Most people go through life trying to not get hit.
-What's up man? -All good.
-Did you see that fight? -Oh did I? I think I could've won.
The trick is to roll with the punches
and hope that you don't get floored by one.
Again.
Our world was born out of violence...
and a storm that has raged since the beginning of time.
A storm with the power to destroy planets.
One mighty collision can change everything.
It's done it before
and it could do it again.
Most of us live in blissful ignorance of the chaos around us.
But,
eight astronauts
with over 1,000 days in space between them
can tell us how being 'up there'
helped them to truly understand
what goes on down here.
Everyday
the earth ploughs through
about 40 tons
of material in space.
There is so much activity,
so much action,
and our planet is right in the middle of it.
Space isn't vast and empty space but
a dynamic,
cosmic storm.
It's a storm that could kill us,
but without it...
we wouldn't be here at all.
This is a story about the weird connections,
the near misses,
the lucky breaks
that created this amazing world.
For 4.5 billion years our planet has been battered and
bruised and punched and pummelled
but we're still standing.
It's actually the battle that's built us,
and this is the tale of the tape.
-Thanks guys, awesome. -Al right.
Nicole Scott is an engineer,
pilot
and oh yeah...
These are cool, huh?
...she lived for three months in space.
You can even stick your hand in it.
Left hand.
Okay I'm coming out.
Nicole, your right waist tether to the forward UIAD ring.
Frankly she's a bad ass.
Now imagine them all pressurized and you're having
to work against it really hard.
Here I was, it was so unbelievable.
I'd spent almost 20 years helping build spaceships and
now here I was myself on one...
just amazing.
Okay I am clear Nicole.
Remember watching me do a space walk?
-Yeah. -Yeah.
Was that fun?
-Scary. -Yeah, why was it scary?
Cause I thought you were gonna fall off.
When you're in space, 250 miles above our planet
and looking at these things you thought you knew,
you see them in a totally new way.
For example, the first time I saw a
shooting star
from the space station
was this very visual reminder that there's
a lot of other things
travelling through the same space,
in space.
What did I see and the first time I saw it,
it kind of startled me was,
a shooting star coming in below us.
That's a micro meteorite coming into the earth
and burning up in the atmosphere and
you see this sort of firework display thing going on.
I was doing earth observation
and I'm taking a photo and all of a sudden I see a hole
just magically appear about that big in the solar panel,
you know, that was probably hit by a grain of sand,
something that size,
coming at 17,500 miles an hour in a different orbit.
You get hit by rocks all the time,
you can hear them ricocheting off the hull.
You can see the scars of them
in the windows of the spaceship.
It's a little mind boggling,
when you think about
how much is really out there.
Mostly the stuff up there is pretty small,
burns up in the atmosphere,
nothing to get worked up about,
but there are some pretty big rocks up there too,
ask the dinosaurs.
We believe the asteroid that caused the extinction
of the dinosaurs started way out in the solar system.
You know, travelling that distance,
it's incredible that
it found this target of earth.
Bad for the dinosaurs but ultimately good for us.
We all think we know this story,
but there's something special about the place where it happened,
in the jungles of Mexico.
Here in Mexico I have the chance to dive in what is
the most magical place
to free dive
in the entire world.
This incredible place was created
with very strong violence
when the asteroid hit.
And the result of this is
this calm place,
this paradox.
This place
which is now very quiet
was, at some point, where
something dramatic happened.
Life almost disappeared.
But at the same time, this is where our story started and
this is why we are here now.
When this area was scanned,
we saw that hundreds of these flooded Mexican caverns
connected together into a vast semi-circle.
The edges of a huge crater,
110 miles across and 12 miles deep.
An asteroid that big hitting the planet anywhere
is going to be devastating,
but scientists think it was especially devastating
because of where it hit.
A bulls eye strike on a large Sulphur reserve.
The Sulphur rock vaporized
sending billions of tons of polluting gas into the atmosphere...
blocking out the sun.
The earth froze and the dinosaurs died.
So this big old asteroid
has been journeying for billions of years
through space before it gets to us
and the earth spins, right.
So if the rock had arrived just a few seconds later,
it would have crashed out in the deep ocean,
no bulls eye,
no fire storm,
no dino extinction.
Earth's history is full of moments like this.
It's a tale of destructive good fortune
that connects the death of a planet,
ten million African bats,
a clock in the sky
and tiny rocks from the birth of our solar system,
some about the size of my fist.
There's a lot of rocks hitting us from space.
If they make it through our atmosphere
and hit the surface of our planet,
people go in search of these
in very remote places to try to find them.
They're extremely valuable
because they contain
really the story of where our earth came from.
Boom!
In Morocco we have
a couple of buzzes every year of something that's way cool,
a super awesome meteorite.
If a meteorite is found in the desert
and word gets out...
especially if it's of extreme value.
then there is like a gold rush.
We're talking about the building blocks of our planet.
Some of the most valuable meteorites
are carbonaceous chondrite meteorites.
They're the oldest form of solid material in the solar system.
All the universities want it,
all the museums want it.
The Bedouins are getting amazingly good at recognizing these things.
To the untrained eye,
these might just look like a normal rock,
but the really old ones
contain all the raw materials
to build a planet like earth.
4.6 billion years ago,
where earth is today,
there was just a giant cloud of gas and dust,
all swirling around the new born sun.
This was where the cosmic storm started.
First off with tiny particles
attracted by an electrostatic force.
It's a slow process
but eventually clumps grew into solid matter.
Still only as big as a grain of sand,
but now with just enough gravity of their own,
to pull other grains in.
These grains fused into rocks,
and as they smashed and clumped,
the collisions grew in intensity.
Under immense heat and pressure,
the rocks began to build our planet.
There seems to be nothing subtle
about the way earth was built.
It would almost be like building a space station
with a sledgehammer.
All those bits smashing together,
they were everything we needed to build a living planet.
The calcium in our bones, the gold in our wedding rings,
even the iron in our ships
was all here from the beginning,
except one thing was in short supply,
water,
but it was on its way and coming in fast.
A lot of astronauts will tell you
that from six years old,
watching the moon landing that they knew
from that moment on
that astronaut was a job that they wanted to do.
For me, it wasn't that way.
My background is aeronautical engineering.
I wanted to do something with flying that allowed me to learn
about how things fly
and then ultimately if you wanna know how things fly,
I can't imagine not wanting to know how rocket ships fly.
And then one day I got this phone call
to say that I was assigned to fly
a long duration flight on the International Space Station.
Nicole didn't set out to fly on the ISS,
her job was to build the thing,
but once she got up there,
she still had an eye for design.
So as an engineer you can imagine,
I couldn't help but look at the earth and wonder,
how does that work?
What's blindingly obvious when you look at earth,
is water is the key.
But earlier it didn't look like this blue planet that I
saw, it was a dry and baron rock.
For life to thrive like it has done,
the earth needed delivery of water.
We believe soon after the earth was formed,
our water came from space in a hail of violence.
It must have been brutal.
We think it lasted for about 100 million years.
Icy comets and asteroids
collided with the planet in that.
To supply us with that top off of water.
But unlike Mars and Venus,
who were surely bombarded by the same storm,
we kept our water.
As luck would have it,
the sea that would one day grow,
into earth as we know it,
found its place
at the perfect distance from the sun,
what we now call the Goldilocks zone.
Not too hot, not too cold.
The solar system is vast.
Earth could have easily wound up somewhere
where every drop of water either froze up or boiled away.
But here it's solid, gas and liquid all the time.
It only takes a tiny change like a sunrise
for things to get a little bit slippery.
Solid,
liquid,
gas.
Earth's water,
it's a shape shifter,
constantly changing forms
and as it moves from snow to sea,
from stream to steam
it helps make the weather
that keeps this planet a paradise for life.
From space you can see clouds at the tops of the Amazon Basin
but you can also see them evaporating
on the oceans and so these systems are all interconnected.
That natural, seemingly inevitable process
of turning the oceans into rain,
it's the very essence of life itself on earth.
Without it
they'd be no rivers,
no ground water,
no plants,
no animals.
The continents would be dead.
It actually surprised me how dynamic the planet is,
clouds whirling,
lightning storms propagating over the surface,
the ocean currents visible
and you realize this thing is not a dead rock down there,
this thing is alive.
So we can thank our lucky stars I suppose that
the seed that started earth
was in the right place
for water to exist in its three states.
Our planet was born out of cosmic dust then
watered by a storm from above,
but all those blows were nothing compared to one that
literally ripped the earth apart.
You see earth had a twin.
A twin that threatened our existence.
The earth
is the result of many, many collisions
but the most violent collision of all,
was unknown to humankind,
unknown that is,
until we went to the moon.
I have really vivid memories
of our first moon landing.
Sitting in front of the black and white TV,
for some reason I remember having a grilled cheese sandwich, who knows?
We thought, how could there possibly be anything
in common between the earth and all its beautiful earthly colours
and the grey of the moon.
Oh that looks beautiful from here Neil.
This cratered surface.
It's different but it's very pretty out here.
What we found surprised us,
moon rock and earth rock had striking similarities.
-We'd like you to press on. -Yeah right.
Suggesting that both the earth and the moon
had somehow originated from the same place.
It's one small step for man...
Well there's only a handful of ways that could have happened
and none of 'em are pretty.
The prominent theory is that there was something else
in the Goldilocks zone.
Another planet called Theia
and it was on an intersecting orbit with earth.
In space when
two things are in an intersecting orbit,
with enough time,
it's inevitable that those two things will
collide.
Both planets became molten on impact.
We have debris thrown out into space.
When this cloud of debris eventually cools,
it condenses into a new cosmic partnership.
Planet earth and a uniquely large moon.
Our moon was ripped right out of us,
because of that,
it's big and close and has a lot of pull,
pulls the sea in, pulls the sea out,
tides,
simple right?
But things get harder when that same sea
is covered by ice.
Which is something that grand dads know
and modern kids could stand to learn.
Lukasi knows when the moon is full,
the tide is strongest
and he'll have a few more minutes under the ice,
the best chance to grab their catch.
We shouldn't underestimate how influential
the moon is in all of our lives.
Those regular tides
also help give us another kind of rhythm,
one you might assume had been with us all along.
The collision that ended up forming the moon
sent the earth just spinning.
A day back then was just five hours long.
It was the drag of the tides
that eventually slowed the earth down
to where a day became 24 hours,
like we know now.
The 24-hour day;
waking up, having breakfast,
working eight hours.
Making dinner,
day in, day out.
These cycles,
they're embedded in our DNA.
The violent whack that gave us our moon,
our tides and our 24-hour day,
it gave us one more thing too;
summer in Philadelphia.
When I think of the space station,
I think of this, like, beautiful masterpiece in space,
just hanging there.
The ultimate engineering challenge was,
how do you make your spaceship as much like earth as possible?
Crossing the hatch
from the space shuttle into the space station the first time.
I remember thinking,
wow, it's not the neatest place I've ever seen.
There was wires and cables and
computers and equipment all strung along these walls.
The way we live there is,
we've essentially mimicked
what we have naturally occurring on our planet.
We have to generate the oxygen to breathe.
We have to generate the electricity
to power all of our systems.
We have to figure out a way to clean the air,
so we can continue to breathe.
Because we're human beings and can only live comfortably
really within a certain temperature range,
the whole space station,
all of the systems are working
really hard to maintain that environment for us.
And then you look down at earth
and you realize that's exactly what nature is doing,
just on a mind-blowing scale.
And we've got that cosmic collision
that made our moon
to thank for it.
Wow.
That collision between earth and Theia was so violent
that it actually knocked earth off its axis.
There you go.
So let's just pretend,
this is our sun
and this is our earth
and our earth is tilted,
due to that collision, tilted
23 and a half degrees.
For six months of the year the northern hemisphere
is favouring the sun
and for six months of the year,
the southern hemisphere is favouring the sun.
The shift in the sun's energy from north to south
throughout the year
is constantly trying to move
the hot areas to the cold areas
and the cold areas to the hot areas.
This tilt of the earth results in our seasons.
The seasons constantly change in shape and contour
the land underneath.
The world is constantly adjusting itself.
From the vantage point of space you can see the ever-changing
planet through the seasons from
snowcapped mountains to desert plains.
I really never thought of this until just very recently
you know, I'm seeing all the seasons at once,
so I'm seeing the winter in the northern hemisphere
and it's summer in the southern hemisphere.
If we had no tilt, nearly half the planet
could be frozen all year round.
Nicole would be fine in Florida nearer the equator but
growing up in Philly,
there'd be a glacier in my backyard.
Because of our tilt,
there really are few places on this planet
where life can't thrive.
Life on our planet has synchronized with our seasons.
Raising its young in the spring
and readying them for winter.
Four and a half billion years ago
we started with a smash
that created a tilt
that made our seasons,
that gave us the rhythms of existence.
But more than that,
it gave us the diversity of life we see around us.
Hard to imagine
but for most of the year,
not a single one of these bats lives here.
All ten million arrive from across Africa,
chasing the rains,
to gorge on ripening fruits.
These bats are essentially
a flying forest delivery system.
The tilt of the earth means cold moves to hot and hot to cold,
means winter gives way to spring
just as summer yields to fall.
It means
bats fly across a continent seeding forests as they go.
The world is connected
in a 1,000 ways
and all because of one massive whack.
So is the danger all the in past
or is the calm
before another storm?
This planet is only here
because we've weathered just enough body blows
to build our world.
So far it's been
a perfect storm that's made our perfect home,
one that feels stable,
safe,
reliable.
It isn't.
Imagine yourself on a boat.
Out in the middle of the ocean.
In the middle of a storm.
A big storm.
It's very real to you.
It might even be a little bit scary.
But if you had the opportunity to just zoom in
on one of these tiny little droplets
and see that
inside that little droplet
are these tiny little micro-organisms that are just
oblivious to this storm going on around them.
And if we look at our earth,
if we look at where we live,
this planet that's out in space,
we in some ways
go about our daily lives oblivious to all the action
that's going on around us,
in space,
in the solar system,
in the universe.
This cosmic storm that actually has a violent nature to it,
is the reason why we're here.
The reason why we're able to live so comfortably
on this planet.
Before flying in space I tried really hard to learn from
the people who had flown before me,
to get some idea of what the experience meant to them.
These astronauts had seen
the whole earth from space.
While they described it as a really incredibly beautiful place,
there were also some that said,
they felt a sense of insignificance.
From the very first time
I looked out the window,
I felt like this is significant.
The significance of it to me
is how something so overwhelmingly beautiful
could have come from chaos, violence and collisions.
It's just amazing to think about this
fine line, this,
this balance between
being here surviving,
thriving and not.
The storm has not been our enemy.
We aren't here in spite of it.
We're here because of it.
And when the storm blows over,
it's anything but blue skies and rainbows.
Next time...
Here comes the sun.
It is the fuel of life,
but it is not our friend.
The sun is a planet killer.