All language subtitles for How The Universe Works S04E03 Earth Venuss Evil Twin_ENG_Subtitles01

*

Our galaxy,
a billion years from now.

A planet shrouded in
turbulent, dense clouds...

..buried deep below
an alien landscape.

The surface scorched...

..the temperature sky-high...

..the pressure unbearable.

This is not a distant
extraterrestrial world...

..this is Earth.

This is our future.

We know it to be true
because Earth has a twin...

..Venus,

and Venus has already
descended into hell.

The solar system.

Eight planets orbit a central star -

the sun.

Among them,
Earth and its neighbour Venus.

Earth is an oasis for life.

Venus, the stuff of nightmares.

Venus and Earth couldn't
be more different.

The Earth is this beautiful planet
and there's water everywhere.

It's ice at the poles,
it's water in the ocean,

it's in the atmosphere
as water vapour.

But then you look at Venus,

it is the worst place imaginable.

It is so hot on the surface,
crushing pressures.

It couldn't be any less
supportive of life.

To me, the planet Venus
is sort of a classic definition

of the word "hell".

If you were to transport to Venus

and experience
the environment there,

you'd quickly want
to return back to Earth.

The conditions on Venus
are among the most inhospitable

in the solar system.

It's just a horrible place.

It's so hot and there's no water
and the atmosphere is so thick

and it rains sulphuric acid.

It's going to be a competition
between whether or not

you're gonna be cooked to death
or crushed to death.

Earth and Venus may seem
like very different worlds...

..but they shouldn't be.

They're roughly the same size,
the same mass,

and made from the same ingredients.

At first, they were twins.

Early Venus and early Earth
were very similar.

They were twins,

probably nearly identical twins
at their earliest stages.

Given that Venus is
so Earth-like in so many ways,

it's really odd that it is
so different than the Earth,

and this makes it one of the biggest
mysteries in the solar system.

Somewhere in their two histories...

..the Earth and Venus took
two very different paths.

The results -
two totally different worlds.

Their paths were so different,

you can hardly believe that one
would've been related to the other.

But now the opposite
thing's going to happen,

we're gonna catch up with our twin.

We're gonna evolve to be
a lot more like Venus in the future.

In the future,
the two planets' paths will converge

and they will become twins once more.

Like Venus...

..Earth will descend into hell.

The oceans will vaporise,

the land will melt.

Our hospitable blue planet
will vanish,

replaced by a fiery molten world.

We are actually on
the Earth at a time

when there's water and rain

and it was so easy
for life to take hold.

But that's gonna change,

and take a look in at Venus
and have a look at our future.

Earth will even surpass
the horrors of Venus.

A billion years from now,

Earth could be
an unimaginably terrible place.

But how will this happen?

And can we stop it?

The roots of our home
world's destruction

are buried deep in the past
of our twin planet.

It's very much true that
in studying the past of Venus,

we are also studying
the distant future of Earth.

Both planets shared a violent birth,

scarred by brutal planet formation,

giant cosmic impacts
and rampant volcanism.

We're trying to reconstruct things

that happened in
the ancient, ancient past.

It's almost like
forensic planetary geology.

4.6 billion years ago,

hundreds of infant planets
began to form around the new sun.

Among them, the baby Venus and Earth.

As they hurtled around the sun,
collisions were inevitable.

Planet formation is like
a demolition derby.

In a derby, the cars are
racing around a track,

going around in circles
at different speeds.

Well, it's the same thing
with planets.

The material is orbiting the sun.

It's going around and they're
all going at different speeds,
angles and trajectories.

And sometimes - "Boom!"

In the chaos, planets collide.

The scale of the impact
is unimaginable,

as two planets...

become one.

You have these large bodies

that are hitting each other
at really high velocity.

It's really a very hot,
uh...violent mess.

The amount of energy released
in these impacts is huge.

It completely dwarfs all of the
nuclear weapons on Earth combined.

And yet, somehow, on these scales,
you wind up forming

gigantic objects
that we call planets.

Earth and Venus became
veracious planet-eaters.

But two spectacular collisions

set the twins
on very different paths.

That was the moment Venus and Earth
went through this divergence

to what has now become these really
dramatically different worlds.

The divergence began when
a Mars-sized object hit Earth.

The impact made our
planet spin faster.

The spinning core generated

a powerful magnetic field
around the Earth.

The field fended off the worst
of the sun's radiation

and would go on
to protect life on Earth.

At around the same time,

Venus took a head-on hit
from another infant planet...

..but this impact had
an unusual side effect.

Venus is actually rotating
in the wrong direction.

How could that be?

Well, what if it got hit
really hard by some object?

That could do it.

An object so huge

that it didn't only
stop Venus in its tracks,

it actually made the planet
spin backwards.

If you think about how much energy

and what size you need
to change a planet's spin,

that is an incredibly large hit.

But the backspin was slow...

..243 times slower than Earth's.

Without a fast spin,

Venus's core couldn't generate
a strong magnetic field.

It had no protection from
the deadly stream of particles

blasted from the sun.

Venus does not have
a strong magnetic field,

and so it has suffered
the full brunt of this wind

blasted out from the sun.

This is where the story
of the two planets split radically.

Venus was destined to roast under
a violent, suffocating atmosphere...

..while the Earth would give birth
to oceans, life and intelligence.

But ultimately,
these twin's fates will be the same.

Venus's present is Earth's future...

..pure hell.

*

*

Venus is a vision of hell,

and one day,
we'll meet our twin's fate.

It turns out that what Venus
went through in its distant past

is what Earth is going to go
through in its distant future.

The clues to the fate
of our blue planet

are locked inside the super-heated
wastelands of Venus.

Something happened to Venus
long in its past

to make it a completely
different planet

with a completely
different personality than
the Earth as we know it today.

(BEEPING) Two, three, four.

The first probe was sent
to our sister planet in 1967.

We've been sending them ever since.

What they found was incredible...

..rocks that look like granite.

What makes that interesting
is that to make granite,

you need water.

That means that there
must have been abundant water

for it to have formed
in the first place.

Venus once harboured oceans.

Dr Lewis Dartnell thinks
you can get a glimpse

of what it was like here...

in Iceland.

There's the possibility that
maybe in the early solar system

there were not one
but two planets with oceans,

two water-worlds - Earth and Venus.

And if Venus did once have oceans,

maybe they would've
looked a lot like this here.

With a raw volcanic landscape
descending down into the ocean

with the waves lapping
against the coastline.

And maybe a overcast,
kind of misty, hazy atmosphere,

not unlike what we
are seeing here today.

If there were oceans,
there might even have been life.

If Venus did have an early ocean,
maybe something a bit like this,

around four billion years ago, when
life was getting started on Earth,

then maybe life got
started on Venus, as well.

Maybe some kind of microbial life
got started in the Venusian oceans.

Just like Earth,

Venus could have been
a habitable, wet planet...

..but Venus couldn't
hold onto its water.

All of that water is gone.

It's just gone. Where did it go?

Something happened,
either catastrophically or over time

to basically dry out
this twin of the Earth.

The culprit was the sun.

Since its birth it's grown stronger.

Our sun, when we look out
at it during the day,

seems the same today
as it was yesterday,

but that's on a human timescale.

On cosmic timescale, the sun has
been getting hotter and hotter.

Every billion years,

the sun gets 10% hotter...

..slowly turning up
the temperature on Venus.

Not only that,

Venus formed 42 million kilometres
nearer the sun than the Earth.

As it turns out, that distance
to the sun was critical.

It's just an unfortunate
circumstance

of being in the wrong place
at the wrong time.

Earth is far enough from
the sun to hold onto its water...

..but Venus is slightly too close.

The intensity of its sunlight got
sort of just a little bit too much.

It passed this threshold
where Venus couldn't hold its water

on the surface any more.

As temperatures rose,
the oceans started to evaporate.

All of that water in the oceans,

all of those millions
of cubic miles of water

would become water vapour.

Basically, steam clouds
covering the entire planet,

hiding the surface from the outside.

Water vapour traps the sun's heat.

As the clouds start to engulf Venus,
the temperature rises.

Which, in turn,
causes more water to evaporate,

and more clouds to form,

which raises
the temperature even higher.

But the process can't go on forever

because the clouds of water vapour
in the atmosphere start to disappear,

ripped away by the solar wind.

Venus does not have
a strong magnetic field,

and so the full brunt
of the solar wind

has been slamming into Venus
for billions of years.

Over time, if a water molecule

was in the upper part
of Venus's atmosphere,

light from the sun could break
it apart into oxygen and hydrogen.

And then the solar wind
could blow that stuff away.

Over billions of years,

this torrent of subatomic particles
blasted out from the sun

has stripped the water
out of the atmosphere of Venus
and has desiccated it.

Venus Express was the most
recent mission to the planet.

Surfing the atmosphere,
it found hydrogen and oxygen

streaming from the top,

confirming that water
was leaking into space.

We see sort of a tail
of these atoms being stripped off

and blown away
from the planet itself.

And really the only way
that could happen

is if there was
a little bit of water left

that is still being destroyed,
picked up and swept away.

Wisps of water are all that remain
of Venus's oceans.

It's a terrifying vision
of our own future.

So if Venus were, in the past,
a lot more Earth-like,

then that tells us that
having a habitable world

is something that
is actually very precious,

and maybe is transient.

It's not something
that lasts forever.

By losing the clouds
that trap the heat,

you might think that Venus's
temperature would have simmered down.

But in fact, it was about to
rise to astonishing new heights.

It would become so hot
that metal snow

would fall on its mountains.

Clues to how this happened
can be found on Earth.

In Hawaii,
planetary geologist Jani Radebaugh

studies the islands' volcanoes.

These volcanoes are
a perfect model for early Venus.

What we're seeing out here
are lava flows

come all the way down
from Pu'u O'o vent

which is about 15 miles away.

Oh, there's hot...
you can see the hot stuff.

You can see hot... Quick, quick,
quick, quick. Right there.

It's really beautiful.

Hawaii's volcanic lava fields
look like Venus in miniature.

Both produce the same kind
of runny lava,

building flat shield-like volcanoes.

The big difference is there are only
five active volcanoes on Hawaii...

..whereas Venus is covered in them.

One thing that really jumps out
all around the planet

is uh...the number
and variety of volcanoes.

I mean, Venus could almost
be nicknamed Volcano World.

Venus has tens of thousands
of volcanoes all over the planet.

It's not the erupting lava
that turns up the heat,

it's what comes out with it.

If we think back
to the histories of Venus,

I think we must have seen a
landscape very similar to this one.

We have massive amounts of lava
flowing out of the surface,

dumping huge amounts of gases
into the atmosphere,

carbon dioxide, tons of gas into
the atmosphere every single day.

It would have been amazing to see.

On the surface,
the source of the gases is revealed.

If we look behind us we can see

volcanic gases
gushing out of steam vents.

We've got carbon dioxide
being delivered to the atmosphere.

It's exactly like
what has happened on Venus.

Carbon dioxide has been
delivered out of volcanoes

over and over and over again
throughout its history.

So that now we have
just a tremendously thick,

dense atmosphere.

The result of all of these volcanic
gases pouring out of volcanoes,

major greenhouse gases,
is that they've been absorbing heat

for the billions of years
of the history of Venus.

The temperature's been
gradually creeping up,

until today, the surface
of Venus is 900 degrees.

It's like if you go into your
kitchen and set your oven to broil,

wait a couple of minutes
and stick your head in it,

and even that's not
quite hot enough.

It's a crazy, horrible,
hellish spot.

It's hard to imagine
such extreme temperatures...

..but probes orbiting the planet
reveal just how incredibly hot it is.

Scientists studying the images

noticed something strange
on the planet's mountains.

It looks like, on the mountains,

that there's apparently
snow-like structures.

But this is not like
any snow found on Earth.

So if you look at the
white-peaked mountains of Venus,

you would think that it was snow.

But it's actually metals
that have rained down

and deposited on the top
of those mountains.

Metals like bismuth and lead melt...

..then they evaporate
into the atmosphere.

As they rise, they cool,

until they finally fall like
snow on the mountain tops.

I'm not sure even the imagination
of science fiction authors

would've come up with
something as weird as Venus.

I mean, just think about that,

you have possibly metal frost
on the top of mountains?

I mean, how weird is that?

(CHUCKLES) It's pretty insane.

Raining metals,

where would you ever
think about that existing?

On Venus.

In the future, metallic snow
is forecast for Earth, too,

and our scorching mountain caps
will glitter like Venus's.

But that's not all.

Venus tells us that things
will get even worse...

..our atmosphere will grow
heavy enough to crush cars.

*

*

Earth and Venus were born twins...

..but they took different paths.

Earth slowly evolved
into a habitable world.

Venus was covered in
thick volcanic gases,

trapping the sun's heat.

Temperatures rose to
over 450 degrees Celsius.

But Venus wasn't just blighted
by high temperatures.

The volcanoes kept spewing
gas up into the atmosphere,

forming a 250km-deep cloud
of carbon dioxide around the planet.

We don't think about gases
as weighing anything,

but they actually do.

Trillions and trillions
of tonnes of gas pressed downwards.

There is simply so much air on Venus

that on the surface it's pushing
down with a huge amount of force.

The atmospheric pressure
on Venus is a monster.

Think about it this way.

All right, car. It's time
for you to be crushed, baby.

If you're on Venus,

you're gonna have 155 miles
of atmosphere above your head.

As a result, atmospheric pressure
is 90 times that on Earth.

So on Earth, it's about
14.6lb per square inch.

On Venus, we're talking about
1,300lb per square inch.

So if you're driving your car
in Venus, this is what might happen.

The crusher delivers the same force
as the weight of Venus's atmosphere.

This is pretty serious stuff.

And this is why
it's so hard on Venus,

you get down to the surface,

you have the crushing
atmosphere to deal with.

A spaceship tasked
with landing on Venus

must first survive the violent
weather on the way down.

The extreme heat powers a vortex

the size of Europe
over the south pole.

As the Earth heats up, we see
storms that are more violent.

You can only imagine
the level of storms on Venus.

The upper atmosphere of Venus
is whipping around

hundreds of miles per hour.

Wind speeds reach 400km per hour.

That's faster than
most hurricanes on Earth.

It must be a weatherman's
paradise in a sense.

There are also huge
lightning strikes.

But these bolts are not formed
in water clouds like on Earth...

..they form in something
much more toxic.

Venus's volcanoes release
sulphur dioxide gas,

which mixes with water vapour,

creating sulphuric acid.

You have clouds that
are raining sulphuric acid.

It rains sulphuric acid!

Sulphuric acid in your lungs,
your eyes, your mouth, your nose -

that would be deeply uncomfortable.

The extreme pressure and heat

make Venus nearly
impossible to explore.

Only one nation has ever succeeded

in getting a probe
to the planet's surface.

Truly one of the engineering
triumphs of the human race

was the Soviet Union's
Venera programme.

The Russians sent over a dozen
probes to the planet Venus

and only a few of them
were able to survive

long enough to even be able to
take pictures from the surface.

The Venera missions were incredible.

It's such a hostile environment
on the surface for electronics,

and they were able to land
on the surface and survive.

The probe that sent back these images

was crushed and burnt out
in 90 minutes.

Some day in the future,
there are going to be

interplanetary tour guides,

taking people to every planet
in the solar system.

And you can imagine going to Saturn

and seeing the rings and Jupiter
and its panoply of moons.

There are all these great tourist
attractions in the solar system.

At the very bottom
of that list is Venus.

That is the last place
in the solar system

I would ever want to visit.

The sun's heat and volcanic gases

have transformed Venus
into a vision of hell...

..the most lethal rocky planet
in our solar system.

Suppose you decided
that you were gonna put me

in a star-ship transporter beam

and transport me to
the surface of Venus.

What would happen?

Well, the pressures there
are incredibly intense,

and the rain there,
as I say, it is acidic.

The atmosphere is acidic.

So I would be unaffected,

but the average man
would be crushed and melted.

If you could imagine
standing on Venus,

it would be a torture
in the extreme.

Your feet would be burning
from the molten fire below you

and your head would be hurting

from the incredible pressure
pushing you down.

You probably wouldn't
survive long enough

to even notice it, actually.

So why hasn't Earth
followed the same path?

Our volcanoes also spew out
carbon dioxide,

and we orbit around the same sun...

..but we're not being
crushed and broiled.

One reason is, Earth formed
farther away from the sun...

..and stayed cool enough
to hold on to its oceans.

Oceans do a lot of things
for us on Earth.

Because not only, obviously,
are we water creatures

and we depend on the water cycle
for our existence in so many ways.

But people don't realise the oceans

also help to regulate
the climate of Earth.

Our oceans are full of tiny
creatures that eat carbon dioxide.

Richard Zeebe from
the University of Hawaii

is diving on
the islands' coral reefs.

He's studying how
tiny marine organisms

turn carbon dioxide into rock.

What you see here, the white stuff,

this is what we call
calcium carbonate.

And on top of this, what you see,
these brown layers,

this is essentially
the living organism.

This is the coral itself.

It takes calcium out of the seawater

and it takes carbonate
out of the seawater,

combines them and makes
this piece of calcium carbonate.

There's over 70 million
billion tons of carbon

locked up in carbonate rocks.

This helps regulate carbon dioxide
levels in the atmosphere,

keeping temperatures from rising.

If all the carbon that is being
locked up in carbonate rocks

in these corals would be put
into the atmosphere as CO2,

that would be certainly
bad news for us.

Currently, our carbon cycle
helps stabilise our climate...

..but in the future this
won't be able to save us.

Forces far greater
than the ones at work on Earth

will overpower our natural defences.

Like Venus, our oceans will burn off.

Temperatures will rocket
as our life-giving sun

starts to kill the Earth.

Right now we live just the
right distance from the sun,

where it's just the right
temperature for water to exist

as a liquid.

But that's going to change,
just as it did for Venus.

Venus started off, probably,
in the habitable zone

and then the inner limit
to the habitable zone crossed

the distance of Venus's orbit.

Well, it's gonna cross the
distance of Earth's orbit, too.

There is an expiration date
to the Earth,

and that's due to
the sun's evolution.

Ever since its birth,
the sun has been getting hotter.

That increased heat devastated Venus,

and in the future,
it will destroy Earth.

In 1.1 billion years,

the sun will be 10% hotter
than it is today.

The oceans will start to
evaporate into thick clouds,

which will trap more
of the sun's heat.

Catastrophically, very rapidly
on a geological timescale,

the oceans will put so much
water vapour into the atmosphere

that we will get
a runaway greenhouse effect.

The clouds forming in the atmosphere
will trap more and more heat,

driving temperatures even higher.

Spiralling temperatures
will cause even more evaporation,

so the clouds will get thicker.

Which led to more heating,
which led to more evaporation

and you can see where this is going.

It's a vicious cycle,
it's a positive feedback.

All of the oceans' water will boil
away, millions of cubic miles of it.

We have all of this water
that will go into the atmosphere,

covering the Earth and
shrouding it in, basically, steam.

Earth has had oceans
for billions of years,

but it will take just
10,000 years to lose them.

All of the water in the Earth's
oceans will be in the atmosphere.

We'll have an incredibly
dense cloud-coverage system

where the temperatures on Earth
will be approaching 1,000 degrees.

Like Venus in the past,
Earth will get hotter and hotter.

But unlike Venus, which
plateaued at 500 degrees Celsius...

..temperatures on Earth
will keep climbing.

Venus lost its water to space,
blasted away by the solar wind.

But Earth will hold on to its water,

because it's protected
by our magnetic shield.

However, that is
no longer a good thing.

Unlike Venus, Earth has a strong
magnetic field which protects it

from the erosion of the solar wind.

That water will stay with us.

The Earth could have a thicker,
hotter greenhouse atmosphere

than Venus does today, much worse.

This huge volume of water vapour
will push down on the surface...

..increasing the surface
pressure by 270 times.

If by some miracle, a human stepped
out onto the surface...

..they would instantly
be crushed by the atmosphere.

Its weight would be more
than a fully armoured tank,

pushing down on their head.

It is ironic to think that
the water on Earth will one day

help contribute to its demise.

After all, the water has been
the source of life on Earth.

But in the far future,
it'll become our enemy.

And with no oceans
and their microscopic creatures

to absorb the carbon dioxide,

there's nothing to hold back
the rising temperatures.

Earth is doomed.

*

*

In 1.2 billion years,

a probe visiting Earth
would see an alien world...

..a scorched, barren landscape.

The pressure is crushing.

Temperatures reach
650 degrees Celsius.

Molten metals snow down
on the mountain tops.

It's so hot, granite rock melts.

The surface liquefies.

At that point, the Earth
will become a molten ball

very similar to what it
was at the very beginning.

Earth and Venus started as twins.

Venus was destroyed by
rampant global warming.

Earth will follow the same path,
then overtake it.

It is inevitable that the Earth
will someday not only be like Venus,

but actually put it to shame.

In 1.3 billion years, Earth
could hit 2,000 degrees Celsius...

..four times hotter than Venus.

It'll be the hottest and deadliest
planet in our solar system.

For Earth and its inhabitants,
it's the end of the road.

Maybe we'll escape to space

and send probes back
to study our former home.

A billion years from now,

Earth could be
an unimaginably terrible place.

Right now, today,
Venus is the evil twin of Earth,

but in the distant future, Earth
could be the evil twin of Venus.

Earth's surface temperature
will be far hotter

and its surface pressure
far greater than Venus's.

At these kind of temperatures where

rock on the surface
of the Earth is molten,

it's hard to imagine any place
there could be life.

But there is hope.

Astrobiologist Lewis Dartnell thinks
that some forms of life could survive

such terrible conditions.

We're here on top of
a volcanic outcrop

in Iceland with this howling gale
whistling past our ears.

The stench of hydrogen sulphide,

of sulphurous fumes,
filling our nostrils.

And this is about as close
as we can get on Earth

to high up
in the Venusian atmosphere.

About 30-35 miles above
the surface of the planet Venus,

the air pressure is about
the same as on Earth's surface,

the temperature
is pretty similar as well.

But the cloud droplets are full
of concentrated sulphuric acid,

many, many times more
concentrated than battery acid.

It's a hostile,
horrible environment.

But bizarrely enough,

there's good reasons to think
that there may be life,

Venusian life, high up
in the clouds there.

A kind of high-altitude
aerial biosphere.

If life can live up there,
then perhaps it might survive

high up in the clouds
of future Earth.

You can easily imagine these
microorganisms evaporating

in water particles and being
transported to the upper atmosphere.

Even though it turned into
this toxic greenhouse planet,

life could potentially still
survive in that upper atmosphere.

But what about us?

We couldn't survive
the high temperatures

or pressures at the surface...

..and a life in the clouds
doesn't seem likely.

What's our future?

If there was this life on Venus,

clearly they weren't
advanced enough to stop

the changes in their atmosphere
that led to Venus's current state.

The question is, are we?

Perhaps we'll leave our
planet and find a new home.

As the sun gets brighter,
Earth will go the way of Venus,

but then the world's further out
will get warmer and warmer.

It'll be a progression,
outward, of habitability.

First, the polar ice-caps
on Mars will melt into oceans.

Then even further out,
the sun's heat will unlock the water

on Jupiter's moon Europa...

..transforming it into a water-world.

If we do this right,

we could maybe sort of
hop from world to world

and, like, move farther out from
the sun as the sun warms, sort of.

Because these are gonna be slow
transitions, so there'd be, like,

plenty of time to kind of
engineer the right environments

and sort of hop from world to world,
farther from the sun.

So that might be one way that,
you know, if there is
intelligent life on a solar system

where this is happening, it might
just be a matter of sort of skipping

from world to world and following
the habitable zones as they...

as they move outward
in your solar system.

But there is another solution...

..stay and move the Earth
further from the sun.

Moving the Earth is at least
imaginable because, in fact,

as objects exchange
gravitational energy

they move in or out
in the solar system.

It has happened to our planet,

so I could imagine
engineering things where we

directed large asteroids
and comets close to the Earth
but not to hit it.

The gravity from these large objects
would slowly alter our orbit.

Gravitational energy
would be exchanged

and the Earth could slowly move out.

Each gravitational jolt would
only move Earth a short distance.

But do it thousands
or millions of times

and we could push the Earth
away from the sun...

..in theory, at least.

Over a billion-year period,
it's possible to imagine.

It would require
incredible technology

and incredible coordination.

The technology is possible,

whether humanity as a species
could ever coordinate it

is something I'm a little
more sceptical about.

It sounds like science fiction,

but if we don't do something
the Earth will die

and we'll become just like Venus.

Earth and Venus were probably
born together as identical twins,

but then their paths diverged.

But now lifetime is gonna send
that cycle all the way back

and they'll die
as identical twins again.

In the grand scheme of things,
they'll just be two charred twins

spinning to oblivion in
a backwater of the universe.

On the cosmic scale, life is short.

When you look at how Earth evolved
and how Venus evolved,

you can see the difference, even
though it's two almost twin planets,

how life and habitability
could change over time.

So habitability isn't
always a permanent thing.

On human scales, the universe
seems the same every single day.

But of course, that's because

human life and human civilisation is
but a brief instant in cosmic time.

On cosmic scales,
the universe evolves and changes,

and that makes the history
of the universe remarkable.

Our tale of two planets
converges in the end,

a cautionary tale about
forces beyond our control.

Perhaps a billion years
of learning from Venus

will ultimately save us
from the same terrible fate.

subtitles by Deluxe