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
here.
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,
Neptune,
lies
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.
Excellent.
- -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.
Micro-gravity
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
kickstarted
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?
Scientists
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.
Recently,
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
formation,
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
laboratory,
scientists
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
extraordinary.
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
4-and-a-half-billion-year
lifetime,
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
history,
it carried Ceres with it.
Jupiter
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,
astronomers
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
discovered
something
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.
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,
super-earths
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.
Astronomers
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.
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
here.
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,
Neptune,
lies
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.
Excellent.
- -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.
Micro-gravity
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
kickstarted
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?
Scientists
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.
Recently,
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
formation,
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
laboratory,
scientists
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
extraordinary.
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
4-and-a-half-billion-year
lifetime,
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
history,
it carried Ceres with it.
Jupiter
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,
astronomers
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
discovered
something
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.
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,
super-earths
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.
Astronomers
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.