Our world was once a world dominated by dinosaurs.
They walked where we walk.
They drank the same water...
Breathed the same air...
And fought on the same battlefields.
But then they faced the day
that none of us can imagine...
Some of the most critical hours
in the history of life on Earth.
This is the story of the day their world ended...
the last day of the dinosaurs.
THE LAST DAY OF THE DINOSAURS
Earth 65 million years ago...
A warmer place than it is today.
Along the west coast of what's now North America,
mountains tower over a large forested valley.
It's the domain of the ultimate form of prehistoric evolution.
Dinosaurs.
And more than 350 pounds with a wingspan of 40 feet,
Quetzalcoatlus is the largest flying creature of all time.
A mile down,
a breakfast no carnivore can not resist.
It will take this tiny hatchling 18 years
to become the most fearsome predator.
But for now, Tyrannosaurus Rex,
is just few inches tall,
not very scary and completely exposed.
But... not completely unprotected.
The father, a fully grown T-Rex is on a hunt.
Its acute sense of smell,
helps him sniff out prey from great distances,
and it also serves him well as a parent.
He knows when something is wrong.
Quetzalcoatlus' metabolism
demands that it eat regularly.
and powering this streamline body
means finding rich sources of protein,
like a 3 pound baby T-Rex.
Quetzalcoatlus' huge wings
are perfectly adapted for long distance gliding.
But its sheer size
makes it hard to lift off when it's backed into a corner.
It's lucky... this time.
Of the entire clutch of T-Rex eggs,
only one chick survived.
And if it grows up,
it will grow to be 17 feet tall
and weigh more than 7 tons.
But surviving to adulthood,
even for Tyrannosaurus Rex
isn't written in stone.
Because a storm is coming.
Born of events that took place long before.
100 million years earlier
This is the asteroid belt between Mars and Jupiter.
200 million miles away.
Billions of rocks all hurdling through space,
in the same direction,
like traffic on a freeway.
All, except this one.
which is moving diagonally on a completely different course.
It's like a 40 mile wide semi
suddenly slicing across the highway.
But this truck is going 22,000 miles an hour.
The two asteroids shattered into millions of fragments.
But this fragment over 6 miles across,
has a special destiny.
100 MILLION YEARS AFTER
It's a rock poised to change history.
Because it's heading for the fifth largest planet
in the solar system.
The only planet known to harbor life.
Planet Earth.
Meanwhile, the planet's reptilian lords live
completely unaware of what's heading their way.
Triceratops are among the most widespread
dinosaurs on the North American continent.
They're herbivores, but that doesn't mean they're wallflowers.
Male Triceratops take their mating rights...
very seriously...!
And weighing 6 tons each,
a face off can be fatal.
This time, intimidation does the trick.
But there's another enemy waiting in the wings.
He's not after mating rights.
The Triceratops is fast and well-armed enough
to stand a chance against T-Rex...
...but not against two of them.
Hunting as a pair
one T-Rex go get behind the deadly horns
and armored core.
There's enough meat here to feed them both for weeks,
but they may not have the time to enjoy it.
A quarter of million miles up,
is the earth's last hope of defense.
The Moon has saved the planet before.
Its pockmarked surface
bears the scars of countless collisions.
This crater known as Tycho,
is more than 50 miles wide.
Created by a rock
only half the size of the one that's on its way.
But the moon is rarely in the right place,
at the right time.
Nothing can stop the asteroid now.
This cosmic missile isn't as alien as it seems.
Like the earth itself,
It's made up largely of rock and water.
In the cold vacuum of space
the water freezes into a hard permafrost.
But on the inside, there's a chemical cocktail
composed of carbon, hydrogen and oxygen.
Key ingredients for life.
Asteroid fragments like this one
may have provide the building blocks for life on Earth.
Life, it evolved into dinosaurs.
But what gives life, can also take it away.
THE PACIFIC NORTHWEST
Most dinosaurs in the valley
hunt and forage during the day
and sleep at night.
This giant herbivore, an Ankylosaurus
keeps one eye open for predators.
Under the cover of darkness,
very different creatures emerge from their hiding places.
Like Mesodma,
a primitive mammal about the size of a possums.
like most other mammals, Mesodma's life
is all about being with the dinosaurs earth.
It only comes out at night, to forage for tasty roots and insects.
While the giants sleep,
It's the meek that witness a cosmic event.
A meteor shower.
Each streak of light
is a tiny fragment of the asteroid collision.
Burning up as it entered the atmosphere.
But these are mainly outrider of the much larger missile
hurdling through space.
An asteroid locked into a head-on collision.
The Day of Reckoning is here.
After a journey last in a hundred million years,
an enormous chunk of cosmic rock
is approaching the end of the line.
And the end of the line is Earth.
In what is today Central Mexico,
a herd of Alamosaurus,
is wandering the plains in search of food.
They're recent species to evolve.
And even by dinosaur standards, they're huge.
They're the last of the Sauropods,
the biggest animals ever to walk the Earth.
70 feet long, and a staggering 40 feet tall,
Alamosaurus weigh up to 30 ton.
To maintain that bulk,
they need to eat up to a ton of leaves every day.
A vast herd like this one strips a landscape of vegetation
in just a few hours.
Because she's a nomad on a constant search for food,
when it's time for this female to lay her eggs, she doesn't nest.
She simply lays eggs in groups of 5 or 6,
to improve the chances that some will survive.
Under normal conditions,
only one in 3,000 will produce a mature Alamosaurus.
But the odd stacked against these eggs,
are about to get astronomical.
Because now, just 20 minutes away
2 trillion tons of rock is racing right at them.
The asteroid fragment's enormous mass
is only part of the threat.
The other part is velocity.
But as it get closer to the planet,
The Earth's gravitational pull gets stronger
and the asteroid accelerates,
past 40,000-45,000 miles per hour
And mass times acceleration equals force.
As the asteroid encounters atmosphere,
friction turn it into a fireball
swooping over the Atlantic and aimed at Mexico.
And... the Alamosaurus.
It takes just four minutes to cross the ocean.
It crushes and superheats the air surrounding it,
transforming gas and debris into white-hot plasma.
At 35,000 degrees,
it's burning brighter than a million suns.
It takes just 5 seconds to flash through the atmosphere.
Impact seems instantaneous.
But hidden within the cataclysm,
are a series of discreet events
invisible to the naked eye
but key to understanding what follows.
The asteroid's trajectory is shallow.
It flies in at about 30° angle to the surface.
This means the full brunt of its destructive power
will be thrown to the north of the impact point.
Even before the fireball touches down,
its sheer brightness in the sky is unimaginable.
500 miles from ground zero,
the light is so intense
that makes the Alamosaurus' flesh seem transparent.
And burns flash frames of their shadows onto the ground.
The scorching light sears their eyeballs,
They have no way of seeing what's headed their way,
but they can feel it.
An explosive force of a hundred million megaton,
more powerful than all the nuclear weapons ever built.
If the asteroid had crashed into deep ocean,
some of the force would have been absorbed.
Instead, it hits the shallow waters of the gulf of Mexico.
which instantly vaporized.
In fraction of a second,
the entire asteroid disintegrates into the planet.
Earth and rock also vaporized
in our hurled skyworld at 100,000 miles an hour
Behind them,
80,000 cubic miles of the
earth's crust explode from the ground.
500 miles from the crash site,
the air temperature now reaches 600 degrees
Hot enough to boil away the water in the dinosaurs' skin.
which escapes with sudden bursts of steam.
The fiery blast suck every drop of moisture from the vegetation.
Anything directly exposed to the blistering heat...
is simply boiled alive.
Just 108 seconds after impact
in the Gulf of Mexico
The bright streams of vaporized rock
can be seen in the Pacific Northwest.
From their clifftop ruse a breeding pair of Quetzalcoatlus
can see the glow of the fireball high above the horizon
... 3,000 miles away.
That's how big it is.
Just 2 minutes has passed
since the asteroid slammed into the Earth.
The body count back near the crash site is amass.
Surprisingly, there are survivors.
Those lucky enough to be shielded by a mountain
are spare the worse of the light in heat blast.
But three more waves of destruction are coming.
On impact, boulders the size of buildings
blasted into the air at supersonic speeds.
But what goes up...
... Must come down.
Hundreds of surviving Alamosaurus
are bombarded from above.
A second wave hits from below.
An earthquake measuring 11.1 on the Richter scale.
Nearly 60 times more powerful
than any earthquake humans have experienced.
The third wave is the blast postwave.
Radiating outward in a perfect circle.
Packing a force that rips through air
faster than the speed of sound.
Stripping skin from flesh.
Lifting 30 ton dinosaurs into the air like so many ragdolls.
Just 5 minutes have passed since impact.
And three waves of destruction have decimated an entire species.
Many other species of dinosaurs in the region
shared the Alamosaurus' fate.
Most of the eggs too, have been destroyed.
And the Earth is a powerful protector.
Some eggs, buried in a cold ground have survived.
New Alamosaurus life is growing.
There is still hope...
...for now.
An immense boulder the size of mount everest
crashes into the gulf of Mexico,
driving entire species of dinosaurs to extinction
in less than five minutes.
But the worst is still to come.
On the other side of the planet, there is still no sign of trouble.
Mongolia is 8,000 miles from the impact.
This scrubland here supports hundreds of dinosaur species.
For a family of Kronosaurus,
it's business as usual at a favorite watering hole.
They can weigh 4 tons and grow to 40 feet in length.
But they're vegetarians and docile,
except when they have to defend themselves or their offspring.
which are now at their most vulnerable
to the hungry predators that lurk around every corner.
Armed with a Razor-Sharp, oversized claw on its hind feet,
this is the jackal of the Cretaceous Period.
Suurornithoides, a very smart reptile.
Its brain-to-body-weight ratio
is among the highest of any dinosaur.
It's hungry, but it knows better than to take on a full grown Kronosaurus...
not when there are easier targets,
In its rush to eat
The thief doesn't get as far away from the enraged mother
as it should.
And it can smell its mistake.
It's a Mexican standoff
between two very different kinds of dinosaur.
One has the speed and smart of a carnivore
but the other is 80 times larger.
But the large herbivores of this world aren't made for fighting
And that's exactly what the Saurornithoides is counting on,
especially when he's got backup.
Speed and strategy give these small hunters the edge.
But neither great size nor great intelligence is any guarantee
of safety from the kind of enemy that is now approaching.
On the other side of the planet,
A fireball rises 100 miles above ground zero.
70 billion tons of pulverized stone and earth
fill the upper atmosphere
with a cloud of microscopic dust and glass,
and it's spreading fast.
This is the Ejecta Cloud.
As the dust spreads at high altitude,
trillions of tiny particles re-enter the Atmosphere.
The friction creates intense heat...
A 15,000-degree dust cloud heating up everything beneath it.
From their Cliff-Top Perch in the Pacific Northwest,
the male and female Quetzalcoatlus have a clear view of the approaching cloud.
Down in the valley, a thick ocean fog blocks out the sky.
The heavy blanket of moisture makes it impossible to see the coming apocalypse.
But the animals down here do get a warning.
Not from above, but from below.
When the asteroid struck,
most of the energy is deflected out or up.
Only 1% of the force travels down into the ground.
But it's enough to ring the planet like a bell.
Seismic waves radiate both across and through the Earth.
16 minutes and 40 seconds after impact,
they reach the Pacific Northwest.
In the valley, the ground shakes as the 11.1 earthquake ripples through the ground.
Triceratops panic of the sight of the valley
in a desperate attempt to escape the tremors
and falling debris.
Smaller animals take shelter on the ground.
Meanwhile, The ejecta cloud is approaching
at 10,000 miles/hour
It bakes the Earth with unrelented heat.
Million of volts of static electricity
charge the cloud like a giant battery,
creating a vast electrical storm.
Superheated rocks shower the valley.
A burning hell.
The Quetzalcoatlus are fleeing the quake's devastation below
But there's no way to hide from a rain of fire.
Only the valley floor can provide shelter,
but there too big to descend quickly.
Until the males' tattered wings
can no longer keep him aloft.
If his mate doesn't find shelter, she'll be next.
On the mountain slopes,
a pair of Triceratops emerges above the cool sea nest.
They're almost out of the quake ravaged valley
when the ejecta cloud arrives...
Like a blowtorch.
A dinosaur paradise just hours ago...
North America is now a living hell.
But the Ejecta isn't finished yet,
not by a long shot.
Less than an hour since the asteroid impact,
hundreds of species of dinosaurs
lie devastated across the western hemisphere.
The ejecta cloud continues to spread at high altitude.
As it spans the globe, the effects on the ground very dramatically.
8,000 miles away in Asia,
the cloud rolls in silently from the east.
In Mongolia, temperatures on the ground tick upwards
a few degrees hotter every second.
There's no audible warning, only mounting heat.
As the air reaches 120 degrees,
the only hope is shelter.
At 160 degrees, survival is measured in minutes
Over 200 degrees, just seconds.
90 minutes after impact,
The temperature on the ground in Mongolia peaks at 300 degrees.
But not every dinosaurs's baked alive
The micro climate of a cave
can keep a handful of survivors cool enough to breathe,
but it's a refuge that has to be shared,
forcing an uneasy peace between sworn enemies...
one that's already fraying at the edges.
Back in the Pacific Northwest,
the dense fog still shields the valley from the intense heat above.
In sheltered areas like this,
small pockets of dinosaurs hang on.
For the Triceratops here,
the high temperatures and humidity force them to keep moving.
For scavengers There's no shortage of food.
But most animals caught by Ejecta Cloud aren't so lucky.
The female Quetzalcoatlus,
is one of the few survivors of her species.
The last thing these animals need is a new threat.
But the aftereffects of impact
are just getting started.
Above the valley, and across North America
The intense heat of the Ejecta Cloud has ignited fires.
blazes so intense they generate their own winds.
Down in the valley the air pressure plummets,
creating a vacuum that sucks in the flames.
The dry vegetation goes up like a powder keg.
Building a wall of fire.
The front of the fire burns hottest and fastest...
moving across the valley floor at nine miles an hour.
T-Rex can run twice that speed,
but it can't keep the pace up forever.
The valley basin is now a fire storm
1,800 degrees
hot enough to melt solid aluminum.
The panicked animals race up the valley slopes.
but fire goes faster uphill.
Some lucky creatures escape below the flames.
But large dinosaurs have no place to hide.
Her wings still damaged from the falling ejecta,
the wounded Quetzalcoatlus struggles to take off.
For dinosaurs, time is running out.
Two hours after the asteroid impact,
the entire planet is covered in dust and smoke.
Fires rage across The Western Hemisphere.
One of the few remaining Quetzalcoatlus,
a flying pterosaurs as big as a giraffe,
is struggling to get airborne.
From above, what was once a lush valley
is now an inferno.
Animals that fly can escape the flames,
but there are few places to land
and almost nothing to eat.
A food chain once is enough to support giants
now lacks its basic components,
... Plants.
8,000 miles away in Mongolia,
the temperatures are finally dropping.
A handful of animals remain safely holed up in their cave.
It seems the worst is over.
The Ravenous Saurornithoides
can't resist the sight of an easy meal.
Soon, The Braver Kronosaurus follow,
making their way back towards the watering hole.
One stays near the protection of the cave.
As the ejecta begins to clears,
the parting clouds reveal the shift in temperature
is throwing earth's weather systems
into turmoil.
And in Mongolia, powerful winds are gathering
billions of tons of dust and sand.
A dust storm forms as hot air rises.
Thermal imaging shows how it builds,
whipping up loose particles of sand and dust
and gaining energy from the heat of the sand itself.
The 300 degrees temperatures that baked Mongolia
turn a common weather phenomenon
into a superstorm.
As it hits, The Saurornithoides
are small enough to crouch for cover.
But the Kronosaurus are out in the open.
The sand blasts their bodies.
The harder they struggle
and the deeper they gasp for oxygen,
the more sand fills their lungs...
until finally they can't breathe.
The superstorm engulfs much of the continent.
It's hours before the winds die down.
The last Kronosaurus,
protected once again by the cave,
heads to the watering hole on her own.
Halfway there,
she finds she's the last of the herd.
But she's not the last remaining dinosaur in the neighborhood.
Huddled close to a Kronosaurus Corpse,
the Saurornithoides was sheltered
Sukentang
from the worst of the storm.
But the sand has swallowed their meal.
Instinct drives them back to their prime hunting spot...
the watering hole,
where the last surviving Kronosaurus
is taking in the much-needed fluid.
She's lucky to be alive.
But too exhausted to run from any new sign of danger.
And danger has arrived.
The Saurornithoides are desperate for food.
But they're weak from hunger
and abofitting from the sandstorm.
Only one has the confidence to attack.
Its prey is still too exhausted to run.
But this time, size dose matter.
The remaining Saurornithoides moves in.
But it has no intention of making a run at the Kronosaurus...
not when fate offers it a meal that can't fight back.
A week after impact,
food is in very short supply across the entire planet.
Life is hardest for the plant eaters.
Huge herbivores have to eat vast amount
just to sustain their massive bulk.
But there are simply no plants to be found.
They can only hope that something, somewhere is growing.
The Carnivores are more fortunate.
they can eat the Herbivores.
But two triceratops
are a little too much to take on...
for now.
Three days after the asteroid impact,
A once blue planet is shrouded in darkness
and the landscape is anything but green.
Fire, heat and acid rain
have battered the terrain until it's unrecognizable.
Normally, Triceratops wouldn't travel more than a few miles a day.
They wouldn't have to.
But now most of the continent is stripped of vegetation.
Hunger drives the giant herbivores
toward the Pacific coast.
The devastation reaches all the way to the sea.
But Geography has a way of protecting certain places
from Cataclysmic events...
in this case, an island,
apparently untouched by the surrounding desolation.
There may still be food here.
The female Quetzalcoatlus has been flying for three days.
She's weak and in desperate need of food.
From 1,000 feet up, the island comes into view.
But all is not as peaceful as it seems.
Deep below the surface,
The Ocean floor was shaken by the asteroid's initial impact.
Sedimentary rock disintegrates under the strain
and Collapses hundreds of feet into the ocean floor.
On the surface Sea level plunges,
triggering a massive swell.
At the coast,
the ocean is dragged back hundreds of feet from the land.
Exposing huge expansive seabed.
The path to the island is suddenly dry land.
The forest ahead of them appears untouched
by the hellstorm of the ejecta.
it seems too good to be true.
Half a mile from the coast,
the three Triceratops finally reach the Promised Land.
Sheltered from the ejecta by sea mist
and protected from fires by the surrounding ocean,
the island has all the food they need.
The Quetzalcoatlus hasn't had a decent meal for days.
The asteroid has awakened the ocean's most destructive force...
A Mega Tsunami.
A wall of water, 300 feet tall.
Within seconds, the land is deluged.
And as quickly as it came, The flood is gone.
But this is only one in an amens army of mega-tsunami.
The asteroid impact against
more than 13,000 miles of coast.
Huge wafts of shoreline simply wash away into the sea.
The avalanche of water leaves countless dead in its wake.
But as devastating as the first wave of disasters is,
there's more to come...
In the days following the asteroid's arrival,
a series of plagues have been unleashed on the planet.
Firestorms...
Earthquakes...
Sandstorms...
and towering tsunamis.
But these are only the outward signs of a catastrophe
that reaches much deeper.
Across all continents,
thousands of dinosaurs may be walking,
but their species are already dead.
Because to survive
any species needs to maintain a critical mass of population
Fall below that threshold,
and there's no way to climb back from certain extinction.
The final nail in the coffin
may take a while to develop, but it's no less deadly,
and no less final.
The coup de grace for the dinosaurs
comes from inside the planet.
Because when a rock 6 miles across
slams into the Earth at 45,000 miles/hour
it shoots 1,000,000 megaton of energy
straight into the ground.
Seismic shock waves ripple through the planet.
The aftershocks continue for months
As tectonic plates shear and tear.
Deep inside the planet,
they trigger molten rock to force its way to the surface
through newly formed fractures...
until it explodes from the earth's crust
in violent Volcanic Eruptions.
The seismic waves awaken
dormant Volcanoes around the world,
adding to the debris clouds of dust and toxic gases
that already surround the globe.
The shroud is already many miles deep,
a thick blanket stopping light
and warmth reaching the earth surface.
The planet plunges further into a nuclear winter.
In the days and weeks that follow,
the only growth to thrive is fungus
which lives off the rotting remains.
Here in Mongolia,
few signs of dinosaurs remain.
and for the starving Kronosauraus
the future looks bleak.
But it stays near the cave
that has saved it twice in the past.
The watering hole that once provided plenty.
But the last Kronosaurus
doesn't fall victim to starvation.
Bubbling to the surface
is one of nature's most toxic gases...
Hydrogen Sulfide.
Released from deep underground by Volcanic activity,
it collects invisibly in low lying areas
like the waterhole's natural basin
the gas paralyzes the lungs,
making escape impossible. Then it kills by suffocation.
What was once a refuge...
is transformed into a death trap.
The last dinosaur in this part of Mongolia is dead.
Mexico, too is a graveyard.
Just 500 miles from ground zero
It's been hit by wave after wave of devastation
There would seem to be little that nature could throw at it.
And yet, amidst all this destruction,
beneath the thin layer of charged soil,
a lone Alamosaurus egg survives.
In the Pacific Northwest,
just a handful of dinosaurs
patrol the gray wasteland.
An Ankylosaurus, severely weakened by hunger,
searches the charred terrain for something to eat.
25 feet long and weighing 4 tons,
this heavily armored herbivore
is used to getting nearly 300 pounds of food every day.
All it can find now is a small bush.
And even that won't come without a fight.
But hunger is the least of their worries.
It's two of this world's best armored warriors
versus a hungry Carnivore that won't take no for an answer.
The Ankylosaurus's main defense weapon
is a heavy tail club.
But it's too weak to get in a good shot.
Not so T-Rex.
With food sources disappearing,
starving giants are forced to fight for every calorie.
Even to the death.
So the dinosaurs that outlast the ejecta,
firestorms, and poison gas
ultimately fall victim to the demands of their own massive bodies.
It took 160 million years
to bring the dinosaurs to this point of their evolution.
It took just one rock to bring them down.
The events triggered by the impact
flashed by a breakneck speed.
Seismic shocks caused massive earthquakes
boulders the size of buildings raining down
followed by a brutal blast wave
all within the first 3 minutes.
By the time the super heated Ejecta Cloud hit Mongolia
just 44 minutes later,
the whole planet was in shock.
In the coming days, forest fires race the earth.
Violent dust storms destroy entire ecosystems.
Titanic waves wreck coastlines.
Put all these together,
it is hard to believe that anything on Earth
could have survived.
But something has.
Mexico, 500 miles from the point of impact
the very first landmass to feel the force
of the asteroid's strike...
a region that has suffered wave upon wave of violence...
yet even here, even now,
life remains.
a last surviving Alamosaurus egg.
Buried safe within the soil,
a chick has survived the barrage of destruction.
And he's not alone.
All around the world,
small handfuls of dinosaurs try to start over.
But inbreeding and disease,
weaken their tiny populations.
Eventually,
the huge numbers of dinosaurs that had ruled the world
are reduced to a single, solitary dinosaur.
And it too, is gone.
And with it,
a dynasty that had ruled the Earth
for 160 million years.
But dinosaurs weren't the only animals on the planet.
There were other, humbler lifeforms that had lived
in the dinosaurs' shadow for a very long time.
When floods and fire storms hit,
they found shelter on the ground.
Some hid deep inside trees and plants.
Others took refuge beneath the soil.
And small mammals, like Mesodma,
survived by scampering into burrows.
Down here they were protected
from the worst the asteroid could throw at them.
The earth would be inherited by animals that were good at hiding.
Fish were sheltered beneath the water.
So are the aquatic reptiles.
Birds, especially waterfowl,
could survive by diving underwater or hiding in burrows.
It will be years before all the Sun's energy
could reach the land again.
But the heavy cloud slowly begins to clear.
In the Gulf of Mexico where the asteroid struck,
a shallow crater can be seen.
A tiny scar for such a fatal wound.
Out of the ruins, nature starts over.
Simple organisms like mold and fungus dominate
the burnt and rotting landscape.
Then new growth emerges,
and one plant in particular...
Ferns...
Tough and resilient, they soon carpet the planet in green,
It takes thousands of years for ferns to give way to forests.
Breathing Oxygen and life into the planet again,
and setting the stage for a new era...
because waiting in the wings
are creatures whose development
had long been thwarted by the dinosaurs...
The mammals.
Unlike the dinosaurs,
the mammals are fast breeders,
brilliant adapters.
They multiply...
And diversify
10,000 species,
exploding across the planet.
But it's millions of years before one very important species
branches off from its relatives,
and comes down from the trees.
They walk on two legs,
evolve bigger brains,
and eventually... rule the planet.
Just as the dinosaurs once did.
But unlike them, They'll reshape the world,
building cities that touch the sky...
vehicles that can leave the planet...
and weapons that can destroy it.
But none of it could have been possible
if a chance collision in space
165 million years ago,
hadn't sent an asteroid hurdling toward earth
and doomed the dinosaurs to extinction.
Only because they died
can human beings live.