National Geographic: Asteroids - Deadly Impact (1997)

"Asteroid: Deadly Impact"
When he first came to the high desert,
Gene Shoemaker wondered
if he was too late.
Was the West all explored,
the battles fought,
mysteries solved?
But geologists are taught that truth
lies in the rocks and dirt underfoot.
Step by step he pressed the Earth
for its secrets.
What Gene Shoemaker found
has made the ground itself less firm
Planet Earth not nearly as safe as
we always assumed.
It's like being in a hail of bullets
going by all the time.
They are bullets.
They're bullets out there in space.
These things have hit
the Earth in the past;
they will hit the Earth in the future.
It will produce a
catastrophe that exceeds
all other known natural disasters
by a large measure.
Before Gene Shoemaker,
few people gave it much thought
One of the most powerful forces
in the making of our planet,
and perhaps the
deadliest hazard we face
This is the story of impact!
March 23, 1993:
Great telescopes around the world
aimed their sights deep into the night
They were peering far into space
searching for traces
of the Big Bang at
the outermost reaches of the universe.
But at one tiny telescope on a
lonesome peak in California,
three old friends were rummaging in a
part of space much closer to home.
Five, four, three, two, one, I'm on...
Gene Shoemaker, geologist,
was looking for rocks
not on the ground but in the sky.
That night he and his team
found something astounding
a portent of another kind of Big Bang.
Comet Shoemaker Levy 9 first appeared
as a faint smudge in space.
It grew into a blazing streak of light
By the time it smashed into Jupiter
every major telescope
in the world was watching.
The impact unleashed fiery plumes
large enough to incinerate the Earth.
And it raised a terrifying question
could it happen here?
And what if it did?
When we get to something in the
ballpark of a mile in diameter
hitting the Earth, it'll produce a
catastrophe that exceeds all other
known natural disasters,
by a large measure.
In fact, the energy delivered
would be like taking all of
the world's nuclear weapons,
putting them all in one pile
and setting them all off at once
actually, it'd be a little bit
more energy than that.
Once, scientists had said
it could never happen.
Now many were shocked;
some talked about the end of the world.
If something sneaks up on us then
there's very little we can do.
In fact, today, the most likely
situation is zero warning.
The next impact of a mile-sized object
will probably happen without
any prior discovery of it at all.
The first thing you will know is
when you feel the ground shake
and see the plume of fire
coming up over the horizon.
He'd been taught cosmic collisions
are inconceivable.
But Gene Shoemaker likes to make up
his mind for himself.
It was a path that I personally
traveled in small steps.
I had to teach myself that the,
the fact,
if, if one really pursues
the observations,
the world is telling us that big
things do fall out of the sky.
What the world told Gene it said most
eloquently at Meteor Crater.
The gaping hole in the Arizona desert,
nearly a mile wide,
spoke of sudden disaster
catastrophe falling from the sky
with deadly impact.
There were similar craters
in other places.
But most geologists said they were the
remnants of ancient volcanoes,
formed over eons of time by constant,
predictable forces.
Nothing this big happened
quickly or suddenly.
Fiery rocks falling from the sky have
long been believed to predict disaster
not cause it.
Meteorites have been feared as omens
and cherished as
relics around the world.
For thousands of years they were our
only way of touching the sky
mysterious messengers from space.
The intrigue they held for
ancient oracles
still captivates modern scientists.
It was inside a meteorite - a Martian
rock that landed in Antarctica
that researchers discovered the most
compelling intimation ever
of life beyond the Earth.
Meteorites are chunks broken
off larger celestial bodies.
When they crash through Earth's
atmosphere, most lose speed and power.
So even big ones,
measuring up to 10 feet across,
usually don't cause
damage on a large scale.
Still, if you or your house happen to
stand in the path of a stone from space
repairs will be necessary.
Tons of meteorites rain
on the Earth every day
most smaller than a pea
but that's enough to light up the night.
This fireball was seen
by thousands of people along
the eastern seaboard in 1992.
Many were attending high school
football games,
and some had brought
their video cameras.
A piece of the meteorite touched down
in Peekskill, New York
and cratered Michelle Knapp's
I was sitting in my house watching TV
and the next thing you know,
I heard this loud noise,
sounded like a car accident.
It was a chunk of stone
speckled with iron,
about the size of a football.
They told me the rock was estimated at
about as old as the Earth itself
and that's exciting.
The Peekskill meteorite did make
the local news,
but like most meteorites,
its impact was minimal.
In 1972, a rock the size of a bus
blazed so brightly it was seen
in daylight and was filmed by a
tourist near the Grand Tetons.
There was no impact, confirming
what most scientists thought
that Earth's atmosphere would
incinerate even giant boulders,
or break them into
relatively harmless pieces.
What was it, then, that violently shook
the Earth on June 30th, 1908?
A blinding fireball exploded over a
remote part of Siberia.
As far away as England an eerie
glow lit up the sky.
Two decades passed before scientists
could mount an expedition
to find the site
where the blast occurred.
It was an arduous trip
to an uncertain destination;
but the scientists knew they had
arrived when they saw
the staggering devastation on the
banks of the Tunguska River.
Over hundreds of square miles
the forest lay flattened
in vast concentric circles.
The scientists suspected the
destruction had been caused
by a huge meteorite, an asteroid.
They set out to unearth it.
Long months spent draining the swamps
and digging into the
wasted land yielded nothing.
For years to come,
Tunguska would remain one of the
great mysteries of the Earth.
At about the same time,
on the other side of the globe,
a similar mystery haunted this
giant bowl in the Arizona desert.
In the early 1900s Daniel Barringer,
a mining engineer,
found little chunks of
meteorite around the crater.
He drilled the crater floor in
search of an asteroid
but came up empty handed
and deeply disappointed.
Geologists weren't surprised,
but years later,
a young Gene Shoemaker was intrigued:
what had happened here?
It did seem like a
giant wound in the Earth.
It appeared as though the ground
had been dealt a devastating blow.
Massive beds of rock
that once lay flat were broken
and thrust violently into the air.
The rim was strewn with giant
limestone boulders
that could only have come
from deep beneath the surface,
flying hundreds of feet in the air.
But like all geologists,
Gene had been taught that even
the most dramatic landscapes took
shape at a creeping pace
Meteor Crater could not
in fact be a meteor crater.
People say, Ah, yes, meteorites
fall out of the sky.
We accept that.
A chunk that big - I accept that
that falls out of the sky.
But it was a, it was a,
an intellectual leap to go from a
fist-sized stone to a mountain,
and, and have a mountain
come down out of the sky.
As an undergraduate student,
I didn't learn anything about impact.
It wasn't part of geology at that time
Geologists are the kind of
folk that like to say,
I'd like to see what the process is.
I'd like to see it happen then I'd
believe that it's happened in the past.
Gene Shoemaker was one geologist
who saw something happen that would
lead him to question the fundamental
principles of his profession.
He was in his twenties
when he took on a job
at the top secret Nevada test site.
Here he witnessed a new mechanism
by which craters could be made...
It all takes place in utter silence,
until finally, the shockwave...
BAM... and then it's followed with,
with roiling thunder.
It's throbbing, I mean, you can feel
the sound in your whole body,
uh, and, and it's, that's a very
dramatic thing to watch, too.
Never before had so much energy
been harnessed or released.
Could nature do the same?
This crater had not taken
shape over thousands of years.
It was created in an instant.
And it reminded Gene
of another place he'd seen.
It was the largest crater, at the time
formed by a shallow,
underground explosion
and so, I could go directly from
this to Mother Nature's crater.
My hunch was that I would go have a
look at Meteor Crater
and see what the structure was
because it had never been
thoroughly mapped and described.
And so I didn't know what the
structure was until I went.
By having mapped this first,
I went to Meteor Crater and, voila.
I was astounded that all of those
parts of the crater that I could see
in the little nuclear crater were
reproduced here on a giant scale,
including, right down to the
pieces of melted material.
Around the crater Gene found
tiny beads of glass
rock that had been melted
and sprayed out;
he'd seen these too in Nevada.
Some rocks would reveal a newly
discovered mineral... coesite
An intensely squeezed form of quartz
that no volcano is
powerful enough to produce.
In this microscopic sample was encoded
a story of violent devastation
wrought by a 100-foot asteroid,
hurtling so fast the
atmosphere could not slow it down.
Gene Shoemaker had found
the fingerprint of impact.
It was the first conclusive proof
of an impact crater on Earth;
an affront to centuries of
scientific conviction,
and a challenge even to the
professor's devoted students.
Dr. Susan Kieffer once studied
with Gene in graduate school.
One day, Gene said I'm going to show
you what an impact is.
So, he grabbed a,
a fairly large rifle and we...
This is my favorite rifle
This is it?
I don't want to see this rifle again,
after what happened that day.
Do you recognize this, Sue?
And then Gene told me to shoot the,
the rock... which I did.
What happened is it just kicked...
The rifle came back
and hit me in the nose,
and broke my glasses
and he looked at me and said,
Haven't you ever fired a gun before?
And I said, No!
It's all right.
Here's Annie Oakley... with her nemesis
The ideas that Gene was
proposing not only made
individual people uncomfortable,
but, at a gut level,
whole schools of academic thinking.
That was the battle
that had to be fought against.
And he, I feel,
really did it almost single-handedly.
That's a nice lookin' crater.
Sue's lesson was simple
but revolutionary
a relatively small object traveling
at great speed will blast
a huge hole upon impact,
and, at the same time,
almost completely disintegrate.
The mysteries of Tunguska
and Meteor Crater were solved.
It came from over there,
from that direction.
You look up in the sky
and we see a brilliant fireball,
that's being made by the asteroid
or meteorite as it's coming in,
and it gets brighter
and brighter and brighter.
Gene's explanation of Meteor Crater
was controversial;
but the reason he studied craters
in the first place
seemed down right crazy.
When he was 20 years old, more than
a decade before the space program
Gene had a hunch America
would soon go to the moon.
And why would you go to the Moon?
To study the Moon.
And who do you send to study the Moon?
You send a geologist. Right?
I was going to do whatever I could do
to stand at the head of the line
when the time came to be the
geologist chosen to go to the Moon.
Can you imagine any greater adventure?
I couldn't.
I thought, well,
I better learn something about craters.
Oh, Gene, look, that's good.
Uh, I, uh, oh, look at that, I'm ready.
That looks so nice and slimming...
Gene dared confide his dream
only to one person
This was, uh, 1951.
When we first met, I just thought that
she was the neatest gal I had ever met.
That's it. His wife Caroline
would become his lifelong accomplice
in dreaming and scheming.
What attracted me to you...
What's that?
I think it's your
enthusiasm about things.
He gets this big smile and,
and you know he's just full of joy and
enthusiasm for what he's talking about.
Gene has a way of
getting what he wants.
We choose to go to the Moon.
We choose to go to the Moon...
In the early sixties,
it seemed Gene might actually
get what he wanted most.
We choose to go to the Moon
in this decade and do the other things
not because they are easy,
America was going to the moon,
and he was already
an expert on craters.
There were many thousands of them on
the near side of the moon alone.
Gene believed they could yield
tremendous knowledge about the role
of impact in shaping not only
the moon but the Earth, as well.
The Moon is this slate
that nobody's been erasing.
The record that we're
seeing of bombardment,
all of those craters that we see
on the Moon,
are a record of the, of the flux,
uh, of the hail of bullets coming
by that's hitting
both the Earth and the Moon.
If we want to see what a very fresh,
big impact crater looks like
when it's first formed,
you look at the Moon.
That guy up there.
The people who ran the space program
didn't look at the moon that way.
They were pitted in a furious race;
what mattered to them
was getting there,
not what could be
learned once we arrived.
There's no question that
NASA managers, NASA engineers and,
indeed the astronauts themselves,
were not particularly interested
in doing science in space.
Uh, that was not their mission,
they had signed up to, to,
uh, beat the Russians to the Moon
and the farthest thing from
anybody's mind was actually doing
some science and
collecting some samples.
But, nevertheless,
eh, even though he was considered,
uh, probably a weirdo by,
by some in the engineering community,
Gene did not give up in trying to,
uh, push this idea,
uh, that doing geology
on the Moon was important.
But geology on the
moon was a hard sell.
Few scientists thought Gene
was right about the effect
of impact on the Earth,
much less the moon.
Many believed lunar craters
too were old volcanoes.
Before Gene got to ride a rocket,
he took a fateful trip
in a more modest vehicle.
The Shoemakers were on
vacation in Southern Germany.
Gene was eager to come here
to visit the Ries Basin
a 15-mile wide depression
that was universally believed
to be an ancient volcano.
Gene and Carolyn went
strolling through the
medieval town of Nordlingen
in the heart of the crater.
And there Gene came upon the largest
geologic sample he'd ever found:
St. George's Church, 500 years old,
was built of local stone.
Just looking at the rock made
me stop and say,
Whoa! Wait a minute. What's this?
I think I know what this is because
I've seen something like that before.
The walls were riddled with glass
formed from shocked and melted rock.
Gene didn't need a microscope to know
they contained coesite.
He was, was thrilled beyond words and,
and I was for him.
Just to go along and just admire all,
all of this evidence for impact and,
and the formation of a giant
crater and here it is in,
incorporated into the cathedral
and it was just,
just a very strange and
interesting feeling and,
and saying, Ah, yes, you know,
we know what this is now!
The Ries is nearly 20 times
as big as Meteor Crater.
It was the first big impact crater
on the Earth
which we could prove
was an impact crater
and that just changed
the whole ball game.
This was impact on an
entirely different scale
brought on by a mile-wide boulder
that drastically changed
the landscape 15 million years ago.
Suddenly, giant circular scars of impact
were recognized all over the globe
some were 200 miles wide.
Now we really understood there were
big craters made on the Earth and,
of course, that meant those big
craters we saw on the Moon
which I was also pretty sure
were of impact origin
now we had a way of saying, yes,
it's happened on the Earth,
the proof is here,
but they're also on the Moon.
Gene had finally earned the credibility
to convince NASA and
the United States Geological Survey
to establish a program aimed
at doing geology on the moon.
Gene was appointed to run it.
Dr. Shoemaker, as the man in charge of
the Astrogeology Program,
what are you telling the astronauts
to look for when they
start exploring the Moon?
Small features of the Moon that will
be close by around the landing site.
And, of course, we also want them to
bring back a large number of samples.
Gene brought the Apollo astronauts
to his favorite hole in the ground
to teach them geology.
This seemed to me like a natural place
to train astronauts
who were gonna go to the Moon
and look at craters.
In fact, the best place
in the world for it.
You really get a feel of
what a crater's like,
and everyone of them wanted
to get on the Moon,
so they wanted to have a good idea of
what they were gonna get into.
For added realism, Gene's team blasted
a replica of a lunar crater field
not far from his home.
There, he participated in the design
and testing of many of the vehicles
and tools used on the moon.
Gene's youthful dream
was becoming a reality.
His vindication as a scientist and his
greatest adventure would soon be won.
guidance internal
Engines on, 5, 4, 3, 2,
all engines running.
Launch commit.
Lift off, we have lift off
go for orbit.
Uh, no, I've, I, I'm not going
to make it to the Moon.
Just at the critical time
when I could have been standing at the
head of the line to go to the Moon,
my adrenal cortex quit, my adrenal
glands stopped functioning
and I knew that that would, uh, uh,
that would just knock me out
of the running - medically.
When you had that idea in your
head for 15 years,
it doesn't go away right away.
Gene remained with the lunar program
as one of its chief scientists.
His dream of doing geology on the moon
came true vicariously;
his friend and protg,
Dr. Jack Schmitt,
flew aboard Apollo 17.
As Gene watched,
his theories about the effects of
impact on the moon
were confirmed live on TV.
...job to get down and back up.
They just hit rocks,
so they'll come out easy...
Every rock you looked at.
You pick up a, a rock or look at a,
at a large boulder and there's a little pit,
uh, there that's caused
by a micrometeor impact.
It became clear that the dominant
geological process on the Moon was,
if I go down there,
that thing's about 15 feet deep...
I was immensely pleased
and proud of Jack,
but of course, I was wistful, too.
I couldn't help feeling that there,
but for that failed
adrenal gland, go I.
I'm getting in your back here.
Got it?
I used to have dreams that I,
that I got there.
You know, I got to the Moon.
I was there doing geology.
Even after, you know, for a long time.
I had to go do other things.
His feet would never leave the ground,
but Gene was intent on making
his own way into space.
He'd found the scars of impacts
that happened in the distant past.
Now, he'd be one of the very first to
find out if there were bullets
out there that might strike
the Earth in the future.
It was an obscure,
lonesome effort and involved frequent
nightlong drives to an
observatory far from home.
But, in time Gene found a
new collaborator
and companion for the road
a housewife who decided she, too,
would become an astronomer.
For Gene, it was a journey
from deep disappointment
to new dreams and adventures.
I had some real misgivings
because I thought this means
that I'm going to go to Palomar
and I'll have to stay awake
all night long and observe.
Because I'd never stayed
awake all night in my life.
It was kind of a surprise to me
to discover
that I really loved the observing.
I could, if I was very busy,
stay awake all night.
In the early morning hours
the Shoemakers would wend their
way up Palomar Mountain,
home to what was then the most
powerful telescope in the world.
The 200 inch Hale was the temple
of deep space astronomy
it was called the Big Eye,
and was not designed
for observing asteroids.
In fact, before Gene came along,
no one here or anywhere else
had ever systematically searched for
asteroids that could hit the Earth.
Down the slope from the Big Eye
was a tiny telescope
that was virtually unused.
The Little Eye was just
what Gene needed.
This is kind of suited to our,
our style,
a level that we,
we call it our Mom and Pop operation
and that's basically the
way we've done it.
It turned out to be a perfect
instrument for our purposes.
Compared with the giant up the slope,
the Little Eye did not look far
but it looked very wide.
It was ideal for patrolling the inner
solar system for stray bullets.
Most astronomers saw the solar system
as a harmonious arrangement
of planets orbiting the sun.
They paid little attention to the
hundreds of thousands of asteroids
chunks of iron and rock left over from
the formation of the major planets.
Most of them orbit harmlessly between
Mars and Jupiter the Asteroid Belt.
But if an asteroid veered out of
its normal orbit
into one that cuts across the path
of the Earth,
it would be anything but harmless.
Most scientists believed that
asteroids almost never
became Earth-crossers.
Were the Shoemakers searching
for something that wasn't even there?
The answer would not come easily.
Asteroids look so small on film
that Carolyn had to look for
them with a microscope.
Even then, they would be almost
invisible amid the stars.
But slowly, they emerged from the dark
tiny dim blurs.
Since they're so much closer to
Earth than the stars,
they seemed to streak through the sky.
In 1989, other astronomers captured
the first ever close-up of an
asteroid using a giant radar dish.
This huge rock was
more than a mile across.
Later radar images showed even more
ominous asteroids
mountains tumbling through space.
Toutatis... a giant boulder doing
regularly cuts across the
path of the Earth.
first of only two asteroids ever to be
actually photographed
is as large as the island
of Manhattan.
Like Gaspara,
it isn't an Earth-crosser.
But if it were, it could blast a hole
as wide as the state of Texas.
Gene didn't make it to the moon,
but together with Carolyn
he's discovered scores
of new celestial bodies.
Between them they've found hundreds of
asteroids and dozens of comets,
and helped transform
the map of the sky.
The solar system would never again
seem stable or predictable.
The harmony of the planets turned
into a threatening cacophony.
What we've been able to show,
using this good old telescope
right here,
and by seh, concentrating on,
uh, surveying a near
region around the Earth,
we've been able to show
that the Earth revolves around the sun
in its own swarm of asteroids.
These things will hit
the Earth in the future,
they have hit the Earth in the past.
These are the Earth-crossing asteroids.
In the 1980s,
new evidence emerged
of the terrible threat impact
poses to life on Earth.
Deep beneath Mexico's Yucatan
Peninsula is a 190-mile-wide crater,
made by a 100 million megaton impact.
It dates to the time,
when two thirds of all living species,
including the dinosaurs,
disappeared from the
face of the planet.
On March 22nd, 1989,
an asteroid came within six hours
of striking the Earth,
but was not detected until much later.
Other asteroids have come even closer.
One would have hit the Earth if it had
come just four hours sooner.
I don't think that people took the
notion of a, a, of the hazard of,
of impact seriously, uh, in the early
days of our, of our work here.
Uh, first of all, it took a while
for the news to get out.
The news that would change everything
began to break on the
night of March 23rd, 1993.
The Shoemakers and their collaborator,
David Levy, decided to take some
pictures of the sky
despite persistent clouds.
This was not a good night
for observing,
much less for making
historic discoveries.
Five, four, three, two, one, open.
Open. I'm on.
Okay, you're on it.
I could hardly see the star
I was supposed to be following,
because Jupiter was so close
that the glare of the big planet was,
was swamping the eye piece.
plus 37, 59...
I started to examine the film,
looking at all the things
that I knew would be there,
the ghost image of Jupiter, and the spikes
from, that we see on the films
when we've got a very bright
star or a bright planet.
And then I started to go
by something and I thought,
That's a galaxy?
No, that's not a galaxy.
And here was this most unusual
looking object.
And I thought, It looks like a comet.
It looked like a comet all right,
except it was a comet
that was stretched out.
Our films don't have enough resolution
to really see what the details
are because we're covering a big area
of the sky and so the comet's
actually quite tiny.
The team called their friend,
astronomer Jim Scotti,
who was manning a more
powerful telescope,
and asked him to check their finding.
He promised to call back as soon as
his telescope could be repositioned.
Well, by now, it's about two hours
that has gone by and then
I decided the time had come,
Jim had had enough time to take a
look and I called Jim Scotti
and he answered the phone in a voice
that I had never heard before
and I said, Jim, are you okay?
and he says,
Uhhh, yes. David,
the sound you heard is me trying
to pick my jaw off the floor.
And I said, Do we have a comet?
And he said,
Boy, do you have a comet.
And he started describing what he saw
and I was repeating everything
to the two of you and every sentence:
It had these five tails,
at least five discrete nuclei,
but, he said, I think there's more.
And, meantime, that music, we had,
we had just had
Beethoven's First Symphony,
it was playing in
in our room, just happened to be on,
and the Fourth Movement started
and it starts with this very
slow little introduction.
As, just as, as Jim said,
Boy, do you have a comet,
then the symphony went
into its full motion,
And then, right at that point,
Jim says, Boy do you have a comet.
The comet essentially an asteroid
with a long tail of dust and gas
had been torn into several pieces
by Jupiter's gravity.
Of course the big kicker, the, the big
news that it was going to hit Jupiter,
didn't arrive until
about six weeks later.
Here is this man looking at a
computer screen and it's saying,
Your comet, with your name on it,
is going to collide
with Jupiter in 14 months,
and Gene was sitting there
and he was looking at it, and his,
he was shaking his head and he said,
I don't believe it,
I'm going to see an
impact in my lifetime,
I just don't believe this.
Now the question is what would,
what was going to happen,
were we going to have a big show
or was it going to be something that
no one could see?
Even as Shoemaker Levy 9
approached Jupiter,
some eminent scientists remained
skeptical it would make
much of an impact.
Many astronomers believed the
giant planet would swallow
the comet into its vaporous depths.
On July 16th, 1994,
when the comet's leading fragment
was due to cross Jupiter's path,
scientists and reporters gathered
at the headquarters
of the Hubble Space Telescope.
Gene found an empty office
to call for news from
distant ground-based telescopes.
We have heard that there have been
some observations from Spain...
Dan? Gene Shoemaker here... fine.
in which a... I want to hear this...
uh, what we're, the question is,
uh, how soon will Brian be...
There would be no reliable data until
the Hubble Team downloaded the
day's first images of Jupiter.
See, there's nothing in the sky...
And they did,
in fact, detect the plume...
In the auditorium,
Gene had little more information
than the gathered reporters.
we should all take these reports
very carefully and cautiously at this time,
they need to be confirmed.
Look! Oh, my God!
Look at that!
The tiny spot on Jupiter was in fact
a fiery plume about half
the size of the Earth.
Whoa! Whoa! Look!
I'd like to introduce Dr. Heidi Hammel
We just downloaded the first
two orbits
which I have a raw laser printer
output, this is as raw as it gets.
Um, we can actually see
the impact site itself.
And I'll remind you,
this is for "A" the first one,
not the brightest one,
so we're gonna to
have a really exciting week.
I think we're
very, very privileged tonight
to see an event that's,
that's not once in a lifetime,
it's, it's once in a millennium.
Gene's vindication was a
long time coming
now it arrived with
a million megaton bang.
Few scientists have seen their ideas
demonstrated on this magnificent scale.
That was one great moment in our lives.
And it vindicated what Gene had been
trying to tell everybody
all these years and,
that it, eh, the, eh,
the SL 9 impacts spelled it out in
black and white that:
Gene, ya got it right.
Over the next week,
some 20 separate pieces of the comet
rained spectacular
devastation on Jupiter.
If anyone had any lingering doubts
that collisions take place
and that they can have
frightening consequences,
watching those events
on Jupiter convinced us.
To actually finally see an impact
on a planet was a, was crossing a threshold.
That event finally convinced most of
my geological colleagues that,
yes, there really are large impacts,
not just on Jupiter,
but on, on the Earth, as well.
Could you imagine what SL 9
would have looked like,
in its 21 pieces,
if they had been near the Earth?
Had any one of the fragments of SL 9
hit the Earth,
uh, one of the bigger fragments,
we, we probably would have had a dark
cloud covering the whole Earth
in the time of an order
of an hour and a half.
And we saw that the clouds
on Jupiter lasted for months,
as fairly dark clouds.
What about even before the cloud,
what about the rising temperatures
with the in-falling material?
What about before that?
If people knew that a fragment
was going to hit the Earth,
I wonder about the mass hysteria
that could have resulted.
Where would you go?
People would say, Where can we hide?
What can we do?
You would feel as though you
were in an oven turned on to broil.
An enormous hole has been gouged
in the Earth,
then finally the sky will
just turn black, absolutely,
completely black, everywhere,
all over the world.
Impacts today are a risk,
they're a hazard,
they're something we need to
protect ourselves against.
If we don't learn how to protect
ourselves against impacts
then on the long term, we are likely
to be wiped out by impacts.
If it happened to the dinosaurs,
it could happen to us.
In SL 9's wake, scientists
and weapons experts
from Russia and the United States
met at
Lawrence Livermore National Laboratory.
You've got fires.
You've got massive tidal waves.
So, we have a very complicated...
The topic was the end of the world.
Multiple mechanisms
to produce extinction.
You're gonna have
everything burned down around you...
Asteroids big enough to kill a
quarter of the world's
human population collide with the
Earth about twice in a million years.
Smaller bodies, capable of
wiping out a major city,
could hit once every
two to three centuries.
it's going to glow for about
a half an hour
and set everything on fire around you.
Then it's going to be pitch black.
One thing that makes the comet and
asteroid impact hazard so important,
relative to other hazards,
is that it is the one hazard that is
capable of killing billions of people,
of putting at risk
our entire civilization.
We could have any number of storms
or earthquakes or volcanoes
and they can do
terrible damage locally,
but they do not put the entire
planet at risk the way an impact does.
Incredibly, impact is the one great
natural disaster
which we may be able to prevent.
Many of those gathered
at Lawrence Livermore
were veterans of the Cold War,
and already knew something about
confronting assault from the sky.
These bombs obviously, of course,
characteristically of about a
hundred times their mass in a,
in chemical high explosive.
In this case, a nuclear explosion,
you blow off some material,
you get a reaction...
If an approaching asteroid or comet
is detected in the near future,
the scenario might
involve the most powerful long
range rocket in the world
the Russian Energia.
Tipped with an
accurate American warhead,
the rocket would be detonated off
the surface of the asteroid,
nudging it out of its
Earth-approaching orbit.
But before you launch a missile,
you need to know where to aim.
Only a fraction of large Earth-crossing
asteroids have been located.
This may prove to be the
greatest oversight in human history.
I can tell you with confidence
that for the 10% of the big ones
that have been discovered,
there is no danger,
but I can tell you nothing about the
So, yes, we understand the general
nature of the risk,
but we have not yet taken any real
concrete efforts
to protect ourselves or even to look
and see if there's
anything headed our way.
More telescopes have joined the search
Even the U.S. Air Force has
contributed technology and expertise.
Big science has taken up
the hunt for asteroids.
Still, the most experienced team
in the business is leading
the charge from a tiny new
telescope in their backyard.
Both Carolyn and I,
we're eyeball scientists.
We like to look at the sky.
It's kind of an old fashioned brand
of science - eyeball science
uh, eyeball observations
but there's still,
there's still a window there
for the eyeball scientist
who's got the right idea,
uh, to go and make
wonderful discoveries.
Gene and Carolyn Shoemaker should know
it's the story of their lives.
Now, they await with all of us the
next messenger from the stars.
The question is not if, but when...