Space's Deepest Secrets (2016–…): Season 2, Episode 8 - Race to Planet 9 - full transcript

The solar system... our home.

But how well do we really know

our own corner of the cosmos?

There are all kinds of things

- we don't know
- about the solar system.

Astronomers now believe

that the solar system could hide

an extraordinary secret...

A missing planet.

There might be a large planet

out there

- on the edges
- of the solar system.

Where could an extra planet,

planet nine,

have come from...

And where is it hiding now?

Finding planet nine

is not gonna be easy.

It might take years,

but we will get it.

Astronomers are

undertaking a historic quest

to discover

the mysterious ninth planet

that might lurk out of sight

93 billion miles

from the sun.

Captions by Vitac...

captions paid for by

discovery communications

the solar system...

Our cosmic neighborhood.

Over the past 50 years,

we've explored

nearly all of its alien worlds.

We've observed

the planets in the solar system,

- we've visited them
- with spacecraft,

- but does that mean
- we understand the solar system?

Absolutely not.

- It's the place
- we've observed the most

over the last 400 years

of telescopic astronomy,

yet there are still enormous

mysteries waiting for us

in the solar system.

It's amazing to me to think

that there may be hidden parts

of our very own home

that we haven't even gotten

around to discovering yet.

Today, astronomers

are making discoveries

that will transform

our understanding

of the solar system...

Discoveries that suggest

something massive is out there

waiting to be found.

This is Palomar observatory.

Its massive dome

houses a 200-inch telescope.

80 years

after its construction,

it's still one of the largest

in the world.

This dome is enormous.

- It's actually the same size,
- almost exactly,

as the pantheon in Rome.

Caltech astronomer Gregg Halinan

is on a mission to map

the frozen lumps of ice and rock

at the far edge

of the solar system.

If, as some scientists believe,

there's a massive object

hidden beyond Neptune,

it should leave its Mark


All the worlds

in the solar system

orbit the sun...

Four rocky planets...

Two gas giants...

And two ice giants...

But beyond the eight planet,



the mysterious Kuiper belt...

A vast region

nearly two billion miles across,

where countless lumps

of ice and rock

drift through the darkness.

Now, on the belt's

outer fringes,

scientists have found

evidence of a massive

and mysterious presence.

To map the lumps of frozen

debris in the Kuiper belt,

Gregg mounts his specially

designed camera, chimera,

onto the telescope.

Up slow.

If anything slips out of place,

it's a long way down.

With chimera installed,

the Palomar scope is ready

for a night with the stars.

Oy! Full systems online.


- -Wunderbar.
- -Let's flip the cameras.

Gregg's colleague,

Hilke Schlichting,

- has developed
- a clever technique

to hunt for distant lumps of

rocky debris in the Kuiper belt.

Okay. Good.

Hilke and Gregg

want to find out

how much debris lurks

in this shadowy region of space.

- And we're about to
- take some science data.

Some lumps of ice and rock

in the Kuiper belt

are so distant and so small

that they reflect

very little light.

They're almost impossible

to detect directly,

but Hilke has figured out a

clever way to track them down.

We tried to catch them

when they move in front of

a background star.

In the brightness of a star.

She looks for shadows

- as the Kuiper belt's
- frozen body

blot out the light

from distant stars,

much like an eclipse.

But these eclipses last

for just a fraction of a second.

To have any chance of

catching these fleeting events,

chimera must image

thousands of stars

in quick succession.

We've got two cameras,

and each camera's

making 40 images per second,

and in each of those images,

you've got 5,000 stars.

And we're gonna do this

for 70 nights.

Hilke has programmed software to

make sense of this massive data.

It automatically hunts

for the dips in the light

coming from these 5,000 stars.

This is the light from a star,

and we see here

that the light we receive

is decreased significantly

during this time here,

- and then
- it goes back to normal.

And this is the time

during which

the Kuiper belt objects moves

in front of the background star,

blocking some of the light.

Every piece of Kuiper belt

debris that chimera spots

reveals more

of our solar system's secrets.

But a few of these icy rocks

have orbits that don't play

by the solar system's rule book.

The most famous

Kuiper belt object of all

is Pluto.

Once considered a planet,

it's the biggest

lump of rock and ice out here.

And when it comes to the rules

of orbiting our sun,

Pluto is a bit of a Rouge.

As Pluto orbits,

it rises far above

and then dives below

the main Kuiper belt.

And there's another bunch of

objects out here

whose orbits

are even more extreme...

So extreme

that there must be

another force in place.

Could the gravity

of a massive ninth planet

be hurling these lumps

of frozen rock and ice

in all directions?

The search is on

for the mysterious planet nine

within our solar system,

and in Pasadena,

at the California institute

of technology,

Konstantin Batygin models the

orbits of Kuiper belt objects

using a supercomputer.

To generate a single realization

of the evolutionary history

of the solar system

in a supercomputer,

it takes about three weeks.

To explain the

Kuiper belt's chaotic orbits,

Konstantin must first rule out

any gravitational effect

due to the planet Neptune.

This huge ice giant orbits

closest to the Kuiper belt.

What we have here is a top-down

view of the solar system.

What we see here in purple

are the most distant

Kuiper belt objects.

What's remarkable

is that all of these orbits

tend to point

in the same overall direction.

They all swing out in the same

way within the solar system.

Konstantin doesn't believe

that Neptune's gravity alone

is responsible for the strange

orbits of these objects.

This configuration

can only be explained

by the existence of a ninth

planet in the solar system.

Neptune's gravity

does, indeed, influence

the path of objects

in the Kuiper belt.

But recently, we realized

that there was something else

going on,

- that the orbits
- were being lined up

in a way

that Neptune couldn't do.

- There must be
- something else out there,

and it must be pretty big.

A new planet in the solar system

would be

a mind-blowing discovery.

If there really is

a planet nine out there,

our best guess

for what it looks like

would be that it's something

a bit like Neptune.

It's an icy world

surrounded by an envelope

of hydrogen and helium gas.

Scientists predict

that planet nine

should be an astonishing

93 billion miles from earth.

It would take 10,000 years

to orbit the sun.

The light it reflects would take

a week to reach our telescopes.

To understand why this potential

world could exist so far away,

we need to know

how the solar system was born.

So there we have

some pretty good ideas

about how planets form.

Our theories

are still very incomplete.

What we do know

is that the solar system

started with a bang.

Four and a half

billion years ago,

our sun ignites

into a thermonuclear fireball.

Around it spins a huge disk,

9 billion miles across

with no trace of any planets.

There's nothing but gas

and clouds of super-fine dust.

The particles are 4,000 times

smaller than a grain of sand,

with virtually no gravity

between them.

So how did

eight massive planets,

and maybe a ninth,

form from a feeble cloud

of leftover stardust?

At Bremen in Germany,

a huge tower

rising above the city

should provide the answer.

Jurgen Blum is a professor

of extra-terrestrial physics

at Bremen university.

I've been working on this

for half of my life, actually,

and when I wake up

every morning,

- I cannot stop thinking
- about it.

We're on the top

of the Bremen drop-tower,

130 meters

above the experiment.

Planet formation starts off

with very, very tiny

dust particles,

and they have to come together

and collide and stick.

Jurgen Blum recreates

- the conditions
- in which planets are born.

To investigate how dust clumps

in a newborn solar system,

Jurgen uses very fine chalk,

a capsule

rigged with a camera

and a 479-foot tower

that lets him cheat gravity.

We're shooting up the whole

capsule at really high speeds.

It will fly up and come down,

and all together,

we have just over 9 seconds

of almost perfect

micro-gravity conditions.


allows the dust in the capsule

to behave

exactly as it does in space.

Inside the control room,

Jurgen and the team

purge the drop-tower of air

to create a vacuum

and launch the dust capsule.

Can Jurgen's experiment

uncover the secrets

of how planets are born?

Eins, zwei, drei, vier...

In Bremen, Germany,

Jurgen Blum and his team

recreate the conditions

in which planets are born,

using very fine chalk,

a capsule rigged with a camera,

and a 479-foot tower

that lets him cheat gravity.

The mechanical catapult

fires the capsule.

It shoot up

at 104 miles per hour.

It then drops back down,

creating weightless

conditions inside.

High-speed cameras

capture the entire flight,

and Jurgen immediately

checks out the results.

I'm actually

pretty excited here,

- because we've really gained
- something.

I think there is scientific

content in that movie.

The dust grains are free to

float unhindered by gravity,

but they still feel

a force...

A surface force

caused by tiny variations

in each dust particle's

electrical charge.

This force sticks the dust

particles together into clumps.

Here, we're seeing a clump

that is about to collide with

another clump and stick to it,

like at the moment.

And so, the velocity

was slow enough

for the two clusters

to stick together.

We're really seeing the effect

of the surface force

that makes

the particles stick.

This is what scientists think


the birth of our planets.

Inside a whirling cloud

of primordial dust,

particles begin to cling

to one another,

just as they do

in Jurgen's experiment.

They create

marble-sized dust balls.

As the balls collide,

they stick and grow larger.

Once they reach

half a mile across,

gravity kicks in

and sucks in

more and more material.

What started

as a tiny ball of dust

has become

a massive lump of solid rock.

In cosmic terms,

the formation

of our solar system

took place really quickly.

Maybe in just a few

tens of millions of years

to go from a clump of

interstellar gas and dust

to a set of young planets.

Scientists now better understand

how a dust cloud

condenses into planets.

But there's still a lot about

planets they can't explain.

We know a lot

about the solar system,

but we don't know

a lot of things, either.

In particular,

there are various theories

of the formation

of the solar system.

- Where did the giant planets
- form?

- Where did
- the terrestrial planets form?


must answer these questions

if they're to understand how

a ninth planet may have formed.

This is the very large array

at Socorro, new Mexico.

Its two dozen giant dishes

allow astronomers to watch

planets as they are born.

As an astronomer,

being able to come out here

and actually

be around the telescopes,

the only way I can put it

is it's fantastic

and it's good for my soul.

Dr. Claire Chandler

uses this giant radio telescope

to investigate

alien solar systems.

She wants to find out

exactly how far from

their parent stars planets form.

Is it even possible

to form a planet

like the proposed planet nine,

so far away from the sun?

To use the very large array

for our science,

it is just...

It's just awe-inspiring.

The solar system Claire has

her sights set on is Hl Tauri,

450 light years from earth.

Recent observations have made

the star and its surroundings

a tantalizing target.

Claire uses the very large array

to take a closer look.

So when I first

observed hl Tauri...

When I saw this fantastic

structure within the disk

that had all these rings,

both dark and light rings.

Hl Tauri

is a star much like our own sun,

except for one big difference.

Hl Tauri is

only one million years old.

This is the birth

of a solar system.

The huge disk of dust,

18 billion miles across,

spins around the new star.

What makes it so special

is that it has a really massive

disk of gas and dust around it

that we think is going to end up

looking like the solar system.

Claire's radio telescope

can peer through the dust

to reveal the detailed structure

of hl Tauri's rings.

The image it produces

reveals the distribution

of dust particles

that will form planets

around the star.

This image means Claire doesn't

have to rely on theory alone

to find out how planets form.

She can finally watch

the process for real.

In that very inner ring,

we actually found a significant

clump of the larger particles

coming together

and accumulating.

Hiding in the dust

around hl Tauri

is a spectacular discovery...

A gigantic swarm of dust

the same distance from its star

as our own ice giants.

Inside, pebble-sized dust balls

spin in huge vortices.

The vortices create

the ideal conditions for the

formation of larger objects...

Maybe even baby planets.

This cloud of whirling dust

could be a planet factory.

The dust ring around hl Tauri

looks set to produce

a solar system

very similar to our own.

But strikingly,

at the distance

scientists predict

planet nine is from our sun,

there isn't enough material

to form a planet.

As you go further away from

the central star and the disk,

then the material

becomes cooler,

it is less dense,

and it just becomes harder

to form a planet.

Claire's work helps to define

where massive planets

can form...

But scientists predict

that planet nine orbits the sun

way beyond this limit.

So how could it get there?

The answer requires

a revolution in the way we think

about the whole solar system.

We actually think

that that may not be the case,

that back in the deep past,

around 4 billion

to 4.5 billion years ago,

- things may have been arranged
- somewhat differently.

For the longest time,

- we've assumed that the solar
- system is pretty stable.


we realized we may have been

very, very wrong about that.

Liftoff of

the delta ii rocket... liftoff.

New missions to

uncharted worlds are revealing

that our solar system

has changed

more than we ever realized.

Astronomers believe that

a ninth planet could be hiding

at the edge

of our solar system.

But how such a massive world

can end up so far from the sun

is an unsolved mystery.

Scientists believe

the answer may be found

in the newly explored worlds

of the asteroid belt.

Asteroids have gotten

a bad rap in space movies.

You see this debris of rocks

that you have to go through,

or you have to... collide,

and disaster will unfold.

So, asteroids

in the great asteroid belt

are kind of

an extraordinary mixture

of pieces of primordial planet


chunks of matter that never were

incorporated into a planet.

The asteroid belt

is a time capsule.

It's a remnant

of the disk of rock and ice

that gave birth to all

the solar system's planets.

And surprisingly,

it may help provide the answer

to why a potential planet nine

has ended up so far away

from the sun.

At NASA's jet propulsion



are finally revealing

the ancient secrets

of the asteroid belt.

Marc Rayman is director

and chief engineer

of the dawn space mission.

Right now dawn is

orbiting dwarf planet Ceres

more than a million times

farther away from earth

- than the international
- space station,

and the spacecraft

is spiraling around Ceres,

gradually moving

to a higher and higher orbit.

Is to investigate not one,

but two of the belt's

largest worlds...

The 329-mile-wide Vesta,

and the even larger Ceres,

which at 590 miles across

contains one third of the mass

of the entire asteroid belt.

This world,

a planet that never was,

could help explain planet nine's

extreme location

so far away from the sun.

We are pushing humankind's

technology and capability

to its limits.

These are among

the last uncharted worlds

in the inner solar system,

and both Vesta and Ceres

were in the process

of growing

to become full-sized planets

almost 4.6 billion years ago

- when their growth
- was cut off.

Dawn's camera sends back

the most detailed photographs

of Ceres ever taken.

And they reveal something


As dawn began

photographing Ceres,

the first thing we notice

was this bright spot,

and it was just mesmerizing,

and the closer we got,

the more intriguing

these spots became.

These bright spots are a clue

that something incredible

lies beneath Ceres' crust...

An ocean of water ice.

There could be more water frozen

inside this dwarf planet

than there is fresh water

on planet earth.

When the sun hits Ceres,

some of the ice beneath

the surface vaporizes

and drags traces of minerals up

from the depths.

Over time, this leaves bright

patches of salt on the surface,

telltale signs

that there is more to Ceres

than meets the eye.

To find this much frozen water

so close to the sun

is surprising,

and when dawn looks even closer

at Ceres' surface,

the results

only deepen the mystery.

We found quite a surprise

with the chemistry on Ceres

that is

it incorporates ammonia.

Now, this is a familiar chemical

here on earth.

People use it

as a cleaner at home.

But it's not expected in

that part of the solar system.

Ammonia, like water,

can freeze into an ice.

But in the solar system...

Grains of ammonia ice

only become frozen

if they are much further away

from the sun

than the asteroid belt.

But at Ceres current location,

it should have been too warm

for ammonia to be incorporated

into the forming planets.

It should have been incorporated

much farther from the sun,

farther than Jupiter is,

perhaps even farther

than Neptune is.

And so why it's in Ceres

really is a mystery.

The evidence points

to an intriguing possibility.

Ceres could be an intruder

from the frozen wastes

of the outer solar system,

the home of

the proposed planet nine.

One possibility is

that maybe Ceres formed

much farther from the sun

than it is now,

where it was cold enough

to incorporate ammonia,

and then then

the subsequent gravitational

jostling of the planets

moved Ceres

into where it is now.

How could jostling planets

move a dwarf planet

across a solar system?

And what

can this incredible journey

reveal about planet nine?

One of the big ideas

in the last 20, 30 years

has been planet migration,

- the idea that planets are born
- in one part

and move to another part

of their solar systems.

The only way to get the

populations of asteroids

that we see with the orbits

that they have

is to have Jupiter move

into the inner solar system,

and then turn around

and move back out.

Over its



the solar system has undergone

a remarkable transformation,

a transformation

driven by Jupiter.

Scientists now believe

that Jupiter,

a planet 300 times

more massive than earth,

has undertaken an incredible

voyage through the solar system.

As this renegade giant

swept inwards

early in the solar system's


it carried Ceres with it.


dragged the dwarf planet

all the way

to the asteroid belt.

Could such huge

planetary migrations

also explain why we appear

to have a missing planet?

High up at the

lick observatory in California,


are looking for more clues

to support

the extraordinary idea

that our solar system

has undergone

some major transformations.

Planet hunter Steve Vogt

thinks our solar system

is missing not one,

but several planets.

This is the primary mirror of

the automated planet finder...

2.4-meter chunk of glass

made at a cost

of about $4 million

that was born and bred

to do one thing,

which is to find planets

around other stars.

It does so every night,

365 nights a year.

But even a robotic observatory

needs an occasional checkup.

Today, Steve and his team

must clean

the telescope's mirror.

The surface of this glass

is good to a fraction

of a wavelength of light.

- We're talking millionths
- of an inch here.

And it needs a new coating.

- This aluminized coating
- is all dirty,

- so it needs to be stripped
- and cleaned.

- So, we're going to be taking
- this whole mirror out.

Steve and his team

use the telescope

to analyze the light

from distant stars.

All right. Wait a minute.

A spotless mirror

allows them

to speed up their search

for new star systems

that harbor planets.

As a planet orbits a star,

what actually is happening is

the star and the planet

are orbiting each other

about a common center.

Much like two children

on a see-saw

would rock back and forth

on the center point

of the see-saw.

As a planet orbits its star,

the planet's gravity

makes the star wobble.

Steve analyzes

the star's light

to determine

how big its wobble is,

and from that,

he can work out the size

and orbit of the planet.

After years of observations,

Steve and his colleagues



completely unexpected.

Most of the rocky planets

around distant stars

are far larger than earth.

These monsters

can be up to 10 times bigger,

earning them the name


Super-earths are unlike

any planet in our solar system.

A dense helium atmosphere...

Blankets a rocky surface that

bakes in stellar radiation.

Thanks to tight orbits

around their parent starts,

these planets look more like

hell than earth.

They may seem exotic and alien

to us,

but in the cosmos today,


aren't the exception.

They're the rule.

What we've realized is that

our solar system doesn't have

anything like this.

- We don't have super-earths
- at all.

So, from that perspective,

even though we now know

solar systems are common,

our type of solar system

is rather an oddball.

Most solar systems

that Steve looks

at are home to a super earth.

So why is there no super earth

orbiting the sun?

Could a missing super earth

have something to do

with our missing planet nine?

Scientists think

they've got the solar system

pretty much figured out.

But could it still hide

a missing planet?

Billions of years ago,

additional planets

may have orbited our sun...

Giant super-earths, 10 times

more massive than earth.

Could these long-lost worlds

hold the secret

to the missing planet nine?

Almost every solar system

astronomers look at

harbors one or more

massive super-earths.

But our solar system doesn't.

If super-earths

did once orbit the sun,

where are they now?

One of the biggest surprises

that was just waiting out there

for us to discover

is that the most common type

of planet in the universe

- is one we don't have
- in our solar system.

We don't have a super earth,

and so, one question is,

why not?

The behavior of

Jupiter could provide a clue.

Four and a half

billion years ago,

in an infant solar system,

Jupiter is on the rampage.

Young and hot

and super massive,

it bulldozes

through the planetary nursery,

rips infant planets

out of their orbits

and tosses others

into the sun.

Any super-earths that bask

in tight orbits around the sun

are toast...

Bombarded and broken

by renegade worlds.

Jupiter sends them

to an early grave.

It's an extraordinary theory.

It explains

why there is no super earth

in the inner solar system.

But could Jupiter

have flung a super earth

in the opposite direction...

A super earth that now survives

much further out from the sun?

In Pasadena,

a model of the solar system

that predicts planet nine

must have an extraordinarily

large orbit.

So the notion
- that the solar system

possesses an additional planet,

maybe even a massive planet,

like a super earth,

is one that sounds

kind of crazy.

But the more we looked

at all of the evidence,

the more it made sense.

Konstantin's ideas push

the frontiers of astronomy.

He thinks planet nine is a super

earth that escaped destruction.

So, if this here is the sun,

and if we draw

the initial orbit of Jupiter

as a big, red circle,

what likely happens,

that within

the first few million years

of the solar system's lifetime,

Jupiter's orbit shrunk.

But Jupiter's travels

don't end

with its devastating swing

into the inner solar system.

Jupiter's orbit

expanded back out.

Its gravitational field acted

a little bit like a snow plow,

picking up the orbits of any

other massive super-earths

that would have resided

exterior to it,

and pushing them back out,

ushering them to ever colder

regions of the solar system.

Jupiter's outward swing

shunts Saturn, Neptune, and

Uranus to their present orbits.

It could also have pushed

planet nine

into the very edge

of the solar system.

This move would have transformed

planet nine into a frozen world

that stalks the boundary

of interstellar space.

Planet nine would be so far

from the sun

that its frigid,

outer atmosphere,

a skin of hydrogen clouds,

would be only slightly warmer

than absolute zero.

Beneath that, a dense layer of

helium gas

would produce pressure

so extreme

that even though

it's hotter than a furnace,

the ice below is crushed solid.

The center of the planet

would have a rocky core

with a heart of molten iron.

Planet nine would be

10 times bigger than earth.

This won't just be

a missing planet.

It will be

our missing super earth.

Our calculations suggest

that planet nine

is about 1,000 times

as far away from the sun

as is the earth.

This means that if the sun

is the size of a coin,

planet nine

is a kilometer away.

It is so, so hard to see

such a dim, distant planet

that we literally have to go

to the biggest telescope

available on the planet

to even have a chance

to image this object.

Konstantin believes that

if this missing planet exists,

he can find it.

He and his team are searching

for the planet

with the Subaru telescope,

Mauna Kea in Hawaii.

With the data

and the computational modeling

that we have done,

we now have a road map.

We now can point to the right

part of the sky and say,

"aha, planet nine

must be over there."

Finding planet nine

is not gonna be easy.

It's exceptionally dim.

It might take years,

but we will see planet nine.

I am certain of it.

If they're successful,

the discovery

will transform astronomy.

All of a sudden, the solar

system becomes that much bigger.

Such a shift in thinking

only comes around occasionally

in the history of humanity.

So, we are... we are absolutely

blessed and privileged

to be working on this problem

at this time.

The fact that we've

perhaps missed a giant planet

in our own solar system

just tells us that the universe

is gonna constantly surprise us,

and it's a call to study

everything around us

in far greater detail,

because we don't know

what else is lurking out there.


are closing in on their target

in an historic hunt

for a massive, frozen world

far beyond

the heat of the sun...

A ninth planet cast out

into the icy darkness...

A planet that will push

the farthest edge

of the solar system

closer to the stars.

As a scientist,

is when something comes

totally out of the blue

that you didn't expect.

So planet nine

has not been found yet.

There's indirect evidence,

- but I've got
- a bottle of champagne

- just chilling
- in the refrigerator,

and I'm gonna open it

- the minute we discover
- planet nine.