All language subtitles for Spaces Deepest Secrets S01E01

Humans have been explorers
since the earliest days...

From our birth
in the cradle of Africa

and spreading
across the seven continents.

That exploration will never end.

It's something very deep
within us as human beings.

This stretches back to the dawn
of our species.

And liftoff.

Today, a new breed of explorers

are capturing the first glimpses
of worlds beyond our own.

We are absolutely
pushing the limits

of everything we know about
space exploration right now.

Hang on to your seats,

because the roller
coaster ride is on.

Mysterious new images

reveal incredible new
discoveries.

Captions by vitac
www.Vitac.Com

captions paid for by
Discovery communications

January 2016...

NASA releases a new image
of a strange structure

on the surface of Pluto.

It appears to be an enormous
ice volcano

on what should be
a geologically dead planet.

On the flanks
of this big summit depression

is the caldera of the volcano.

Nothing like this has been seen
anywhere in the solar system.

It's got us baffled.

Now scientists believe that

just beneath this volcano
is an entire ocean of water.

The mysterious image
that triggered this discovery

is one of thousands

that scientists
are still downloading

from a historic flyby
of Pluto in July 2015.

Stand by for telemetry.

Three, two, one!

Even today, much of the data
from the flyby...

Between 35% and 40%...

Is still up on the spacecraft
and no human being has seen it.

We don't know what discoveries
will be in them.

How did a team of explorers

become the first people
in history

to capture images
of Pluto's surface,

and what can explain
mysterious new photographs

like Pluto's volcano?

A team
of young university students

and scientists set its sights

on the last unexplored planet
in the solar system.

You know, if somebody said,

"well, were you all obsessed
with Pluto?"

I think we would
all have to plead guilty.

At the time, Ralph Mcnutt

is a physics professor
at M.I.T.

I think I did always
dream of being an explorer.

I'd been a space cadet
since I was a kid.

And at that time, Pluto

was just this incredible
big question mark.

All we knew was
that it was a spot of light

in the sky.

But with a dwarf planet
three billion miles away

and smaller than our own moon,
even the best telescope images

are too small
to reveal any detail.

The best image

from the Hubble space telescope
of Pluto is this fuzzy ball

that's about six square pixels
by six square pixels.

So, here are these upstart kids

that were saying
"we ought to go to Pluto."

We ought to finish out
the exploration

"of the solar system."

So, at some point, the moniker
"Pluto underground" was born.

And the Pluto underground...

I like to call them
the Pluto mafia...

These are the folks who've spent

almost their entire careers
studying Pluto.

You know, Pluto is the endgame.

This was our opportunity
to finish the task

of the exploration
of the solar system.

Young graduate students

united by their fascination
with the outer solar system,

the Pluto underground,

want NASA to make
their dream a reality,

and one man
would lead them there...

Dr. Alan Stern.

We weren't going
to answer specific questions.

We were going
to collect data sets

with our eyes wide open
to see what was there,

literally exploring,

literally flying
into the unknown.

The Pluto underground form
a plan to fly a spacecraft

within 8,000 miles
of Pluto's surface...

Almost 30 times closer
than the Moon is to Earth.

As it flies overhead,

the probe will turn and snap
the first photographs

of the planet's
mysterious terrain.

But the plan
faces an uphill battle.

NASA could be doing
quicker missions closer to home,

and trying to mount
an inexpensive mission

all the way to the edge
of the solar system

is a fool's folly.

Alan...
Alan is a very unique person.

And, you know, I think this was
almost superhuman act

of absolutely dogged
determination over the years

that made this happen.

Dr. Stern is hopeful

that the images will solve
an ancient mystery.

Pluto orbits
in a mysterious region

of space densely packed

with unusual moons,
dwarf planets,

and other misfit objects.

The final frontier
in the solar system

is the Kuiper belt...
This region of leftover objects

from the formation
of the solar system.

And Pluto is the largest
of those objects.

It's a very important region

for understanding the birth
of the solar system.

This means that Pluto

is a 4.5-billion-year-old
fossil holding clues

about how our own planet
was formed.

The Kuiper belt was discovered,

and Pluto went from being
this lone misfit

tinhe outer solar system
to the biggest, the baddest,

and the brightest member
of that entire population.

This was a very rich
scienticif target.

After all, it's a long way away,

so you better have
an awful good reason.

In 2003,

the Pluto underground
convinces NASA,

and the New Horizons
mission is born.

We had a lot
of difficulties associated

with getting to Pluto.

One of which is
it's three billion miles away.

We're driving to,
you know, 33 times

as far from the Sun
as the Earth is.

The longer a spacecraft travels,

the greater chance something
could go wrong.

So the team wants to reach Pluto
within 10 years of launch.

New Horizons spacecraft

was gonna be the fastest ever
to leave the Earth...

More than 30,000 miles
per hour taking off.

That's more than 50 times
faster than a jetliner.

To cross a three-billion-mile
ocean of space

required us to travel
at this crazy speed.

When I was a boy,

Apollo missions took three days
to reach the Moon.

New Horizons was going
to reach the Moon in nine hours.

How's that for speed?

To achieve
that record-breaking speed,

New Horizons must be light.

The less weight a launch vehicle

has to push
against Earth's gravity,

the faster it can go.

The size of a small piano,

New Horizons will weigh
just 1,000 pounds.

And it can carry
only enough fuel

for minor course corrections.

Once it reaches Pluto,

it cannot slow down
and enter orbit.

There is no second chance.

You're flying by.
There's no stopping it.

The spacecraft is on a path,
a beeline, past Pluto.

Either you were gonna get it
or you weren't.

And it's terrifying,
to tell you the truth.

But if it works, New Horizons

will capture thousands of images
in incredible close-up detail.

Three, two, one.

We have ignition and liftoff
of NASA's New Horizons.

It was picture-perfect
launch.

It couldn't have been
any better.

But still, it was yet
another 9 1/2 years

before we finally get to Pluto.

But there's plenty
to do while the team waits,

including a close pass
of another planet.

We needed to pick up
some extra energy

in order to be able to actually
get to Pluto on schedule.

We had this opportunity

to fly near Jupiter,
steal a little, you know,

gravity assist from Jupiter,

and increase our speed by 20%

and cut three years
off the travel time to Pluto.

In February 2007,

Jupiter's gravity
propels New Horizons

like a slingshot
toward its destination.

After nearly 9 1/2 years
of traveling through space,

New Horizons

is a mere 10 days away
from its historic flyby.

I get a frantic call
from Alan Stern,

the principal investigator,

and I could tell
that he was breathing hard,

he was running down the hallway.
And he said,

"we've lost communication
with the spacecraft."

This had never happened
in 9 1/2 years of flight.

How could it be happening today
at the last minute,

just on the verge
of summiting Mount Everest?

Why now? How?
What have we done?

10 days from a
historic encounter with Pluto,

the New Horizons spacecraft
goes silent.

We have no spacecraft,
no signal,

no knowledge of what's going on.

It started to sink in

that we may be
experiencing something

that's abnormal
on the spacecraft.

And I can't tell you
how that feels.

Alice Bowman is the M.O.M.,

or missions operations
manager, for New Horizons.

You allow yourself
those 10 seconds of feeling,

you know, "oh, my god!
What's going on?"

And then, you know,
your training kicks in.

Alice was in charge
of the recovery effort.

And there was no way

she was gonna let this fail
after 9 1/2 years.

Alice scrambles the
team to assess the damage,

and they make
a heart-stopping discovery.

It turns out
that we had overworked

the main computer
on the spacecraft

and caused it to reset.

Six months
of programming are lost.

Now the engineering
team has only a few days

to redo everything.

We knew we could fix it.

The question was,
could we fix it

in time for the flyby sequence

that was supposed
to start on July 7th?

Over the course
of three sleepless days,

the team uploads
command codes to New Horizons

nearly three billion miles
across the solar system.

We're able to get that sequence
or set of instructions

loaded to the main computer...

And we had four hours to spare.

If you've got high blood
pressure to begin with,

this is probably a business
you ought to stay out of.

Seven days later,

the morning
of the Pluto flyby has come.

Hang on to your seats,

be cause the roller
coaster ride is on.

As media
from across the world gathers

at Johns Hopkins university
outside of Baltimore, Maryland,

all eyes are on Dr. Alan Stern.

We passed inside the orbit
of Hydra,

the outermost moon of Pluto.

And he's brought
an early surprise

for the New Horizons team.

The night
before closest approach,

we made a point of sending home
a handful of images in spectrum.

They were the highest
resolution images

that had ever been obtained.

Pluto went from being just
a small image in the distance...

Sort of like a jeweled
Christmas ornament...

To all of a sudden

this massive world
with unparalleled complexity.

But this is not the image

of Pluto the team came to see.

It's New Horizons'
closest approach

that will truly
reveal Pluto's secrets.

In less than an hour,

New Horizons will come
within 8,000 miles of Pluto.

If the timing had been off,

that we had somehow
just messed up

and instead of flying by Pluto
at the prescribed time,

it was 1,000 seconds
earlier or later,

we would have had everything
pointed in the wrong place.

You don't want
to wait two decades

and see a bunch of stars.

Okay, we have 25 seconds, folks.

T minus 25 seconds.

At 7:49 A.M.,
the team counts down

to the actual second
New Horizons

makes its closest approach
to Pluto.

Nine, eight, seven, six,

five, four, three, two, one.

Decades of work...
They don't come down to one day.

They come down to one minute,
to one second.

But no one really knows

if the probe survived the flyby

until it sends a confirmation
signal back to mission control.

Radio signals
traveling at light speed

are expected to arrive

at the APL mission
operations center,

and we'll go live
in the mission operation center

you can watch
some of that activity.

At 9:00 P.M.,

the team gathers
to learn New Horizons' fate.

We are searching
for a frequency.

Stand by.

Waiting for the
spacecraft to report back,

you could probably have cut
the tension with a knife.

Everything's riding on this.
And it's...

It's an incredibly high-stakes
poker game.

Okay, we're in lock
with carrier.

Stand by for telemetry.

You really don't know

if your spacecraft survived
despite all the work

that you've done.

Stand by.

Yes!

Okay. Copy that.

We're in lock with telemetry
with the spacecraft.

P.I., M.O.M.
All clear to one.

We have a healthy spacecraft,

we've recorded data
of the Pluto system,

and we're outbound for Pluto.

When we got that signal,

it was like a celebration

for the 10, 15 years of work
that we'd put into that mission.

USA! We did it!

This has been beyond my wildest
expectations in every regard.

I'm ecstatic.

It's returning beaifutul data,

and the Pluto system
is just mind-blowing.

Within hours, New Horizons

begins to deliver
its first images.

Our jaws were just dropping.
It was incredible.

We'd transformed
this little pixilated blob

into this real world.

What the team
sees in the images...

Wow.

Is completely unexpected.

Even though logically I knew
that it was a rocky,

icy planet,

I didn't expect it
to look so similar

to features
that we have on Earth.

I love this picture.

It's one that was made
about 15 minutes

after closest approach
of the very rugged terrains.

Many of these mountains
are 10,000 feet tall.

The team
has discovered mountains

of water ice
the size of the rockies

on a planet smaller
than our own moon.

You felt like you're there,

seeing the giant ice mountains
and giant chmsas,

you know, much bigger
than the Grand Canyon

in the United States.

We can auactlly
see glacier flows.

It's molecular nitrogen ice.

It's almost like water ice
is on the Earth,

and so it can float.

The discovery
of water ice mountains

and nitrogen glaciers

leads Alan
to one shocking conclusion.

Pluto is geologically alive
after 4.5 billion years,

which upended many
geophysical theories

that did predict

that small planets
would cool off

and die early in their history

and just be a frozen relic
of that time.

That tells us that our ideas

of how planetary engines
work were wrong

and that we had to rethink them.

But one recently downloaded
image further fuels

Pluto's mystery.

This is one of the most
amazing finds we made at Pluto.

It's a giant ice volcano
that was apparently active late

in the history
of the solar system.

There are almost no craters
on the flanks of this structure.

The big summit depression
is the caldera of the volcano.

Nothing like this has been seen
anywhere in the solar system

from Mars all the way to Pluto.

Sometimes I pinch myself
that this is a real place

that we actually went
and visited.

It looks like something
out of science fiction.

And why Pluto
should have these features

has got us baffled.

An active volcano
would mean a source of heat

somewhere on the planet.

And now the New Horizons team

be lieves that heat could e
warming an ocean of water

beneath the surface of Pluto.

It is a stunning discovery.

You have, you know, all of these
other exotic things going on,

but it looks almost
like tectonic activity.

And, you know,
were is that coming from?

Why is Pluto still alive?

New images
might solve the mystery.

The blue sky image...
This is something

that was absolutely,
totally unexpected.

The discovery
of active geology on Pluto

has defied expectations
of a frozen, dead world.

There were mountains of pure ice
that were 10,000 feet high.

There were active glaciers
of nitrogen and methane ice.

Nobody was expecting the drama
and the beauty that we found.

But Pluto's biggest mystery
may lie above the surface.

After we fly by Pluto
and look back towards the Sun,

and we can actually
see the atmosphere

and see this blue.

Pluto has blue skies.

Who would have thought?
This is just amazing.

This blue atmosphere of nitrogen

should have dissipated into
space billions of years ago.

Something is replenishing it,
but what?

Could volcanic activity
spew fresh nitrogen

from deep beneath the surface?

New images
might soon solve the mystery.

We've got over a year's worth
of data to still get down.

There's a lot of people
that are losing a lot of sleep

these days trying to do this
as fast as possible.

But by far the best
images are still to come.

The search for answers

takes us from the edges
of the solar system

to the edges
of the universe itself.

March 4, 2016.

NASA releases an historic image,

one that many believed
was impossible.

This red dot
is an entire galaxy,

whose light took 13.4 billion
years to reach us.

It is a photograph
of our universe

in its infancy...
A mere 3% of its current age.

All of a sudden now,
you have a ringside seat

to watch
the entire universe evolve

and change in front of you.

All of that is down
to the Hubble space telescope.

What could this
mysterious red galaxy reveal

about the origins of the cosmos?

That story begins

when the Hubble telescope
is still on the drawing board.

Hubble was meant
to solve a problem,

because people were trying
to use ground-based telescopes

to measure how fast
the expansion

of the universe was,

and that means the factor
of uncertainty in the age

of the universe.

How and when
did our universe begin?

Solving that mystery
would be an historic success

at a time when the space program
needs it most.

In 1986, the nation

is in mourning after the loss
of seven crew members

aboard the space
shuttle Challenger.

This is truly a national loss.

The members of the Challenger
crew were pioneers.

We'll continue our quest
in space.

The future doesn't belong
to the faint-hearted.

It belongs to the brave.

They needed something
to get back into the game.

And Hubble was sort
of that big, shining star.

This was a big space telescope,

and we're gonna put this thing
into orbit,

and it's going to look
at black holes,

it's gonna figure out
where the universe came from.

It's gonna revolutionize
astronomy.

In charge
of this daunting mission

is Charlie Pellerin.

The primary role of Hubble

was to fix things
after Challenger,

to show we could still
do hard things.

I kept reminding myself
of John Kennedy when he said,

"we choose to go to the Moon

not because it's easy
but because it's hard."

We chose to do Hubble
because it was hard,

and it was damn hard.

Hubble will far surpass
all ground-based telescopes

for one simple reason...

Earth's atmosphere.

If you look up at the night sky,

the stars are gonna appear
keli they're twinkling.

But the star is not changing.

What's happening
is that the same kind

of irregularities
in the atmosphere

that you encounter when you get
turbulence in an airplane,

it's all over the place.

W, the solution
to that is put a telescope

above the atmosphere.

But unlike ground telescopes,

Hubble would be orbiting the
Earth at an astonishing speed

of almost five miles per second.

And that's a problem.

Now, of course, the Hubble
is this thing in space,

moving thousands and thousands
of miles an hour in orbit,

which means its natural tendency

is that it's going
to be tumbling end over end.

It's doing everything
but holding still.

If you want to take a snapshot
that's clear,

you know you have to hold
your camera very steadily.

If you shake your camera,
you get a fuzzy picture.

Same thing is true with Hubble.

The team must find a way

to stabilize Hubble perfectly.

The solution is a gyroscope.

Like a top, a gyroscope

maintains stability
by spinning quickly on one axis.

The team will equip Hubble

with six of the most
finely balanced gyroscopes

ever constructed,
each with a wheel

spinning 320 times per second.

But even the tiniest imprecision

in the gyroscopes
will smear Hubble's images.

So, if you asked me before the
launch "is this all gonna work?"

And people did...

I would say, "of course
it's gonna work,"

because there's no other answer.

What would you say?
Would you say...

After you spent
almost $2 billion in 15 years,

would you say,
"hell, I don't know,"

or would you say,
"let's hope so"?

What would you say?
There's only one answer...

"of course it's gonna work."

Go for auto sequence start.

And liftoff
of the space shuttle Discovery

with the Hubble space
telescope...

Our window on the universe.

All go.
We have a go for release,

and we're gonna
be a minute late.

Okay, Charlie.

- Telescope's released.
- Okay, thank you.

So, the telescope's up.
Hubble's working.

It's deployed into space,
and the shuttle comes home.

Feeling really pretty good
right now.

The flight systems
are all working extremely well.

Almost everything
we agonized and worried about

has done a great job for us.

I think that, today,
everything's going exactly

as we would have hoped.

We had an event
about two months later

where we're gonna look
at what's called "first light."

Charlie is with
chief engineer gene Oliver

when the first images arrive.

And I said,
"gene, waia t minute.

Wait a minute.
That's a fuzzy spot."

Okay? He says,
"oh, don't worry."

I said,
"what do you mean don't worry?"

He said, "well,
if it's out of focus",

we just re-drive the stepping
motor in this direction

"until it's in perfect focus.
So no big deal."

Charlie becomes convinced

all that's needed
is a technical adjustment.

He leaves for a trip overseas.

When he returns,
he calls his boss to check in.

So, he comes on the phone
and says, "Charlie",

where are you?" I said,
"I'm in the red carpet lounge

in St. Louis airport."

And he says to me,
"what do you know

about spherical aberration?"

And I said, "well, all I know
is that when people..."

Amateurs, typically...

Make a telescope mirror by hand
and they do it sloppily,

"then the telescope's useless."

He said,
"well, I'm glad you know that,"

because you launched
Hubble space telescope

"with a spherical
aberrated mirror."

I said, "did not."
Heai sd, "did so."

This is two phd's, right?

He says, "go find the front page
of any national newspaper"

and bring it back
and read it to me."

So I come back,
and above the fold,

"national disaster... Hubble
launched with flawed mirror."

And he says,
"now what do you say?"

I said, "you guys are good."

How did you get a fake newspaper

"into this very lounge
that I'm landing in?"

The headline is no fake.

Charlie has launched Hubble
with a fatal flaw

and not the one he had feared.

Yesterday, NASA admitted

that its multi-billion-dollar
eye in the sky

has developed blurry vision.

We had failed in the most
visible possible thing

we'd done in many, many years.

I'd have to say it was
like a family member died.

It was like that.
I mean, it really was.

May 1990...

Charlie Pellerin had just
launched Hubble into space

with a fatal flaw.

Well, we're looking here
at a star field

and these blurry stars,
and there's no doubt

that we had a disaster
on our hands.

Yesterday, NASA admitted

that its multi-billion-dollar
eye in the sky

has developed blurry vision.

The observatory
will not be sending back

the spectacular pictures
that NASA had promised.

The reason is that the mirrors
are not focusing light properly.

To achieve focus,

a telescope's mirror
must be perfectly curved

so that its reflected
light converges

at a single point.

After so much worrying

about Hubble's ability
to stabilize itself,

Charlie's team
made an amateur mistake.

Hubble uses a mirror.

It's 2 1/2 meters across...
Eight feet.

And it focuses the light
to a very, very specific focus.

And if it's off
by even a little bit,

the light won't come to a focus.

The problem with Hubble is
that it wasn't the right shape.

I believe that
the edge of the mirror,

the whole error was like 1/50th
of a human hair.

No human could ever look
at that mirror

and suspect there's a problem.

We had so many safeguards.

And I look at this,
and I just go, "my word."

Boy, we were in so much trouble
and didn't knoitw ."

What a tragedy.

Basically, without some novel
technical answer,

we're screwed.

NASA is embarrassed,
while across the country,

Charlie and his team are mocked.

There was also much
in the media.

Hubble was the butt
of so many jokes.

People were saying,
"well, how did we spend

almost $2 billion
and come up with this?"

I tried to avoid
the news as much as I could,

but it was impossible.

It was even in New York times,
Washington post.

They had crying breaking out.

Astronomers
are crying everywhere.

One of my most senior
people is drunk at his desk.

When I realized
what h hadappened,

I didn't believe my personal
reputation was in danger.

I believed it was ruined.

I mean, it was gone.

I mean,
for this level of failure,

arguably the biggest screw-up
in the history of science,

and I was the leader
of the team.

So, yeah, it was bad.

But Charlie is determined
to find a solution.

I'm not waiting a minute

longer than I have to get
this telescope fixed.

Didn't know how to do .It
I had no idea

if it even was possible yet.

After months of searching,

his team thinks
they might have an answer.

If the mirror
was simply poorly ground

to a very sloppy weight,
it'd be hopeless.

But the mirror was perfect,
just ground

to the wrong prescription.

When we humans
have vision problems,

we correct that problem
by wearing eyeglasses,

which then are correcting
the direction of the light

and making sure
that it is focusing properly.

That is basically
what the Hubble needed.

These glasses
would come in the form

of a machine called
C.O.S.T.A.R.

Contains five pairs

of small mirrors
on motorized arms.

These mirrors correct the light
beam entering the telescope.

We finally just sort
of go, "my word."

We can fix this thing."

But with Hubble
already in space,

this repair won't come easy.

Kathryn Thornton
and her fellow astronauts

must risk their own safety
to save Hubble from disaster.

A lot of things can go wrong
when you're on a space walk,

but most people,
when they leave the airlock,

are not so much afraid

that something's gonna
happen to them,

they're afraid
they're gonna mess up.

That's the biggest concern

is that our mission
was so critical,

and it was critical
that they be done right.

Hubble's science instruments
are containeind four bays.

Kathryn
must replace one instrument

called a high-speed photometer
with C.O.S.T.A.R.

Once installed,

the corrective mirrors
can deploy.

I mean, remember...
This is a huge instrument

the size of a bus.

Nothing like that has ever
been done before,

and it represents a huge number
of technological challenges.

But Thornton is far from certain

that everything will go
according to plan.

I would have bet money

that when we were putting
these instruments in Hubble

we would have run
into some problem

that we weren't expecting.

Okay.
I'm gonna slip over.

You got another foot
to keep coming up.

Is a great big silver box

the size of a phone booth.

And I would have bet

that things wouldn't fit,
that we're gonna slide

this thing in
and it's gonna get halfway in

and it's gonna go
"ka-thunk" and hit something.

And as bad as it was,
we could always make it worse.

We could have killed it.
We could have killed it.

This is opening the door
for C.O.S.T.A.R.

I'm on the end
of the mechanical arm,

and I can recognize
that from this picture

because I can see
the broken red stripes

around my thighs there.

I haven't seen
some of this in a long time.

This is nice.
I like this.

We had a lot
of eyes watching us.

We had everybody
on the ground watching,

we had everybody
in the crew module watching us.

You know, "don't hurt it.
Don't hurt it."

Don't hurt it.
And it's all up to you.

"Don't screw this up."

Is a pretty big instrument.

It weighs several
hundred pounds,

maybe 700 pounds on Earth,

and I can move it
with just my fingertips.

As C.O.S.T.A.R.
Slides into place,

Thornton can only hope
that everything will fit.

And it just slid right in.

Could feel it hit a stop.
That was a bit of a relief.

The nightmare
I hadid dn't happen.

But they couldn't calibrate it
until after we were long gone.

And so we had no idea

that our mission was successful
even after we landed.

All anyone
can do is wait for the pictures.

11 days later,
the calibrations are complete.

You know,
this is what was happening

in December of 1993...

Everybody gathering
around the monitors

and looking at the first images
taken by Hubble space telescope.

- Whoa!
- Hey, hey, hey!

And they were gorgeous.

- Oh!
- We did it!

- Wait, wait, wait, wait.
- No, no, no.

I'm sitting there
with tears running down my face

looking at this stuff,
and everybody's spellbound.

I had no clue that the images

would be as powerful
as they are.

I never imagined something
like this.

This is... this is astounding.

That's got to be astounding
to anybody.

But these are more
than beautiful images.

Each pixel helps unlock
another scientific mystery.

'Cause people were trying
to use ground-based telescopes

to measure the expansion
of the universe,

and that means uncertainty
in the age of the universe.

But by looking deeper
and deeper,

it's looking farther
and farther back in time.

And it's measuring the expansion
of the universe,

so we can tell precisely

when the universe
formed, you know,

13.7 billion years ago.

Hubble has solved, you know,
one of the biggest mysteries

in astronomy and in science.

With each image,
the discoveries keep coming.

They pointed Hubble at a place

in the sky
where there was nothing,

and there are like
1,500 galaxies in that photo.

1,500 galaxies.

You know, our milky way
is just one tiny, little galaxy.

We now know that there are more
stars in the universe

than grains of sand
on all the beaches

in the world.

But Hubble is also
a time machine.

You see, there's this wonderful
look-back effect,

where the farther out
in space you look,

it took ghlit a long time
to get to you.

And now
you look at thesime ages,

and you effectively look back
almost to the beginning of time,

the beginning of the universe,
wi th Hubble.

This new image from march 2016

is the furthest look
back in time yet.

The light from this young galaxy
dates to just 400 million years

after the big bang.

It is surprisingly bright,

which means that galaxies
were growing much faster

and much earlier
than we ever knew.

25 years after launch,
Hubble continues to amaze.

The idea that someone
could be interviewing me

and putting these images

up in front of me
and having me comment on them

and telling me
that we're in our 25th year

of successful science
operations,

that's a mind-blower.

In NASA, I think Hubble's
only second to the Moon landing.

I mean, it's that big.

Coming up,
a team of scientists searches

for the origins
of life on an asteroid

that can also bring us death.

Could cause a tremendous amount
of damage in the local area

where it hit.

As we look farther
into the universe

than ever before,

we may be looking deeper
inside ourselves.

One of the most surprising facts

about our relationship
with the larger solar system

we live in is that the organics
in our body

were most likely
brought here to Earth

on comets and asteroids.

Rich in molecules
called nucleobases,

the same molecules
that make up our DNA,

asteroids could be the key

to unlocking the mystery
of life on Earth.

And maybe the very origin
of your body, of the chemistry

that you're using
to watch TV right now,

came from the asteroids.

One asteroid
is especially intriguing.

Its name... Bennu.

In the case of Bennu,

it's about half
a kilometer across rock.

Bennu itself is
an exciting object.

It's a carbonaceous asteroid.

Carbonaceous means

that it contains
the element carbon,

which, as we all know,
are associated with life.

Bashar Rizk is a scientist

at the university of Arizona.

But it's not just
the possibilities of life

that makes Bennu
interesting to Bashar.

It's also the possibility
of death.

Bennu is a class of asteroids

that share the same region
of space as the Earth

as they move around the Sun.

Every six aryes,

it's in the same general region
as the Earth.

That increases the opportunity

that it would actually hit
the Earth and cause damage.

To understand

whether Bennu truly poses a risk
to Earth, we need to see it.

In the mountains
outside Tucson, Arizona,

Eric Christensen
searches the skies above Earth

for asteroids and comets.

This object
that's circl iedn red

here in the middle,
it looks like a faint star,

but it just happens to be
the asteroid Bennu.

Or the Catalina sky survey
is our first line of defense

against asteroid impacts.

Asteroid impacts are really
a fact of life.

They always happen,
they have always happened,

they will always
continue to happen.

We will point our telescope
at a particular area of the sky,

and we will build up
over time, essentially,

a very low resolution movie.

We can compare the images

and identify stars
that are stationary.

And then anything
that is not stationary

is a potential moving object.

When astronomers
discovered Bennu,

they quickly realizethd at
of all the near-Earth objects

in their sights, this asteroid
has one of the highest chances

of impacting Earth.

Bennu had come near the Earth
near enough

that we could get
radar reflection off of it.

Therefore, we know something
about its shape.

To fully understand
where Bennu is going,

Peter and Bashar need more
than just fuzzy radar imesag.

So in September 2016,

they will launch
a spacecraft called Osiris-Rex.

After two years
of traveling through space,

it will intercept the asteroid.

Once there,
its mission is two-fold.

Osiris-Rex will collect a sample
of the asteroid

to return to Earth,

and it will photograph
the entire surface

in extreme resolution,

taking pictures down to the size
of a pebble.

Our cameras will go
and try to characterize

the asteroid's environment.

We're gonna image this object
to a higher degree

of resolution
over a larger piece

of its terrain
than has ever been done before.

Mapping Bennu
with these cameras is essential,

because we'll understand
the gravity of this object

to a much more precise degree.

Predicting where this object

will be 100 years
into the future

is very important,
because this is one

of the potentially most
hazardous objects

in the solar system
for the Earth.

To precisely determine
Bennu's future orbit,

scientists need to know
the asteroid's exact size

and shape.

That's because of a phenomenon
known as the Yarkovsky effect.

Any object in the solar system

experiences
the Yarkovsky effect.

Now, what is it?

Well, it's a thermal asymmetry

that happens because of
the rotation of an object.

As the Sun's
energy strikes Bennu,

it gradually
changes the asteroid's orbit.

Things have had a chance
to heat up.

Now, when something is hot,

it tends to emit photons,
thermal ones.

Photons carry momentum.

So, what this is doing
is acting like a little bit

of a thrust in this direction.

If I thrust that way,

I'm kind of increasing
the energy of the orbit

and moving it out
from the Sun a little bit.

The high resolution images

from Osiris-Rex
will tell the team exactly

how the Yarkovsky effect
is influencing Bennu's path.

If an object the size
of Bennu struck the Earth,

there would be
a regional catastrophe,

perhaps taking out as much
as a state or several states.

It could cause a lot of damage
and the loss of a lot of life.

Space is all about exploration,

and it's something we humans
seem to kind of be wired with.

History's shown
that you've got two choices...

You could either
keep marching ahead

or you could fall behind

and end up
in the dustbin of history.

Standing still is not an option.

Revealing the deepest
secrets from space

can inspire wonder,

but they can also incite fear.

This grainy image
shows an asteroid called Bennu,

and it may be on a collision
course with Earth.

Odds of Bennu hitting the Earth

are less than 1 in 2,000.

That's still considered high
for this class of object.

Typical odds would hopefully
be lower than one in million.

Bennu is smaller
than the asteroid

that killed the dinosaurs,

but it could cause
a tremendous amount

of damage in the local area
where it hits.

For instance,
it could really damage something

the size of a large city.

Or if it hit just off shore,
it could create a tidal wave.

In September 2016,

Bashar and Peter
will send a probe

to photograph Bennu in detail

and reveal its secrets.

But a mission like this is
fraught with potential pitfalls.

In August 2014, a spacecraft

called Rosetta arrived
at another small body,

a comet caught
in Jupiter's gravity.

Three months later,
the Rosetta team

attempted to land
a probe called Philae

on the comet's surface,
and it ended in disaster.

Philae was equipped
with a couple of harpoons

so that when it made
its landing,

they would shoot out and ideally
try to moor it there.

Except that, apparently,

the harpoons did not fire
when Philae landed.

So, because of that, Philae hit
the surface and bounced.

And it bounced several times
because of the comet's rotation

and the lander's own velocity.

And it wound up coming down
in an area of the comet

that we didn't have
good maps for.

And so basically,
the lander was lost.

The team is determined
to see their mission succeed.

That's because there is more
to learn from Bennu

than whether or not
it will collide with Earth.

It could unlock the origins
of life on our planet.

the Earth formed when objects
slammed together.

But later on, as it cooled

and water became a large part
of the surface composition,

then it was possible
for future impacts

with smaller objects

to actually bring in
organic materials

that could survive
on the surface.

That's how many people think
organics came to the Earth...

Through those impacts
from asteroids.

When we get a sample of Bennu
back into our laboratories,

we're gonna be looking at
material that formed

in the initial phases

of the formation
of the solar system.

If we could someday prove

that the building blocks
of life on Earth

actually came from space
and not from our own planet,

it would turn everything
we understood about the origin

of life on its head.

Osiris-Rex will not attempt
a landing like Philae.

Instead, it will get a sample
of the asteroid

with a revolutionary
new system called

T.A.G.S.A.M.

"Tag" stands for "touch and go,"

and "Sam" is
"sample acquisition maneuvers."

So T.A.G.S.A.M.
Is the actual act

of reaching out,

touching the surface
of the asteroid

and gathering the sample,
then pulling away.

Once samples
from Bennu arre ivback on Earth,

we can test them for the kinds
of organic materials

that could have seeded
Earth four billion years ago.

But to successfully
retrieve the sample,

the cameras
must function perfectly.

The cameras are one
of the critical experiments

on this mission because,
as we get closer,

it can refocus and actually
become more like a microopsce,

and it can detect grains

that are just
a few millimeters across.

So when we get
to our sample site,

we want to get
the highest resolution possible.

With only months
to go until liftoff,

the clock is ticking
to get Osiris-Rex right.

We'll be launching in September
of 2016.

So we have a schedule
pressure here

that I think does
take its toll on the team.

There are a number of things

that we're trying out
for the first time,

and that keeps people up
at night at NASA.

Should the mission fail,

NASA will need another way
to reach Bennu.

Scientist Ben hockman
cread tea backup plan,

and to test it,
he's hitting the beach.

I think most people assume

asteroids are
just big rocks in space

when in fact they have very
interesting surface geology.

We've found
through recent missions

that there can be a wide variety
of different surface features.

With its mix of sand and rocks,

this beach mimics terrain

that NASA has observed
on comets and asteroids.

It is the perfect place

to test Ben's rover
nicknamed dgheehog.

Hedgehog is a whole
new class of rovers,

very different
from the previous rovers

that we've sent
to the Moon and Mars.

We have seen that the topology
of asteroids can be very uneven,

so there's potential

that a rover could fall
into a pit or a crater

and be unable to escape.

All right.
Hopefullthy is works.

It may not look like much,

but on an asteroid,

where gravity is a tiny fraction
of the Earth's,

this same hop would propel
Hedgehog

far across the surface.

It uses three internal flywheels
to build up momentum internally.

And by doing that, it can hop
and tumble across the surface.

These spinning
flywheels build up momentum,

and when Ben applies the brakes,

he transfers that momentum
into motion.

Think about it
like you're driving your bike

and you come to an obstacle
and you hit your front brakes.

You have a lot of moment
about your front wheel,

so you have a tendency to want
to flip over your front wheel.

The same is true for Hedgehog,

but we do that to our advantage
to hop in a controlled way.

But to see
how Hedgehog will work

in a near-zero-g environment,

Ben must head to the lab
at Stanford university.

So, this contraption is called
a microgravity testbed.

The microgravity
testbed allows us to emulate

what the rover might do in
actual microgravity conditions.

The bed shows Ben

how Hedgehog will behave
on an asteroid like Bennu.

At those scales, gravity

is about 1,000 or 10,000 times
lower than that of Earth.

So on an asteroid,

a human would weigh
as much as a paperclip.

One of the key advantages
of Hedgehog

is that there's no right way up.

In other words,
it can land on any side

and be just as capable of moving

as if it were to land
on its fit, so to say.

And Hedgehog
holds one other advantage.

Because Hedgehog
is so compact and cheap,

you could store potentially many
of them in a spacecraft

that you send to a small body.

So you could imagine an myar

of Hedgehogs hopping
around the surface,

exploring the physical
properties of an asteroid.

For now,
Hedgehog is only a prototype.

So it will be up to Osiris-Rex

to unlock the secrets of Bennu.

The answers
won't come until late 2018,

when Osiris-Rex and its cameras
finally reach the asteroid.

I think that the images of Bennu

are going to be revelatory.

Waiting for those images

to come back
in 2018 and 2019 will be...

The only thing
I can compare it to

would be waiting for the births
of my two children,

because it's something
very important to you

and you're not quite sure
of the outcome.

Until then, scientists
can only wonder if Bennu

will change our understanding
of life on Earth.

How did all that get going?

Did it start it here,

or was it brought here
from outside?

We don't really know the answer
to that.

We're gonna go find out.

If the building blocks
of life did come on an asteroid,

perhaps Earth wasn't the only
planet where they landed.

Today, a team of scientists

is driving a rover millions
of miles away to see

if life could have thrived
on another world.

You get a flat tire
on your car, no big deal.

You call AAA.

You get a flat tire
on the rover,

that's the end of the mission.

For years,

a satellite called
the Mars reconnaissance orbiter

has been photographing
dark streaks

on the slopes of a crater...

Mysterious lines

that appear to change
with the seasons.

On September 28, 2015,

NASA scientists announced
their groundbreaking conclusion.

What we're going
to announce today

is that Mars is not
the dry, arid planet

that we thought of in the past.

Today, we're going to announce

that under certain
circumstances,

liquid water
has been found on Mars.

Scientists have never found
liquid water on a surface

anywhere beyond Earth.

The discovery is historic.

Life as we know it on Earth
needs liquid water to survive,

so that's kind of the key
first thing that we need.

We also need organic materials.

So those are some basic elements
like carbon and hydrogen

and oxygen.

In 2012, a rover

called Curiosity landed
in an ancient martian lake bed

known as Gale crater.

A roving chemistry lab,
Curiosity drilled into the soil

in search of organic molecules.

One of the last pieces
of the puzzle with Mars

is that we'd never been able
to detect the presence

of organic molecules.

And Curiosity put that
puzzle piece in.

We know that there are organics
in the soil.

We also discovered...
And this is really important...

We found an environment
that wasn't very acidic.

And that was really
our first discovery

of a habitable environment
on Mars

where we think
life could have existed.

We have found evidence
of water and organics.

But were they both plentiful
on Mars for billions of years,

perhaps even long enough
for life to take root?

Mount Sharp,

the three-mile-high peak
at the heart of Gale crater,

may hold the answer.

It is a time machine.

The higher up the slope you go,

the further back

you travel in Mars's
geological history.

We really were looking
to Mount Sharp

to tell us the record

of environmental change
through Mars's history.

We think that there's
a possibility that,

as you go up through the layers
of Mount Sharp,

we may be exploring different
habitable environments.

And so what we're interested
in finding out

is how does the habitability
as a whole change through time?

Today, Curiosity is entering
a new phase of exploration

by climbing Mount Sharp.

Along the way,
it will alanyze the soil,

piecing together
three billion years

of martian history.

But for rover driver
Matthew heverly,

the path ahead
is fraught with danger.

We're always pushing
the limits of this vehicle.

I mean, the rover's amazing.
It can handle so much.

But as we go to Mount Sharp,

we've got some pretty
gnarly terrain

to head over.

Here we go.

To find out just what kind

of terrain Curiosity can handle,

Matthew and Katie take a rover
out for a spin.

So, we built three rovers.

We sent one off to Mars,
we built an exact copy

that we keep here on Earth

for testing software
and cameras,

and then we built
another one, scarecrow,

because we have
to adjust for gravity.

Mars's gravity
is 3/8 that of Earth's.

So Curiosity's 2,000 pounds
become about 750 on Mars.

Scarecrow rover's stripped down,

but it weighs on Earth
what Curiosity weighs on Mars.

So it's got the right
ground pressure.

It's got the right, you know...
As we're going up a hill,

it's carrying the right amount
of weight up that hill.

So we can test in the Mars yard

how steep a slope
can we climb up.

Satellite photos reveal
that the most direct path

up Mount Sharp would take
Curiosity through sand dunes.

So Matthew
and Katie decide to see

just how much sand
the rover can take.

Sand is scary for us

because we understand
what's going on,

but we get constantly surprised.

What angle do you have there?
- We're at like 16 1/2.

We would not do
this much slip in operations

unless we were very sure
we could get out.

Yeah.

And then it just gets harder
to extract yourself.

What we're learning
is that the sand dunes

are really just too great
of a challenge

for the rover to handle.

The rover
actually does a better job

with the steep, rocky slopes.

The team chooses
a path around the dunes.

And curiosity
continues on its journey

up the slope of Mount Sharp.

Will Mars prove to be a planet
where life once thrived?

Only time will tell.

Coming up,

these mysterious images
take the search for life

to a totally unexpected place...

A tiny moon called Enceladus.

This is the single most
important and interesting place

for astrobiology
in our solar system.

October 28, 2015.

The Cassini probe
captures one of its final images

of a mysterious moon
orbiting Saturn.

Its name... Enceladus.

Its diameter
is just 310 miles...

Less than 15% of our own moon.

But these photos
reveal what appear to be

volcanic geysers
spewing from its surface.

Scientists are trained
not to jump to conclusions,

so we weren't gonna
say "definitely",

we've found something."

We thought, you know,

"Toto, we're not in Kansas
anymore."

This is something really,
really outstanding

and something very significant.

Why do these plumes exist?

What is inside them?

To me,
it eclipses everything else

we know about the other worlds
in the solar system.

This is the single most
important and interesting place

in our solar system
beyond the Earth.

Could this tiny ball of ice

actually contain the ingredients
necessary for life?

In 1977, NASA
launches two spacecraft

on a 12-year journey

to the outer edge
of the solar system.

The Voyager probes send back
the first detailed images

and data of the gas giants
beyond the asteroid belt.

But one planet captures
the heart of Carolyn Porco.

I was a graduate student
when Voyager flew by Saturn.

I did my thesis
on Saturn's rings.

And it's, you know,
like your first love,

where it's the jolt

that we scientists
get is finding something new

that nobody else knows about.

And all that happened
for me at Saturn.

But one moon seems to hold

more mysteries than the others.

Covered in a thick
orange atmosphere,

its name is Titan.

It was Titan,
completely enshrouded in haze,

and we didn't know
when we got there with Voyager

whether or not we'd be able
to see down to the surface

with our cameras,
and it turned out we couldn't.

Unable to see
past the atmosphere,

Voyager cannot solve the mystery
of what lies beneath.

Titan was an object
of immense interest.

This was the place
that we need to go back to.

So when NASA put out
this announcement of opportunity

saying, you know,
"come apply to be involved

"in our next adventures
at Saturn," I applied.

And I'm so grateful
that I had the chutzpah

to think

"I'm not just gonna be a member
of the imaging team,

I'm gonna lead it."

In 1990,
Carolyn's dream comes true.

NASA places her in charge
of the imaging team for Cassini.

And this mission
will be different.

Voyager, mind you,
was a reconnaissance mission.

It was just a flyby.

And the whole purpose
is just to see

wh'sat there
in the brief period of time

that you're allowed.

But Cassini
will enter Saturn's system

and stay there for years,

imaging the planet and its moons

with high-powered cameras
and scientific instruments.

Three, two, one.

And liftoff
of the Cassini spacecraft

on a billion-mile trek
to Saturn.

In July 2004,
Cassini arrives at Saturn.

And right away,
it delivers on its promise,

taking the most
detailed images ever

of the ringed planet
and its moons.

I had been thinking
about Voyager imagery,

and then I walk into my lab
and I see this picture,

and it's incredibly detailed.

And that's when I thought,
"oh, my god."

This is gonna
be just spectacular.

This is gonna
be a wondrous thing,

"what we're gonna
be doing at Saturn."

The Cassini mission
brought us a wealth

of scientific discoveries
about Saturn.

For example, it helped discover
four new moons.

Cassini revealed
entirely new detail

about Saturn's amazing rings

and the way that they're moving
around the planet.

But for astrobiologist
Chris McKay,

the real star
of the show is Titan.

The reason
Titan was so interesting

for astrobiology was
that it is so rich in organics.

There's an organic haze
in the atmosphere.

We thought that there would be
organic liquids on the surface.

Organics are the carbon-based
molecules needed f lorife.

Could organic liquids

indicate some form of life
on the surface of Titan?

Carolyn and the team

have equipped Cassini to do
what Voyager could not...

See beneath the haze.

And it will happen by sending
a probe called Huygens

right down to the surface.

So Huygens was designed
to drop from the Cassini probe

and deenscd
through the atmosphere

and make a soft landing
on Titan,

sending back
information the whole way

about what Titan

was actually like
and finally giving us a chance

to peer through
these murky clouds

on the surface.

On January 14, 2005,
Huygens makes its descent.

When the Huygens probe descended
through Titan's atmosphere

on a parachute, it was taking
images of the surface.

We didn't know what to expect.

But it showed what look
like shorelines.

When we got pictures
of the surface,

it was very clear

that there had been liquid
of some kind on the surface

for a long time.

But Titan's surface

is nearly
minus 200 degrees Celsius,

so that liquid cannot be water.

So Titan has clouds,
it has rain,

it has rivers, it has seas.

But it's methane and ethane.

And the real question
for astrobiology is,

is there some sort of chemistry
that could make life

that could live
in this kind of liquid?

For life to exist on Titan,

it would have to be so alien

that it survived on methane
instead of water.

Although Chris McKay is hopeful,
it's a long shot.

But Titan is not the only moon
orbiting Saturn.

Enceladus was a moon

that we knew from Voyager
was unique.

It was the whitest object
in the solar system.

It was the brightest object
in the solar system.

It was associated
with the very big ring

of very, very fine
smoke-sized particles

that had been discovered
around Saturn in the 1960s.

Enceladus was the place
that we were just pulezzd about.

And other than Titan,
Enceladus was the Moon

that, on Cassini,

hwead planned to have
the greatest number of flybys.

Carolyn Porco turns
her attention towards Enceladus.

And once Cassini arrives,

a single photograph
transforms the entire mission.

I was focused on Titan,
but then my world changed.

For me, it was really
an "oh, my god" moment.

In February 2005,

the Cassini space probe

makes a shocking discovery

on Saturn's icy moon, Enceladus.

Our first observation turned out

to have something coming
off the south pole,

and it was clear.

Everybody just went all abuzz
with this. Like, "wow!"

There's something
coming off the south pole!"

Everybody was getting excited.

Scientists knew that the Moons
of Saturn were cold.

And then they suddenly
see these images of Enceladus,

and they noticed
a kind of activity

that you don't expect
from some sort

of cold, dead moon.

The image shows a plume
of material streaming miles

above Enceladus.

The Cassini team suspects
that it's water somehow ejected

by a powerful amount
of heat and energy.

Carolyn Porco
immediately contacts Chris McKay

with the news.

Carolyn calls me up.
I'm in a meeting.

But I know if it's Carolyn,
it's an importt anmessage.

So I ducked out of the meeting,

and I listened to the phone
call, and I was stunned.

And that's when I learned
about all the interesting stuff

coming back from Enceladus,

evidence of energy coming from
a subsurface ice environment.

My world changed.

The reason why this
discovery mattered so much

is that it meant that there
might be an enormous amount

of really interesting chemistry
going on there...

The kind of chemistry
that might be similar

to what we saw in the early days
of the Earth,

maybe replicating the kinds

of conditions
that might give rise to life.

Our first thought was
"we got to get a closer look.

Okay, we've got
to figure this thing out."

A few months later,

the probe makes
another flyby of Enceladus.

And this time, there's no
mistaking the power hiding

underneath the icy surface
of this moon.

And that's
when we really had our,

you know, our socks blown off,

because that's the picture

where you see about
a dozen narrow jets

coming off the south pole.

We found out
that heat was coming

from these four fractures.

But what is producing something
so extreme?

Scientists believe
the gravitational forces

of Saturn
are tugging on Enceladus,

creating friction
inside the moon.

The evidence indicates Enceladus
has massive amounts of water

and a powerful source
of energy...

Two key ingredients
in the search for life.

And the next step is, can we say
something from the molecules

we see about the conditions

of what's going
on this subsurface?

Can we say anything
about the presence of biology?

Can we see anything

that could be
consistent with biology?

The team looks to find
signs of organic material

in the plumes.

And what Cassini finds provides
even me orevidence

that the building blocks of life

may be brewing
underneath the icy surface.

We have found that the particles

in the plume close
to the surface were salty

and they had a salinity
comparable

to the Earth's oceans.

And that said
that this body of water

had to be under the ice shell

and in contact with a core,

in contact with a rocky core.

It could be an environment

similar to hydrothermal vents

at the bottom
of Earth's oceans...

A place where life exists.

So, all of this put
together said that we had a zone

that could possibly
sustain life, okay?

It had the basic irengdients.

It doesn't mean
it has the secondary

and tertiary ingredients,

but could it possible be a place
where, you know,

if biological activity
is not taking place now,

it might be well
on its way to taking place.

Over the next veseral years,

Cassini continues to gather
data and photos

from Enceladus and its plumes.

But in December 2015,

after 10 years of flybys,

Cassini approaches Enceladus
for the last time.

Carolyn and Chris
are among the first people

to see the final images.

This is the last flyby
of Enceladus by Cassini.

These are
the last close-ups.

That's right.
Are you strapped in?

He re we go.

Look.
Oh, my god. What...

Oh, those are just craters,
but look at them.

It's incredible, isn't it?

Really nice.

Wow, I wasn't expecting that.

We're gonna be working with this
now divine set for a long time.

Oh, very long time.

I mean, Cassini's
been so incredibly rich.

I bet we'll be working
with Cassini data for 50 years.

But this final pass by Cassini

doesn't study the plumes
on Enceladus.

If scientists
are going to continue

looking for signs of life,

a new probe
will have to go back,

because in September 2017,

Cassini will end its mission
and plunge

into the atmosphere of Saturn.

For scientists who are looking
for possibilities

of life in the outer
solar system,

seeing these jets on Enceladus,

this is winning the world series

and the super bowl
all rolled into one.

This is the best possible
discovery they could make.

That's why Dr. Porco
and her team

are determined to return
with a new spacecraft.

We're not sure
that there's life there.

We just have strong indications
that there is at least

an environment there
that could support life,

and maybe even an environment

where life
might veha originated.

So, the thing

that many of us want to do
is we want to go back,

and if at all possible,

eventually bring back
a sample to Earth.

To me,
it eclipses everything else

we know about the other worlds
in the solar system.

This is the single most
important and interesting place

for astrobiology
in our solar system

beyond the Earth.

Could you tell
I'm enthusiastic about it?

Coming up,

there are many
unexpected dangers

to exploring the universe.

But it turns out one
of the most likely threats

we've created ourselves.

Radar detected that something
was moving very, very fast

in the direction
of the space station

and that a collision
was a very real possibility.

Our exploration of the universe

has opened the door
to a world of new discoveries.

Hubble has revealed

that the universe is expanding
faster than anyone realized.

Cassini has opened new
possibilities

for life beyond Earth.

But the most
important discoveries

could be in our own backyard.

The thing about
the international space station

is that it's in about a 200-mile
above-the-Earth orbit,

and so there's
this wonderful detail.

Pictures from the I.S.S. To me

often seem like
abstract paintings.

There are details
of river deltas

or sand dunes

or forests,

and they're works of art.

They're so beautiful
that I have to stop

and look at these
and just soak them in.

For six months,
astronaut Ron Garan

lived and worked on
the international space station,

and he saw our world in a way
few people can imagine.

The Caribbean
is like a glowing jewel.

The himalayas,
the middle east...

There's many, many
really interesting,

beautiful places from space.

The space station
gives us the ability

to explore our home planet
in a way we never could.

But that god's eye view
is getting dangerous.

We have a somewhat risky
environment

that we've created
because we are surrounded...

Our planet is surrounded...
By this cloud of space debris.

Three, two, one, zero.

And liftoff!

For almost 60 years,

we've launched rockets
and spacecraft

into Earth's orbit.

But now thousands of objects,

from tiny screws and bolts
to dead satellites,

encircle the Earth,

transforming the space
above us into a junkyard.

It seems kind
of comical the idea

that someday the Earth
might actually be surrounded

by some ring of space garbage,

kind of a like
a less-nice version of Saturn,

but it's a real possibility.

Now the international
space station

is in the cross hairs.

The international space station

has already been hit
by little bits

of debris on a number
of occasions,

and there are no guarantees
that other substantial things

might not hit it again
in the future.

It's the job of the military
to monitor the thousands

of pieces of debris
orbiting the Earth.

The men and women
at Vandenberg air force base

in California
are keeping their eyes

on the skies 24 hours a day.

So, currently we monitor

and track approximately
23,000 objects in space.

Among those is about 1,300
active payloads or satellites,

and the rest being space debris
from prior launches

or prior collisions.

Everyone on Earth should care

about what's going on
with space objects

and space debris

because we're so reliant
nowadays upon technology that,

if something were to happen
to a satellite, it's going

to severely degrade our ability
to do certain things,

whether it be
atm withdrawals, GPS,

or anything.

It's critical
that we track space debris

because it poses a risk
to all active payloads,

including the international
space station.

Some of this debris we track
up to c10entimeters.

Even a piece of debris

the size of a small screw
could destroy the space station.

If you can think of a
two-centimeter ball bearing

up in space, it's traveling
at 17,000 miles per hour.

That force is equivalent
to a Jeep wrangler

traveling at 70 miles per hour.

So as the object's
size increases,

the impact and the force
behind that collision

could be astronomically larger.

In June 2011, Ron Garan

found himself facing
that danger firsthand.

I was maybe four months
or so into the mission,

and we got a call
from mission control

that a piece of space debris

was gonna pass a lot closer
than people wanted.

If we know about it soon enough,

we will change the orbit
of the space station.

We can boost it up higher
or lower

and change it so that
we avoid that object.

But for whatever reason,
this one caught us by surprise

and we did not have enough time

for us to be able to move
the orbit of the space station.

With the astronauts

staring down the threat
of a collision,

they're faced
with only one choice...

Abandon ship.

The international space station
has several different ways

of trying to deal
with potential collisions,

but the last-ditch defense are
the two soyuz space capsules,

because those are basically
lifeboats.

Ron and the crew race
to the soyuz capsules.

Now the only thing
they can do is brace for impact.

And then it was just a waiting
game after that.

We didn't know
if it was gonna hit it or not.

In June 2011,

the crew of the international
space station learns

their lives
are in imminent danger.

Space debris
is heading towards them.

Nbc Jeff Rossen,
watching all of this.

Jeff, good morning to you.

Space junk was
on a collision course

with the international
space station,

spotted so late
there was no time

to move out of the way.

Instead, the six astronauts

got the order
from mission control.

If all else fails,
the astronauts on board

the space station can climb
into those soyuz space capsules

and wait to see
whether a collision

actually takes place.

If it does, they can,
in a few seconds,

detach from whatever's left
of the space station

and then immediately
try to return to Earth.

Mission control orders

the astronauts
to the soyuz lifeboats.

It's only the second time

a crew has been told
to potentially abandon ship.

Once we got all
the hatches closed

and we were all buttoned up
in our soyuz spacecraft,

there really was nothing
to do but wait.

We discussed, "okay,
if things get really bad",

this is what we're gonna do.
We're gonna undock."

You know,
we started to talk about that.

And then it was just a waiting
game after that.

But we didn't know
if it was gonna hit it or not.

Finally, after 15 minutes,

word arrives
from mission control.

When the object
passed the space station,

we got a call
from mission control

that, you know,
it was all clear.

And it turned out
that this object

passed within a football field
of the space station,

and relative velocity
was eight miles per second.

So a fairly large object
traveling that fast,

it probably would have destroyed
the space station had it hit.

But with thousands
of objects orbiting the planet,

the next time,
they might not be so lucky.

There is evidence
of hits on the space station,

and, you know,
a little piece the size

of a grain of sand
could really make a bad day.

It's something
that should be a major concern

if we're gonna continue
to use the environment of space

for the things
that we want to use it for.

Exploring Earth
in the 21st century

means capturing it from above.

But space debris
is not the only threat

to this unique perspective.

the Sun seems to be always there
and unchanging.

It's just this bright ball
of light in the sky.

But in fact,
it's changing all the time.

And that affects us here
on Earth

because we are bombarded
by radiation from the Sun,

both in the form of light
and subatomic particles.

the Earth's atmosphere

is a protective shield
for anyone on the ground.

But in space, there's no escape
from the power of the Sun.

Solar flares and other
kinds of violent eruptions

from the Sun
are very, very dangerous

for anybody who's in space.

The amount of radiation

that suddenly is pouring
off of the Sun

at that point jumps way up.

And we can try to create certain
kinds of very shielded areas

that the astronauts can hide in,

but even those can only offer

very inadequate protection

against the level of radiation

that the Sun can suddenly
release at those times.

An extremely
powerful solar storm

could send the crew
looking for cover.

What we would do
is we would find a place

on the space station
that offers the most protection.

Water turns out
to be a fairly good insulator

of radiation.

And we do have bags of water
on the space station.

We'd probably huddle some bags
of water into a location

and get behind that
as best we could.

But in spite of that danger,

the same powerful burst
of energy

also gives the astronauts

on the space station
front-row seats

to the greatest
light show imaginable.

The auroras are just incredible.

And there were times
on my mission

where we flew so close
to the auroras

that you could reach out
and touch them.

I mean, they were going right
by the windows.

It was absolutely incredible.

The pictures
really don't do them justice.

They really do dance.

But what you're seeing, really,

is the aftereffect
of a tremendously energetic

and dangerous solar storm.

These subatomic particles

screaming
across the solar system

at just under the speed of light

are getting swept up
by the Earth's magnetic field

and funneled down
into our atmosphere.

It's humbling and amazing.

From discoveries at the edge

of the solar system
and beyond...

to mysterious asteroids
hurdling through the cosmos

and the search for life
in our own backyard,

images have transformed
our undersndtaing

of the universe.

Everyone knows the cliche

"a picture is worth
1,000 words."

But to me, being a scientist,

you have to find a way
to turn cold numbers,

just data,

into something that emotionally
resonates with people.

We are trained
to be very, very logical,

but all of us, really,
are just like everybody else.

We're emotional and, you know,

we get excited
about a beautiful scene

and can, you know,

just spend hours
looking at something

and imagining what it would be
like if we were there.

And these images are the result

of cutting-edge missions

driven by the explorers willing
to put everything on the line

to capture space's
deepest secrets.

These days, I think we've seen

that there's a whole
new team of heroes.

These teams of scientists
and engineers,

they're the ones
inventing these craft.

They're the ones
devising these missions.

They're the ones making sure
they come off without a hitch.

They're the realer hoes now.