All language subtitles for Spaces Deepest Secrets S01E03 Death of the Solar System

Our sun...

The heart of the solar system...

The giver of light, heat,

and, of course, life.

But what does its future hold?

Scientists are looking
to the stars to find out.

Between these two stars is
what's gonna happen to our sun.

Scientists today are almost
like modern-day prophets.

They foresee
an apocalyptic future.

Imagine the ball
is Andromeda galaxy

on a head-on collision
with the Milky Way galaxy.

The fate of the Earth
hangs in the balance.

Wow! Look at this.

The temperature of the surface
of the Earth

will be enough to melt rock.

Enough to melt the whole surface
of the Earth.

This is the story of how our sun

will transform the solar system

it binds together...

Before bringing it
to a spectacular end.

Captions by vitac...
www.Vitac.Com

captions paid for by
Discovery communications

Peoria, Illinois,

an average city
in midwest America,

but it has one claim to fame
that's out of this world.

In the middle of town,

there's a 46-foot-wide mosaic

of the Sun,

the centerpiece
of a huge-scale model

of our solar system

created by local astronomer
Sheldon Schafer.

And here we are at the Sun.

And, boy, is it hot.

It's about 10,000 degrees
here at the surface.

And over a million Earths
could fit inside of the Sun.

Peoria's solar system,

99 million times
smaller than the real thing,

accurately reveals
the relative sizes

of our sun and its planets...

Okay, we're all together?

And the distances between them.

My job title is curator
of the solar system.

And we just went
33 million miles,

until we got to this tiny
little two-inch Mercury.

All right.
So, we're headed off to Venus.

From Mercury,

the inner planets
are strung along

a picturesque riverside park,

all the way to Mars.

These planets
are relatively close together.

The outer planets
are much further away,

in some bizarre locations.

Five miles
from the image of the Sun,

above the local airport's
check-in desks,

is five-foot-wide Jupiter...

Well,
if you're gonna have a planet,

you may as well have
the biggest one, right?

So, it's fun to have Jupiter.

Occasionally we have birds
that decorate,

so we've had to clean it.
But not very often.

While the children's section

of a neighboring town's library
is home to saturn.

Uranus is in princeville,
Illinois.

From there, it's a 10-mile drive

along route 91,

or almost a billion miles
in cosmic terms,

to the old railroad depot
in Wyoming, Illinois,

and Neptune.

And finally,

in a furniture store

40 Earth miles away
from the center of the Sun,

in kewanee, Illinois,
is distant Pluto.

Peoria's models

are a perfect likeness
of the solar system today.

But it won't always be this way.

Scientists know that one day,

the Sun
will fundamentally change,

and transform the planets.

Imagine fast-forwarding through
the next seven-billion years

to watch the end
of the solar system.

Dr. Eva Villaver
can predict this future...

Because everything
that will happen to our sun

is already happening
to countless other stars.

Some, known as solar twins,

are remarkably similar
to our own.

We study solar twins
because they are very important

to understand not only the Sun,

but to tell us how the future
of our own solar system will be.

In 2013,

a solar twin called
corot sol 1 was discovered.

Corot is over there, in
the constellation of monoceros.

It's a star like the Sun,
and it has the same mass.

Exactly the same mass.

But astronomers found

one particularly significant
difference...

It had a lower concentration
of the element lithium,

which helped them
to accurately calculate its age.

It's a star
that is a little bit older

than the Sun,
a few billion years older.

And if we observe a star
that is older than our sun,

we know what will happen
to the Sun.

Eva and her team discovered

that this older version
of our sun

was giving out more radiation.

So, it helped us
put the pieces together.

As the Sun will get older,

it will become brighter,
much brighter.

Our sun's luminosity
is slowly increasing

because of a change
deep inside the Sun,

where two opposing forces
are in constant battle.

Similar forces to those
that act on a hot-air balloon.

Pushing up and out is
the immense pressure of hot gas.

In the Sun, this is created
by nuclear fusion.

The Sun has been
burning hydrogen into helium

for thousands
of millions of years now.

This is like
the propane bottle here.

It's generating heat
that warm up the air

that keeps the balloon going.

That's what happens in the Sun,
too.

But pulling down
into the core of the Sun

is an equally powerful force...
Gravity.

The life of the Sun is nothing
but a battle against gravity.

We have the gravitational force
trying to pull the star,

crash the star together.
I mean like pushing it in.

And then we have
the thermal pressure

of the gas pushing outwards.

So, the balance
between the two forces

is what keeps the Sun stable.

For 4.5-billion years,

the two forces
have been in perfect balance.

But as time passes,
this balance is shifting.

As the Sun fuses hydrogen,

it produces
around 600 million tons

of helium every second,

which is a denser gas.

This change in density

has a profound affect
on the nuclear reactions.

As the core gets denser,

hydrogen is burned
at a higher rate.

It's like turning
the burners up.

I mean,
we are increasing the energy

that is coming out of the core
at that point.

As a result,

our sun is getting 10% brighter
every billion years.

So the older it gets,

the more it heats
up the solar system.

And scientists know
that will one day

have serious consequences.

The Earth has oceans and clouds

because it orbits a band
around the Sun

called the habitable zone,

which means it's just the right
temperature for liquid water.

And that makes it the only
planet in the solar system

where we know life can thrive.

But as the Sun
becomes more powerful,

the habitable zone will move.

For a vision of the Earth
in two-billion years' time,

astrobiologist
professor Lynn Rothschild

believes we should
look to Venus.

Venus is up in the sky, there.

It's the brightest object
after the Sun and the moon.

It's right near Jupiter
this morning.

It's just an absolutely
spectacular day to see it.

Venus and the Earth formed
out of the same materials.

They're roughly the same size.

The difference is that Venus
is closer to the Sun.

It's no surprise
Venus is warmer than Earth.

But strangely, Venus
is even hotter than Mercury

despite being further
from the Sun.

In 2006, the Venus express probe

launched towards
our nearest planet

to analyze
the venusian atmosphere

in unprecedented detail.

It found a vital clue
among the clouds

to how Venus became so hot.

Venus express allowed us to see

that there was a lot
of deuterium,

which is a heavy form
of hydrogen, left.

And that's indicative
of the fact

that there was once water here.

It soon became clear
that in the past,

Venus was a very different
world.

So, here was this beautiful
water world

not too dissimilar to, maybe,

what the Earth is like today.

There was liquid water

and reasonable
atmospheric pressure

and organic compounds.

There's no reason that there
shouldn't have been life.

The evidence suggests

that Venus
was once in the habitable zone.

But as the Sun grew brighter
three-billion years ago,

it would have had a dramatic
effect on the planet's water.

As the Sun
started to get hotter,

the surface of Venus
started to get hotter,

and therefore
the water turns into steam.

And steam is a greenhouse gas,

so that means it traps
the solar radiation.

And therefore,
just like a greenhouse,

it starts to get
hotter and hotter.

It seems a runaway
greenhouse effect caused Venus

to become the hottest planet
in the solar system.

Mercury,
although closer to the Sun,

has no atmosphere and no water.

Earth has both.

And as the brighter sun
evaporates our oceans,

the affect is likely
to be far more intense

than the man-made global warming

we see today.

Over the next two-billion years,

temperatures on Earth
will rocket.

Life here must adapt or die.

Yellowstone national park
is a natural laboratory

for Lynn to study how life can
survive in extreme conditions.

The reason it's so great

is that we have the whole range,
from the top predators...

Things like wolves and bears
and so on,

all the way down to the beavers
and the herbivores,

and down to the very
tiny organisms,

and even some
incredible microbes.

Life here is used
to dealing with extremes.

But in about
a half-billion years' time,

these extremes will go
in the opposite direction,

as temperatures could climb by
up to 20 degrees in some places.

By then, life as we know it

will have evolved
to be very different.

But just as some of today's
animals have adapted

to survive harsh winters,
in the future,

they may use similar strategies
to cope with scorching summers.

As the Sun gets hotter,

you could imagine the winter as
being the very pleasant season,

and the summers become
unbearably hot.

So, if you're thinking about
a bear

that lives in an area like this

that would normally
hibernate in the winter,

if you turn the thermostat
on the Earth high enough,

it might be the reverse,

so that now animals would be
hibernating in the summer

and be active in the winter.

And grasses would be setting
seed now in the spring.

The seeds would be
what would carry the plant

through this harsh summer.

And then, as the rain
started again in the Autumn,

they would germinate,

and you would get the lush green
in the winter.

In less than
a billion years' time,

the greenhouse effect
is expected to take off,

sending temperatures soaring.

As it gets hotter
and hotter on the land,

eventually even the winters will
be too hot for most organisms,

certainly, to live.

So, if you had a large animal

like, say, a bison,

that's also warm-blooded,
as it gets hotter and hotter,

it won't be able to cool down,
and it will eventually die.

And so, ultimately,

large animals like that
will go extinct.

In just over
a billion years from now,

the land could be nothing but a
parched desert, devoid of life.

The air is gonna
heat up much more quickly

than water will,
and so I predict

that, just like the ancestors
of whales and dolphins

and so on moved
from the land to the water,

so will the descendants of bison
if they want to survive.

But models suggest
that in two-billion years' time,

even the water will have gone.

As it boils away,

the Earth would increasingly
resemble Venus today.

In less than
three-billion years' time,

it's thought that that
the searing sun

and a runaway greenhouse effect

will have wiped out
virtually all life on Earth.

But intelligent life
may just find a way out.

We have something
that the other organisms

out there don't have,
and that is we have technology.

And we're gonna have the option
of going to other planets.

As it gets too hot
for the Earth,

Mars will start to warm up.

And so that means that it's
just possible

Mars will become a better place
for life.

Who knows? I have great faith
in our descendants.

By then, Mars is expected

to be in the habitable zone,

so it could provide a refuge,
but not forever.

Because the next threat will be
the entire solar system...

from 100-billion stars
racing towards us...

the Andromeda galaxy.

Scientists have long suspected
it will one day

crash into our galaxy,
the Milky Way.

But until recently, no one
had been able to say for sure.

In 2012, Dr. Tony sohn
stepped up to the plate.

He and his team set out

to precisely measure
Andromeda's path,

and discover
if it would be a near miss,

a glancing blow,

or a head-on hit
with our galaxy.

To predict the outcome,

he used a technique familiar
to baseball players.

I found a thought experiment

that can help explain how we
measure the motion of Andromeda.

Imagine a game of baseball.

The batter
is waiting for the ball,

thrown by the pitcher.

To work out
if the ball is on target,

the batter needs to see

whether it's drifting
to the side or not.

So the instinctively
compare the motion of the ball

against the background.

Tony needed
to apply the same principle

to discover if Andromeda
was heading towards us

but in order to measure
the galaxy's motion,

he had to find
fixed points behind Andromeda

to compare it to...

A daunting task.

Most of the stars we see
in the sky are in our galaxy,

so they cannot be used
as background objects.

Instead, Tony had to
search for distant galaxies

hundreds of millions
of light-years away.

Only one telescope
was up to the task.

We used the hubble space
telescope to do this project

because we need
a very stable instrument,

and we need to be above
the Earth's atmosphere

to get very high resolution
of the image.

With data from hubble,
Tony painstakingly tracked stars

in Andromeda
against distant galaxies,

just like a batter
tracks a ball.

Imagine the ball
is Andromeda galaxy,

and the fence behind that
are background galaxies.

And what we did was we compared

the position
of the Andromeda galaxy

against the background galaxies
over time,

and that's how we measure
the sideways motion.

The results were conclusive.

The sideways speed
of Andromeda we measured

was effectively zero,

so we can say with certainty

that Andromeda is
on a head-on collision

with the Milky Way galaxy.

Tony's team confirmed

that over 100-billion stars

are on course
for a strike at 2,000 times

the speed of a fast ball.

But since it's so far away,

the galaxies won't collide

until nearly four-billion years
from now.

Tony's precise measurements
allow him to predict

how this clash of the titans
will look.

To anyone on Earth,
it would be a spectacular sight.

We'll see the Andromeda galaxy

getting bigger
and bigger in the sky.

And then eventually, in about
four-billion years from now,

we'll see the collision
of the two galaxies.

On impact,

clouds of dust will be
crushed together,

with sensational results.

What we'll see is a lot
of stars getting formed.

And this will look
something like

stellar fireworks in the sky.

Tony can even calculate the odds

that our solar system

will crash into one
of Andromeda's billions of stars

during the collision.

Surprisingly,
the prognosis is good.

Galaxies
are essentially empty space.

So the chances of stars
colliding with another star

is very slim,

because the distance
between the stars is vast.

So when the collision happens,

the solar system will pass
through an empty space

between the stars.

After passing
like ghosts in the night,

the irresistible pull of gravity
will draw them back together

over the next two-billion years

to finally settle as a new
supergalaxy nicknamed milkomeda.

Our galaxy will no longer exist.

Yet calculations suggest
the solar system will survive.

It will merge into
one big galaxy,

and it will look like
a giant ball in the sky.

Sadly, it's unlikely
anyone will be on Earth

to witness this colossal
galactic collision.

But there's a slim chance
an extreme form of life

could be clinging on
as the two galaxies meet

despite the searing heat
from the aging sun.

In yellowstone, professor
Lynn Rothschild has found

evidence of what
those last remaining Earthlings

might be like.

This area of yellowstone

is extremely acidic,
and it's also hot.

You can see the steam rising.

So, in other words, it's sort
of like boiling battery acid.

Very few living things
can actually live

at this high temperature,

but there are a couple
of organisms

that are very well-adapted
for it.

You can see the beautiful colors
behind me.

The kaleidoscope colors

of yellowstone's Springs

are caused
by heat-loving microbes.

We can pretty much
use these as a thermometer.

Anything that is green means

that it's got chlorophyll,
just like plants.

And once they get
to a temperature

above about 73 degrees or so,

their chlorophyll breaks down.

And so when you start
getting warmer than that,

you start to move
into other sorts of organisms.

Organisms that,
for example, eat iron,

and then you see
these beautiful orange colors.

Once all the water
on Earth has turned to steam,

it's possible
that heat-loving microbes

could continue to live
in the clouds.

We know some
of the earliest organisms

on the Earth were thermophiles,

organisms that lived
at high temperature.

And so at some point,

it may be organisms like this

that once again
inherit the Earth.

The microbes
will have their day,

but their reign
will inevitably be cut short.

Because when the Sun
is twice the age it is now,

astronomers foresee a turbulent
new phase written in the stars.

On a clear night,

many of the stars you can see

with your naked eye today
are going through a phase.

You can tell which ones
they are because of their color.

They're known as red giants.

It's very easy
to see red giant stars,

because they are very bright.

They are giant
and they are bright.

So, they are everywhere
in the sky.

Some red giants are so large

you could fit our own sun inside
them millions of times over.

Yet astronomers are confident

our sun will one day
grow to become one itself.

So these stars are a glimpse
of our future.

If we study stars
that grow in size,

we can tell the fate
of the planetary systems

that are orbiting them.

Stars like that
give us already clues

about what will be the future
fate of our own solar system.

The transformation
of our sun into a red giant

will begin deep below
its surface,

where all the heat is generated.

The burning core

is the only place hot enough
for hydrogen to fuse.

And yet it makes up less than 2%

of the Sun's total volume.

For the next five-billion years,

it's thought
the core will be stable.

Finally balanced between two
phenomenal opposing forces...

The crushing pull of gravity

and the explosive push
of nuclear heated gas.

But like a hot-air balloon,

the core will eventually
run out of fuel.

Just as gravity
pulls the spent balloon down,

in the Sun, gravity
would pull on the core.

When the balance is broken

because the hydrogen
runs out in the core,

the dominant force
will be gravity.

It will try to squish the core.

But the Sun
will be far from spent.

As gravity crushes the core,

it will trigger a transformation
in the rest of the Sun.

For the first time,

the hydrogen gas surrounding
the core will begin to fuse,

giving the Sun access
to far more fuel

than it's already burned.

We run out already
of one bottle of propane,

but we have three more.

So, it's like the Sun.

The burning shell of
hydrogen releases so much heat

that gravity is overwhelmed,

tipping the balance
in favor of rapid expansion.

Gravity's not winning
the battle.

So, the star expands
as a red giant.

Astronomers predict that
in about five-billion years,

the Sun will start
to grow into a vast,

seething ball of fire...

A red giant,

sending temperatures soaring
across the solar system.

The inner planets
will become far too hot

to support any kind of life.

But the distant outer planets

will bask
in the warm glow of the Sun

for the first time.

The habitable zone, where
life can exist, will sweep out.

In Peoria's solar system model,

it would have meant
the habitable zone

would leave town and head
for the outskirts.

Here at the airport is Jupiter.

When the Sun grows, Jupiter
will come in from the cold.

And although life as we know it

could never survive
on gassy Jupiter,

the solar system's biggest
planet has several icy moons.

These are likely to melt
and become cosmic watering holes

for any refugees fleeing
the parched inner solar system.

Astronomers have speculated
that Jupiter could change color.

As clouds of ammonia vaporize,

it might turn
into a deep shade of blue.

After Jupiter, astronomers
expect the habitable zone

to move swiftly towards saturn.

If saturn
still has its icy rings by then,

they're forecast
to vaporize and disappear.

But like Jupiter,
saturn's icy moons

could melt and be
safe havens for life.

Then models
predict the habitable zone

will sweep out
faster and faster,

past the solar system's most
distant planets and their moons.

First, uranus.

Then deep-blue Neptune.

Astronomers think they, too,
will be transformed.

But exactly how they'll look in
the future is still a mystery.

Eventually, the habitable zone
is forecast to pass beyond

all the planets and their moons.

Although Neptune's
the final planet,

the solar system
doesn't finish there.

In July 2015,

the New Horizons mission finally
revealed Pluto's secrets.

The first clear images ever
captured of the dwarf planet

revealed some startling terrain.

Strange troughs, cliffs,

and even dunes.

After a 12-billion-year-long
winter,

the expanding sun

may bring spring to Pluto.

But while the red giant
nurtures Pluto,

it poses a grave threat

to the planets
of the inner solar system.

They face total annihilation.

Studying the night sky,

Dr. Eva Villaver
uncovered grisly evidence

of what red giants can do
to their inner planets.

A search for distant worlds

had led to the constellation
of perseus,

where a star called bd+48 740

caught her attention
for two reasons.

There we have a star,
a red giant,

that was very peculiar,

because the star itself has
a very high content in lithium,

and that's very unusual
for these type of stars.

So, that was one of the pieces
of the puzzle.

And the other one was that it
has a Jupiter-like planet

orbiting the star that has
an orbit that is very unusual.

Eva thought
the two strange features

must be somehow connected.

Something had happened

that had affected both
the planet and the star itself.

In around 5.5-billion years,

our own sun will enter this
extraordinary phase of its life.

Evidence suggests its surface
will reach out towards Mercury,

Venus, and Earth,

threatening
their very existence.

Local astronomer Sheldon Schafer

is leading his weekly
interplanetary bicycle tour,

with the Sun's surface
hot on his heels.

And here we are,
approaching Mercury.

You can see it's easily a stunt
double for the Earth's moon.

It's a heavily cratered world
without an atmosphere.

Hot in the Sun
and cold in the darkness.

But the solar system's smallest
planet will get hotter still.

Off to Venus.

Because astronomers predict
that less than a billion years

into the red giant phase,

the Sun's surface
will reach Mercury.

After more than 10-billion years

of relative calm,

the solar system
will lose a planet.

And the Sun
will continue to expand,

growing ever closer to Venus.

The next planet is Earth.

By the time
the Sun engulfs Venus,

the Earth's oceans are expected
to have boiled away.

The ultimate fate of our world
appears to be on a knife's edge.

For a vision of those final days
on Earth,

Dr. Eva Villaver
has come to a unique facility

in odeillo, France...

The world's largest
solar furnace.

As the Sun becomes a red giant,

we will have a red star
occupying most of the sky.

And the energy that
every single inch of the Earth

will receive will increase.

I hear that this is exactly
what these mirrors are doing.

Around 10,000 mirrors
focus the Sun's rays

like a giant magnifying glass,

which allows them
to replicate the conditions

the Earth will face when the Sun
becomes a red giant.

Dr. Eva Villaver
is calculating the temperature

of the Earth's surface
when the Sun's radiation

will be nearly 3,000 times
more intense than today.

So, to simulate our future,

the solar furnace has magnified
the Sun's power by 3,000 times.

We are focusing
the light of the Sun in a beam

and trying to see what will be
the effect on a rock,

because the Earth is a rock
floating around the Sun.

Wow! Look at this.

There it goes.

The temperature
of the surface of the Earth

at that point will be
of the order of 1,400 degrees...

Enough to melt rock,

enough to melt the whole surface
of the Earth.

It's thought
the planet will be covered

in a vast ocean of molten lava.

But even after
the Earth's surface is melted,

the heat is expected
to increase further

as the planet is engulfed.

The maximum intensity
of the solar furnace

is 16,000 times
the Sun's power today.

Still only a fraction

of what the Earth would
encounter inside the red giant.

The rock would be stripped away,

leaving just
the planet's iron core.

Wow! Look at this.

Just sun radiation.

That's iron being melted
by the radiation of the Sun.

This is how the last
moments of our world would be.

So, everything,
the whole material of the Earth,

will melt, all the way
down to the core.

Even the iron core will melt.

And the whole material
of the Earth

would be part of the material
of the Sun.

Everything
would be mixed together.

According
to the latest calculations,

the world will end in fire.

But our solar system's
story is not quite over yet,

because the final phase
of the Sun's life

will be the most
spectacular of all.

There's seven sisters.

Like an upside down "l."

Nick, you wanted
to see the Andromeda?

It's really cool.

Wow.

In Peoria, every Saturday night,

the astronomy society meets
by the northmoor observatory

at the edge of town.

Between these two stars
is the remnant

of what's gonna happen
to our sun.

So, we're gonna move
the telescope.

And, Brian, do you want
to move the dome?

Tonight, Sheldon
is searching for a distant,

dying star...

The ring nebula.

Okay. That's good, Brian.

Ha!
I think it's there.

Okay. So, come on over
and take a look.

Look through the eyepiece.

And you should see
a lot of stars.

And then right in the middle, do
you see that little smoke ring?

Yes.

- It's just barely there, right?
- Yeah.

Wow.

And, so, this is a star

that, after the red giant stage,

it puffs off shells of itself.

It expels most
of its matter into, like,

bubbles of gas.

The planetary nebulae
produced by dying stars

are some of the most
spectacular celestial objects

in the night sky.

When our sun dies,
it too could make a nebula.

Astronomers have calculated that
up to half of the Sun's mass

could be thrown off
into space as gas and dust.

Including much of the material
that came from the Earth.

The vaporized remains
of half the solar system

would glow brilliantly
for around 10,000 years.

Then, as it spreads into space,

the light would slowly fade...

And our solar system will end.

But in a sense,
it's just a new beginning.

The materials
that make up our bodies

may well ultimately get spit out
into the cosmos

and be the raw materials

for another generation
of stars, planets,

and maybe even life forms.

We're all famously
made of star stuff.

And one day,
we may return to a star...

Our sun.

But then, in an extraordinary
process of cosmic rebirth,

the Sun would return our atoms

to interstellar space

to form new worlds,

and perhaps new life.