Narrator: 3.5 billion miles
From earth,
Beyond jupiter,
Saturn,
Past uranus and neptune
Hides pluto and its five moons.
Discovered in 1930, for decades,
We knew almost nothing about it.
As a child, I learned that pluto
Was a mysterious gray rock.
Narrator: So in 2006,
Nasa launched a rocket carrying a lightweight probe.
Man: All telemetry is nominal.
Narrator: The spacecraft returned the first ever close-up images
Of pluto's surface...
Bowman: We've recorded data of the pluto system.
Narrator: ...And sent our understanding of this icy world into disarray.
Hand: The data return has forced us
To rethink everything about pluto.
Narrator: Incredible new discoveries about pluto are even changing
Our understanding of life beyond earth.
Howett: No one in their right mind would have thought
Pluto had life, but now it's a possibility.
And that in itself is kind of mind blowing.
Narrator: This is the story of how pluto came back from the dead.
♪♪
-- Captions by vitac -- www.Vitac.Com
Captions paid for by discovery communications
In 2006, a visionary team of scientists
Began a groundbreaking mission --
To send a craft father into deep space than ever before.
Its mission -- to explore the far reaches
Of our solar system
And take the first ever close-up image of pluto
Before continuing into deep space.
Named new horizons, it would take more than nine years
To make the 3.5 billion-mile voyage to pluto.
♪♪
Keeping things on track
Was mission operations manager alice bowman.
This is the best picture of pluto
That we had before new horizons arrived,
And this was taken by the hubble space telescope,
And it was the picture that inspired us
To send a spacecraft to pluto.
[ lock beeps ]
Narrator: But just days before the probe's arrival,
A crisis occurred.
[ static ]
The team lost all contact with new horizons.
Bowman: Pluto "a" mom on new horizons, pluto 1.
Could you advise why we are not locking up to telemetry?
Woman: Mom, pluto "a," stand by.
I'll check with the station on the status of telemetry.
Narrator: New horizons was designed to fly past pluto,
Taking pictures as it went.
If they didn't regain contact,
It would fly past without recording a thing.
Woman #2: Station 43, pluto "s."
Woman: Mom on new horizons, pluto 1.
Go ahead, pluto "a."
Narrator: After a nerve-wracking hour,
The team finally received a weak signal from the probe.
We found the spacecraft, it was responding to us,
It was giving us information, but it was in a state
That could not accomplish the encounter with pluto.
We determined that we had asked the processor on board
The spacecraft to do too many labor-intensive things,
And the spacecraft switched over to the redundant
Or backup computer.
Narrator: New horizons was back online,
But not functioning at 100%.
All non-essential systems had shut down,
Including the cameras.
If the team couldn't re-upload the mission code in time,
New horizons would miss its fly by.
And it took us three days to do that.
We slept in our offices.
No one wanted to leave because we had waited all this time
And there was no way
That we were going to let this opportunity slip by.
Narrator: Once the team re-uploaded the computer commands,
All they could do was wait.
Bowman: It was a very anxious time.
Narrator: Traveling past pluto more than 10 times faster
Than a speeding bullet meant every new line of code
Needed to work with meticulous precision.
Until the spacecraft beamed back a signal,
The team would have no idea if the new commands had worked.
♪♪
Bowman: The atmosphere was very intense.
We were all anxiously awaiting that first bit of telemetry
To tell us that the spacecraft had survived.
Mom on pluto 1.
We have a healthy spacecraft.
We've recorded data of the pluto system.
And we're outbound for pluto.
[ cheers and applause ]
Narrator: The fly by was a success, and pluto's surface
Came into focus for the very first time.
Bowman: It was amazing.
It just blew our minds that something could be so beautiful.
Narrator: What new horizons sent back was astonishing.
♪♪
The probe had taken thousands of photographs
Of pluto's surface.
Multiple cameras had charted the topography.
A spectrograph detected what the surface was made from...
...Revealing pluto's secrets
For the first time in spectacular detail.
Leslie young and jeff moore
Are two of the project's leading scientists.
Their job -- to decipher this mysterious alien world.
When these images arrived,
The team was struck by pluto's familiar appearance.
These mountains down here, they look an awful lot
Like earth mountains. They're snow capped.
These guys are four kilometers tall,
Just like the rocky mountains are.
But unlike earth,
These mountains were made from ice, not rock.
Pluto is so far from the sun, the scientists were expecting
An almost featureless frozen sphere.
Instead, new horizons revealed
Pluto to be a world of puzzling complexity.
There were craters of every size...
...Gaping canyons and vast plains covered in snow,
And ice-forged mountains,
All of it mysteriously colored from deep red to bright white.
Young: We knew pluto was going to be scientifically astonishing.
We didn't know it was going to be so beautiful.
Nobody expected to see anything like this.
♪♪
Pluto's full glory had finally been revealed
85 years after it was discovered
By american astronomer clyde tombaugh.
Its distance from earth has meant that
For much of the time we've known about it,
Pluto has remained a mystery.
The first thing to know about pluto
Is that it's very small and really far away.
We're standing on a lake bed, a frozen lake in colorado.
Let's pretend that this is the plane of the solar system,
And over there, the ice resurfacing machine,
We'll call that the sun. That's where the sun is.
Then we're roughly where earth is.
But of course, earth is much smaller, if I don't break it.
Here is the earth,
Roughly a centimeter across, something like that.
Now, pluto, by comparison, would be a grain of sand.
That grain of sand would not be here,
Of course, in this part of the solar system.
It's in the outer part
And it would be roughly on that mountaintop right over there.
So about six kilometers away would be pluto.
Narrator: Pluto's extreme distance from earth meant that
Very little was known about it before new horizons arrived.
Astronomers knew that it was cold enough to be made from ice.
They knew that it was small and that it had company.
Showalter: Pluto is not alone. In fact, it has five moons.
Narrator: Tiny pluto isn't one body,
But a whole system of icy worlds,
All engaged in a strange and complex dance.
And as new horizons approached pluto,
The scientists were able to see them in detail
For the very first time.
Pluto's first and largest moon is charon.
Showalter: Charon is remarkably large compared to pluto.
It's about half the size, and they're very close.
Sometimes we call them a binary planet
Because, in fact, they orbit together
As if there were a rod between them
And they were two ends of a lopsided dumbbell.
Narrator: Pluto's moon, charon, doesn't orbit pluto.
Unusually, the two bodies orbit each other
Around a point in empty space.
Beyond charon are for smaller moons --
Hydra, kerberos, nix, and styx.
But why does a tiny dwarf planet have so many moons
In such an unusual configuration?
The data sent back from new horizons offered a clue.
♪♪
Pluto has largely remained a mystery
Since its discovery in 1930.
Why does this tiny planet have so many moons
And why has it formed a binary orbit
With its largest satellite, charon?
So there was a proto pluto
Out there very early in the history of the solar system,
And something else hit it, something very, very big.
Pluto kind of blew apart...
And eventually re-coalesced,
But all that material that was floating around,
A lot of it formed into charon.
And the two got kind of stuck together
As they evolved into this perfect
Circular dumbbell system.
Maybe there were some debris left over
That landed further out
And that became hydra and kerberos and nix and styx.
Narrator: And the photos new horizons took a pluto's surface support
Mark's early impact theory.
♪♪
We think this was a big impact crater
Just from the shape of it, really.
This is probably an ancient crater rim
Of a huge impact
That must have happened early on
When pluto was still very young.
So this is about 1,000 kilometers across.
Probably something about 200 kilometers across
Came in and hit pluto.
New horizons carried a spectrograph,
An instrument that analyzes chemical composition.
It revealed that much of pluto's freezing surface
Is covered by soft nitrogen ice.
Normally a gas on earth,
The scientists believe that vast amounts of nitrogen
Flowed into this enormous crater.
We're pretty sure we understand that what makes up the plane
Is a vast reservoir of solid nitrogen ice,
Which, even though it's solid, is very soft.
Like a glacier, but made from nitrogen ice.
The area was informally dubbed pluto's heart,
And it raised some big questions.
It had all these weird forms and textures on the surface.
Some stand out quite clearly, some are very subtle.
What scientists saw was astonishing.
But what they didn't see was just as remarkable.
The other thing that struck us was the fact
There was no impact craters anywhere in this huge expanse,
The field's lack of impact craters was a revelation.
This isn't an extinct world. This is an active world
In which geological processes are operating today,
And they're destroying any evidence for past cratering.
And that was truly remarkable.
The new horizons planetary scientists were stumped.
Their photos showed no craters and a mysterious pattern.
♪♪
And here's the reason why.... Meteorologist mary lee
Was not involved in the new horizons mission.
And that will bring showers for us.
But to her, the shapes are a familiar sight.
All right, mary, thank you. Sure.
These are stratocumulus clouds. So really, you can see
That puffy, lumpy texture of those cloud tops.
You can actually see the boundaries of these clouds
And it kind of forms a bit of a hexagonal shape
Across our atmosphere.
Narrator: These repeating shapes are very similar
To what scientists see in pluto's heart.
They're a result of the unique way
That these clouds are formed.
You have the sun heating the surface.
That warm air rises, and the liquid droplets,
They condense, and so they form these clouds.
And the top of these clouds,
It's very cold air, so that cold air sinks.
This process is called convection.
You have this cycle of warm air rising and cold air sinking,
And that's a convective cell.
Narrator: Scientists recognized convection cells
Across pluto's heart and realized
That the soft nitrogen ice there is slowly churning.
With the process behind the pattern identified,
Scientists had a new question.
The images are telling us
That there's some sort of geological processing going on.
How could that be powered?
Narrator: On earth, the heat that powers geological activity
Doesn't come from the sun,
But from radioactive elements deep within earth's mantle.
Hand: Radioactive decay within the earth provides enough heat
To produce all of the volcanoes that we see,
The tectonic activity that leads to the uplift of mountains,
The earthquakes, and all of the geology
That we see here on planet earth.
Narrator: But icy pluto was supposed to be different.
Hand: Prior to the arrival of new horizons,
The conventional wisdom
Was that it's probably too small and too low in density
To have enough rock in its interior
To drive enough radiogenic decay, enough heating.
But once new horizons started returning images and data
About pluto, that all changed.
Narrator: Could pluto be heated from within after all?
Images sent back by new horizons
Support this groundbreaking theory.
♪♪
We're looking at a large mountain,
Which is about five kilometers high,
It's about 150 kilometers across,
And in the center is a large pit, and the pit goes down
To about the same depth as the mountain is high.
And when we first saw this, we were really surprised
And puzzled as to what it might be.
Nothing like this had ever been seen on another world.
And to jeff, there was only one extraordinary explanation --
A volcano.
It's a real challenge to imagine how water ice
Could erupt under the surface
The same way lava erupts up to the surface on the earth.
The question became can ice flow like lava
On a world that's 380 degrees below zero?
♪♪
Hidden in new horizons' images,
Space volcanologist kelsi singer spotted
Something that could explain
How ice flows like lava on pluto's freezing surface.
This fracture is called virgil fossae.
It's a couple hundred kilometers long
And at least five kilometers high,
And it's got a unique red coloring.
And that red coloring turned out to be associated
With ammonia.
Narrator: Confirmed by new horizons' spectrograph,
The presence of this nitrogen-hydrogen compound
Changed our understanding of the dwarf planet.
The detection of ammonia on pluto was very important
Because it lowers the melting temperature of water.
Narrator: In fact, ammonia can lower the freezing point of water
By up to 180 degrees fahrenheit,
Temporarily allowing it to behave like molten lava
And pluto's frozen surface.
Kelsi believes that this thick,
Freezing liquid erupted through pluto's crust,
Flowed across the surface like lava,
And then froze solid to form the ice volcano
That new horizons revealed.
But volcanic eruptions still need heat.
And heat on pluto would mean something incredible.
The fact that we see something that could be an icy volcano
That had to form from a flow of material
Means that the interior of pluto must be somewhat warm,
And that means that we could have
A subsurface liquid water ocean on pluto.
Narrator: Liquid water has not been proven to exist
Anywhere beyond earth.
But for a subterranean ocean to exist in liquid form,
Pluto must have an internal heat source.
The problem with pluto in terms of its heat from the interior
Is that it probably doesn't have enough of the raw materials.
There's not enough radiogenic decay to keep it warm
From within for a very long period of time.
And yet the evidence is that
Something is driving this geological processing.
So there must be another piece of the puzzle.
♪♪
Narrator: The new horizons mission
Provided scientists with the first-ever
High resolution photos of pluto's surface,
And they suggested something amazing --
The presence of a liquid-water ocean beneath pluto's crust.
Researchers were faced with a new question.
How could this distant planet
Produce enough warmth to sustain a liquid ocean?
The problem with pluto in terms of its heat from the interior
Is that it probably doesn't have enough of the raw materials.
Narrator: A small amount of radioactive rock in pluto's core
May provide some heat,
But something else must be helping the planet retain it.
♪♪
This mysterious source of insulation
Could be a special type of snow called a gas hydrate.
Scientists at the national oceanography center
In southampton make it in their lab.
It looks like ordinary snow.
It's freezing cold like ordinary snow.
But take a match to it and...
♪♪
Best: This in my hand looks like ice, but it is actually burning.
And that flame is actually methane gas
That's been coming off the ice as it melts.
Narrator: It burns because flammable gas like methane
Gets trapped within the crystal structure of ice.
Dr. Carly howett designed the cameras
On the new horizons probe.
She believes the hydrate's ability to trap gas
Could be the answer to pluto's heat mystery.
♪♪
Howett: The water ice forms a hexagon almost like a cage.
And then inside is gas.
In this case, we think it's probably methane.
These are incredibly small.
You'd end up with millions upon millions
Of very, very small cages,
Each holding its own little methane gas bubble.
Narrator: The gas bubbles on pluto don't ignite
But act like a thermal insulator trapping heat.
Howett: So the heat comes from the rocky core,
And it can't escape through this insulating layer.
And maybe it's warm enough that you end up being able to sustain
Liquid water form and sustain liquid water
And maybe even in the form of a sort of global ocean,
Which is incredible.
Narrator: The scientists found a way
That liquid water could exist on pluto.
Everything they thought about this icy world
Was turned on its head,
Which has led some scientists to think the impossible.
Hand: If we've learned anything from our study of life on earth,
It's that where you find liquid water,
You generally find life.
Narrator: But there was still something missing.
As well as heat and liquid water,
Life requires a complex array of chemical ingredients.
Could they exist on pluto?
♪♪
The first clue about pluto's chemistry came in 1988,
Long before new horizons,
When images like this were all that scientists had.
So here's a picture you can take
From the ground-based telescope like this,
And there are a lot of beautiful background stars here,
But there's one particular important one
We are talking about today.
It's pluto here in the middle of this picture
It's not much, right? It's only a few pixels.
Narrator: Yet what scientists learn from this rudimentary image
Would ultimately inform one of new horizons'
Most important mission objectives.
Narrator: From earth,
Pluto was nothing but a tiny white dot in the late '80s.
So astronomers waited for a rare event
Called an occultation to learn more about the distant planet.
So look at those background stars here.
They are relatively stationary, but pluto is moving in the sky.
Narrator: As pluto passed in front of a background star,
Rather than blocking the starlight abruptly,
The starlight was slowly dimmed.
This could only mean one thing.
That pluto had an atmosphere
Here. Dry ice.
Okay, look at this atmosphere we just made in the laboratory,
And if there is a light source behind there,
The light source will get dimmed
Because of the absorption and scattering of the atmosphere.
And that's similar to what happens in pluto's occultation.
Narrator: Here, dry-ice vapor scatters the light
In the same way that pluto scattered the starlight.
It was proof that pluto had an atmosphere.
But the question remained,
What was pluto's atmosphere made of?
The new horizons probe was sent to find out.
And when it returned this picture,
The scientists were able to see the atmosphere in detail
For the very first time.
This is such a beautiful image.
This image says we were really there
Because this is the kind of image
You can only get after you pass by pluto.
This picture was taken
Looking back toward the sun and earth
And we're seeing pluto backlit by the sun.
The onboard spectrograph revealed that pluto's atmosphere
Was made mostly of nitrogen gas, just like earth's.
As new horizons moved further away from pluto,
The long-range camera took one of
The most important photographs of the entire mission.
Like everybody, I was surprised
At this beautiful structured atmosphere.
All these layers were wholly unexpected.
There is so much going on in this picture.
We can actually see these layers
In the haze in pluto's atmosphere.
There about 20 kilometers or so between each one,
And we see the haze going up for 200 kilometers
Or more in this image.
The layers in pluto's atmosphere were a complete mystery.
Invisible nitrogen gas alone couldn't explain the layers.
Planetary scientist xi zhang thinks
It could be caused by sunlight.
Zhang: You can see the air quality is not good.
The air pollution is mostly volatile organic compounds
Like hydrocarbons, soot particles.
Narrator: Large soot particles hang in the air above the city.
They are created by a chemical reaction.
Exhaust fumes from cars are baked by the sun,
Causing them to break down and reform into larger particles.
Those marks are actually pretty similar
To what we see on pluto in terms of chemical processes.
Narrator: But there are no cars on pluto,
So why is its atmosphere choking with smog?
When new horizons analyze pluto's atmosphere,
It discovered that it wasn't just made from nitrogen.
There were also tiny amounts of other gases
Like methane and carbon monoxide.
When those air molecules hit by the u.V. Light from the sun,
The chemical bonds are broken
And those coagulate and make big particles.
It's similar to the soot particles we have here.
Gas molecules in pluto's atmosphere
Are broken apart by the sun
Before reforming into large soot particles
And settling out into layers.
Zhang: Those haze particles are produced
In the upper atmosphere of pluto
And gradually settle down due to gravity.
Narrator: The soot particles suggest that something special
Is happening in pluto's atmosphere,
But exactly what chemicals are formed in the process?
Salama: Ready? High voltage down.
The probe told scientists
What gases exist in pluto's atmosphere...
The mses are off.
...Which allowed them to do something
That had never been done before...
Cylinders are closed.
...Recreate pluto's atmosphere here on earth.
♪♪
Narrator: For the first time, new horizons was able to identify
The gases present in pluto's atmosphere.
Now scientists are using that information
To recreate those atmosphere conditions in the lab.
What this machine allows to do
Is to simulate space environment.
In the case of pluto,
We can simulate the atmosphere of pluto.
Okay.
Sciamma-o'brien: Doing this experiment
Will allow us to get a better idea
Of the type of chemical processes
That are occurring in the atmosphere.
Pressure.
That's the base pressure?
[ speaks indistinctly ]
Narrator: Pluto's atmospheric gases enter this machine
At -270 degrees fahrenheit,
Where an electrical discharge simulates the sun's rays.
And after 10 hours in the machine,
The gases are transformed into an entirely new substance,
Tiny grains of dust.
These are these grains that we make in the gas
And that get deposited onto a window
And piled on top of each other
Until we have a thin layer of these dust grains.
And, as you can see, the color is a dark brown.
Narrator: These are the same particles
That caused the layers in pluto's atmosphere.
Eventually, they grow so big
That they fall to the surface like rain,
Painting pluto in a broad spectrum of browns and reds.
So this is an enhanced color image
And we can see that this area is really red and quite dark
And much redder than the rest of pluto's surface.
Areas that receive more sunlight
Appear much redder than elsewhere.
So what can these surface colors reveal about the dwarf planet?
♪♪
Dale cruikshank studies
The surface of small objects in space.
And since new horizons, he has turned his attention
To the chemical reactions occurring on pluto.
Pluto has a very thin atmosphere,
And we know that the basic components are nitrogen,
Methane, and carbon monoxide.
Sunlight coming in in the ultraviolet part of the spectrum
Has enough energy to break the energetic bonds
That hold the atoms in the molecules together.
Narrator: These simple gases reform randomly
Into more complex molecules.
Cruikshank: Like that.
Narrator: And experiments to recreate this
Have produced something extraordinary.
Eventually, these materials form what we call precursor molecules
To molecules that are of biological interest,
Including what are called nucleobases.
There are many different nucleobases,
But five of them are of biological interest
Because these are the principal components of dna and rna.
Nucleobases are the main ingredient of dna.
All life on earth uses dna.
From these complex molecules, life is just a few steps away,
And some scientists believe it's possible
That they're being produced on pluto.
Cruikshank: The new horizons mission has given us these fantastic images
From which we now deduce that the colors are,
In fact, from organic material, complex organics
That have fallen from the sky, literally.
We are making precursors to the things
That eventually we think on earth
Resulted in the origin of life.
Narrator: And the surface isn't the only place
Where prelife organic molecules could be developing.
Cruikshank: Complex organics are also being produced in water
And have emerged onto the surface through cracks
In the crust in a process that we call cryovolcanism.
Narrator: The red color of the ice around virgil fossae
Is evidence not only of ammonia but also organic material
Erupting from an underground sea.
Scientists were stunned.
Cruikshank: There may be habitable zones on pluto.
For example, in the interior, if there's still a liquid
And it's full of organic materials,
This may be a habitat where life could exist.
So if we were trying to survey the entire solar system
For a potential habitable zones, habitable regions,
You'd have to include pluto in that list, I think.
♪♪
Narrator: Evidence suggests that pluto has the raw ingredients
To produce the molecules needed for life.
And even though the complexities
Of how organic molecules spawn life
Are not fully understood,
This and other findings made by new horizons changes
What we thought we knew about the dwarf planet.
Hand: Within pluto, you might have liquid water mixed with ammonia,
Mixed with methane and any number of different kinds
Of organic compounds,
Carbon compounds that life could utilize.
And so, along with pluto potentially having
This liquid-water environment
That could be conducive for life,
It might have some of the elements and energy
That life as we know it needs.
Howett: No one in their right mind would've thought
Pluto had life, but now it's a possibility,
And that in itself is kind of mind blowing.
Hand: What might life on pluto look like?
Who knows?
But I would be happy with even the tiniest
Of single-celled microbial organism somewhere out there
In our solar system and beyond.
Narrator: And if on pluto, the most unlikely of places,
Then why not elsewhere?
Showalter: We used to think that life could only exist
On a planet like earth,
With ocean on the outside and atmosphere,
Sunlight falling in, and so on.
Now we learned that there are liquid oceans
Elsewhere in the solar system.
They are around jupiter, they are inside pluto,
And it changes our concept of what the goldilocks zone is,
The zone in which life could potentially form.
Howett: If places like pluto, you know, really small,
Very distant from a star, are able to have liquid water,
It could mean that pluto maybe has life.
But also as we move into other solar systems
And we understand more about other solar systems,
Maybe life could be more abundant than we thought.
♪♪
Narrator: Once viewed as a world of little importance...
...Pluto has been revealed
To be a place of unimaginable complexity.
Mountains carved from ice rival
The most dramatic landscapes on earth.
A frozen volcano like nothing else in the solar system.
♪♪
A churning nitrogen glacier
That puzzles scientists' greatest minds.
It's a place where extraterrestrial life
Might exist...
♪♪
...And could tell us where else in the universe
We might find it.
This great mystery on the very edge of our solar system
Has led scientists to call for another mission.
Howett: The only way to really study the surface of pluto in detail
Is to go back to pluto,
And that's why I'm leading a concept study
To figure out how we would go about doing that.
Narrator: They plan to send another probe.
Singer: We need another mission to go back to pluto
And this time orbit pluto.
And we can bring different instruments
That can get us different answers.
Narrator: And peer beneath pluto's icy crust.
Hand: If we committed ourselves to exploring these ocean worlds,
It could be that within the next few decades,
We might finally have an answer
To that primordial age-old question
Of whether or not we are alone in the universe.
To the romans, pluto was the god of the afterlife.
But this tiny dwarf planet may, in fact,
Be a gatekeeper to life itself.
♪♪
Pluto is truly back from the dead.