Original subtitles

(ominous music)

What asteroids are are really

remnants from when the solar system was forming.

Comets are always seen as kind of the

building blocks leftover from

the formation of the solar system

four and a half billion years ago.

Comets and asteroids retain the secrets

of the formation of our solar system.

And also retain the secrets

of the formation of our planets.

(ominous music)

(dinosaur roaring)

We also have to respect them

as something that could actually

change our way of life even today.

(exciting music)

We have high confidence that the dinosaurs

were ended by a very large impact

of an asteroid on the earth.

(exciting music)

If a large enough asteroid were to hit the earth,

it would be quite cataclysmic.

(explosion booming)

(music fading)

Is there an imminent threat?

Is there a big one that's on the way?

And the answer there is no.

(sustained instrumental music)

The impact frequency of a 10 kilometer asteroid

which is about the size of

the body that killed the dinosaurs

is every hundred million years.

So it's very long compared to a human lifetime.

The good thing is that we are going to

save the life of Bruce Willis,

because we don't need him to save earth, fortunately.

(slow piano music)

Impacts are not necessarily just bad things.

The earth was very dry when it formed.

There was hardly any water, there were hardly any carbon.

And we think that most of that material

was actually delivered at a late stage by impact.

So it's quite probable that the ingredients for life

(seagulls cawing)

were delivered by asteroids and comets.

I want to learn in the end, how life evolved.

Exploring comets and asteroids

will tell us how life developed on our planet.

(sustained piano music)

(comet whooshing)

10, nine, eight, seven, six, five, four--

So the NEAR mission was designed and conceived

so that it would actually show up at an asteroid,

stop, be in close proximity to it

for an extended period of time.

One.

Just to see what an asteroid was like.

Zero, and liftoff.

(rocket engines blasting)

NEAR launched in 1996.

Temp and pressure rising

in all six powered motors.

And like all planetary missions,

it takes a long time to reach the target.

We'll trim the pressure on the management.

So it didn't arrive at Eros

until the 20th of December in 1998.

We have a good engine control

in the main engine, good engine control in the rears--

(anticipatory music building)

(music halting to a single note)

As you fly into the body,

you've never seen it before,

and you start to see the images.

(slow orchestral music)

At first they're very fuzzy,

but then they come more and more into focus.

And at every stage you're seeing new things.

When you see these pictures, it's just awe.

It looks like it's two asteroids

that are just sort of resting on each other.

And it's got this beautiful saddle regions

where they sort of touch each other.

To me it's a very beautiful asteroid.

It's got this beautiful shape and smooth curves.

(sustained orchestral music)

It's a very, almost sensual experience.

(music building)

That phase of the mission

lasted from December 1998

all the way to February, 2001.

The spacecraft was nearing the end of it's life,

it couldn't fly back to earth.

The mission manager had people start studying,

well what would it take to actually

bring the spacecraft down to the surface,

to have a soft landing so that maybe

the spacecraft could even survive?

When it was launched it was never designed

to actually land on the surface.

I remember thinking that, "There's no way

"this is gonna work."

We have successfully de-orbited around Eros,

and we're on our way down.

There's no turning back now.

(piano music building)

It was a complete success.

I'm happy to report that the NEAR spacecraft

has touched down on the surface of Eros.

It landed, perched itself on the surface.

It was quite exciting.

This is the first time that any spacecraft

has landed on a small body.

(group applauding)

NEAR-Shoemaker was a forerunner of the later missions.

It showed that it's possible

to touch down on an asteroid.

The next big target is to bring a piece

back to earth.

Got it.

Nope, it dropped.

See if you can pick it up again.

I think it'll fit in a bag, Jim.

We went to the moon, we got lunar rocks,

then brought them back to the earth,

and have been analyzing them ever since.

It allows us to understand

our own earth so much better.

It's sort of like archeology of the solar system.

(speaking in a foreign language)

So, Hayabusa set the stage

to answer that next question.

And ignition.

(speaking in a foreign language)

There shall be ignition and liftoff!

(speaking in a foreign language)

The Hayabusa mission was incredibly ambitious.

JAXA, the Japanese space agency

wanted to send spacecraft to an asteroid,

grab a piece, and bring it back to earth.

The very first sample-return mission.

(group applauding)

That was really the first time

that you had the (speaker mumbling) to try something.

So you really have many, many, many unknown.

Oh geez, it's crazy.

It was a very ambitious mission.

From the start it was also sort of a cursed mission.

There was very big solar flare.

It kick the solar panel over Hyabusa.

The solar flare compromised their solar arrays

so they had less power to push

themselves on towards the asteroid.

Furthermore, they were carrying some reaction wheels.

Reaction wheels are used to

stabilize a satellite, and one of them was damaged.

That was also a very large complication

because it changed the whole way

that they controlled the spacecraft.

Space is harder.

It's not a friendly environment.

When everything goes well, it's a miracle.

Especially when you go to a new world.

Took two years for Hayabusa One to reach Itokawa.

The first images started to come.

When we saw the images of Itokawa,

we discovered

really a new world.

(orchestral music building)

It's a new thing, it's a new image,

a discovery, it's fantastic.

It's really fantastic.

(soft orchestral music)

Hayabusa One is there to collect

pieces of the asteroid.

And that all begins on November the 5th, 2005.

The spacecraft went down to the surface.

Spacecraft's gonna slowly come down to the surface,

and then they have a funnel,

and that funnel touches down on the surface.

It would fire a projectile into the surface,

and the debris comes up the funnel,

and it's then collected into the container.

And then away it would go.

So it was a touch and go.

All this in one second.

One second.

So stroomp, one second, poomp, and then you're going.

Well, actually it stayed 40 minutes on the surface.

The dangerous thing is the

surface temperature can destroy the spacecraft.

That was really a panic,

a source of panic.

There was every danger.

The projectile was not fired.

So there was nothing to make that plume of dust

go up into the sample container.

Eventually the spacecraft leaves the surface,

and unfortunately there is

now a leak in one of the fuel lines.

There was a leak, we're generating the torque,

so the space travel is really bad.

(ominous rock music)

When you're leaking material into space,

it's like having another engine.

It's like a jet.

We had a very serious problems.

We couldn't control the spacecraft.

What can we do?

Never run faster than when you have

a bull running after you.

You have to find a solution,

and when you are in an emergency

you find it in a much clever way.

We never gave up.

Every time were able to find some solution

to overcome our troubles.

They were able to tell that in a few months

they would actually be able to get

small commands into one of the antennas.

Finally, we found how to operate the spacecraft.

At that time, we are very happy.

For Hayabusa, the struggles were not over.

So it had to get back to earth.

Here is this crippled spacecraft,

you know, literally limping home.

It's like you have,

you know, you have to guide somebody

with just one leg, one eye,

and then try to make him go straight.

It's very crazy.

People are worried that the mission

is going to fail at this stage.

That we potentially may or may not

have collected samples,

and that it might not actually make it back to earth.

So they're hanging on by a thread.

(anticipatory music building)

But, they were able to hang on.

We (speaker mumbling) that looks like lower right.

They were able to successfully navigate

all the way back to earth.

Nice flashes.

Oh, wow.

(inspiring music)

40 kilometers.

The capsule landed, but may be empty, nobody knew.

All these efforts

maybe was for nothing.

Everything else then went to (speaker mumbling)

and they could open and then see

where they discovered that there were samples.

(instrumental music)

They did it.

The thing was quite emotional.

I was very moved to see the sample.

They have indeed collected

maybe 1,500 dust particles.

Hayabusa One brought back a lot of science.

Hayabusa came back in 2010.

Nine years later, we still do find out more

discoveries with these teeny samples.

One of the things we're interested with asteroids

is whether they delivered the oceans to earth.

So a few weeks ago, there was a measurement

of the water properties of the sample.

They measured the properties,

and they're the same as the property

of the oceans on earth.

It is the same kind of water.

They are a match.

So it's the first clue that maybe

all this wonderful water on the surface of the earth

actually comes from asteroids.

(music fading)

(gentle piano music)

Asteroids are fascinating,

but further out away from the young sun,

is where very bizarre objects were created.

The comets.

Comets are the most primitive objects we can study.

What is, so to say, the source of this wonderful

display in the sky?

People have always been intrigued

by these messengers that come out of the night sky.

What are these objects?

Where do they come from?

What are they made of?

(orchestral music)

What's locked up as treasures, secrets in comets?

For a long time they were mysterious.

We didn't even know their orbits.

(music swelling)

And it really wasn't until the observations

of Halley's Comet where it was realized

that they actually orbit the solar system.

That it comes back every 76 years.

Halley's Comet has a special place.

1986 was a really special year

because we got a first look.

It's a once in a lifetime opportunity.

First stage servo motor started.

The object of Giotto was pretty simple, really.

To intercept Halley.

Final arming, ready to go.

(countdown in French)

Was excitement, because this is new.

This was an adventure, never done before,

and now we go.

Ignition.

(rockets firing)

Now they have first stage ignition and takeoff.

We launched early July in '85,

so it's a eight months journey.

(crowd applauding)

The comet has an atmosphere that we call the coma.

And then the tail streams away from the comet.

And the tail also contains dust.

Dust particles, although they might not seem hazardous,

if you fire them at a spacecraft

at many kilometers per second,

even a small dust particle can destroy the spacecraft.

(music building to a crescendo)

This is basically a kamikaze mission, so to say.

Fingers crossed.

Giotto made it's rush towards Halley's Comet,

and it's getting closer and closer to the nucleus.

And it's being hit by particles.

They're picking up impacts.

Dust impacts were increasing.

It's a tense time.

Just before the actual encounter,

It gets hit by a big one.

And it puts the spacecraft into a spin.

And so all of a sudden, it's protection, it's shield,

is not facing the dust particles.

We got anxious because we couldn't do anything.

We tried to keep cool and quiet,

and see what happened.

(suspenseful orchestral music)

All of a sudden, images stopped.

The camera goes dead,

and the spacecraft is still flying through,

through that debris.

And I think there were a lot of people there

who thought that they were going to lose the spacecraft,

and that was it, that was the end of the mission.

(quiet, suspenseful music)

But thankfully, it survived.

It went all the way through and lived on.

And it took about a couple of minutes

until we received all the data.

First of all, you see the image.

And you are one of the first ones

to see a comet nucleus.

(peaceful instrumental music)

It's beautiful.

They were just truly incredible.

The comet, surprisingly, is not this

bright, clean, ball of ice.

It's dark, it's almost black.

It was active only in a few spots.

That was the first big surprise,

because we thought the nucleus would be

active all over the surface.

(peaceful music)

We've learned about processes that are going on

inside a comet, that we would have never have guessed

unless we had gone there.

Giotto was remarkable.

(crowd applauding)

Sort of was really a unique mission.

Was the first mission go to a comet,

was also the first time seeing a comet nucleus.

These are things you don't forget.

Stays with you.

(peaceful music)

When Giotto flew past comet Halley in 1986,

the fly-by was around 68, 70 kilometers a second.

You see it for a few minutes and then it's gone.

It's all over.

To learn more, you want to go

and rendezvous with a comet.

You want to fly alongside it.

Can we learn about the evolution of these objects

by studying it over time?

And of course, then the idea comes up,

you would want to touch down on the surface.

You want to land there, sample material.

To do all of that in one mission is incredibly gutsy.

(countdown in French)

The first time I heard about the mission,

I thought, "They must be joking."

(countdown in French)

The Rosetta mission was incredibly ambitious,

but we jumped on it.

Take-off.

We launch in March, 2004.

The whole travel to the comet

was an adventure for Rosetta.

The comet is on an orbit with a different energy level

compared to the one of the earth,

so where to actually impart this energy

to our spacecraft to get the same orbit.

(anticipatory music)

So we did this thing to use the planets,

and to use their gravity

to slingshot us through space

on a different trajectory with more speed,

in order to be able to get to the comet.

After one year, we would come back to earth.

The next appointment was fly-by on Mars.

And very soon, we came back to earth.

And this launched us towards the main asteroid belt.

After this, we came back to earth.

This one gave us the last big kick.

We were really launched very fast,

but getting very far from the sun.

(music fades to a single note)

We could not keep all the systems on board active,

because the illumination of our solar panels

was getting very weak.

So the decision was made, in fact, to turn it off.

I hated that concept from the very beginning.

I've been fighting it for years.

I was convinced we would never do it,

it was too crazy.

Switching off the radio signal

is like cutting a vital link.

We've been flying a spacecraft for seven years

it's at hundreds of millions of kilometers away,

and what do you do?

You send a command to switch it off,

and wake it up three years later.

It just doesn't make sense.

And this is what we did.

(soft orchestral music)

We spent two and a half years without contact.

And we waited.

We couldn't talk to it while it was in hibernation.

We need it to wake up,

which it was due to do on the 20th of January, 2014.

(clocks ticking)

(alarms ringing)

Three, two, one, wake-up!

Wake up, wake up, wake up!

Okay, great.

We were sitting all in the control room,

waiting for the signal to come.

This was probably the most tense moment of the mission.

This was everything or nothing.

It was life or death.

I was sitting in the main control room

with a bunch of people that had

worked on this mission for most of their careers.

And they had run a sweepstakes

when they thought the spacecraft would wake up

and send it's signal back.

So when the first time went past,

people you know, said, "Well, you've lost."

And everybody laughed, it was a jolly moment in the room.

"Yeah well, no, you didn't win the sweepstakes."

Then the second person, the third person,

the fourth person, and then it got a bit more serious.

It was building up tension at that stage.

Why it's not coming?

Then the last person who had the sweepstakes

was about seven o'clock, and it hadn't woken up.

Everybody was getting very nervous.

It was very difficult to bear.

We started really getting worried.

Have we lost the mission?

Then suddenly, the signal came.

(crowd cheering and applauding)

When the signal came

it was a big relief for me, personally.

It was an explosion of joy.

A little blip on a noise spectrum

told us Rosetta was there, and it was calling home.

And this for me was the toughest emotion I went through

on the story of Rosetta.

We made it!

Yes, yes, hi!

That's a big success for everybody.

We have it.

We're ready, we now have the spacecraft back,

we can go and do the rest of this mission,

and finally get to the comet.

(group cheering and applauding)

But now the mission starts,

because now we have to get to the comet,

fly around the comet,

orbit the comet, and land on the comet,

all within the next 10 months.

Rosetta took 10 years from launch,

'til we finally got to the target

that we were going to study.

The comet we ended up deciding to go to

was 67P/Churyumov-Gerasimenko.

(ethereal music)

In the beginning, the comet was just very small dot.

And then day by day the comet was growing

in the field of view of the camera.

(ethereal music building)

We saw this incredible shape.

Some people have described it as a rubber duck.

It was amazing, it was beautiful.

Scientists were just stunned with their mouths open.

(sustained music)

Comet 67P is about four kilometers in size.

If you were standing on the bottom of the comet,

you might see a flat, dusty plain.

If you were standing on the head of the comet,

it might look more rocky.

If you were standing on the neck of the comet,

you would be in this interesting valley,

kilometer high cliffs on either side,

and running along the neck between your legs

is a huge crack.

There is so many different types of surfaces

and variety, you could spend the rest of your life

exploring every little part of the comet

and not see the same type of thing twice.

(instrumental music building to a crescendo)

The first thing I thought was,

"We're never gonna land on that thing."

Was the morning of the 12 of November 2004.

It was excitement, but also tension for the upcoming events.

Great news, we are a go from the lander.

The commands have already been sent,

now we just have to wait for separation.

(sustained instrumental music)

Rosetta just pushed very gently away.

It was like pushing it really like this,

18 centimeters per second, it's nothing, like this.

(building instrumental music)

The fall lasted seven hours.

They could get the images of Philae

getting closer to the surface during the descent.

(group cheering and applauding)

It was a very, very emotional moment for me.

After the seven hours of descent,

Philae was approaching the surface of the comet.

(gentle instrumental music)

As we got closer and closer,

you know, the tension began to rise.

I was looking at the data coming from Philae,

I wanted Philae to survive the landing.

So I was just staring at the screen

seeing this data coming.

We actually saw several subsystems activating.

These were the subsystems

supposed to be activated at touchdown.

We got the information

that it had reached the surface.

(crowd cheering and applauding)

We definitely confirmed that the lander is on the surface,

and I leave it to Stephan.

I think it's up to him to judge

how it's going now on the lander.

We were in the major success.

We had landed on a comet.

This was the moment of my mission.

This was a huge success.

We are sitting on the surface,

Philae's talking to us.

More data to come, and to--

(audience cheering and applauding)

I can tell you for me personally,

that the lander touchdown,

that was the biggest achievement.

Philae started taking pictures,

taking measurements, doing it's job.

Said, "I'm on the surface here, I touched down."

(camera's clicking)

Yes, it had touched down on the surface,

but it hadn't stopped moving.

(men talking over each other)

Nominal is one, three, eight, five.

It took us 10 to 15 minutes

to realize that something was wrong.

This one is not going down though.

The lander, the elevation did not go down.

Yeah, it's the same as (speaker mumbling).

We realized that the radio signal was not stable.

It couldn't have been on the surface.

It was definitely lifted up and flying again.

I said, "That's not possible, it cannot be."

Quite quickly people began to realize

that we must have bounced.

It bounced, had a very long travel,

and then it hit the edge of a cliff, started tumbling.

We were scared to death.

My fear was we are gonna lose the contact now.

And if we lose the contact, that's it.

This is the end of the mission of Philae.

(suspenseful orchestral music)

And then finally, after two hours,

it touched down in a very dark place.

(ominous music)

Of course, we hadn't the faintest idea

where Philae was on the surface of the comet.

Then, half an hour later,

the signal was abruptly interrupt,

and Philae wouldn't transmit anymore.

We haven't the faintest idea

when the signal would come back.

When I came in the morning,

few seconds away, spot on, we see alarms coming in

to the control system, and it's the signal of Philae.

(music building)

This little baby has been

surviving on the face of the comet.

So we started receiving data.

Guess what we get?

The first image of the surface of the comet.

Here, real time, we saw it real time coming in.

(gentle instrumental music)

This is just fantastic.

It's something that happens once in our life.

You see the surface of the comet,

you see a portion of the leg,

and you have the feeling that there is something odd.

Indeed, we found Philae,

that it was tilted on it's side.

But it was just the surface of the comet.

(music building to a sustained note)

The images came back,

and it was then that we realized

that we were in this place that was

almost completely shady.

It was in a dark area,

so it would have not had the chance

to recharge the batteries.

We knew then that we were

gonna run out of power after three days.

The whole three days on the comet

were certainly three of the most

incredible days of my life.

When you see the images,

you get this very strong feeling,

you are on a completely new world.

You are seeing a new world for the first time.

(gentle music)

The formations were really, totally unexpected.

The first image I saw,

it looked to me like coral formations,

like what you see in the bottom of the oceans.

Fractal geometries.

Ruptures everywhere, at every dimension,

from millimeters to centimeters.

It gives an impression of how this surface suffers.

The extreme variation of temperatures

by getting close to the sun and then back away.

It's a continual thermal stress.

Seeing the images so close, it was like sitting there.

It was clearly another world.

Philae was part of our adventure

and especially in those three days,

it was part of us sitting on the comet.

After three days, it was Friday afternoon,

it was clear that the battery was getting to the end.

You could see Philae fading out

during the night, during the last contact.

And then gradually the energy in the battery finished.

And that was the end of the three days

of Philae on the comet.

(hushed engines whooshing)

But if we look carefully,

the bulk of the scientific mission of Rosetta

still had to come.

Because we flew there to follow the comet

in it's orbit around the sun.

The comet's getting close to the sun.

It's activity increased significantly.

(gentle orchestral music)

We could really see how the surface

is completely revolutioned by the sun.

There were explosions.

(music building)

Holes observed in the surface

with a underground structure which is

still today, totally unexplained.

There were landslides that we have observed.

(music building)

You could see jets, gas jets,

fountains coming out of the comet.

You could see actually like snowstorms

going around the comet.

Well what they saw in front of their eyes

was totally surprising what was happening there.

(music builds to a stop)

So on Rosetta we had a dozen instruments,

and not all all of these instruments take pictures.

They get data in different ways.

Such as the spectrum, or measuring molecules.

It's squiggly line data.

And those squiggly line data

can sometimes have much more information

than the pictures do.

The Rosetta instrument found

that there is molecular oxygen

trapped into the nucleus of the comet.

Molecular oxygen couldn't have survived

the formation of the solar system.

Therefore it means that it was

inside the nucleus of the comet

before the formation of the solar system.

We were able to see molecules

some of which had never been seen before.

For instance, glycine, the amino acid,

a building block of life.

And if the oxygen was trapped in the nucleus

before the formation of the solar system,

then also the amino acids were trapped there.

If these two things which are the ingredients of life

were trapped there before

the formation of the solar system,

they are not specific to our solar system,

they are universal, these ingredients.

So the likelihood that life has formed

somewhere else as well.

There's all the material in there

that you need if you want to produce life.

This confirmation is very important,

because it shows that comets could have been

the objecs that brought the components of life onto earth.

(slow instrumental music)

As we had been with the comet for more than two years,

we were moving back out again, away from the sun.

The mission had accomplish all the results.

Nobody had thought about how to finish the mission.

Shall we hibernate it again,

taking the risk of a much longer hibernation?

Shall we switch it off in September,

that's it, bye bye Rosetta?

Then we proposed to land with

the mother ship on the comet.

It's not designed for landing.

It was like a suicide landing.

But this was taken as a good idea

because this would allow us to observe

and measure the last few kilometers

where we had never been.

The decision was indeed taken

to say, "Let's go down, let's do it."

And as Rosetta itself got closer and closer

to the end of the mission and we came down

to lower and lower orbital heights,

we were taking pictures all the time.

And so we got closer and closer,

getting more and more detailed images

than we had ever had before.

(gentle instrumental music)

Only a few days before the end of the mission.

Right there, at the edge of the image was a shape.

You could see there, in a sort of crack

in between some rocks on the comet in shadow.

Finally, we got the picture of Philae

on the surface of the comet.

To see Philae there, under a rock,

this was extremely emotional.

Going away without having seen

Philae on the surface would have been a pity.

And this was the last present this mission gave to us.

It was just a few hours before my birthday,

so it was a very nice present.

(sustained orchestral music)

Good morning!

(man speaking in a foreign language)

Welcome, for Rosetta's grand finale.

We are here live, in Rosetta control room

at ESOC in Germany.

So at this point in September,

we had planned to put Rosetta down onto the comet.

It is a special day today.

The European Space Agency's comet-chasing

Rosetta mission is coming to an end.

We have such a great job,

and now we put it to rest.

And then give it a proper end.

It will be the end of a mission that lasted

4,595 days in space.

This slow farewell of Rosetta

going down on the surface of the comet,

I think is a perfect closure of this fantastic mission.

The orbiter will land on the surface of the comet.

It's going to be a big moment for everyone.

You can feel the tension already here in the room.

Everything we had put into this,

in terms of the human story,

but the science, this several decade long effort

was coming to an end, and we were choosing to do it.

And even sitting here now, several years later,

I mean, it brings back those emotions.

We commanded the spacecraft to do

the final plunge down to the surface of the comet.

The spacecraft is taking images during the descent.

(gentle instrumental music)

We could see some of the images

and we could see the surface coming closer and closer

and time passing by,

and we knew that the mission was coming to an end.

(gentle music)

Everybody was crying.

I mean, I get the tears in my eyes

even now, thinking about it.

It was super emotional.

It got closer and closer

until finally,

we lost contact.

And that was the end of Rosetta.

(speaker mumbling) on the briefing rooms,

we just have had loss of signal.

And so, this is the end of the Rosetta mission.

Thank you and goodbye.

When the signal shut down on that day,

people were shell-shocked.

Even though they knew it was coming.

But I remember walking around the corridors,

people just leaning up against walls,

just staring into the distance.

It was yeah, I mean it's something

those of us who were involved will never forget.

(sustained instrumental music)

It was quite an adventure.

(upbeat orchestral music)

Our understanding of how asteroids and comets

might contribute to our existence.

We know the kind of rocks that appear on their surface.

We know the minerals in those rocks.

We know about the organic molecules.

We know about the water.

None of those things we would have learned

by looking at asteroids and comets from a distance.

We are explorers in a lineage of explorers

going far, far back in time,

and we hope far into the future.

If we were to stop our curiosity,

our species, the human beings,

would have extinguished many, many years ago.

Each time we further our knowledge,

we get a little bit closer to the story

of where did we come from?

(inspiring orchestral music)

(gentle orchestral music)