All language subtitles for planetary.defenders.2025.1080p.web.h264-grashopr_track3_[eng]

NASA+

[music]

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]