Original subtitles

NASA's OSIRIS-REx is on a mission to intercept a giant space rock

and crack the mysteries of a potential killer asteroid.

If this mission sounds familiar, it's because it's like something right out of

a Hollywood script.

Can OSIRIS-REx help to stop this asteroid colliding with Earth in the

22nd century?

Are asteroids dangerous?

Well, ask a dinosaur.

Can it unlock how asteroids kickstart life on planets like our own?

Turns out the whole story of our existence, our origins, is wrapped up in

those space rocks.

And reveal why they might be our ticket to other worlds.

They could be the key that enables us to explore the outer solar system.

To find out, we take a ride with one of NASA's most ambitious missions.

To investigate a space rock in more detail than ever before.

To reveal how asteroids will rewrite the past and forge the future of our

solar system.

Over 1 million asteroids hurtle through space between Jupiter and Mars.

They are the debris left over from the violent birth of the solar system 4.5

billion years ago.

Many of these ancient space rocks contain a pristine record of the

conditions that existed before the Earth was born.

Telescope analysis of asteroids reveals that many of them carry organic

material.

Astronomers think that the chemistry of this space soil could unlock the secrets

of how life starts on a planet like Earth.

Think about all the mysteries of how we got here, how life began to evolve.

Is there any way we could actually have a sample of what the early solar system

is like?

Well, it turns out we can, in an asteroid.

But asteroids also...

pose a threat nasa has identified 9 000 asteroids that are large enough to

destroy a city if they were to hit the earth

some asteroids are so big they could wipe

out all life on our planet some of them would have energy associated with their

impact that could exceed the binding energy of the earth's crust That means

after the impact, the Earth's crust would turn into an ocean of magma. That

would cause a global extinction event at all scales. Now, I don't want to scare

you, but they are out there.

How can astronomers unlock the secrets of the origins of life from inside

asteroids?

And can they solve the mystery of why some space rocks end up on a collision

course with our planet?

Telescopes struggle to see the details of small, dark asteroids against the

vast blackness of space.

Astronomers must get closer if they want to reveal the secrets locked inside

asteroids, as well as assess the threat that space rocks pose.

So NASA launches OSIRIS-REx.

It is the first US-led mission with the aim to return a sample of an asteroid to

Earth.

Engineers equip the spacecraft with a suite of special instruments.

These can map the geology of an asteroid in unprecedented detail.

And then take a sample from the surface of the space rock.

So that OSIRIS-REx can bring it to Earth for scientists to study.

This is NASA's most ambitious asteroid mission.

The stakes are high.

These missions take decades to develop and hundreds of millions of dollars.

Not to mention the hearts and souls of thousands of people who have dedicated

their careers to this mission.

Building a robust and well-equipped spacecraft is just one part of the

mission.

Success depends on selecting the right asteroid to intercept and study.

Out of the 18,000 asteroids close to the Earth, which one should OSIRIS-REx go

visit?

Telescopes on Earth analyze thousands of space rocks to identify the perfect

candidate.

Astronomers narrow down the list to just one.

The asteroid is called Bennu.

Bennu is a bulging space rock 500 meters wide.

It orbits the Sun on a similar path to the Earth.

The asteroid has a slow and steady rotation.

This makes it easier for OSIRIS-REx to get close.

It is dark in color.

A sign that this asteroid could contain organic material.

Such material will help scientists solve why life thrives on Earth.

And Bennu is second on NASA's list of most dangerous space rocks.

This asteroid makes the perfect target for OSIRIS-REx.

NASA had a lot of criteria when they were trying to find the perfect asteroid

to send OSIRIS-REx to.

Well, it turns out Bennu just snaps them off one at a time.

OSIRIS-REx arrives at Bennu in December 2018.

The first objective for the spacecraft is to find out just how much of a threat

Bennu poses to Earth.

When? Could this space rock hit our planet?

An asteroid the size of Bennu hits the Earth roughly, very roughly, every 100

,000 years.

Now, that's not like clockwork. It could be a year from now, or it might be a

million years from now, but over time, that's about how often it happens.

We know that Bennu is a danger to us, but we don't know exactly how dangerous,

and that's why we have the OSIRIS-REx mission, to go there and figure it out.

A clue to unlock when Bennu could hit Earth lies in changes to the asteroid's

trajectory that happen each time it swings by our planet.

Bennu laps Earth every six years.

Each time, there's a chance it'll pass through a gravitational keyhole.

This is a narrow corridor where Earth's gravity pulls the asteroid onto a

dangerous trajectory.

Astronomers believe that Bennu could pass through a gravitational keyhole

when it dives between Earth and the Moon in 2135.

If it does, it means there's then a 1 in 2700 chance that Bennu will collide with

Earth 50 years later.

1 in 2700 might sound like really low odds, but when you're talking about an

impact that could destroy a city, it's worryingly high.

Astronomers need to know for sure if Bennu will pass through a gravitational

keyhole and end up on a collision course with our planet.

But it is difficult for astronomers to predict the future path that an asteroid

will take through space.

The first thing people ask about a potentially threatening asteroid is,

will it hit the Earth?

And it would seem like the orbits are easy to calculate, just the gravity of

the Sun driving it around the solar system.

But it turns out there's another effect that can change the orbit, something we

don't understand very well at all.

Telescope observations reveal... that Bennu moves around 280 meters closer to

the Sun with every orbit.

What is the mysterious force that drives Bennu towards the center of the solar

system?

And can it help scientists calculate if Bennu will end up on a collision course

with Earth?

Astronomers believe that it could be the Sun that drives this unexplained

behavior.

Bennu makes one full rotation every 4.3 hours as it flies through space.

Sunlight warms the surface of the asteroid.

As the heated rocks rotate away from the Sun towards Bennu's dark side, They

radiate their heat into space on the asteroid's leading edge.

This gives the asteroid a tiny push backwards.

Astronomers call this process the Yarkovsky effect.

Like a low-intensity thruster, it slows down Bennu and allows the Sun to pull it

closer with every orbit.

The Yarkovsky effect is very small in any given moment, but over a large

amount of time, it can actually have a big effect. It's already moved Bennu

from the asteroid belt inward toward the Earth.

Infrared cameras on board OSIRIS-REx measure how quickly the surface of Bennu

heats up and cools down.

This data will help astronomers calculate the influence that the

Yarkovsky effect has.

on Bennu's orbit around the Sun.

This calculation could predict precisely if and when Bennu will pass through a

deadly gravitational keyhole.

Is it changing in such a way that it moves away from one of these keyholes,

or is it going to pass through a keyhole, moving it in a direction of a

collision course with Earth?

If OSIRIS-REx discovers that Bennu is on course to hit Earth,

then what can we do to prevent a catastrophic impact?

So imagine the worst-case scenario turns out to be true.

An asteroid goes through a gravitational keyhole, and we know it's going to hit

the Earth.

What's the best way of protecting ourselves?

Well, you might think, let's just go out there and simply blow the thing up.

But the problem is, now you have a lot of rocks that are all on the same orbit

as the original asteroid.

Instead of one impact, there could be many.

That could be even more destructive.

Some people have proposed detonating nuclear bombs next to the asteroid or

pushing the asteroid out of the way with a laser that you fire at its surface

over a long period of time.

So these ideas work on paper, but they've never been built or tested. This

is an enormous engineering challenge.

Space agencies are working together to develop systems that protect Earth from

dangerous asteroids.

NASA and the European Space Agency are joining forces to crash a spacecraft

into an asteroid.

The mission aims to test if an impact will move a dangerous space rock in the

future.

The DART mission will target an asteroid that passes within 11 million kilometers

of Earth.

Sensors on board an observation spacecraft will monitor how the impact

changes the space rock's speed.

and direction.

If successful, the DART technology could become the blueprint for Earth's defense

against killer asteroids.

The DART spacecraft is just like a dart, and it's slamming into this asteroid,

and it's sacrificing itself so that we humans can figure out how to keep

ourselves safe from asteroids.

Rogue asteroids have the potential to devastate our planet.

OSIRIS-REx will help astronomers accurately assess the threat that Bennu

poses to life on Earth.

The spacecraft carries a suite of instruments that photograph, scan

and analyze Bennu in more detail than any asteroid before it.

OSIRIS-REx studies Bennu's trajectory to help astronomers find out if and when

the space rock will hit the Earth.

The spacecraft will also try to answer a question that has puzzled scientists for

centuries.

How does life start on a planet like Earth?

Scientists think that Bennu contains ancient organic material.

that could unlock the mystery.

If we look at Bennu, it's primordial. It's pure. It's untouched. It's been out

there by itself, isolated from pretty much everything but sunlight.

This material could be older than the Earth. It probably is.

So if we want to understand how our solar system formed, this is where we

need to go.

OSIRIS-REx photographs its first clue in January 2019.

This image shows the surface of Bennu ejecting particles.

Of all the amazing science and images that have come back from the OSIRIS-REx

mission, the absolute coolest one to me is that Bennu is spitting rocks into

space. Little rocks, sometimes pebbles, sometimes a little bit bigger, are

literally shooting out of the asteroid into space.

What is blasting rocks from Bennu?

One theory is that as Bennu rotates into the sunlight, the rocks on the surface

heat up by more than 100 degrees Celsius.

This can stress them so much that they crack and throw asteroid fragments into

space or into orbit around Bennu.

Another theory is that sunlight heats up a material trapped in the rock.

This vaporizes and builds up so much pressure that it can break bits off

Bennu and fling them into space.

What is the mysterious material that produces this vapor?

OSIRIS-REx uses special cameras to analyze the chemical composition of

Bennu's rocks.

The cameras discover that many of the minerals inside Bennu This

means that the molecules of these minerals are chemically combined with

molecules of water.

Astronomers believe that this is evidence that Bennu was once part of a

larger asteroid that contained a reservoir of liquid water.

For a long time it was thought that asteroids were very dry, they didn't

have much water on them.

Well, in recent years we've learned that's not the case. They are in fact

loaded with water.

The discovery that Bennu is hydrated is evidence that space rocks could play a

vital role in the creation of life.

It is possible that they seed entire planets like Earth with water.

Of all of the bodies in the solar system, including moons and planets,

Earth is the odd one out. It is the...

only body with liquid water on its surface.

Water is crucial for organic life.

The liquid mixes lifeless chemicals into biological systems.

Water covers 70% of the Earth's surface today.

But this hasn't always been the case.

Four and a half billion years ago,

Rocky planets like Earth are hot, hellish worlds.

One theory is that a crystalline material called ringwoodite locked

inside Earth's crust releases vast amounts of liquid water.

But many scientists think that this internal water source will boil away in

the super hot conditions of the early solar system.

Anything very easy to evaporate, like water vapor, would have simply gone up

and been blown away into space.

So how did this water come to the surface of the Earth? It couldn't have

started here, so something must have brought it.

Billions of years ago, a cooler region of the solar system exists around 700

million kilometers away from the Sun.

Here, it is possible for water to exist as ice.

It gets colder as you move away from the sun, so there is a region in our outer

solar system that is cold enough to allow for the existence of water ice.

We think that asteroids that form out in this cold region of the solar system can

lock up this ice and bring it inwards toward the inner solar system.

And that might have been how a dry Earth received its water.

Asteroids laden with ice bombard the young Earth.

Over time, this barrage delivers enough water, to turn our world blue.

The hydrated minerals inside Bennu could be evidence that asteroids bring water

to Earth billions of years ago.

But is it also possible that they bring the chemicals needed to create life

itself?

A big question about asteroids is, if they bring water from space to Earth,

could they have more complex chemistry like amino acids, materials that they

could have brought to Earth and seeded it here so that life could begin?

NASA's New Horizons spacecraft uncovers a clue in the farthest reaches of the

solar system.

The probe takes this photograph of Pluto in 2015.

It shows a strange red tar covering the surface of the dwarf planet.

Analysis reveals that this tar, called tholin, is made from a mixture of

complex organic chemistry.

It is possible that this chemistry could contain the building blocks of life.

How can asteroids bring it from the frozen depths of space to Earth?

A clue lies in how carbon-rich asteroids like Bennu form.

Four and a half billion years ago, our Sun ignites within a swirling cloud of

gas and interstellar dust.

Inside the cloud, solar radiation breaks up simple chemicals, and they form more

complex organic molecules.

Carbon-rich asteroids are loosely bound piles of ancient dust and rocks, full of

these organic molecules.

It's possible that such asteroids bring this chemical cargo to Earth and help

kick-start life on our planet.

If Bennu has the basic ingredients you need for organic chemistry, does that

mean that organic chemicals are there?

We don't know yet.

The only way to find out is for OSIRIS-REx to return a sample from

Bennu.

Scientists can then test this sample to reveal if asteroids like Bennu really do

hold the building blocks of life.

But from where on Bennu? should OSIRIS-REx take a sample.

Bennu's surface area measures 780,000 square meters.

That's equivalent to the area of 150 football fields.

OSIRIS-REx can take a maximum of three samples from Bennu.

But take a sample from the wrong place and the spacecraft will return with

nothing but dry space dust.

Sample return missions from the solar system are incredibly difficult. We've

tried them before, but we were only able to retrieve small amounts of cometary or

asteroid material.

How can OSIRIS-REx make sure that it grabs a sample from an area that is rich

in organic material?

The spacecraft carries the solution on board.

Three special cameras precisely map the chemical composition of Bennu.

This data pinpoints the richest potential sample sites.

These sites are scattered across the surface of the asteroid.

Any one of them could contain evidence of the building blocks of life.

There's going to be this wonderful moment when we actually open up the

OSIRIS-REx canister, and inside are a couple kilograms of the most precious

stuff on Earth, more precious than gold or platinum. You actually have a

chemical sample of the origins of life.

The organic material inside the sample could reveal how life started on our

planet.

Think about all the mysteries about how life got to Earth in the first place,

how life evolved over time.

All of that is actually locked up inside the asteroids.

These space rocks turn out to be invaluable treasures.

But scooping up rock from an asteroid that tumbles through space at 100,000

kilometers per hour is a big challenge.

One wrong move, and the $800 million mission could come to a crashing end.

How can OSIRIS-REx complete its objective and avoid getting wiped out in

the process?

NASA engineers believe the solution lies in drawing a pinpoint accurate map of

Bennu's surface.

This chart will help astronomers identify the safest place for OSIRIS-REx

to grab a sample from.

Telescopes on Earth are too far away from Bennu to study the surface of the

asteroid in detail.

They see it as a featureless boulder in space.

We did have radar measurements of its shape. We had some understanding of how

fast it was rotating.

But we didn't know how big the particles would be on the surface or actually what

the terrain would be like at all.

OSIRIS-REx must map the contours of the asteroid in three dimensions to find a

safe sample site.

The spacecraft carries special scanning technology called LiDAR.

It builds up the most detailed picture of any asteroid in space.

A sensor shoots laser beams at the surface of Bennu.

The lasers map the topography of the asteroid with millimeter precision.

There really was this moment when Bennu came into view that I had this moment of

awe. I had seen this fuzzy shape on the radar map, and yet now here it was,

crystal clear. You could see every boulder, every little pebble on the

surface.

When I see an image like Osiris-Rex return from Bennu, I realize that this

is no longer just an idea.

This is a place. This is somewhere.

The high-resolution maps reveal a big surprise.

Instead of it being like a big monolithic rock, just a big chunk of

rock, it actually has an incredibly rugged surface.

It is covered in pebbles and boulders and rocks everywhere.

Why is Bennu's surface so rocky?

Astronomers believe the answer lies in the asteroid's genesis.

A small protoplanet over 100 km wide shatters in a cataclysmic collision

around 1 billion years ago.

Gravity brings together some of the loose, jagged material to form the body

that will become Bennu.

More collisions break its rocks into smaller and smaller pieces.

Bennu is by now so fragile

that the gravitational tug from planets can turn it inside out.

This brings more loose large rocks to the surface to shape Bennu into the

asteroid that OSIRIS-REx sees today.

Bennu is what we call a rubble pile asteroid.

These are almost literally bags of rocks.

They're just a jumble of rocks held together by their own gravity.

The large, jagged rocks on the surface of this rubble pile threatened to

jeopardize the $800 million mission.

A brush with one of these boulders could smash OSIRIS-REx into the dirt.

We were going to navigate a delicate little spacecraft down near the surface

and suck up some of the dust.

We didn't see right off the bat a place where that might even be possible.

OSIRIS-REx must sample an area of Bennu that contains organic material.

Only this kind of material can help scientists back on Earth unlock whether

asteroids brought the seeds of life to our planet.

How can OSIRIS-REx decode the surface of Bennu to identify the richest and safest

site to sample?

NASA scientists overlay the 3D LiDAR map of Bennu onto the areas with the richest

deposits of organic material.

They select a spot that gives OSIRIS-REx the best chance to sample the asteroid

safely.

They call the site Nightingale.

The good thing about Nightingale on Bennu as a sample return site is that it

looks like it has a lot of organic chemicals in it. It's near the North

Pole, which makes it easier to land. Also, it doesn't receive as much

sunlight. It doesn't get heated as much, so it hasn't affected the chemistry

there. And the site looks relatively young, so we're getting fairly pristine

samples from it as well.

But Nightingale does have one big danger.

A 10 meter tall rock that borders the edge of the sample site.

The OSIRIS-REx team name it Mount Doom.

How can OSIRIS-REx avoid crashing into this mega boulder when it swoops to take

a sample?

For OSIRIS-REx to land in the Nightingale Crater on Bennu is like

hitting this tiny cosmic bullseye.

So the spacecraft is about the size of a large passenger bus, but the area that

it needs to target for its touchdown is only about six parking spaces across.

And there's another challenge.

The spacecraft will be more than 300 million kilometers from Earth when it

grabs a sample.

This means that piloting instructions from Mission Control take over 18

minutes to reach OSIRIS-REx.

If the spacecraft has to make a split-second decision in order to remain

safe, then taking minutes to send signals back and forth just isn't an

option. The spacecraft needs to be able to autonomously abort if necessary.

The solution is to let OSIRIS-REx think for itself.

The Nightingale sample site is near Bennu's North Pole.

and it's a moving target.

The safe zone is about the size of six parking spaces, surrounded by large

rocks and Mount Doom.

On approach, OSIRIS-REx will compare live images to an onboard database to

constantly check its position.

If the spacecraft finds itself off target, it can automatically abort and

try again another time.

Sophisticated image recognition allows OSIRIS-REx to guide itself safely to the

surface of Bennu.

But the spacecraft must overcome another big challenge to successfully grab a

sample.

Bennu is a loosely bound ball of dust and rock floating in space.

How can the spacecraft take a sample from the asteroid quickly, in close to

zero gravity?

OSIRIS-REx is going to have to deal with Bennu's very low gravity. That means it

can't just go there and land and start scooping up asteroid material.

As soon as your scoop hits the asteroid, your spacecraft is going to fly off into

space.

Engineers equip OSIRIS-REx with an ingenious solution.

It's called the Touch-and-Go Sample Acquisition Mechanism, or TAGSAM for

short.

The spacecraft extends a 3-meter long robotic arm before it

descends towards the surface of Bennu.

The end of the arm contacts the asteroid.

A blast of nitrogen stirs up the rubble and dust.

This material collects inside a specially designed chamber.

OSIRIS-REx then stows the sample, ready to return to Earth.

All we need is to make contact with the surface, quickly collect that sample,

and then get back toward Earth. That's all we want.

Using this touch and go system, OSIRIS-REx will return to Earth with the

largest sample of space rocks since the Apollo missions.

This sample could solve the mystery of how life starts on our planet billions

of years ago.

We find water in asteroids. We find molecules that look like they're the

precursors of life.

And so studying these asteroids is, in a sense, studying ourselves.

But many scientists believe that Osiris Rex is also a stepping stone for us to

harness the mineral wealth of asteroids.

A clue to how lies 180 million kilometers away from Earth.

The asteroid belt is a ring of space rocks around the Sun beyond the orbit of

Mars.

And this is Psyche.

This mega asteroid measures 226 kilometers across.

NASA aims to send a probe here for 2026.

Psyche is not a rubble pile like Bennu.

This space rock contains untold riches.

And through a slice of luck, they are just waiting for us to pick them up.

As a rocky planet like the Earth forms, heavy metals collect in its hot liquid

core.

Miners can only dig down into the crust, where heavy metals are scattered in the

rocks and yields are low.

Psyche is the surviving core of a protoplanet.

It is made almost entirely of metal.

Mining an asteroid like this could generate a huge supply of metals that

are rare on Earth.

OSIRIS-REx travels millions of kilometers to touch a space rock.

This NASA mission paves the way for a new generation of spacecraft

that could make asteroid mining a reality.

I've heard that the world's first trillionaire will be the first person to

mine an asteroid.

The potential is clearly huge.

Asteroids could unlock more than just a new gold rush.

The sample that OSIRIS-REx brings back to Earth could contain the solution to

the biggest challenge we face in space exploration.

How do we power spacecraft that carry astronauts beyond the moon?

Spacecraft need a lot of fuel to escape Earth's gravity.

A SpaceX Falcon 9 rocket burns over 500 tons of propellant to send astronauts

into low Earth orbit.

450 tons of that is liquid oxygen.

Fuel weighs a lot, and it takes a lot of fuel to get off the ground and into

space. So by the time you get there, you don't have much left.

Refueling in space could solve how we power rockets to Mars and beyond.

Mining asteroids for fuel means that we could collect or even manufacture fuel

very close to the Earth and then use that as a launching point for distant

explorations.

OSIRIS-REx will return its sample to Earth in 2023.

Locked inside could be evidence that carbon-rich asteroids contain water.

Where there's water, scientists can make rocket fuel.

You can break that water up into its individual atoms of hydrogen and oxygen.

This becomes rocket fuel. Just having liquid hydrogen and liquid oxygen and

combining them, igniting them, that gives you a lot of thrust.

That's what a rocket needs.

NASA is funding the development of missions that promise to unlock the

potential of asteroids.

Mini B will mine water from an artificial space rock.

to show how it is possible to release the liquid inside larger asteroids.

This stuff isn't just science fiction.

It's real.

Asteroid mining is here.

NASA is even planning a concept feasibility mission at this very moment.

Concepts like Mini-B harness the energy of the sun to unlock the fuel we need to

explore the solar system.

And this is how a scaled-up version could work.

A mining station pulls up alongside a water-rich asteroid.

A giant hood latches onto the space rock and forms a gas-tight seal.

A reflector collects sunlight and focuses it onto the asteroid.

The rock heats up.

And the water trapped inside vaporizes.

The station stores the water in supersized tanks.

And an onboard processing plant splits the water into oxygen and hydrogen,

ready to refuel spacecraft.

Asteroid mining is going to be a complete game changer because now people

are going to be making money. That means that access to space is going to get

cheaper, is going to get safer, and space travel for the average citizen now

becomes a reality.

We've already seen it happen with air travel.

Now it's going to happen with space travel.

Space tankers will move the fuel closer to Earth.

Refueling stations near to our planet.

will springboard our exploration of the Solar System.

Astronauts on board a next-generation rocket blast off from Earth for a deep

space mission.

Their rocket carries just enough fuel to break out of low Earth orbit.

It then docks with a fuel depot in orbit around the Moon.

Here it loads up with hydrogen and oxygen before continuing its journey

across interplanetary space.

Stations like this will dramatically cut the cost of deep space exploration and

open up travel to Mars and beyond.

Imagine how much easier it's going to be to explore space if you don't have to

bring all of these things with you. You just use up what you have.

go to a nearest asteroid way station you don't have to come back to earth to

refuel nasa has launched just nine missions to the outer solar system since

the 1970s metals and fuel mined from asteroids make it possible

to launch a whole fleet of missions to jupiter saturn and beyond

There are so many treasures that are beckoning us in the outer solar system.

There may even be worlds that support life out there. It would be wonderful to

have just mission after mission headed out there.

There may come a day in a few centuries from now when we truly are a space

-faring civilization.

OSIRIS-REx is one of NASA's most ambitious ever missions.

The sample that the spacecraft returns from Bennu promises to unlock the

mystery of how life started on our planet.

The true treasure lying up there on Bennu is a look into the origin of life

itself. They are rich with the history of how life got started.

The data that OSIRIS-REx gathers will help scientists combat the threat that

space rocks pose to Earth.

And this pioneering mission helps to lay the foundations for the next stage of

our exploration of space.

It's easy to think of asteroids as a threat, and they are.

But we can learn how to prevent that threat.

And they could literally be the key to our future of space exploration.

OSIRIS-REx promises to unlock the mysteries of our past.

and help us realize our space traveling future.