Original subtitles

NASA+

Downloaded from YTS.BZ

[music]

Official YIFY movies site: YTS.BZ

This next set is finishing up.

We'll have some new data here pretty quick.

Potentially hazardous asteroids can show up anywhere

in the night sky at any time.

We're up here for 12 to 13 hours sometimes making decisions about

the objects we're seeing

if they're real or if they're just noise in the background.

[background noise]

The odds of finding an asteroid are going to increase

as we move toward the east.

[background noise]

Sixth, 3025.

[music]

Oh, this might be something.

Oh, you guys, look at that.

Based off these four images,

this is a brand-new near-Earth asteroid.

We got one.

No, I didn't think that was going to happen.

No, it's brand new.

I just got the notice back from the Minor Planet Center

that they published it.

There it is, bam, live.

This is actually a big rock, too.

Right now, it is absolutely a potentially hazardous object.

If you guys were going to be here for a discovery,

a PHA is definitely what you want.

[laughs]

This is a big rock, yes.

It is nominally about 230 meters in diameter,

which is quite large.

And its minimum orbit intersection distance

with Earth, which means how close it comes

to the Earth's path and the Earth's orbit,

is between us and the Moon.

It's only about 150,000 kilometers away,

which is a significant PHA.

A PHA like this only comes up a couple of times per year.

These are the ones we want.

Yes, that's a nice one.

[music]

When a 2 mile-wide fragment

of the comet traveling 40 miles a second.

Pieces of the comet that will hit Jupiter.

Three fragments are scheduled to hit the planet.

Will slam into the same area,

the same spot on the planet Jupiter.

About 1993, we learned that there was

a comet heading for Jupiter.

Comet Shoemaker-Levy 9 was a comet

that was discovered by Eugene and Carolyn Shoemaker

and David Levy.

It was shown to be broken up into a bunch of pieces.

They traced back the orbit.

This thing had gone by Jupiter and got disrupted.

And then they tracked the orbit forward

and found out these are getting to hit Jupiter.

And that got everyone excited.

It's really the first time

that these impacts have been observed.

Impacts were very important

in the formation of everything.

We could observe an impact on another planet.

Scientists still don't know

what they're going to see tonight, but they do know

that they've come to the best place in the world to see it.

The whole world community, scientific community, was preparing

to observe these events.

Any telescopes that could observe the impacts did.

Many, many ground-based telescopes.

The Hubble Space Telescope.

All of the images from Hubble that went

on the web suddenly got everyone's attention.

Which was a real key to many of the scientific results.

Also, Galileo.

Which was on the way to Jupiter at the time.

The NASA Infrared Telescope Facility

had a campaign dedicated to observing Shoemaker-Levy.

This observing run for the Shoemaker-Levy 9 impacts,

that was my first observing run ever.

We're starting tonight with the near-infrared spectrometer.

God, that's gorgeous.

I remember seeing something pop up on the screen.

We were shouting.

[laughter]

We're literally dancing around.

And we saw this bright thing just light up.

It was like, "Yes, we did it."

We were all like kids in a candy store, I guess. [laughs]

A lot of the energy we saw wasn't just

the impact itself, but it was the splashback.

When those pieces plowed into the atmosphere,

they brought up big plumes of material that rained

back down on the upper part of the atmosphere.

We're able to measure changes in the upper atmosphere of Jupiter.

It taught us a great deal about how impacts take place.

Scientists say if a fragment the same size hit Earth,

it would leave a crater the size of Rhode Island.

It was one of those wake-up calls

that not only impacts something that happened in the past,

but they're happening now in our solar system.

Here it is this awakening.

It kind of precipitated this

NASA Planetary Defense Coordination Office.

To make sure to find the asteroids that come close

to Earth and the comets that come close

to Earth, get them cataloged, figure out

where they've been and where they're going to be

in the future just so we understand,

are we at risk of being impacted on the Earth?

That's a big component of what NASA does.

Now, it has planetary defense to find potential impacts

for the Earth and protecting it.

[music]

[background conversation]

Let's go back to Senator Cruz's question.

What would an asteroid that is a kilometer in diameter,

what would it do if it hit the Earth?

That is likely to end human civilization.

[music]

The impacts of Comet Shoemaker-Levy 9

with Jupiter in 1994, that showed us that, you know what,

impacts are still happening in the solar system today.

That really spurred some interest on the part of Congress.

NASA was tasked by Congress in 1998

to catalog 90% of all the large near-Earth objects,

so those that are 1 kilometer or more in size.

[music]

Those objects are big enough to cause

what we would call truly global devastation,

meaning that they could cause global extinction events.

The good news is that we've found more than about 95% of them.

The catalog includes almost 900 asteroids,

1 kilometer or larger in size.

That said, none of these known large NEOs pose any threat of impact

to the Earth within the next 100 years.

[music]

Then eventually in 2005,

that direction from Congress to NASA was set to find

the population of asteroids

that are 140 meters and larger in size

that could do regional damage should it impact Earth.

A city killer.

Now, the picture's not so rosy.

We know of about 40% of those objects today.

Today, we do not have a complete inventory

of all the possible impactors.

That is something that NASA

and the worldwide planetary defense community has been endeavoring to do.

Well, here at NASA, what I lead

is the Planetary Defense Coordination Office.

We are helping to coordinate efforts not only in the United States

and across U.S. agencies, but also around the world.

Finding asteroids, tracking them,

calculating their orbits, figuring out

where they're going to be in the future,

studying their physical properties,

and then you get that information you might need

in the event an impact threat is discovered.

We have discovered more than 30,000 near-Earth objects so far.

And we are discovering hundreds every year.

But we haven't found them all, so that's really the big question.

There's almost certainly a decent-sized asteroid out

there that is going to pose an impact threat to the planet.

We're just trying to find it right now.

[music]

The way we approach finding near-Earth objects

is basically just to make a short movie

of the night sky that consists of four frames,

and then our software will pick out objects

that are moving inside of the four frames.

We have to identify

if they are real or if they're false detections.

I first started hunting asteroids in my backyard

and I just had the hope of maybe discovering one.

When that happened,

it was a very special moment in my life.

My interest in astronomy started at a fairly young age.

I remember as a kid seeing Comet Hale-Bopp

in the sky from southern Utah.

It was really a spectacular sight as a child.

Just trying to wrap my mind around

what I was looking at was difficult.

[music]

This is one area of science where discoveries

are still happening on a nightly basis.

It's really a neat feeling to step

into that where you can be sitting in a telescope at night

and discover a new minor planet that's in orbit

around the Sun that nobody has ever seen before.

It's a special thing and I think that's what draws

a lot of people into this business.

[music]

The first order of planetary defense is finding the asteroids.

One aspect of the program is funding institutions

with telescopes that can image wide swaths

of the sky to be able to look at that starry background and look

for objects moving with respect to the stars to see,

is there something there that we haven't seen before?

This is the whole sky.

That's a whole sky camera.

You can see, this is a live video feed

from the end of the telescope.

You can make out the Milky Way right here.

This is the size of the images we're taking right now.

Then we subtract the known objects and the stars from those images

and then we look for moving targets.

The object is moving because it's closer

to the Earth than the background stars.

I can tell this first one is a star.

You can see that that object stays there.

If I load up a catalog image, which is a very old image,

you can see that first.

It is actually a star.

That one's actually a star.

Those moving targets are going to be asteroids

that are in orbit around the Sun.

That's a known asteroid.

It comes up green and it has the designation above it.

Oftentimes, they're new.

We've never seen them before.

What we have here is a near-Earth asteroid that is likely brand new.

I can already tell that it's not coming up

in any of the known databases.

Then what you have to do is go

and identify whether it's a known asteroid

or a new asteroid, so that's the next step.

When the asteroid is first discovered,

we submit the information almost immediately

to the Minor Planet Center at Harvard.

We are going to send this data off in real time here.

The temporary designation we're going to assign to it,

the date and the time

and the location on the sky that it was located,

and then its approximate visual magnitude.

I'm going to report it

as a brand-new near-Earth object candidate.

It's important to turn that information around quickly.

The different survey telescopes

quickly feed those position measurements

to the Minor Planet Center,

which is the internationally recognized repository

for position measurements of small bodies

throughout the solar system.

The Minor Planet Center is, I like to think is the link

between the astronomy community and everything that comes

after that in planetary defense.

My name is Federica Spoto and I'm the project scientist

of the Minor Planet Center.

Part of the role of the Minor Planet Center

is to actually distinguish what is known and what is not known.

We keep all the observations and all the orbits of the objects.

We don't see the image.

We just see these points.

Those represent the different position

of the object moving since it tells you very accurately

the time of the observations and then the position.

Once we have the position and the time, we can get the orbit.

All the data comes in from everyone gets consolidated there.

We have a common catalog that we are working from.

An archive of everything that is known

and everything that is not known.

The cool thing about the Minor Planet Center

is that everything we do is public.

As soon as we receive the observations,

the observations goes out.

That information can all be rolled up

there and available for other observatories to see them

and then go get additional observations

so that there is enough information to get an orbit.

Anyone can then access that data

to track these objects down and help us determine

if they are going to be an impact risk in the future.

Once we find an asteroid and we've got an orbit for it,

the next logical question is, is it going to hit the Earth?

Fortunately, there's a group here

at the Jet Propulsion Laboratory called

the Center for Near-Earth Object Studies, or CNEOS for short,

that is tasked with doing exactly this.

[music]

They assess the hazard potential

of this newly discovered near-Earth object.

They do orbit determination to see

both short-term and way out into the future,

100 years into the future.

Could any of those pose an impact threat?

My name is Ryan Park.

I'm the supervisor of the Solar System Dynamics Group

at the Jet Propulsion Laboratory.

I'm also serving as the project manager

for Center for Near-Earth Object Studies.

To date, we maintain about a little over 1.3 million objects,

most of them being asteroids.

We predict the motion of all known asteroids.

And we process the entire data set

from the Minor Planet Center to predict

and reconstruct the orbit of the asteroids

so that we can perform statistical assessment

of the potential Earth's impact.

What we do is we process the astrometry

collected by ground-based observers.

We feed those through what we call

the orbit determination process

to get the orbit of the asteroid as a function of time

so we can propagate backwards,

forwards, and figure out where the asteroid is in real time.

This basically catalogs

all the potentially hazardous asteroids

that might come close to the Earth.

And we document the probability of potential Earth's impact.

And if it were to hit the Earth with certain probability,

when is it going to be and where is it going to be?

And we do this for next 100 years and assess

whether it's going to be hitting the Earth and,

if so, with what probability.

That information gets shared with the CNEOS website

as well as with the entire world.

This data gets disseminated

immediately to many different organizations.

NASA's Center for Near-Earth Object Studies runs watchdogs

that are constantly ingesting this data

and calculating the odds of an impact in the near future.

If they find that this object has any probability

of hitting the Earth in the near future,

we will get an alert on our systems within about 10 or 15 minutes.

And then when people start receiving this type of warning,

then there's a huge community of astronomers

that start observing it from all around the globe.

As the Earth rotates and nighttime falls across Asia or Europe.

And so we start getting observations from all over the world at every time

and we start processing them really quickly.

It's a very smooth-running machine.

[music]

It transcends boundaries of countries.

Asteroids don't care about international boundaries.

It doesn't matter where the asteroid impacts.

It affects the entire humanity.

In fact, anything alive on the Earth.

It transcends basically anything, except what makes us human

and what it means to help discover and protect

the planet from a hazardous asteroid that might be incoming.

Yes, I'm really proud of it, I would say.

I'm proud.

I'm proud that I'm working on something

that is actually very useful for the community.

For planetary defense but also like

we do everything so that we can help the community.

It was a great honor to have an asteroid named after me.

There's Ryan Park asteroid.

I mean, this was a huge deal for me.

This basically led me to believe

that I'm making some contribution to the field.

We didn't even know asteroids existed 200 years ago.

And it's only been in the last few decades

that we even had the technology to be able to detect these things.

So yeah, I might be referred to as the Father of Planetary Defense.

I created the term perhaps, but it is only because I stand

on the shoulders of those asteroid hunters before me

that we are now able to protect the world from a asteroid impact.

So this object has already been ingested

by the Center for Near-Earth Object Studies Scout watchdog.

Right off the bat, it tells us that the probability this

is a near-Earth object is already 100%.

And the probability it is a potentially hazardous asteroid is 67%.

There is no real impact rating or probability.

So it's not currently a threat, but

long-term after the arc is extended

and we have a better idea of the orbit of this object,

this might be a brand-new unknown,

potentially hazardous asteroid.

[music]

So finding asteroids, that's probably the most important part

of planetary defense

or the fundamental part of planetary defense.

But it doesn't help to see an asteroid if you don't have enough information

to know where it's going to be in the future.

You can't do anything about them unless you find them

and know where they're going.

That means the race is on to try to figure out,

how can we get more data?

Can we get more exposures of it

so that we can figure out which way it's actually going

and then eventually get a really good orbit for it

so that we can predict far into the future

where it's going to go, especially with respect to the Earth?

So then there are telescopes that go zero in

on those initial observations by the surveys and they get

even more measurements of those positions.

My name is Cassandra Lejoly.

SPACEWATCH® is, we're a follow up survey essentially.

So the telescope behind me is a 0.9 meter telescope

that we use to follow up near-Earth objects.

When they're first discovered, they have very short orbital arcs.

So they have very imprecise orbits.

And so if we follow them up, we get a better orbit

to determine if there's a higher chance

of them hitting the Earth or not.

So these are the type of images that we get back from the telescope.

And so you can see that our asteroid is essentially a dot that's moving.

And then the stars look like long lines

because of how we track on the asteroid and not on the stars.

When an asteroid is first discovered,

the Minor Planet Center is able to calculate

a location on the sky where it should be.

So we already have an idea

of how the asteroid's going to be moving.

So we take that assumed motion and move with it.

So my typical day or night, I guess,

we typically observe for four to six nights straight.

And we come up to the mountain and we have dorms up here.

So we stay up here the whole time we're observing.

And what happens is that we'll open the two telescopes.

We then have on our computers,

a list of all the objects we can see that needs follow-up right away.

There's a few objects we can choose here.

I like to go for virtual impactors because they're top of our list.

They have a probability of hitting us.

We'll pick the best targets for the night.

Some of them come in as we're observing overnight

if they're newly discovered and they need follow-up then.

So let's say I want to go for this object.

What I would do is I would accept it

in my queue and then I would accept

the value and send it for recovery.

What that would do is that would move the telescope.

So we get three images of it to see it move and to see

at what speeds and move and then we measure

its location on the sky.

That is the measurement we report back to the Minor Planet Center.

Well, that's an asteroid right here.

It's really cool when you're looking

at an image from the sky and you see a moving dot.

Every time I find that moving asteroid,

I'm excited by it because it means you found it.

You found a thing in space that is moving.

It's right there on my image, I can see it.

So right there is our object and it's moving right there.

The first image is in the star, so we can't measure that,

but then the second and third image are right there.

We can actually measure those.

That new measurement then helps better predict

the orbit fit and thus better predict where it would be in the sky

next time someone needs to observe it to follow it up.

The most important thing is always get more data

because the more data you get, the better you are at refining

the orbit and know where the object is.

And if you take another image a little bit further,

you can then put another data point,

and then you can keep tracing that orbit around.

As you collect more observations,

the orbit of the asteroid in question will get better and better.

I really like that I'm protecting the planet and, yes,

I'm not the one that's with a cape pushing the asteroid away.

That's not what I do.

In some ways, my little contribution

might help not just myself but someone in the future.

And I think it's very important to do that.

[music]

Last night while surveying in an area

of the sky where we don't typically find a lot of objects,

I discovered an object that had to be fairly large

to be visible for where it was in the sky.

So here is the asteroid

that Catalina Sky Survey discovered a few days ago

and we can also tell that it's a pretty big object.

The asteroid has to be observed for many weeks and months

into the future so we can extend that data arc.

So the orbit of that potentially hazardous asteroid

is known into the future.

The discovery arc of the asteroid consists

of just four points of data over 20 minutes.

And that is a really small snapshot of the entire orbit of the asteroid.

And it was able to be followed up all around the globe

so that we didn't lose that asteroid.

And you can see that it's been followed up

by several different telescopes right here.

So the arc length means

it's been observed for more than a day.

So that is where it comes the closest to intersecting the Earth's orbit.

And telescope around the world will continue taking observations

of this object to keep seeing

if it has a potential of hitting the Earth or not.

[music]

Well, at the current rate of detection of near-Earth asteroids,

it's going to take us about another 30 years

before we'll have this catalog

that we've been tasked by Congress to do.

We've only discovered less than 40% of the 90%

of the object we need to discover.

Finding the asteroids isn't something

that can just happen overnight

because telescopes can only see so far away

or they can only see so faint

into what they might be looking for out there.

Ground-based telescopes are kind of limited

to looking at night away from the Sun.

And we have to wait for the solar system to bring asteroids around.

The Earth is traveling around the Sun.

The asteroids are traveling around the Sun.

And so it isn't possible to see the entire solar system at the same time.

It's hard to find asteroids because relative to the size

of the Earth and the distances within the inner solar system,

they don't get bright enough

to spot until they get closer to the planet.

One of the tricky things with searching for near-Earth objects

is that some of them are extremely dark.

They're darker than lumps of coal.

And that means that when we look for them using

the sunlight that reflects off their surfaces,

they're actually hard to spot because they're dim and faint.

There are asteroids out there that are very darkly colored

and don't reflect a lot of light from the Sun.

They're difficult for the telescopes

on the ground to discover that are looking

at the light that we can see with our eyes.

So how do you overcome this?

We have to go into space.

We have to use different wavelength than reflected light.

All the telescopes on the Earth

that are currently finding near-Earth asteroids

are discovering in the visible wavelength.

They're primarily looking at light reflected

by the asteroid from the Sun.

The sunlight hits, the asteroid deflects just like everything

in the solar system.

One way we can get around this is instead of looking

at the sunlight reflecting off their surfaces,

we can use the heat that they emit to search for them.

If we have a heat-seeking telescope working

at infrared wavelengths,

even the dark objects just pop right out.

They stick out very brightly because they've got

a lot of heat that they re-radiate and we can see that energy.

Once you go into space, you're away from the heat of the Earth.

You can start looking in the infrared wavelengths.

Because in the infrared wavelengths,

asteroids have more energy being given out

because a lot of them are darker.

They absorb that radiation in the daytime.

And in the nighttime, they re-radiate, so they're very bright.

You don't need that big a telescope in space to detect

the asteroids that you would

from the Earth using visible light.

And Near-Earth Object Surveyor is one such telescope.

The Near-Earth Object Surveyor mission

or NEO Surveyor for short, NEO Surveyor, is a space telescope

that we're building that's designed to detect,

track, and characterize asteroids and comets

that have the potential to get close to the Earth.

It'll also be positioned in such a way that it can survey closer

to the Sun than the telescopes on the ground.

Because of this nice, tall sunshade,

we can actually point relatively close to the Sun.

And that lets us look far across the solar system

so that we can spot the asteroids when they're far away from us.

So that, working in concert with the telescopes on the ground,

is going to really accelerate

those objects getting into the catalog.

With NEO Surveyor, we should be able to see something

like a few hundred thousand new near-Earth objects

over the course of its survey.

We expect the numbers will increase by somewhere between factor

5 to 10 in the next decade.

They're going to give us lots of data.

And they're going to require from us to have different tools ready

to handle the data in the best way we can.

This increased rate of detection

in the number of observations that will be coming

into the Minor Planet Center does require

the Minor Planet Center to be able to process

things at a more rapid rate.

And we're ready for it.

And hopefully, that's going to tell us a lot about

the largest objects in the populations.

The ones that are really truly large

that have the potential for a large amount

of ground damage if they were to impact the Earth.

[music]

This is still kind of a golden age of discovery for asteroids.

One day in the future,

we will have found all of these objects.

And this period of asteroid discovery will come

to a close for the most part,

at least the rocks that can pose a significant threat to the Earth

Will eventually all be cataloged,

characterized, and either dealt

with or removed from the risk lists.

Any piece that you can do to help, you should do it.

And I think that's really important.

You don't have to be a planetary scientist

to go into planetary defense.

It's just an amazing thing to take science and apply it

in such a way that it affects people's everyday lives.

Well, for me, it's very personally satisfying

to be involved in an effort like this.

I found my role in life, so to speak.

So for me, it is very personal because I have a chance,

I'm fortunate enough to contribute using science

to protect the humanity, to protect

the planet for that matter, and everything

that is on it because we only have one Earth.

[music]

The explosion of a meteor over Russia last month

injured 1,500 people.

The recent meteorite that hit the Russian Urals

with the force of an atomic bomb

was a stark wake-up call regarding threats from space.

When the asteroid passed through the Earth's atmosphere,

it did so at a really high speed,

something like 40,000 miles an hour.

It had an explosive energy about 25 times

the bomb used in Hiroshima or about 470 kilotons of TNT.

It did cause a massive shockwave

that shattered windows all over the city.

[music]

This much smaller meteorite was not observed prior

to its entry into the atmosphere.

The Chelyabinsk impact came from the direction of the Sun.

It was on a very difficult trajectory for us

to be able to see from ground-based telescopes.

Scientists testified about how these objects are tracked

and how those risks can be minimized.

As we were reminded a couple of weeks ago,

the Earth is sometimes hit by asteroids.

Impacts have happened and they will happen in the future.

That asteroid was only about 18 meters across.

That would fit inside this room roughly.

This asteroid never made a big impact crater on the ground.

That's because it wasn't big enough

originally to make it to the ground fully intact.

So the impacts of air bursts are different from an impact

that is physically going to touch the ground.

As the asteroid slammed through the Earth's atmosphere,

it was like hitting a brick wall.

It just pulverized it into a million little pieces like this one here.

Even just from that 20 meter asteroid disintegrating

in Earth's atmosphere, the shockwave from that, that did damage.

The inside of the asteroid is stony.

It looks like an ordinary rock.

We need to know more about these objects that could impact us.

How big is it?

What's it made out of?

How does it spin?

How much potential for damage it might pose on the ground?

The Earth has been bombarded by asteroids

in its history and it will be hit by asteroids again.

The questions that we're trying to answer

in planetary defense are when, where,

and which rock is going to do it.

[music]

So what we have here is a diversity of meteorites

where they range from stony meteorites

like the ones you see here.

A great example of that is Chelyabinsk,

which fell in Russia in 2013.

We want to understand the threat that is coming towards us.

Part of understanding the threat is understanding the capabilities.

Oftentimes, the physical makeup

of an object tells us about its capability, its impact potential.

What can it do on the Earth?

So studying the composition tells us whether it's an iron,

whether it's stones or stony iron or carbonaceous.

A weak object which has low density

is not going to make it into the atmosphere

and intact onto the Earth.

So you would have an air burst, for example.

Whereas if you have a really dense object like this iron meteorite,

it'll punch right through the atmosphere

even if it's a small object.

And then it will create a crater

like the Meteor Crater we see in Arizona.

[music]

So what do these meteorite tell us?

Why do we need to characterize these objects?

So by understanding the composition, we can figure out,

what is the mitigation mechanism we're going to use?

Because the tools we would use vary vastly,

depending upon what they're made of.

[music]

To understand what asteroids are,

you have to go back to kind of the beginning of our solar system.

Asteroids are rocky bodies that are kind of leftover fragments

from when our solar system first formed a long time ago,

more than four billion years ago.

The major planets formed And the first solids condensed out

of the solar nebula.

These solids slowly coalesced, came together

eventually to form what you call as planetesimals.

These are objects that are a few tens

to a few hundred kilometers across.

And you had internal heat.

That led to what you call as differentiation.

They'll have a core, a mantle, and a crust.

So these iron meteorites we see here represents

the cores of those planetesimals.

We believe that there were more than 100 planetesimals

that differentiated between the orbits

of Mars and Jupiter, but most of these planetesimals

were destroyed catastrophically due to impacts

over the next few hundred million years.

And what we see now in the asteroid belt are remnants

of those catastrophic destructions.

Most of the material that made up our solar system got swept up

into the Sun and to the individual planets, but not all of it.

It's like shattering a plate on the floor.

You have a few big pieces, but lots and lots of small pieces.

So asteroids are those leftovers of the formation of the solar system.

A lot of them keep their distance

very nicely in the asteroid belt

between the orbits of Mars and Jupiter,

but some of them over time, because of being tweaked

by the gravitational pull of Jupiter and whatnot,

have made their way into the inner solar system.

And so, some of these leftovers from the formation

of the solar system can get a little too close for comfort to Earth.

That's how we end up with near-Earth asteroids.

We'd really like to understand the distribution of these objects,

their compositions, and where they come from.

So that's what we're trying to find out.

How do they leak into the inner part of the solar system

and get into this region near the Earth's orbit?

[music]

You don't want to just know that the asteroid is there.

You want to know, how large is it?

What is it made of?

So there are telescopes that then go out

and study particular characteristics

of asteroids to the extent they can from the ground.

So we want to find out

what is the composition of the object,

how fast it's spinning,

whether it's one object or two objects.

Of course, we want to know the mass of the object.

For that, we need to have an accurate idea on its size.

That's where radar comes into play.

[background noise]

Yeah, that's cool to finally see it.

This is the biggest one in this complex.

It's 70 meters in diameter.

All the other ones are 34.

This is the most powerful planetary radar on Earth.

So here we are at the Goldstone Solar System Radar

in the middle of the Mojave Desert, about a few hours' drive

from Pasadena at the Jet Propulsion Lab.

This is where I connect remotely to observe near-Earth asteroids.

I'm Shantanu Naidu.

I'm an asteroid radar researcher here

at NASA's Jet Propulsion Laboratory.

That's amazing.

Whenever an asteroid comes close to Earth,

we use this radar to observe it,

which can tell us about the shape of the asteroid.

It can show details on the surface

of the asteroid such as ridges, concavities, craters.

We can also measure the precise distance to the asteroid.

And then from all of that, you get really fantastic science,

and then you get that information you might need

in the event an impact threat is discovered.

So radar is an active form of observing

an asteroid in the sense that we generate

our own electromagnetic waves.

We use really high-power transmitters

to transmit electromagnetic waves in the direction of the asteroid.

The asteroid reflects these waves.

They get distorted during this process

and they come back towards Earth.

So you have signals from space coming in,

reflecting off the primary dish,

reflecting onto the secondary dish,

and then they reflect onto the instruments.

We can compare the distorted received waveform with what we sent.

And using this comparison,

we are able to generate highly detailed images

or maps of the asteroid.

One example I can show you is 2024 MK,

which was a recent target that we observed.

We were able to obtain these very high-resolution images

where each pixel is under 2 meters in resolution.

If I zoom in here, you can see all these intricate details

on the surface of the asteroid.

You can see these radar dark regions.

You can see, it's a very irregular shape.

There's a lot of things that look like ridges.

So we can track these features

and we can measure the spin rate of this asteroid.

[music]

So there's a control room in the pedestal.

So this is where the telescope operators sit.

We send them the orbits of the asteroid.

We send them the observing plan.

We send them the configurations

we want to observe the asteroids with.

So this is where the telescope operators sit

and this is where they control all the equipment from.

And that's where the data gets collected in the computer behind.

And that's what we connect to,

to download the processed images at JPL.

This seems like a nice setup,

so I'll send it to the telescope operators.

When we start observing an asteroid,

we need a very accurate orbit

so we can point accurately at the target.

We get a spectra, update the orbit.

We get a course-resolution image.

We update the orbit again.

And so we transmit for a fixed amount of time,

which is the round-trip light time to the asteroid.

And as soon as that time elapses,

that is when we start receiving the echo.

We switch from the transmitter to the receiver.

It takes a few seconds to travel a few million miles back into space

and reflect off the asteroid.

So we transmit for an entire round-trip time.

And then as soon as the echoes start reaching back to the telescope,

that's when we switch to the receiver.

And then we record the whole transmitted wave, so for one round-trip time.

And that constitutes one image.

And once we get a good orbit,

we can start getting these higher-resolution images.

[music]

It's always exciting

because it's the first time anyone is looking

at the features on the surface of this asteroid.

Most of the asteroids that we observe,

we've not seen them before.

And so whatever you see with the radar is a surprise.

And a lot of the times it's discovering something new.

It is very cool to know that at least for a few minutes

or maybe even a few days, you are the only person

in the world who knows this thing.

It's very exciting.

It's a very exciting feeling.

There's a sense of responsibility knowing

that I'm part of such an important team.

And we are all tackling such an important problem

of asteroid threat assessment and mitigation.

Let's say we discovered something,

and we only had a small window to observe

it and quickly turn around information

about its properties.

What if we find an asteroid

that's going to impact the Earth next week?

Then all of a sudden,

an opportunity came up that nature gave us,

an asteroid designated 2023 DZ2 was discovered.

So this object was discovered by a team

in the Canary Islands in Europe.

When it was discovered, the observations were directly sent

to the Minor Planet Center, and then we publish everything.

The role of the Minor Planet Center

is to distinguish what is known and what is not known.

We define them as a complete new object.

And so in the following couple of hours,

a lot of observers from all over the world,

they start observing it.

Then it was a really large impact probabilities,

which means it could impact the earth.

Over a period of a few days

it had a high impact potential three years

from the discovery date.

And originally it had a decently high probability

of hitting Earth at its first discovery,

and then it was followed up and the probability went up.

And then this impact probability stayed high

even if people were sending more and more observations,

which means that the path on which the asteroid was,

was really towards the Earth.

2023 DZ2 was a significant asteroid.

That kind of close approach to the Earth of a rock that size

might only happen a handful of times per century.

And then eventually it turned out that it was coming really close,

but it wasn't hitting the earth.

Other observations had been made to take 2023 DZ2 off the risk list,

so that was a good thing.

Suddenly the probability of hitting Earth goes down,

and that's because the more points you gather,

the better refined your orbit can become.

At NASA, we thought this would be a good opportunity

to launch an observing campaign in coordination

with the International Asteroid Warning Network,

to try to get the worldwide community together

to gather observations about physical properties

of an asteroid and turn that around quickly.

So we essentially had a very short five-day campaign

where we had to reduce the impact risk by observing

the object and collecting more positions along its orbit,

understand its rotation period,

understand its composition, try and observe it with radar

to get some physical information like the size and volume,

and try and input all this information

in an impact hazard model

to see what would be the impact on the ground.

So we were able to pull all of this stuff off

within a matter of five days.

We took this real-world opportunity

to exercise the whole system and campaign

that would be done if a potential impactor was found.

In case we were ever faced with a situation

where we needed to do that,

to measure the properties of an asteroid during a short window

in a coordinated fashion with the worldwide community.

So we used the Goldstone Radar to observe it.

And we managed to obtain images with the resolutions

of under four meters on this asteroid,

which showed that it was an irregular body.

It was spinning extremely rapidly.

Based on the visible extents in the radar images, we could tell

that the asteroid was somewhere about 30 to 40 meters,

so a bit smaller than what we could estimate

using just the visible.

It was an important target to practice working together

to exercise the systems in order to refine the orbit and improve

the characterization of the asteroid.

So my students and I,

we observed this object using telescopes, one on campus.

We also used the NASA Infrared Telescope Facility,

which is on Mauna Kea, Hawaii.

It is one of the few telescopes in the world that is capable

of telling what asteroids are made of.

So we try and do geology with a telescope.

We're trying to do prospecting.

Trying to understand what minerals

are there on these asteroids and using those mineral signatures,

the spectral fingerprints to identify what fingerprint matches

with those of meteorites that we have in the lab.

So that's what we were trying to do with DZ2.

This is the 2023 DZ2.

This is the motion, the object that's moving there is DZ2, correct?

Yeah, so you can see it moving through the star field.

Star field and that's the spectrum, the visible spectrum right next to it.

The first order visible spectrum?

Yeah.

So in the end, what we assessed about DZ2

was that it was much brighter than we expected

because when an asteroid is discovered,

we don't know how bright or dark it is.

So that says a range in size.

You can slowly narrow down the size

depending on more characterization information.

So if you have radar, that gives you a very accurate diameter,

pretty close to the final thing.

If you have thermal infrared measurements,

you can constrain the observation.

So you can constrain the diameter for that,

but you also have composition.

Composition tells you something about how bright the object is.

So that gives you an additional piece of information.

So no one technique gives you the ultimate answer,

but complimentary sets of information from different telescopes,

different techniques, kind of let us converge to one answer.

In the case of DZ2, what we've done is with the IRTF,

we spectrally characterized.

We looked at the light reflected off DZ2 in different wavelengths.

And in the infrared, in the wavelengths we cannot see,

but rattlesnakes can see, kind of like heat seeking stuff.

What we see is a unique spectral signature

for a specific mineral that is only found

in this particular type of meteorite called aubrites.

We have a few of those in our collection,

both that fell on the Earth, fell in Antarctica.

So here's an example of it.

This is an aubrite, it's essentially white.

It's reflecting 60% to 70% of the light.

What we do is that take this meteorite,

crush them into a powder and put them

in a lab spectrometer to get the spectrum of this meteorite.

In other words, how is light interacting

with it at different wavelengths?

So what we do here is that we take a sample

and then we crush it and we have it being

observed by the spectrometer that we have it here.

Instead of the Sun, we have a light source

that is reflecting off the sample and we're collecting

visible near-infrared spectra off that sample that we have.

Spectrum is nothing but light split into many wavelengths.

And using that spectrum, we compare

the same thing we get from the NASA infrared telescope.

And we can try and match the spectrum of the meteorite

in the lab versus the telescopic spectrum

off the near-Earth object itself.

And by taking this spectrum and comparing

to the one that's coming off the telescope

off the near-Earth asteroid,

we should be able to compare and tell

what the near-Earth asteroid is made of.

Because it was so bright,

you don't need the object to be that big.

So it ended up being smaller

than what we expected of the size range,

and because if it's smaller, hopefully we pray

that the atmosphere takes care of it

and we won't have much impact on the ground.

So that's what ended up happening, is that we managed to nail

the composition of the object very well using

the NASA Infrared Telescope Facility.

So 2023 DZ2 was a really interesting example

of planetary defense working on an international scale.

So it's really a resounding success in multiple organizations

across the planet coming together.

And the fact that we were able to discover it,

characterize it, determine it was a risk,

and then remove that risk all before it passed close

to the planet, was a pretty amazing feat.

Let's say we do find something that poses an impact threat to Earth.

What next?

The day is coming when Earth will get impacted.

The dinosaurs went extinct

because they didn't have a space program.

We do have one.

We can, so why stop there?

10, 9, 8, 7, 6,

5, 4, 3, 2, 1,

and liftoff of the Falcon 9 and DART

on NASA's first planetary defense test

to intentionally crash into an asteroid.

We're embarking on a new era of humankind.

We're doing this mission to prove that we can deflect an asteroid.

Even if we do everything right,

our sensors work well, our spacecraft is doing well.

Even then, we might still miss.

4, 3, 2, 1.

[applause]

For the first time ever,

humanity has changed the orbit of a planetary body.

NASA confirms that DART successfully changed

the targeted asteroid's trajectory.

Now, this is a watershed moment for planetary defense

and a watershed moment for humanity.

[music]

As was demonstrated with the DART mission,

if an asteroid were ever discovered

that could pose an impact threat to Earth,

we do have the capability to deflect an asteroid in space

and to change its orbit.

Once we've found an object

and determined that it could be an impact threat

to the Earth, what do we do to mitigate it?

Eventually, we have to be ready to nudge an asteroid off its course.

NASA has recently demonstrated a particular type

of mitigation technique that we call kinetic impact.

In case there was an asteroid coming towards

Earth and you are there, you can actually stop it.

That's kind of fantastic.

Our Double Asteroid Redirection Test, DART,

was a demonstration of using a kinetic impactor technique.

And the idea is pretty simple.

You basically just take a spacecraft

and you run it into an asteroid and bump it out of the way.

What? You think science fiction but this is real.

Never in my life would I have thought

I would take a couple hundred million dollar spacecraft

and crash it into an asteroid.

Its main goal was to go to an asteroid with its moon, to hit

the moon and see how much it changed the orbit of the moon.

The moonlet, Dimorphos,

which orbits the asteroid, Didymos,

in order to change Dimorphos' orbit and show

that we can deflect incoming asteroids if we need to.

DART will only be changing the period

of the orbit of Dimorphos by a tiny amount.

And really that's all that's needed in the event that an asteroid

is discovered well ahead of time before it might impact Earth.

In space just a little bit is just enough

to make an asteroid actually miss us.

So behind me, you see the spacecraft.

It's really cool to see it coming together in real life.

It is fantastic to see it in real life.

To see it turn from ideas into real pieces

that are going to go into space.

The solar arrays will actually roll out to 28 feet in length.

Once the solar arrays are deployed,

it's going to be the size of a school bus.

As the solar array opens out,

it's going to swing out in this direction.

To me, the most important thing

and the most exciting things is all the technical challenges.

My job is primarily to make sure

all the systems on the spacecraft work together.

On top, you see the NEXT-C thruster.

Over here is our star tracker,

and then over here is our high gain antenna.

My job is to make sure we launch.

My job is to make sure we're able to receive data back.

My job is to make sure we hit.

There's DRACO on the bottom of the spacecraft

as well, of course, as integration and test.

The asteroid is only two football fields in size.

We're flying at over six kilometers a second.

30 days out, we see one pixel on our field of view.

You can see Didymos and Dimorphos is one point of light.

About four hours out, our spacecraft becomes autonomous.

And then that's where everything gets really exciting.

And you actually are seeing impact.

The algorithm has to identify and hit the target

in the field of view of the camera.

And so you could just imagine

if it was a human being joysticking this.

Because we don't know for sure what the asteroids look like,

our simulation gives us the capability

to use different asteroid shapes

and asteroid objects to see that our SMART Nav algorithm

performs against all these unknowns.

Astronomers are going to measure how much DART changed

Dimorphos' orbit using ground-based telescopes all over the world.

These curves show the brightness change

due to Dimorphos moving in front of and behind Didymos.

We can tell how quickly Dimorphos is moving around Didymos.

We make these measurements before DART arrives,

and then this is the same technique that we'll use

after the impact to determine how much we've changed the orbit by.

This is Lowell Observatory.

Lowell is one of many observatories around the world

that will be observing the DART impact,

NASA's first ever planetary defense test mission,

to see how much a spacecraft impact can deflect

an asteroid in its orbit.

So this is where Pluto was discovered

and we are still doing research in all areas of astronomy today.

So let's go check it out.

This is the Pluto telescope, the telescope that was used

to discover Pluto almost 100 years ago.

So here we are at the Clark Telescope.

This is where, Percival Lowell sat to observe Mars.

Let's head on over to the Lowell Discovery Telescope

about an hour south of Flagstaff,

which is where we are going to be collecting

data for the DART mission.

The reason we're all the way out here in the middle of this forest

is that we have really dark skies here.

And this is the Lowell Discovery Telescope.

This is what a 4.3 meter telescope looks like.

This is what we'll be using to study Didymos and Dimorphos

in the days and weeks after DART impact.

The DART spacecraft will be hitting an asteroid called Dimorphos.

It's special because it's a binary asteroid, which means

a satellite around a larger asteroid called Didymos.

DART will actually be hitting Dimorphos.

What we will be measuring is how much DART changes

the orbit of Dimorphos around Didymos.

This is an important test for planetary

defense mitigation strategies

in case we ever have to do this for real.

The Lowell Discovery Telescope is one of many telescopes

around the world which will be used

to study Didymos and Dimorphos.

It's really a global coordinated effort.

And what we're looking at here is a large 4.3 meter primary mirror

that's in the middle of the telescope tube here.

Up at the top is a secondary mirror.

The secondary mirror up top there is what is focusing

the light down onto the instruments and allows us to take images

with the camera that's located down at the bottom.

This is maybe one of my favorite hidden rooms at the telescope.

We're standing inside the telescope

and underneath the telescopes, 100 tons above your head,

held up by this and this, which is cool.

It's sort of, as you can see,

the highest peak around here just over 8,000 feet.

I come up here for sunset.

You see how Sun's setting right there? It's perfect.

For DART, we're going to be collecting

images of the night sky.

And typically an observer would be here

in front of one of these consoles controlling

the instrument and taking images

like these as they're coming in off the telescope.

DART is really a sort of before and after experiment.

We need to understand the system

before the spacecraft intentionally impacts.

And then we have to understand

what the outcome of that impact event is.

As we watch from the Earth, Dimorphos will pass in front

of Didymos and behind Didymos.

What we will be doing with those images is measuring

the brightness of Didymos in those images and looking

at how that brightness changes.

And those dips and brightness allow us to measure when these eclipse happen

and measure the orbit period of Dimorphos.

And so you have essentially a fixed star field here.

All the white dots are stars of different brightness.

And moving through this field is Didymos and Dimorphos,

which again, we can't distinguish them as discrete points of light,

but we have that small object moving

through the field of view.

So after impact, we will then be able to go back

and start observing intensely,

looking for those mutual events, those eclipse events

of Dimorphos passing in front of and behind Didymos.

And on each one of these frames, we're measuring

the brightness to assess whether or not it's undergoing

one of these events where Dimorphos is passing in front of or behind.

This is such a cool experiment

and it's such a singular experiment. Using the ground-based telescopes

like this one and others around the world to watch

the system and see how it's affected by this impact event

because that's really what's going to give us

the answer to what did DART do at the time of impact.

And that will be exciting to see how that evolves

over the days and weeks following that impact.

Good afternoon, everybody.

Two weeks ago,

we conducted humanity's first planetary defense test.

The team has measured that the orbital period

of Dimorphos has changed.

Astronomers have been using telescopes

on Earth to measure how much that time has changed.

These telescopes have been observing this system nightly.

And that's what you see going across here on this graph on the top.

Just this nightly telescopic data night after night after night.

And it resulted in moving an asteroid

and actually changing its orbit

by a few millimeters per second.

Now, that doesn't sound like a lot,

but acting over a long period of time, it could be enough

to help move something out of the way

of the Earth should we ever need to do so.

It was expected to be a huge success

if it only slowed the orbit by about 10 minutes,

but it actually slowed it by 32 minutes.

The whole world has been watching this.

[applause]

Wow.

What an exciting day for the DART team.

In case you're keeping score, humanity one, asteroids zero.

The dinosaurs are made completely extinct

by an asteroid impact so many years ago.

Here we are, we can actually do something about it.

I think this is just wonderful.

There are times in a year or in a decade

when you are in awe of humanity, you know what I mean?

Despite everything that happens

in the world on a day-to-day basis in a new cycle,

there are times when human beings come together to do great things.

I think for me personally, DART was one of those moments,

where you are just in absolute awe of humanity.

Here we are, taking a spacecraft

and flying it hundreds of millions of kilometers away,

and hitting an object with that precision.

And it all happens in a blink of an eye.

You know what I mean?

It was not a long mission.

I think I'm very, very proud of my colleagues

who managed to pull that off.

It demonstrates how far we've come

as a species in the last few centuries even.

From the first rockets launched into outer space,

the first asteroids being discovered,

to the ability to realize what threat asteroids pose

to the planet, and now the capability demonstrated

to send a spacecraft to an asteroid that's in orbit around the Sun,

and show that we have the capability if we have enough

lead time to alter its orbit.

That to me was just a fascinating moment in human history.

Oh yeah, I did watch it.

It was super cool.

I did watch the DART Mission.

Yes, I have watched The DART Impact.

That was pretty amazing.

The last video that they were showing live

and then you saw everything up until to the last moment.

I thought that there was such a big achievement,

something like people work on it for so long,

and it proves that we can do it.

The DART impact day was one

of the most exciting days in my career.

We watched the impact here at JPL.

The impact was bigger than I had expected,

but I was also excited

because we had an observing run

for observing Didymos just about 11 hours after impact.

It would be the first opportunity

to see how much of an effect the impact had.

Didymos was all I was thinking about the whole day.

I couldn't sleep.

The observing run started at about 3:00 AM that night,

and we had our first echo of Didymos after impact.

We weren't expecting to measure the deflection that night,

but the echo was off from where it should have been

if there was no DART Impact.

I couldn't believe my eyes.

I was like, either there's some problems

in the measurement,

or this is a real detection just 12 hours after impact.

This was the first Goldstone radar detection

of the effect of the DART impact on the orbit of Dimorphos.

The yellow circle, it circles

the location where the echo from Dimorphos

should have been had there been no DART impact.

Then the red circles the echo of Dimorphos, which you can see

is this white dot here.

You can see it's quite far away

from where it should have been without the impact.

It just gave it a small nudge.

If you wanted to do this in the future potentially,

it could potentially work

but you'd want to do it years in advance.

Warning time is really key here in order

to enable this asteroid deflection

to potentially be used in the future and is part

of a much larger planetary defense strategy.

The DART mission was the first kinetic impactor demonstration.

It was a successful demonstration of that technique.

There are also other possible techniques.

If you do find one that is coming,

definitely there are several options.

There are different type of mitigation

and they actually depend on when you discover

that the object is going to impact.

One of the most important things

we can do to ensure that mitigation actually works,

is we need to provide time.

Time is your best friend.

I have time to build a spacecraft,

go to space, analyze the object, try to understand what type

of physical properties this object has.

Then what we call the reconnaissance mission

to fly by a rendezvous so that we have

a better understanding of what the asteroid is,

such as the size, the mass,

chemical composition for example.

It is a solid rock as it has boulders, something like that.

Then you want to know its orbit in a very accurate way,

because you want to track it down and go straight on it.

The next step is to figure out the mission

that could potentially deflect the asteroid.

There are other techniques though that still remain

to be tested for asteroid deflection.

A gravity tractor for instance,

where you just have a spacecraft of some significant mass,

stationkeep with the asteroid in the right position and

the mutual attraction between the two objects will allow

the spacecraft to slowly tug the asteroid

off of the impacting trajectory.

Another technique might be an ion beam deflector,

where you've got a spacecraft that turns its ion engines

onto the surface of the asteroid,

continuously bombarding the surface of the asteroid,

does create pressure on its surface

and therefore a force of that changes the velocity of the asteroid.

Of course, all the Hollywood movies

like to use nuclear explosives, it's very dramatic and exciting,

but we wouldn't blow the asteroid up like they do in the movies.

You'd detonate, the device bombards

the surface of the asteroid with heavy radiation. That causes

the surface material to vaporize, and jet off, and creates

an instantaneous rocket engine so to speak,

and shoves the asteroid.

Really the goal at NASA is to find the asteroids

years or decades in advance that could pose

an impact threat to Earth.

Then you have the gift of time

to address possibly not having that impact happen at all.

NASA is just one piece in the puzzle.

NASA has its role as the information gatherer from space

and conveying that information to other agencies.

Every piece of the puzzle must rise up

to the occasion and perform seamlessly.

To do that we have to practice.

NASA also participates in interagency exercises

with many others across the U.S. government, to step

through a situation where an asteroid

is discovered so many years ahead of time.

Here is the type of information that is known about it,

here are the possibilities of what could happen next.

[applause]

Good morning everybody, thank you for coming.

It's been a pleasure.

This is our fifth exercise.

Welcome to the fifth Interagency Planetary

Defense Table Top Exercise.

This exercise is incredibly important to bring together

the world experts and decision-makers.

ESA Planetary Defense.

National Space Council.

FEMA.

NASA Headquarters.

U.S. Space Command.

The Department of State.

To better prepare us

for what is an inevitable future asteroid impact.

We know it will happen.

We just don't know when it will happen.

Really this exercise focuses on is how we plan

and coordinate our activities in response to a potential impact

for it to all to come together into a plan on how we save the world.

And with that, I invite you all to open

the blue envelope in your folder.

And what you have in front of you is a notification

from the International Asteroid Warning Network,

about this hypothetical scenario of a potential asteroid impact

for the near-Earth asteroid 2023 TTX.

At this point in the scenario, the impact probability

of the asteroid is 72% as calculated by NASA JPL CNEOS

and by the ESA NEO Coordination Center.

The impact date would be the 12th of July, 2038.

The potential impact locations would span a corridor

from the South Pacific across North America,

the Atlantic, the Iberian Peninsula,

the Mediterranean coast of Africa,

Egypt to the coast of Saudi Arabia.

Now, the size of the object based on observations

from the ground it's highly uncertain based

on the brightness and the unknown surface reflectivity,

the coloring of the asteroid.

It's most likely estimated to be in the range

of 100 to 320 meters based on what is known about asteroids

but potentially at the extreme range of 60 to 800 meters in diameter.

All right.

The next critical factor to consider

is of course how many people could be affected

by these different damage sizes along the different impact locations.

It's certainly regional to country scale based on that size range.

For asteroids in this general size range

the primary hazard is going to be local blast

and thermal ground damage.

And the larger sizes could also cause tsunami.

So overall, the average population risk is around 270,000 people

among all the potential Earth-impacting cases.

Then of course there's still that 28% chance

that the asteroid could swing by Earth and miss us entirely.

We have filled out the uncertainty in 2038 with a bunch of white dots.

And we really don't know which of those white

dots is the real asteroid.

And so we simulate virtual asteroids,

and we just run them all towards the Earth.

The current situation is that

we don't know where it will hit.

We just know that it'll hit along this line.

For this exercise over the next two days,

we're going to stay frozen in time, right here, right now,

14 years ahead of the asteroid impact, and figure out

what do we do with the information that we have now.

Disaster preparedness planning, international space response,

information sharing and public messaging.

So the challenge now is to figure out

how do we respond and prepare for an uncertain event

like this where we're not sure what could happen,

but the potential consequences could be quite catastrophic.

This gets at sort of what we were hinting

at there starting to talk about not just what the threat is,

but what we could potentially do about it.

The good news is this asteroid impact may be preventable.

We have at least three technologies that we can consider for this.

And they have different physical effects.

The first is kinetic impact, which is like the DART mission,

where a spacecraft impacts the asteroid

to change its speed very slightly.

The second is an ion beam

where you use a controlled electric thruster

to slowly push or pull on the asteroid and change its speed.

And then finally, the nuclear explosive device

where you literally boil off part of the asteroid

in order to change its speed.

We also need to know the physical properties

of the asteroid, because all of these methods,

whether or not they work and the specifics

of how you would design them are tailored

to the specific asteroid properties.

Through forums like this one today

and tomorrow, and bringing together

all of you the world experts, we can tackle

the detection and characterization of asteroids,

ways to improve coordination among allied nations.

That's why we want to exercise

all of these capabilities now and not wait until then.

We took this opportunity to exercise the whole system and campaign

that would be done if a potential impactor was found.

[music]

Planetary defense is a team sport.

Asteroid impacts are a shared risk.

And so we really need to work as a team.

It's really important that we have a global effort

to try to understand the problem.

No one nation can independently

save the world in case of an impending impact.

It's a fantastic community.

I'm part of a global team of planetary defenders.

Very proud to be part of the planetary defense family.

It not only protects Earth today,

but provides protection for the future.

[music]