiny
of the planets,
and the course of life on Earth.
Jupiter is the godfather
of the planets.
Understand it and you understand
how the solar system came to be.
On Earth, we can see glimpses
of Jupiter's power...
in the scars it's left...
on the face of the planet.
This is the famous Barringer
Meteor Crater in Arizona.
It is about a kilometre across,
170 metres from the rim to the
crater floor
and it was created about 50,000
years ago
when a meteorite, 50 metres across,
entered the Earth's atmosphere
travelling at about 13km per
second.
That means it would have taken
around, what, seven seconds
to go from the top of the atmosphere
to the ground
and it hit with such force that the
energy released
was equivalent to ten megatons of
TNT.
And that is a very large
nuclear bomb.
The meteorite that hit the Earth
here
is thought to have come from the
asteroid belt...
the ring of rocky debris
that orbits at the edge
of the inner solar system.
And it was deflected from its orbit
most likely by the gravitational
influence of Jupiter.
Jupiter is a completely different
class of planet to the Earth.
A gas giant.
A swirling ball of hydrogen
and helium so large
you could fit 1,300 Earths inside.
Jupiter can exert such a powerful
influence on the asteroids
because it's so massive.
It's about two-and-a-half times
the mass of all the other planets,
moons and asteroids in the solar
system combined.
And, therefore, it has a strong
gravitational pull.
And this means that Jupiter
exerts an influence
across the entire solar system
that's second only to the sun.
And that influenced us far
more than create the odd crater.
It can change the history
of worlds.
To understand how Jupiter rose
to such dominance,
you have to go back to a time before
the solar system even existed.
Nearly five billion years ago,
a distant exploding star sent
a shock wave across the galaxy...
causing the cloud of gas and dust
that would become our solar system
to collapse...
as the sun began to form.
But further out, something
else was growing.
After 50 million years...
the sun's nuclear furnace ignited.
The light of its first dawn...
revealing Jupiter...
the solar system's first world.
A planet born so early, it swept
up most of the material
left over from the formation of the
sun.
Because of its dominance, Jupiter
had a profound effect
on the newly forming solar system
and paved the way for our living
world to form.
This is a model of our solar system.
So, here's the sun, and then we have
the four inner rocky planets,
Mercury, Venus, Earth and Mars.
Then comes the asteroid belt,
the ring of millions of smaller
pieces of rock
orbiting around the sun.
And then the gas giants.
Jupiter, Saturn, Uranus and Neptune.
Now, this has a pleasing regular
structure about it.
All the rocky planets close to the
star
and the gas giants further out.
And we thought that this must be the
natural order of things,
the way that solar systems
have to form,
until we started to detect planets
around distant stars
and then we found that this
arrangement is not typical at all.
Our sun is just one of around
300 billion stars in our galaxy...
and almost every one of those
stars
is home to its own system of
planets.
In most other systems, the region
where our planet orbits is empty.
Instead, closer to the star, we see
super-Earths,
vast rocky planets
many times bigger than our own.
But, crucially, these worlds are
thought
to have thick toxic atmospheres,
making them completely inhospitable
to life.
And that raises a very interesting
question.
Why, then, is our solar system
the way that it is?
To answer that question,
we've sent spacecraft to every one
of the planets...
and they've uncovered strange
anomalies
that reveal our solar system's past.
Our missions to Venus found
that it once had far more water
than you'd expect for a planet
so close to the sun...
just as Earth does today.
The spacecraft we've sent to Mars
touched down on a world that is
curiously just half the size
of her sister planets Earth and
Venus.
And in the asteroid belt,
we've uncovered a graveyard
of failed worlds...
their growth mysteriously cut
short.
To cause all these anomalies,
it's thought that something
catastrophic must have happened
very early in the solar system's
history.
All the evidence suggests
that around 4.5 billion years ago,
Jupiter's orbit began to change,
triggering a period of unprecedented
violence
which completely transformed the
face of the young solar system.
And we know this because
the marauding planet
left a trail of destruction in its
wake.
Early in its life, Jupiter began
to move inwards towards the sun...
and the effects of that journey
can be seen to this day.
In between the orbits of Mars
and Jupiter...
lies the asteroid belt...
a desolate wasteland of debris
left over from the beginning
of the solar system.
Rocky bodies too small to be planets
in their own right.
In science fiction films, the
asteroid belt is often depicted
as an un-navigable
mass of tumbling rubble.
But it's not like that at all.
So much so, in fact, that modern
spacecraft engineers
can fly a spacecraft through without
making any course corrections.
The reason for that is there's not
much mass in the asteroid belt.
A sum total of all of them is only
about 4% the mass of the moon
and they're spread out in a huge
sort of ring,
out beyond the orbit of Mars.
So, it's a vast amount of space.
That means that the average distance
between any two large asteroids
is about eight times the distance
between the Earth and the moon.
So, I could stand on one of those
large asteroids
and look out into space
and my nearest neighbour would just
be a dim star in the dark.
But scattered amongst the rubble
are objects
that are far more than mere rocks.
Five, four, three,
two, main engine start, one,
zero and lift off
of the Delta II Rocket.
In 2007, Nasa's Dawn mission
was sent to explore the two largest
objects in the asteroid belt.
After a year in orbit around
the giant asteroid Vesta...
in March 2015...
Dawn made its final approach
on a body so large
it makes up almost a third of the
mass of the entire asteroid belt...
Ceres.
On arrival, the first images Dawn
sent back to Earth
contained something entirely
unexpected...
mysterious bright patches in one
of Ceres' largest craters.
Spectral analysis of the images
showed that the patches were, in
fact,
the salty residue left
behind by liquid water...
suggesting there must be large
amounts of ice
just beneath the crust.
Dawn went on to discover over 300
bright spots all over the surface.
And this means that beneath
this thin crust,
Ceres has a thick ice rich mantle
surrounding its rocky core...
evidence that the dwarf planet
is made up of multiple layers.
The interior of Ceres is like
nothing else in the asteroid belt.
The differentiation, that separation
into layers, observed by Dawn
is more characteristic of a planet
than an asteroid.
So, 4.5 billion years ago, Ceres
was well on its way
to becoming a fully-fledged world.
It's thought that's in its infancy
Ceres was very different.
The water that now lies frozen
within its interior was once liquid.
Protected beneath a thin
layer of ice...
Ceres was once covered
by a deep saltwater ocean.
Before Ceres had reached
its full potential,
a great disturbance sent shock
waves through
what would one day become the
asteroid belt
and cut its development short.
As Jupiter circled the young sun,
it started to clear a path
through the gas and dust
that shrouded the early
solar system...
but that process caused it to do
something alarming.
Gravitational interactions with the
gas made the giant planets
spiral inwards towards the sun...
ploughing straight through the
region of space
that would become the asteroid
belt...
scattering the material
from which Ceres
would otherwise have grown.
Computer simulations of the early
solar system
suggest that the asteroid belt once
contained enough material
to build a planet the size of the
Earth.
And perhaps that was Ceres's
destiny.
But when Jupiter passed through,
it scattered 99.9% of the material
away,
and Ceres's fate was sealed.
Within 100 million years, Ceres's
ocean froze
and was buried beneath its crust.
The young planet's development
cut short
before it could fulfil its promise.
But Jupiter's reign of terror was
far from over.
It would continue its journey
inwards
towards the place our planet
was beginning to form...
threatening the very existence of
Earth.
Jupiter had such an overwhelming
effect on the young solar system
because of its powerful
gravitational field...
the effects of which we can
still witness today.
Jupiter exerts its influence
across the solar system
through its gravitational field...
which is by far the most powerful
of all the planets,
because Jupiter is the most massive
of all the planets.
It's about 320 times the mass
of the Earth.
That's why it was so destructive
in the past.
And we see the power of
that gravitational field today
in its influence on the closest
of Jupiter's largest moons, Io.
Io is the most volcanic
world in the solar system.
Its surface covered with hundreds
of active volcanoes...
and lakes of molten lava.
The largest, known as Loki Patera,
is more than 200km in diameter.
A million times the area
of any lava lake on Earth.
Its surface tormented by waves
of molten rock.
Io is a vision of hell...
created by the moon's proximity
to Jupiter.
Volcanism here on Earth
is powered by the internal heat
down below the surface.
Now, much of that is residual heat
left over from the Earth's
formation
four-and-a-half billion years ago,
about half of it, and the other half
is down to radioactive decay of
elements around the Earth's core.
Now, on Io it's different.
Io's a much smaller world
and so it didn't retain
much residual heat.
So, there, the volcanoes are powered
by a different process.
It's known as tidal heating.
The energy that drives Io's
volcanism
doesn't come from heat
stored within the moon.
It's generated by gravity...
because Io orbits just 350,000km
from the tops of Jupiter's clouds.
Io orbits at about the same distance
from Jupiter
as our moon orbits the Earth.
But because Jupiter is so much more
massive,
Io goes around much more quickly.
In fact, it goes around once every
42 hours.
Now, if Io were Jupiter's only
moon,
that orbit would be circular,
but it isn't.
The next moon out - Europa - goes
round Jupiter precisely once
for every two orbits of Io...
which means that every second
orbit,
Io and Europa fall into
alignment.
It's what's known as an orbital
resonance.
That gives it a gravitational kick
and that moves Io's orbit
into an ellipse.
Now, that means that the
gravitational force's on Io
are constantly shifting and changing
and that stretches and squashes the
moon,
and heats it up - by friction.
Now, that is called tidal heating
and that is the origin of
Io's volcanoes.
This process raises the temperature
in Io's interior,
which would otherwise be frozen
solid,
to more than 1,000 degrees
Celsius...
creating its lava lakes...
and powering immense volcanic
plumes...
that rise up to 300km
from the moon's surface...
and out into space.
Io provides the solar system
with a vivid reminder...
of the giant planet's power.
Jupiter's intense gravitational
field...
is the source of Io's
volcanism today.
But we don't feel that gravitational
pull here on Earth,
because Jupiter is so far away,
but four-and-a-half billion years
ago,
Jupiter was migrating inwards
towards the inner solar system,
approaching the region where
Mars and Earth were forming.
After passing through what would
become the asteroid belt...
Jupiter entered the inner
solar system...
continuing its journey, spiralling
towards the sun.
Back then, the area where Mars
and Earth orbit today
was densely packed with gas and
rock.
But as Jupiter approached,
it wrought havoc...
scattering the rocky material
in all directions...
some sent careering into the
sun...
others thrown out
into interstellar space.
And it's this that may explain our
solar system's unusual structure.
Here's the solar system today.
The sun, the four inner rocky
planets, the asteroids and Jupiter.
And what we think may have happened
is Jupiter made it inwards
through where the asteroids
are, as far in as the orbit of Mars.
And that would have cleaned out
quite a lot of the material
in the inner solar system, leaving
less for the formation of planets.
And that's why we don't see
super-Earths in our solar system.
Those big massive rocky worlds
that we see in orbit around so many
other stars.
This also might explain
why Mars is so small.
See, if Jupiter was orbiting
in the region that Mars was forming,
there would have been much less
material here.
And that might explain why Mars
is only a tenth of the mass
of Venus and Earth.
Had Jupiter continued to move
inwards,
it would have had a similar effect
on the Earth...
meaning the world we inhabit
might never have formed.
But just as it looked as if Jupiter
would sweep everything away,
something stopped the giant
planet in its tracks...
because in the shadows of the
outer solar system,
another planet was forming.
The solar system's second gas
giant...
Saturn...
and its birth changed everything.
When a planet forms in a disk
of material around a star,
as Jupiter did in our solar system,
it tends to clear out a gap in the
disk.
Now, the material tends to fall
inwards towards the star.
It's called the accretion
and that drags the whole thing
inwards.
And that's what happened to Jupiter.
But, then, a less massive planet,
Saturn, formed further out.
It cleared out its own disk
and it too fell inwards
towards the sun,
but more quickly than Jupiter.
That meant that Saturn got
into a resonance with Jupiter.
It went round once in orbit around
the sun
for every two orbits of Jupiter
and that has the effect of cleaning
out the whole region
between the two planets.
And that has the effect,
through a series of complicated
gravitational interactions,
of slowing and stopping the in-fall
and eventually causing the two
planets to move back out again.
And that is what happened to Jupiter
and Saturn in our solar system.
Saturn caused Jupiter to retreat...
leaving behind just enough
material
from which the inner planets could
form.
Mercury.
Venus.
Mars.
And our home...
the Earth.
By preventing the formation of much
larger super-Earths,
Jupiter allowed our planet to grow.
And even as Jupiter's reign of
terror was drawing to a close,
it provided one last parting
gift to our world.
The young Earth formed in an arid
region of the inner solar system.
There was very little water
that close to the sun,
but as the Earth was forming,
Jupiter was already tacking back
outwards again into the outer solar
system
through the region that we now call
the asteroid belt,
a region populated by many icy,
water rich comets and asteroids.
And they were scattered back inwards
again,
bringing water back into the inner
solar system.
So, I think it is quite a wonderful
thought,
that Earth is a water world today
because of the motion inwards
and then back outwards again
of the massive planet Jupiter.
This idea does seem quite
contrived, almost fantastical,
but the more we learn about
the formation of solar systems,
and the more we try to model
a system like ours,
with four terrestrial, water-rich
planets close to the star
and then the gas giants further out,
the more we learn that perhaps all
these things had to happen,
these unlikely movements and
interactions between the planets,
in order to produce a system like
ours and a planet like ours.
So, places like this may
be extremely rare.
Today, Jupiter has settled
into a regular orbit
back beyond the far edge
of the asteroid belt...
its days of marauding through
the solar system at an end.
Jupiter has been established
in a stable orbit
for almost four billion years.
If I was to sit here on Earth 3.8
billion years ago
when life began and look
up into the night sky,
I would have seen it shining
there as a point of light
the same as it looks today,
distant and seemingly detached.
And it's remained that way for the
vast expanse of time it's taken
for evolution by natural selection
to transform those first populations
of organisms into all this,
to transform the Earth into an oasis
of life
in the desert of the solar system.
But Jupiter's influence over the
Earth remains to this day...
and that's because, despite its
great distance from us...
it retains a vice-like grip
over the asteroid belt.
It's easy, I think quite natural,
to think of the asteroid belt
as a single structure.
A sort of ring of rock surrounding
the sun.
But that's not
what it's like at all.
In reality, each one of those
millions and millions of pieces
of rock is following its own
individual orbits.
And this remarkable animation
is made up of ten years
of astronomical observations.
And every point you see
on this animation...
is a single asteroid,
apart from all the planets.
And so you see Earth and Mars
and Venus whizzing around the sun.
But the interesting one
is Jupiter...
orbiting just outside the asteroid
belt.
What you can see is that the
asteroid belt
dances to Jupiter's tune.
It's the conductor of the asteroid
belt, if you like.
There are complex patterns
here, but there's also structure.
And the reason for that is
the delicate interplay
between the gravitational pull
of the sun
and the gravitational force from
Jupiter.
Now, what can happen is that
perhaps because of an interaction
between two asteroids,
perhaps they collide with each
other,
or perhaps on their orbit
they line-up perfectly with Jupiter
and get an extra gravitational kick,
those asteroids can be disturbed
from this structure
and be sent
inwards to the inner solar system.
And by that mechanism, Jupiter
has a profound influence
on the planets closer to the sun.
Around 100 million years ago,
an asteroid 10km across was ejected
from the asteroid belt.
Dislodged by Jupiter's gravity,
it was set on a collision
course with the Earth.
When it struck, it generated
a fireball so hot,
anything within a 1,000km
radius would have died instantly.
The impact threw 300 billion
tonnes of sulphur
into the atmosphere.
And during the nuclear winter
that followed,
75% of all species were wiped
from the face of the Earth.
In one fell swoop,
Jupiter changed the course
of our planet's history.
There are a few places on Earth
today
where you can catch a glimpse
of lost worlds,
you can see Earth as it was millions
of years in the past
and perhaps glimpse the Earth as it
might have been.
And this is one of them.
Today, this is the Colorado Plain,
over a kilometre in altitude,
south of Denver close
to the Rocky Mountains,
but 200 million years ago,
this was at sea level.
It was an ancient lake and the
ghosts of those lost worlds,
the imprints of the past, can be
seen over there,
because there are literally
thousands of dinosaur footprints.
And here they are, the dinosaur
footprints.
I find this absolutely remarkable.
This is the footprint
of a sauropod dinosaur.
That's one of the big ones. The big
herbivores with the long necks.
This animal would have weighed
about 30 tonnes.
It was tall enough to peer
over a two-storey house.
What happened here is, probably
a herd of them, a group of them
came lumbering across this lake bed
and, then,
perhaps that same afternoon,
predators came,
maybe following the herd.
And that's these footprints here.
The allosaurus', these three-toed
footprints.
Much smaller animal, maybe
about twice the height of me,
about two tonnes, very nimble and
agile.
So, you see a whole story
played out here, frozen in time.
Today, just their traces remain...
but were it not for Jupiter...
they might still be here.
There are so many chance events,
not only throughout the history of
Earth,
but also spanning the entire history
of the universe
for 13.8 billion years, without
which we wouldn't exist.
There's an unbroken chain of life
stretching back
four billion years here on this
planet.
You interrupt or interject
at any point
and life on Earth is different.
But having said that, there are
major events that affected life.
And one of them is the asteroid
that wipes out the dinosaurs.
And, in that sense, it is certainly
true to say
that without Jupiter, we wouldn't be
here.
The godfather of the planets
paved the way for us
to inherit the Earth.
And although it occasionally
flings rocks
from the asteroid belt our way...
it also protects us...
because for objects heading
towards the Earth
from the far reaches of the solar
system,
Jupiter's gravitational
field acts as a shield.
Around a century ago, a lump
of rock and ice
4km across and weighing
17 billion tonnes...
was hurtling towards the inner
solar system...
until Jupiter intervened.
Five, four, three, two, one...
We have ignition and lift off of
Atlantis
and the Galileo Spacecraft
bound for Jupiter.
70 years later, we witnessed
just how effective a shield
Jupiter can be.
Onboard the space shuttle
Atlantis...
the Galileo orbiter.
Three years after Galileo launched,
comet Shoemaker-Levy-9 had been
captured by Jupiter's gravity.
Locked in the giant planet's
embrace...
tidal forces now began to tear
it apart.
Its journey cut short...
the comet now faced annihilation.
After crossing the inner
solar system,
Galileo passed through the asteroid
belt...
approaching the spots from where
it would witness
the comet's final moments.
On July 16th, Galileo saw the first
fragments of the comet
enter Jupiter's southern hemisphere.
Pieces of comet Shoemaker-Levy-9
struck Jupiter over the course of
six days.
It was the first time a comet strike
had ever been witnessed.
The most destructive impact released
energy
equivalent to six million megatons
of TNT...
leaving behind a giant dark
cloud 12,000km across.
By capturing objects
and incinerating them on impact...
Jupiter sweeps up bodies
from the outer solar system...
that might otherwise collide
with Earth.
Jupiter,
the oldest and largest of
the planets,
is the godfather of our
solar system.
In youth...
it went on the rampage.
For some young planets, it spelt
disaster.
But for others, like our own
world,
it cleared the way for their
formation.
And in adulthood, it created
the conditions
that allowed us to rise...
so we owe Jupiter a great debt.
But as the dinosaurs found
to their cost,
it's a debt that could be recalled
at any time.
To the naked eye,
Jupiter is one of the brightest
points of light in the night sky,
and through a small telescope, it is
a beautiful banded world.
But it feels distant, eternal,
disconnected from events
here on Earth.
But the more we've understood about
the history of the solar system,
the more we've come to understand
that that is not the case.
Jupiter has played an important
and perhaps decisive role
in the stories of all the planets,
including Earth.
So, the solar system is just that.
It's a system.
Complex, interconnected and
interdependent.
So, next time you see Jupiter,
just hold your gaze.
Maybe think for a minute, because it
is so much more than just a point
of light, or a planet, even.
It is the great sculptor
of the solar system,
the destroyer and creator of worlds.
I think people are drawn
in by Jupiter
because it's very mysterious.
It's covered by clouds that hide
what's underneath.
It's very violent.
And it's very intimidating.
It's also very beautiful.
It has all these things going on
and it's hard not to be taken in.
T-minus ten, nine, eight, seven,
six...
Such is Jupiter's mystique,
it's been a recurring
target for space exploration.
And lift off of the Atlas V with
Juno on a trek to Jupiter.
In 2011, Nasa launched its latest
mission - Juno.
When we launched the Juno spacecraft
away from the Earth out towards
Jupiter,
we didn't have enough speed to get
away out of the gravity of the sun,
so we actually had to come back
to Earth,
get a gravity assist from Earth,
and then go out to Jupiter.
After travelling for five
years, Juno finally arrived.
This is a mission that goes closer
to the planet in its orbit
than any other mission ever has.
Only a few thousand kilometres from
the cloud tops and very, very fast.
We go from pole to pole in two
hours,
slipping between the radiation belts
in the cloud tops,
getting the data as fast as we can
and getting out.
So, in every way, Juno is breaking
new ground
and that's allowed us to see things
that we couldn't have ever imagined.
Juno's mission is to explore
the planets inside and out.
And amongst the many scientific
instruments it has on board
is its camera, JunoCam.
You see all these swirls, you see
all sorts of spots coming up.
You see all these vortices, you see
dramatic storm systems interacting.
It's mind-blowingly beautiful
pictures
that this little camera
has been taking.
JunoCam was able to see
the Great Red Spot from up close.
We can see height to the clouds.
We can see features that look
like storms.
Maybe it's hailing or snowing
ammonia on Jupiter.
And the most startling thing that we
saw from JunoCam's imagery
was that the poles of Jupiter
are actually blue.
They are nothing like the orange
and white planet
that we grew up thinking about as
children.
Juno has just begun to unlock
Jupiter's secrets.
And so, at last,
the godfather of the planets
has begun to talk.
A planet that began life
as an unremarkable rocky world...
but transformed into one
of the jewels of the solar system...
where shimmering rings of ice
harbour a potential home for life.
Saturn.
Journey through our solar system
with this free poster
produced by the Open University
and discover more about its planets
and moons.
Order your free
copy by calling...
Or go to...
and follow the links
to the Open University.
Journey through our solar system
with the Open University
and discover more about its planets
and moons.
Explore this and more with our
academic experts.
Go to...
and follow the links
to the Open University.