All language subtitles for How the Universe Works - 2X03 Exoplanets - Planets from Hell

Our universe is violent.

The cosmos is full of planets
from hell.

What we have
is a collection of monsters.

Superhot worlds roasting
at thousands of degrees...

Frozen planets
too cold for life...

Desolate worlds seared
by deadly radiation...

Even planets where rock rains
from the sky.

We have hundreds and hundreds
of these things we've found.

And they're crazy.

We search the heavens
for worlds like our own

and find planets where life
could not possibly survive.

How can the universe
be so weird?

Is the Earth a one-off --

the only habitable planet
in the Universe?

Or are there worlds
like ours out there

just waiting for us to find?

Look out at the cosmos...

...billions of galaxies...

...trillions upon trillions
of stars.

And one profound question --

Is anyone else out there?

We want to find another Earth.

Is there a pale blue dot
orbiting some star

out there in the galaxy?

The search is on for
worlds that could harbor life.

We're searching
for our own vision of ourselves

out there in space.

We're searching for our heaven.

We've already
discovered more than 700 planets

beyond our solar system.

And yet these exoplanets
look nothing like our own.

Boy, were we wrong.

All these solar systems that
we're seeing in outer space,

we find that they don't look
like our solar system at all.

We are the oddball.
We're the freaks.

These are nightmare worlds.

And the cosmos is full of them.

We're finding
all different flavors of hell,

all these different ways
that planets can go wrong.

So, that's where we are
right now --

searching for heaven,
finding hell.

These are worlds where
life couldn't possibly survive.

Could we really be alone,

a cosmic fluke
in a universe hostile to life?

We may soon have the answer.

Now we have discovered hundreds
of exoplanets in outer space

at the rate of
over one exoplanet a week.

In a few years,
that will probably be thousands.

And in the end,

there could be millions
or even billions of these things

waiting for us to discover them.

How could all of them
be planets from hell?

The quest for answers
starts here,

63 light-years from Earth.

We've discovered a planet.

It's even larger than Jupiter.

And it has a serious problem.

Its orbit is incredibly tight.

It's closer to its star
than Mercury is to our Sun...

...and 30-times closer in
than the Earth.

The result
is a superheated hell.

But there's another reason why
nothing could survive here...

...and that's
the ferocious wind.

The surface is battered
by a never-ending storm.

We can't see these winds
with our telescopes...

...but we know
the superstorm exists...

...because of this...

...NASA's
Spitzer Space Telescope.

Spitzer can see things
that we can't.

It doesn't use visible light.

Instead, it sees in infrared.

It's a part
of the light spectrum

we don't see with our eyes.

Infrared is heat.

One advantage of studying
the universe in infrared

is it gives us this opportunity

to see the light coming
from planets around other stars.

When you try to look at
the light of a planet

next to the light of a star,

the star is hundreds
of thousands of times brighter

than that planet,

which renders the planet
very, very faint.

But if we push into the
infrared part of the spectrum,

the internal heat of the planet,
just as my internal heat,

causes the planet to glow.

Now, it's observable
and measurable.

Spitzer gives us
something completely new --

the very first weather map of a
planet beyond our solar system.

This simple image
is a technological triumph.

The colors represent
temperature differences.

But the map also proves
the planet has hellish winds.

That's because the hot spot
isn't where it should be.

One side of the planet
permanently faces the star,

so its center should be
the hottest point on the planet.

It isn't.

Something pushes the planet's
hot spot to the side,

and that takes incredible force.

Only a nonstop,
6,000-mile-an-hour hurricane

could be this powerful...

...20-times stronger than
the strongest winds on Earth,

eight times the speed of sound.

A small shift
on a weather map...

...evidence of supersonic winds
raging on an alien planet.

Truly a planet from hell.

We're finding new planets
at a staggering rate --

an average of one a week.

Each one could be
an earthlike heaven.

But the more we explore them,
the more hellish worlds we find.

And some are
so nightmarishly hot

that they're more
than uninhabitable.

They shouldn't even exist.

This Jupiter-sized, gas planet

is 256 light-years from Earth.

In infrared,
it shines like a star,

thousands of times brighter
than Venus,

the hottest planet
in our solar system.

It's a blistering 3,700 degrees.

It's nearly impossible
for a planet to get this hot.

Its hellish temperature
provides a clue

to its appearance.

Only an absolutely black object

could absorb enough light
from its star

to reach such
scorching temperatures.

If you were coming up on the
nightside away from the star,

you would just see this
blackness in front of you --

very little radiation,
very little light.

It would almost just look like

the stars were avoiding
a part of the sky.

Just as black pavement
absorbs sunlight

and heats up on a sunny day,

the black planet roasts
beside its star.

We don't understand
its atmospheric chemistry.

There's nothing on Earth
that can absorb so much light.

The planet's only color
comes from a scorching hot spot.

As you flew around
to the dayside,

things would begin to glow
red-hot.

There'd be a huge, swirling
storm all red and glowing.

What a hellish world.

Deep inside,

clouds of titanium oxide
swirl around a solid heart

100-times heavier than Earth.

Darkness visible --
another world from hell.

But some planets
are even bigger,

seemingly impossible puzzles.

Here's a mystery.

Every astronomy textbook says

that gigantic,
Jupiter-sized planets

form way out in outer space
where it's really cold.

So, why is
a Jupiter-sized planet --

what's it doing inside
the orbit of Mercury?

Jupiter-type planets
can only form

far form their parent stars,
out in the cold of space.

A gas giant orbiting this close
means these monsters can move.

This is Wasp-12b,
a scorching vision of hell.

It's so close to its star

that its orbit lasts
just one earth day.

This world is so hot.

It's over
4,000 degrees Fahrenheit.

This is just crazy hot.

Wasp-12b is one of the
hottest planets in our galaxy.

We've never seen anything
like this before.

This certainly is one of
the most violent environments

in the universe.

Wasp-12b is only
2 million miles from its star.

Searing heat puffs up
its atmosphere,

giving it the density
of styrofoam.

In a big enough bath tub,
it would float.

We actually think
it's so close to its star

that the gravity --
the tidal effect of gravity

warps it into
almost an egg shape.

It's not even round.
It's oblong.

Thousands of miles
beneath the puffed-up atmosphere

lies a solid core.

It's rich in carbon,
and the pressures are extreme.

There could be mountains
of diamond and graphite

and seas of liquid tar.

But Wasp-12b won't last long.

It orbits so closely

that its star is literally
tearing it apart,

ripping away nearly 190
quadrillion tons of gas a year.

10 million years from now,
Wasp-12b will vanish.

The question is how did it
get so close in the first place?

This is the birth
of a solar system.

In the center, a new star.

Around it swirls a disc
of microscopic dust grains.

These are planets in the making.

Dust grains collide,

and every time they collide,
they merge.

And so they get
bigger and bigger.

And so, they sort of grow like
the dust bunnies under your bed,

and you have 100,000 years
or 1 million years

to make a very big dust bunny.

And they get bigger
and bigger and bigger.

Trillions of miles
from the star,

it's cold enough
for ice to form.

Ice picks up dust and gas.

These gaseous clumps grow
bigger and bigger

over millions of years.

Eventually,
they become gas giants.

In our solar system,

the gas giants, Jupiter,
Saturn, Neptune, and Uranus,

all formed this way

in the distant orbits
we still see today.

So, how did Wasp-12b end up
so searingly close to its star?

The answer -- gravity.

This planet is huge --
40% more massive than Jupiter.

Its immense gravity disturbs
the dust disc it formed from,

creating turbulence.

And so, the planet
creates waves in the disc --

you know, sort of density waves.

And you can sort of think of
them as like waves on an ocean.

The gas giant becomes
a galactic surfer.

Over hundreds of thousands
of years,

the planet rides the waves
inward toward the star.

As the planet gets closer
and closer to the star,

it starts to feel the radiation
from the star more and more,

and so it heats up.

Surfing millions of miles

from the cold, outer reaches
of the star system

into the tight, scorching orbit
we see today...

...an ice-cold world becomes
a planet from hell.

Nobody had any real clue

that you could form a planet a
billion miles out from a star --

it somehow moved in.

That is incredible.

But that's really
the only explanation

of how these planets
got so close to their stars

in the first place.

Wasp-12b is bizarre,
but it isn't alone.

We've found many of these
superhot, super close giants.

We call them hot Jupiters...

...battered by supersonic winds,

blacker than night,

hotter than hell.

But these hot Jupiters all have
one thing in common --

there's no life here.

So, these planets are just about
as different from the Earth

as you can possibly imagine.

In fact, we've now found
over 100 of these things,

rendering them so common

that the question
really emerges --

which ones are the weirdos?
Them or us?

This planetary
roller coaster has consequences.

As they spiral inward,
hot Jupiters cause chaos.

They create a whole new class
of planets from hell --

orphan worlds flung away
from their star

into the emptiness
of interstellar space.

Planets orbit stars.

Between the stars
is a vast sea of darkness.

We've always
thought of space as being empty.

That would be considered
its defining characteristic.

That's why we call it "space."

But when planet hunters

switched from gazing at stars
to staring deep into space...

...they made
an amazing discovery.

Out of the darkness,
between the stars,

planets began to appear.

First, one dark gas giant...

...then several more.

Eventually, 10 dark,
starless planets emerged

from the shadows of space.

I often wonder
what it would be like

to be on one of these
rogue planets in between stars.

The night sky would be
perfectly black.

It would be festooned
with stars.

It would be beautiful.

But if you were
at one of these planets,

you would be in a world
of perpetual night.

There would be
no sunrise or sunset.

There would be
no warmth of the sun.

These planets formed
around a star.

But now they roam the darkness
of interstellar space.

Their journey here
was violent --

each one forced
from its home orbit

by the gravity of a hot Jupiter.

A Jupiter-sized planet
is an 800-pound gorilla.

Where does it sit?
Anywhere it wants to.

Hot Jupiters are killers.

As they surf in
toward their star,

their immense gravity
disrupts the system...

...hurling planets
from their orbital paths.

It flings into outer space
any small planet.

So, any planet
unfortunate enough

to be orbiting close
to the mother star

would be flung into outer space
with a passing Jupiter.

These planets
will never again feel the heat

or see the light of a star.

All the rogue planets we've
found so far are gas giants.

But perhaps there are smaller,
rocky worlds, too...

...worlds that were
once like Earth.

The large, Jupiter-like planets
are just easier to see.

But there's no reason to assume

there also aren't
smaller orphan planets.

Maybe as a Jupiter planet
moves in toward the star

and plays ping-pong
with the planets,

even something like earth
could have gotten kicked out.

Then you would have
this cold, frozen little world

just streaking between
the stars, dark and lonely.

These planets are victims

of a violent,
gravitational battle --

frozen, orphaned earth twins.

There may be hundreds
of billions -- with a "b" --

of these planets
roaming the galaxy.

Now, there are only
a couple hundred billion stars

in the galaxy,

so that means

these rogue planets may actually
outnumber stars.

Right now,

we find an average of at least
one new exoplanet a week.

As our technology improves,

we'll see smaller and smaller
planets orbiting stars --

worlds with a solid surface
like our own.

But the first rocky planets
we've found

are nothing like Earth.

These planets have been
to hell and back.

We have found
hundreds of alien worlds.

And now for the first time,

we're finding small planets
made of rock just like Earth.

Planets this size
are potential homes for life.

But instead, we find
more planets from hell --

weird, nightmarish,
and uninhabitable.

This is Corot-7b...

...a world
of violent extremes...

...two hells in one.

It's so close in

that its star looms 360-times
larger in the sky than our Sun.

On Corot-7b, the first hell
is unimaginably hot.

The surface is a furnace
roasting at 4,700 degrees.

Lava boils, turning the
atmosphere into vaporized rock.

When a cooler front moves in,
small pebbles condense,

and rocks rain from the sky.

If that's not a classic vision
of hell, I don't know what is.

But that's only half the story.

The hot side of the planet
is locked,

permanently facing the star.

Beyond is the twilight zone.

It's temperate here --

cool enough to turn
the lava oceans into solid rock.

But this pleasant zone
is narrow.

Travel further, and you descend
into a second hell.

This is the dark side...

...the half of the planet
that never sees the sun --

eternal darkness
and savage cold.

The temperature is
hundreds of degrees below zero.

So, one side is hot.
Another side is cold.

You either have, you know,
fire or ice in the extreme --

the coldest places
in the Universe

and the hottest places
in the Universe.

You couldn't think of
a worse place to end up.

The planet
was not always this way.

Turn back the clock
1.5 billion years.

Corot-7b is forming.

But it isn't rocky.

It's a gas giant
100-times bigger than Earth.

It migrates in toward its star.

As it closes in,

the star blowtorches gas
from the planet.

Its gaseous shell blasts off
into space

to reveal a rocky core.

Corot-7b is the skeletal remains
of a hot Jupiter.

Its parent star has reduced
this once massive gas giant

to a rocky cinder.

It's hard to imagine planets
more extreme than Corot-7b...

...yet they do exist --

rocky worlds machine-gunned
by deadly cosmic rays.

This is a pulsar 7,000
trillion miles away from Earth.

It's a kind
of cosmic lighthouse.

This unbelievably tiny world,
just 10 miles across,

fires an intense beam
of radiation through space

as regularly as an atomic clock.

A single cubic centimeter --
the size of a keyboard key --

actually has about as much mass
as Mount Everest.

Smash a Mount Everest
into a cubic centimeter.

The whole star, which is only
about 10 miles across,

is like that.

It's one of
the most hostile environments

in the Universe.

Anything nearby gets hammered by
intense gravity and magnetism.

No one expected
to find a planet here.

But this pulsar has three.

Small, rocky, near-earth-sized,

they were the first exoplanets
ever discovered

and the last place
you would ever find life.

It's got
a tremendous magnetic field.

It's blasting out X-rays.

So, these poor planets are just
getting cooked by radiation.

The word earthlike
I don't think could be applied

to these guys at all.

The X-ray beam strafes
the planets over and over,

firing radiation

a million times more deadly
than medical X-rays...

...slowly stripping
their surfaces away.

These are sterile worlds.

Everybody admits
there's no chance for life,

at least as we know it, on the
planets that orbit the pulsar.

Radiation cooks
pulsar planets to death.

The opposite hell
is no better --

frozen worlds too cold for life.

In the constellation Scorpius,

20,000 light-years away
is a red dwarf star.

Red dwarfs are tiny
and relatively cool.

And this planet is too far away

to feel
what little heat there is.

It's so distant,
its orbit lasts 10 earth years.

It's the coldest planet
we have found in the Universe.

Its surface is a frigid
370 degrees below zero.

This is a world
made entirely of ice.

Methane, ammonia, and nitrogen
are gasses on Earth.

Here, they form
a frozen, toxic frost.

Glaciers and canyons and cliffs
of ice are the only terrain.

Here, hell really has
frozen over.

Our search for Earth's elusive
twin reaches another dead-end.

Perhaps we are truly alone.

Or will our first tantalizing
glimpses of an alien world,

potentially perfect for life,
change everything?

Earth, the only habitable world

in our solar system.

But in a galaxy of hundreds
of billions of stars,

can we really be alone?

It's a question that planet
hunters are trying to answer.

The whole purpose,
in my opinion,

of the discovery of exoplanets

is to establish
our true place in the universe.

Who are we?

Where do we belong
in the cosmic scheme of things?

Are there other planets that
can have life just like ours?

That's where NASA's
Kepler Space Telescope comes in.

Kepler lets us calculate how far
a planet is from its star.

That's critical in figuring out
whether it could sustain life.

Life on Earth is only possible

because we're the perfect
distance from the sun --

not too hot and not too cold...

...just right
for liquid water --

oceans, rivers, lakes,
rain, and life.

You know, journalists say,
"follow the money."

Astronomers say,
"follow the water,"

because water
is the universal solvent

that dissolves most chemicals,

and that's where
DNA got off the ground.

And where there's liquid water,
there could be life.

We're looking for planets

that are not too close
to their parent star

where all the water
would boil away

and not too far away
from their parent star

where all the water would be
tied up in a frozen form.

We're looking for
that "goldilocks zone"

where the temperatures
are just right

for liquid water to pool
on the surface.

Once Kepler
has identified a new planet,

astronomers check whether
it lies in the habitable zone

of its parent star.

So far, Kepler hasn't found
a single confirmed Earth twin.

But it has identified more than
2,000 planetary possibilities.

And it's this
sheer abundance of planets

that gives scientists hope.

The important thing to remember

is that even though
we're finding

all of these terrible planets

that are just
completely unlivable

is that we're finding
lots of them.

We're finding hundreds
and thousands of these planets.

And what that's telling us is
that planets are easy to make.

And that means
that even rare things

are probably out there
in large numbers.

Even if the Earth is a rare,
precious jewel in our galaxy,

there may be dozens or hundreds
of them out there.

Kepler has opened our eyes

to a universe full of planets.

We can now guess
at how many there might be

in our own galaxy...

...50 billion.

50 billion worlds
just waiting to be discovered.

And we think 1% could be in the
goldilocks zone of their star.

That's 500 million planets,

each with a chance
of harboring life...

...right here
on our own doorstep.

We haven't found one yet.

But we're getting closer.

This is Gliese 581,

a red dwarf star
20 light-years from Earth.

Gliese 581
is a tiny, little star.

If the sun were the brightness
of about a 100-watt light bulb,

then Gliese 581 would be like
a little Christmas tree light --

a tiny, little fairy light --
very, very small.

This shifts the life zone in

because now
if you want to be warm enough,

you need to snuggle up
right next to the star.

The star has four planets.

Three are too close and hot
for liquid water,

but the fourth is different.

It's a rocky world
twice the size of earth.

And it's right on the edge
of the goldilocks zone.

In theory,

if the planet has a thick,
carbon-dioxide atmosphere,

it could trap enough heat

to have clouds...

rain...

and oceans.

It would be a strange place
to live --

twice earth's gravity, bathed
in permanent red twilight.

But right now, this weird world
is the closest we have

to a planet like ours.

It's a promising start.

When we actually know for a fact

that up there around that star
is a planet like Earth,

that's going to just
fundamentally change

how people look at the sky

and how people perceive
their place in the Universe.

So, that's gonna be
a profound moment

not just for me, but, I think,
for humanity in general.

Our goal
is to find another Earth,

but along that path,

we're gonna find more things

than we could have
ever possibly imagined.

And that's the part I love
about this the most.

We don't know what craziness is
gonna be around the next corner

when we're looking
for more planets.

I can't even imagine.

Two decades ago,

the only planets we knew were
right here in our solar system.

Now, there are hundreds,

all very different
from our home.

The universe is filled
with hellish worlds --

superhot...

ultracold...

...violent...

and bizarre.

But the Universe
is also unimaginably vast.

With so many stars,

there are probably
countless earthlike heavens.

All we have to do now
is find them.