How to Build a Planet (2013): Season 1, Episode 2 - Engineering a Universe - full transcript
Planet Earth.
Our home.
It's unique.
It has life.
But what's amazing,
is none of it would exist
without the sun,
the moon and the stars around us.
We are connected to the universe
in the most fundamental ways.
To find out how,
I'm going to have to build my own.
I'm going to open up a
cosmic tool-box and work it out.
And I'm going to build
my universe up here,
at the top of this
impossibly high tower.
It gives us the perfect platform
to make something really big.
Up here, we can do in seconds
what it takes nature millions
or billions of years to do.
And to build a universe,
I'm going to need a lot of help.
- -I'll be honest,
I'm faintly nervous.
Was that it?
Wow! Beautiful!
Oh, this is really difficult!
I told you,
'70s moves. There they are.
Like any construction project,
there will be mistakes.
But from those mistakes,
we'll get real insights
into what makes our universe
exactly right for us to exist.
As an engineering challenge,
this is about as big as it gets.
How many times have
you marvelled at the stars?
Depending upon
your frame of mind,
the stars might appear
distant and magical,
or cold and remote.
But the fact is,
we are all made of the same stuff.
And if you were to change
anything about them,
or about us,
that connection,
that delicate balance,
would be lost.
And this isn't an idle fancy,
a romantic notion,
it's essential,
elemental and real.
Without that connection,
we wouldn't be here.
And to understand how it works,
we need to build a universe.
It's not a small task
because Earth is
in a solar system
which is in just one
tiny part of a galaxy
that has over 300
billion stars within it.
And there are half a trillion
galaxies in the universe.
So the job isn't really
done until we build it all,
from suns to galaxies.
I'm going to need
to construct all of this
up here,
at the top of my tower,
where there's loads of room.
To do this, we need to go back
to the very start of everything.
We need to start from scratch.
In the case of our universe,
the start of everything
was 13.8 billion years ago.
About.
I do like a challenge.
Most scientists agree that before
the universe, there was nothing, nada.
But out of that nothing,
was created something...
Everything.
It all happened in an
event called the big bang.
Thing is, "The big bang"
is actually a
misleading name for it
because it wasn't a bang at all.
There is an analogy that
scientists and boffins use
to get their head
round this event.
There's no explosion.
It wasn't a bang.
It's more like a balloon.
The big bang was
a rapid expansion.
Just like inflating a balloon.
Now, of course,
the universe expanded
a lot quicker than our balloon.
Unimaginably so.
In a billionth of a second,
it was already the
size of our solar system.
But you take the point.
It's like a big expanding
bubble of space.
But there's something even
more bizarre about the big bang.
That universal expansion
had no single point of origin.
It happened everywhere
and all at the same time.
So one balloon isn't
enough to demonstrate it.
I need countless balloons.
What's more,
the expansion of the big
bang is still happening today.
Which means that wherever I am,
I'm at the very centre...
...of an expanding universe.
And wherever you are,
you, too,
are at the centre of the universe.
So, we've had our big bang,
but there is a little problem.
It's dark.
There is no light
after a big bang
because there are no stars.
So where do I get a star from?
Well, fortunately,
it turns out they make them
just off the M40 near Oxford.
Inside this
billion-pound chamber
we are going to squeeze,
using colossal magnets,
the only thing that was
around after the big bang,
hydrogen gas, until it ignites.
And that is a star.
Sounds simple? It isn't.
Don't try this at home.
It is a job for the
professionals.
The chamber will briefly use more
power than a city like Birmingham.
And the ignition countdown
begins 100 metres away
in the relative safety
of mission control.
We're now approaching the T-minus
one minute mark. T-minus one minute.
I'm joining star maker-in-chief,
Professor Steve Cowley.
- Steve, hello. - Hello.
I haven't touched anything
and I promise not to
because you're effectively
creating a star here.
Yeah.
This looks amazing!
This looks like
I'd want it to look.
Is it running now?
We're about to fire it up,
and for a few seconds,
we'll reach the temperature of
round about 100 million degrees.
100 million degrees!
What if it goes wrong, Steve?
I mean,
it's kind of extreme, isn't it?
If something goes wrong,
and it does do,
the physicist in charge,
she's got a red button, basically,
and she will press
the red button
and it will abort the shot.
The amount of energy in there...
This isn't that far from my house,
is where I'm going.
- I live 50 miles away.
- But it does have a wall that's two metres, so...
- - What's that?
It's the panic button.
You have to run now.
I'm not going to bother running.
Really, what would be the point?
If something really did go wrong,
you could cause a lot of damage.
Right.
And I'm being allowed to
give the trigger command
to turn it on.
So, what I'm going to do now is
trigger the creation of a star,
briefly, on Earth.
Um, ahem.
Er, trigger, please.
Can you accelerate, please?
Okay. Thank you.
Start.
- It's starting up now.
- All right.
Electrical current
going through it.
I'll be honest,
I'm faintly nervous.
How many times a
day do you do this?
...eight,
seven, six, five, four,
three, two, one, zero.
There it is. - Right.
Oh, look at the instability,
it's shaking.
This is mind-blowing.
Inside the chamber is hydrogen.
It was pretty much the only thing that
existed in the darkness after the big bang.
This machine heats and
squeezes the hydrogen
with such force that it ignites,
creating a star and light.
So,
what's happening in that chamber right now,
there, that is...
That is a star on Earth.
What's remarkable is the
process of making a star
doesn't just create light.
It also makes brand
new ingredients,
and this is going to help
me build our universe.
There's little white specks,
which is exactly
what stars are doing.
It's turning
hydrogen into helium.
They start with hydrogen
and they make helium
and then they get helium
and they make carbon,
then they make oxygen.
All the things you're made of,
right, and they're made bit by
bit by bit in the centre of the star.
- Was that it?
- That's it.
And was that the abort button there,
you had all the... Whoa...
Within a star,
these different elements are made...
- Yeah.
- But how do they then...
They've got to get elsewhere.
So, if it's a big enough star,
it explodes,
that's a supernova explosion,
and it spews all that stuff,
all those things you've made,
all the carbon,
all the iron, all the nickel,
all the whatever, right, spews it out
into the universe as dust,
as particles,
as this, that, and the other.
These elements
are created within it
and then, boom,
it's all over the universe.
Stars not only give us light,
they are the element factories
to build everything else.
Back at my tower,
I can now make light
and create all the stuff to
build the rest of our universe.
We just need a
star to go supernova.
A supernova is the
biggest explosion there is,
and for us,
it's an essential stage
in our construction process
because it takes all those
elements created in big stars
and scatters them everywhere.
Just one note of caution though,
when I say "big," I do mean,
"Really, really big."
And that supernova
has now scattered all
the ingredients we need
to build everything.
Floating around the tower,
we've now got carbon,
oxygen,
iron,
and all the other elements
we're going to need
to make the planets,
and even us.
In that sense,
everything really is stardust.
You, me,
everything you've ever seen or touched,
or ever will.
All of it created from the
birth and death of a star.
It's mind-blowing.
And that cloud of gas and dust,
called a nebula,
also provides the
ingredients for other stars.
So we can now build
our own star from it.
We'll call it the sun.
The real one took around
50 million years to form.
Here, we've done it in seconds.
And orbiting it is the
dust and gas we'll need
to make all the planets
in our solar system.
The first planet to
start forming is Jupiter.
But something's
not going to plan.
The young planet is
starting to hoover up
way too much of
the gas and rock.
And this process
is slowing it down
causing it to fall
inwards towards the sun.
Which is a problem
because this is the very stuff
that's going to build
all the other planets.
It's bad. What do we do
to stop Jupiter gobbling up
all our planetary
building materials?
Well, fortunately,
I'm told there is a man who knows.
This is Professor
Alexei Filippenko.
And this is a Fresnel lens.
A simple enough device,
but surprisingly powerful.
- Hi, Richard.
- So, how do we get rid of our rampaging Jupiter problem?
Oh, well, look. Let me show you
a little demo that'll help illustrate it.
Declan,
why don't you tilt it there?
- It's on fire. Right away!
- It is on fire!
But what's that got to
do with Jupiter? It's a bit of wood?
Yeah, well, what's happening
is there's all these photons,
all these little energetic particles
of light coming from the sun
and they're being
focussed here on this wood,
heating it up,
causing it to burn.
In the case of the
early solar system,
the sun was much
brighter than it is now
and it acted for hundreds of thousands,
or millions of years.
So the photons were hitting
the particles of dust and
gas and heating them up,
causing the atoms to
actually evaporate away,
to be blown out of
the solar system.
That meant that
Jupiter was no longer
slowing down and
spiralling into the sun.
Two things. One,
there's a small fire over there.
- Yeah!
- Two,
the stuff in the way of Jupiter,
slowing it up,
wasn't wood.
Yeah, I know,
but look how powerful the sun is.
Here's a rock. Why
don't you put it right there?
I don't want to get
zapped with your machine.
Well, Declan isn't going to zap
you while you're putting it there.
And, yeah, we need to have
some safety glasses on because
it's going to get heated up so
much from the trillions of photons
hitting it that, er, it's actually
going to snap, crackle and pop.
Little pieces are going
to come flying out.
You've got more safety than me.
Well, you know,
my eyes are more important.
- I'm an astronomer, okay?
- Okay.
So let's put the
rock in there...
I can't argue with that, can I?
- I can't argue with that.
- I think you're okay.
Oh, hang on, that is the rock.
Yeah,
that's the rock flaking off
because of all the
energetic photons hitting it.
I am properly
impressed with that.
That is in seconds.
It's heating up to 3,000
degrees Fahrenheit, okay?
Now, over millions of years,
the material is being blown
out of the vicinity of Jupiter,
so it's not growing any more and
also it's not spiralling into the sun.
So that saves us.
Turn it off, Declan,
I'm terrified.
So this is another one of
those events that had to happen
at the right time, in the right place,
and to the right extent.
Too much of this for too long
and there's nothing left to
make your inner planets from.
Yeah, that's exactly right.
Okay, a plan.
I'm going to use light from the
sun to clear a path for Jupiter
to stop it slowing
and spiralling inwards,
gobbling all the building
materials for our other planets.
So,
let's crank up the light from our sun
and get those photons pumping.
Jupiter's way is now clear.
But luckily for us,
the perfect amount of stuff
is left behind to build the
rest of our solar system.
So we've got Jupiter.
Now,
how do we make our other planets?
To find out what planet formation
was like in the early solar system,
I need the help of the
Texas Roller Derby.
Excuse me. Sorry.
Of course I do.
Sorry, ladies,
excuse me. Can I join?
- Oh! Do I really need that?
- You need it to protect your head.
Yeah? Right. Well,
I'll pop it on. Thank you. Er...
What's your skate name?
Your name on the track,
your alter ego?
Hamster. Yeah, it's a long story.
- What about Slamster?
- Slamster!
- Oh! I'm loving that!
- Yeah, that's good.
What sort of injuries can
you acquire doing this?
Broken... Everything!
- Broken ankles. - Broken teeth.
Hands, arms...
I am really scared!
You should be.
Now,
I know what you're thinking.
Actually,
I've no idea what you're thinking.
But bear with me. This is a
genuine scientific demonstration
of what happened in
the early solar system.
See you out there,
girls. Oh, scared!
I should say,
I'm not what you'd call a regular skater.
Imagine the sun in the centre
of the track providing the gravity
to pull around a whole host
of rocks of different sizes.
Go, go, go!
These wannabe
planets are known as planetesimals.
Stop.
Some of these
planetesimals were large,
some very small,
some moving in crazy orbits.
All of them were affected
by one another's gravity.
So there were huge collisions.
Potential planets were
flung out of the solar system.
And some wannabe
planets were destroyed.
Others had huge
chunks ripped off them.
What happened over
just a few million years
was a sort of planetary carnage.
Oh! This is really difficult!
Whoa!
Eventually, some of the larger,
more stable planets emerged
and took the
outside orbital lane.
Whilst closer to the sun,
smaller planets jostled for position.
The remnants of
this orbital tussle,
the dead and never-to-be
planets didn't just disappear.
They still exist.
A graveyard of broken worlds
now orbits the sun
as a ring of debris
known as the asteroid belt.
So here we are.
Our solar system.
There's Jupiter and alongside it,
the asteroid belt.
And then the rest of the
planets in our solar system.
There's Mercury,
nearest the sun.
Its atmosphere has
already been burnt away.
Then Venus,
a big bash early on
has reversed its spin.
And Mars,
there's an enormous
volcano here,
Olympus Mons.
Three times higher than Everest.
Then Jupiter,
bigger than all the planets put together.
Saturn, with its amazing rings.
So light,
it could float on water.
Further out, Uranus, where summers
last 21 Earth years, as do winters.
And finally, Neptune.
Freezing cold with hurricane
winds of 1,000 kilometres an hour.
Of course,
there is one planet missing, ours.
And exactly where
it goes is critical
because we need it to support
one very fragile thing, life.
Earth is unique amongst the
planets in our solar system.
It teems with life.
Life which comes in
countless different forms.
So what is it that
makes Earth so special?
What do we need
for life to exist
when we're building
a solar system?
To find out,
these scientists are attempting to reach
one of the most inhospitable
and extreme places on Earth.
Sandro...
How far is it to the lake?
Where
they're heading is so toxic,
it is like an alien planet.
If they can find
life down there,
it'll help us understand the most basic
requirements for life in our solar system.
Okay, I'll follow you.
Be careful.
To get there, they must
risk a perilous three kilometre-descent
into eastern Italy's
Frasassi cave system.
Caves like these contain some of
the last unexplored frontiers on Earth.
Here I come.
Oh!
The expedition is led by
astrobiologist Professor Jenn Macalady.
Stay left, it's really tight.
If you go to the right you're
going to get stuck for sure.
I'm not far behind.
Use your feet.
Yeah, I am. It's, er, tight.
Breathe out.
Yeah, that's it.
You got it? - HAMMOND: Yep.
You're through! Awesome.
The things I do for science!
After six hours,
they're approaching the final descent.
At the bottom, Jenn's hoping to shed light
on the minimal conditions required for life.
- Aldo, coming down. - Okay!
This is the Crystal Lake.
Wow, it's beautiful.
Okay, I'm going down.
Deep below its surface
is home to what Jenn is looking for.
Long way down, folks.
Down here, all the normal things
you need to support
life have disappeared.
Shall I come all the way down?
There is no light.
No animals or
plants to feed off.
And where they're going,
there's no oxygen.
We made it.
The water is even poisonous,
but Jenn is hoping
to find life there.
The hunt will involve
one of the most dangerous
dives on the planet.
Preparing to make the 80-foot plunge
is ex-Navy diver Alejandro Crocetti.
Perfetto.
His dive
time is strictly limited.
Any kind of
cave diving is very dangerous,
because if there's a problem,
you can't just pop up to the
surface. You have a long way to go.
But also, in this particular case,
the water is actually toxic.
So the chemicals that are dissolved
in the water come through the skin,
so that if you stay in that water
for a while, then you become sick.
You start to have symptoms
that prevent you from
making good decisions.
Very quickly,
the passages become tighter and tighter.
There is no room to manoeuvre.
As soon as you move,
you suspend all the
sediment that's on the bottom
and the visibility goes
to zero very quickly.
Fish would die instantly here.
Very quickly, the water
will become sulphidic and more cloudy,
and more difficult
to navigate through.
We're not meant
to be there really.
It's a place where we can
stay only for a few moments.
Finally,
they find what they've been looking for.
These weird alien
fingers are alive.
They are bacteria,
living on nothing more than
rock dissolved in toxic water.
Wow!
Wow!
Look at that.
This is beautiful.
Were there a lot like this?
- Molti? - Si.
- Amazing sample, bravo.
- Grazie.
This is life that
we don't really understand yet.
It's from water that's toxic,
it's hostile, there's no oxygen.
Where we've lost all the light,
almost nothing to live on.
All that's left, really,
is water and rocks,
and yet there's
this beautiful form
just full of interesting,
weird, strange life,
and it's extraordinary,
because it represents something new
that will help us explore
for life on other planets.
One of the things that we can
learn from a sample like this is that
wherever we have
rocks and water,
then, somehow,
the water is going
to allow life to thrive
because it allows things to mix.
It allows the rock
to interact with life.
So water is really,
as we understand life,
the most essential ingredient.
Life as we know it
can't exist without water.
But it must be liquid.
Water, of course,
comes in several different states.
And where it is in our
solar system is key.
Too close to our sun,
and water boils away.
Too far away,
like in the rings of Saturn
and water freezes
as hard as iron.
Where we place our planet,
then, is critical
if we want to have liquid water.
But how much leeway do we have?
What about here, near Mars,
about 142 million
miles from the sun?
Well,
to find out if Mars is suitable
for liquid water, and for life,
first you've got to get there.
Mars.
And NASA's rover,
driving on the surface.
Well,
as close as you can get to its surface
in Houston, Texas.
Don't look at the bulldozer,
that gives away
that it's not Mars.
Just so you know,
that's not there!
Or those cars.
- - It spoils the effect!
And my guide is NASA astronaut,
Mike Gernhardt.
- Would it look anything like this?
- Yeah.
NASA wants to put humans on
the Red Planet in the next 20 years.
Their goal is to find life.
Problem is, despite there being
hundreds of old river beds on Mars,
all images show that the liquid
water has vanished from the surface.
So, what's happened to it?
NASA is developing the kit to
take us to the Red Planet to find out.
This is Building Nine.
A place I dreamt of as a kid
and as an adult.
You do have the coolest
garage in the world. It's...
Yep,
we got some really cool stuff.
So this thing is
called the Robonaut.
This is actually on the International
Space Station at this point.
This is called the Space
Exploration Vehicle.
This would be going to an asteroid,
or possibly
a moon of Mars like Phobos.
Then with the reaction-controlled jets,
we can hop.
And an astronaut is on
the end of a robot arm
and we can have that on Mars,
or the moon,
or whatever planets
we end up going to.
All of this really informs us how to
support these deep space missions.
It's... Talking to you is just
like going through a movie plot,
constantly, it's so...
Right, that all makes
perfect sense. If you're you.
We're now
approaching the T-minus one minute mark.
T-minus one minute.
T-minus one minute.
And this is how we
might get to Mars, the Orion spaceship.
- Earth... - Are we getting in?
We're going to get in.
- Oh! I so want to get in.
- So...
A born astronaut, me.
Here I go! Right,
climbing across.
You could bang your head
on many things in here.
Yeah. Oh, yeah.
Ooh! Yeah.
I am so in.
All right, good job!
T-minus 20 seconds and counting.
Having been to space,
Mike's going to take me through
what a Mars launch would be like.
So, you climb in here.
- Ten, nine, eight...
- You're strapped in.
Ignition sequence has started.
Then there's check
lists you go through.
Five, four...
The countdown clock hits zero...
Two, one, zero...
...and, all of a sudden,
you have this big thrust in your back.
And you're going up into space.
We have ignition
and we have lift-off.
We're going to be going
faster than we ever have before
so it's going to be a,
you know, a real sporty ride.
Sporty,
that's a good word. Vigourous.
Lift-off...
- So, four of us in here? - Yep.
- Mars. - Mars.
- It's not a short trip, is it?
- It isn't.
Generally think of it
as a nine-month trip out.
Nine months?
What if somebody
snores? I snore.
I have actually flown in space
with a guy that snored so loud
that it kept me awake
for days actually.
Were you not just tempted to,
you know, let him out?
Nah, you can't do that.
Okay, Houston, go in 30 seconds.
Mark one bravo.
Having reached the Red Planet,
we now need to get out
and search for Mars' water.
So, I'll need one of these.
Can I just say, this is an
amazing privilege to get to do this.
This is the Z1,
next gen prototype.
Besides me,
Bruce Willis is the only non-astronaut
who's ever been cleared to
wear a real spacesuit. Oh, yeah.
It's kind of like
putting on a big onesie.
Do I look faintly ridiculous?
- Yes! - I know!
Wow! That's a glove and a half.
That is serious.
- Wow! -
The NASA team are
now putting me through
a full Mars atmosphere
suit simulation.
...and that'll go all
the way up until we get to 4.3,
which is operating pressure.
- Okay. - Sound good?
- Yes. - Okay.
I'm waiting for a massive
burst of claustrophobia.
The atmosphere on Mars is incredibly thin,
just 1% of Earth's,
so we need to pump up the suit,
like inflating a tyre,
to hold my body together.
- Swallowing.
- Doing okay?
You're looking
worried. I'm fine!
Great. You're starting to
look a little more muscular now, you know.
- No, I actually am, I'm actually flexing.
- We're at three.
3 psi. 3 psi.
Four, one.
Four, one. Popping ears.
- We're at operating pressure.
- Operating pressure. Wow!
So, the arms are a little
bit long for you in the suit
but that's as small as they go
- -because
you're at the small end...
This is like every shopping
trip I've ever been on!
"The legs are a bit long on the jeans,
sir,
"but that's the shortest
we have." All right!
- Yeah, it's... - Okay!
Why did I know it
wasn't going to fit?
So the next thing, we're going to
release you from the donning stand.
I only have short legs,
so the bigger steps thing...
It had to happen. I told you,
'70s moves, there they are.
I am super impressed.
My daughters will be just cringing,
"Dad, don't dance!"
I'm dancing, yeah. See,
look, girls, there it is.
Suddenly,
I feel like doing this a lot.
Oh, yeah, moonwalk!
Were I on Mars right now,
the atmosphere on the other side
of this suit would be very different.
- What's it like?
- Yeah, it's basically almost no atmosphere.
As we stand here,
we're at 14.7 pounds per square inch,
on Mars the pressure
is roughly ten torr,
which is, like,
one-hundredth of this.
What would happen to
me if I didn't have this?
You'd be dead pretty
soon. You'd probably have
a couple to three minutes, and then,
that would be it.
Clearly that's bad. Well,
thank heavens for this thing then.
Mars is relatively
close to Earth,
yet we certainly
couldn't live there.
So, for life,
what's wrong with the Red Planet?
Well, Mike's going to show us
with just a glass of water
and a pump.
So that's a pump and you're
just pumping the air out of here
- until you're creating a vacuum in there.
- Exactly.
It actually won't
be a pure vacuum,
it'll be the same pressure
as we have on Mars,
which is very low,
but not a complete vacuum.
So you're
just taking the air out
- to lower the pressure.
- Exactly.
- There it goes.
- There it goes.
So there's no
extra heat in there,
that isn't at 100 degrees C?
In fact that could be
at zero degrees C.
This is why you
should always be careful
- with your spacesuit on Mars.
- Exactly.
- You don't want that happening to your blood. It's bad news.
- Exactly.
And that's why,
so far as you know,
- there isn't any liquid water on Mars?
- Right.
The atmosphere is so thin
that if there were
any liquid water,
it would just
evaporate like that.
So, suddenly,
holding on to your atmosphere becomes
critical to keep your water along with it,
how do you do that?
So you need the right
combination of things
and one of them
is the planet's size
because that
affects the gravity,
and if you don't
have enough gravity
then the atmosphere
that was there
will eventually go away.
And then,
as the atmospheric pressure drops,
then the liquid water goes away.
So there's this
optimal size planet
and Earth just happens
to be one of those,
so you need all these things
to line up just, you know,
shoot through the holes
of the Swiss cheese
in order to get the right
combination to have life.
- And no liquid water, no life?
- Yeah.
Complicated things to build,
planets that you can live on,
as it turns out.
So there are a couple
of things to think about
when positioning our planet.
The best place to put our planet
for us is exactly where we are,
93 million miles away from the sun,
third rock along,
in the part of space that we've
called the "Habitable zone,"
where we get just enough
of a slug of the sun's energy,
not too much or too little.
It's a zone where water
doesn't instantly freeze,
but also doesn't boil away.
Both Earth and
Mars are in that zone.
But even then,
as we've discovered with Mars,
a planet has to be big
enough to hold on to its water
with an atmosphere to
stop it escaping into space.
So our planet has to be not
only in just the right place,
it has to be just the
right size to support life.
Where we place our planet
needs to be precisely right.
It must go between
Mars and Venus,
bang in the middle
of the habitable zone.
So there we are.
All our planets in place
around what scientists call
a middle-aged yellow dwarf,
our sun.
We've built our solar
system! Wonderful.
We started with a supernova
which created light
and the ingredients
to make our sun.
Then we made eight planets,
including one just like ours.
In the perfect
place to support life.
Except, that's not all.
Can you imagine the Earth
without stars in the sky? Miserable.
We need more than that one star,
we need a whole galaxy of them.
Still, that's easy. Build one star,
you've built them all.
We've made over
300 billion stars
and put them all
together into a galaxy.
Just like the one we live in,
the Milky Way.
And we've put our sun with
its solar system right out here,
in a sleepy backwater
on the outer edge.
Astronomers have even
given it a galactic address.
Seriously,
anyone can reach us at the local fluff,
inside the local bubble at the
Gould Belt of the galaxy's Orion arm.
I don't know what number.
Anyway, it's a good job we
are out in the galactic sticks
because we wouldn't
want to make the mistake
of being too close to
the centre of things.
Because that is where lurks
a supermassive black hole.
Yep, they really do exist.
These are once-giant stars that
have collapsed in on themselves,
pulling in millions of
other stars around them.
They sit at the centre
of most galaxies,
including our own Milky Way.
Their gravity is so strong
that not even light can
escape its violent pull.
I think it's best we stay
well away from that.
Where we are is exactly
where we want to be.
This galactic neighbourhood
really works for us.
But if we're
building a universe,
we need more than one galaxy.
We need a whole ocean of them.
Some spiral, some spidery,
some lens-shaped,
but each of them
beautiful and unique.
And scientists have
calculated that to fill our universe
we need more stars
than grains of sand
on all the beaches on Earth.
But all is not well in
the universe we've built.
The galaxies are flying apart.
I'm missing something
that holds them together.
What have we forgotten?
Our universe is
missing a vital ingredient.
It's something that produces
a massive gravitational force.
Without it,
the universe would disintegrate.
Below my feet,
is a lab full of people
all trying to find the stuff that
holds the universe together.
Which is why I'm heading
1.3 kilometres underground.
Scientists have worked out
that what glues the
galaxies together
is the most common
stuff there is.
It makes up a staggering
85% of everything.
They named it "dark matter."
Problem is,
it's totally invisible
and undetectable.
But that may be about to change
thanks to scientists like
Professor Rick Gaitskell.
No music?
Well,
they did actually put some in
- once upon a time. - And?
Nobody could agree
on what to play!
Okay.
We also had a light in here at one point,
it was all mod cons.
Rick's built a dark
matter detector that's so sensitive
he's had to protect it
under 1.3 kilometres of rock.
- Why have we stopped here?
- I think this is it.
These are scientists,
not miners.
I have a desperate
urge to sing...
* Hi-ho, hi-ho!
I'm not going to.
And they've spent $100 million
to look for something
you can't see,
you can't touch,
and we haven't even found.
And this is what they've
spent their money on.
So, is that it?
Yep,
that's the dark matter detector.
Or rather,
this is the water tank
that surrounds our
dark matter detector.
I'm not being funny,
but it's like being in my loft,
except I bet there's no
dead pigeons in there.
- It's a pretty specialised environment.
- It's got to be very clean.
The water inside this
tank is extremely pure
and it isolates our detector
from all the radioactivity in the rock,
and even you.
And in terms of
search instruments,
this is one of the biggest
in the world? Or best?
This is the most sensitive
dark matter detector in the world
and we're running it right now.
- It's on? - It's on.
So, how does the detector work?
Well, suspended inside it
is a capsule of a special gas
called xenon.
It's the same stuff
that's in this novelty toy.
It's very nice,
it's a pleasing distraction,
but why are you
holding that thing?
We've filled this
plasma ball with xenon
and we're exciting
it using electricity.
As you can see,
light is being generated.
The dark matter detector works
on exactly the same principle.
We filled it with xenon,
and when a dark
matter particle comes in,
the particle directly
excites the atoms,
and the atoms emit light,
which we then detect.
So that's the event you're waiting to
observe. It's not a giant one of these,
but that's to illustrate the idea
of seeing these interactions.
That's right,
and the particle
events we're looking for
are extremely infrequent.
We're operating this detector
for weeks, months, years,
looking for very, very
occasional dark matter particles
to interact with the xenon
and we'll see the
light coming from it.
It sounds complicated,
and it is.
Rick's been searching for dark
matter particles for 23 years.
But scientists
know it must exist
because they can see
the effects of its gravity
holding galaxies together.
If they can detect it,
they'll have solved one of the
greatest mysteries in science.
Rick, would it ruin millions
of pounds worth of research
and years, decades in fact,
of your own work if I turn the lights on?
Don't touch any
one of those buttons.
That's six months' delay.
I won't touch anything.
Hands in pockets.
The first live results
have started streaming in.
So, any of these spikes,
that spike, that could be it,
one of greatest
moments in science ever?
That spike could be it,
the event you're looking for?
- That's right.
- So, if that one was it,
- proof of the existence of dark matter, and I'm here?
- Yep.
Will I get my name on it?
Well, I was
here. If that's it, I was here just then.
If it is that event,
we'll name it after you.
Every day you enjoy your unusual
commute a mile under the ground.
If that happens,
if that's the day
that those spikes occur,
it's a big deal!
It will be an amazing feeling.
I think you'll hear
the celebration,
um, even though we're a mile
underground. It will be quite a roar.
I'll hear
the champagne corks open!
But I haven't got time to hang
around talking about champagne.
I need to head back to the tower
to add some elusive dark
matter to the cosmic mix right now.
And it's working.
The gravity of the dark matter
is pulling our
galaxies back together.
Disaster averted.
Scientists have
crunched all the numbers
relating to dark matter
through a supercomputer
and come up with
a way of seeing it.
And for the first time,
we can show you what that looks like.
Each of these points of light is a
galaxy made up of billions of stars.
They're held together in
a vast gravitational web,
created by ribbons
of dark matter.
Adding that missing matter
to a map of the universe
means we can actually see
how we, here on our planet,
really are connected
to even the remotest star.
And it's...
It's kind of beautiful.
This vast web of dark matter
holds the entire
universe together.
As you look up on a clear night
at that band across the sky,
you're looking into the heart
of the Milky Way,
a tiny part of
the great web of galaxies.
We are connected to it all
because we are made
of the same stuff.
And if anything
had been a bit different,
the Earth a bit too small,
the sun too bright,
the other planets too big,
or the solar system in the
wrong place in our galaxy,
then we simply wouldn't be here.
Our home.
It's unique.
It has life.
But what's amazing,
is none of it would exist
without the sun,
the moon and the stars around us.
We are connected to the universe
in the most fundamental ways.
To find out how,
I'm going to have to build my own.
I'm going to open up a
cosmic tool-box and work it out.
And I'm going to build
my universe up here,
at the top of this
impossibly high tower.
It gives us the perfect platform
to make something really big.
Up here, we can do in seconds
what it takes nature millions
or billions of years to do.
And to build a universe,
I'm going to need a lot of help.
- -I'll be honest,
I'm faintly nervous.
Was that it?
Wow! Beautiful!
Oh, this is really difficult!
I told you,
'70s moves. There they are.
Like any construction project,
there will be mistakes.
But from those mistakes,
we'll get real insights
into what makes our universe
exactly right for us to exist.
As an engineering challenge,
this is about as big as it gets.
How many times have
you marvelled at the stars?
Depending upon
your frame of mind,
the stars might appear
distant and magical,
or cold and remote.
But the fact is,
we are all made of the same stuff.
And if you were to change
anything about them,
or about us,
that connection,
that delicate balance,
would be lost.
And this isn't an idle fancy,
a romantic notion,
it's essential,
elemental and real.
Without that connection,
we wouldn't be here.
And to understand how it works,
we need to build a universe.
It's not a small task
because Earth is
in a solar system
which is in just one
tiny part of a galaxy
that has over 300
billion stars within it.
And there are half a trillion
galaxies in the universe.
So the job isn't really
done until we build it all,
from suns to galaxies.
I'm going to need
to construct all of this
up here,
at the top of my tower,
where there's loads of room.
To do this, we need to go back
to the very start of everything.
We need to start from scratch.
In the case of our universe,
the start of everything
was 13.8 billion years ago.
About.
I do like a challenge.
Most scientists agree that before
the universe, there was nothing, nada.
But out of that nothing,
was created something...
Everything.
It all happened in an
event called the big bang.
Thing is, "The big bang"
is actually a
misleading name for it
because it wasn't a bang at all.
There is an analogy that
scientists and boffins use
to get their head
round this event.
There's no explosion.
It wasn't a bang.
It's more like a balloon.
The big bang was
a rapid expansion.
Just like inflating a balloon.
Now, of course,
the universe expanded
a lot quicker than our balloon.
Unimaginably so.
In a billionth of a second,
it was already the
size of our solar system.
But you take the point.
It's like a big expanding
bubble of space.
But there's something even
more bizarre about the big bang.
That universal expansion
had no single point of origin.
It happened everywhere
and all at the same time.
So one balloon isn't
enough to demonstrate it.
I need countless balloons.
What's more,
the expansion of the big
bang is still happening today.
Which means that wherever I am,
I'm at the very centre...
...of an expanding universe.
And wherever you are,
you, too,
are at the centre of the universe.
So, we've had our big bang,
but there is a little problem.
It's dark.
There is no light
after a big bang
because there are no stars.
So where do I get a star from?
Well, fortunately,
it turns out they make them
just off the M40 near Oxford.
Inside this
billion-pound chamber
we are going to squeeze,
using colossal magnets,
the only thing that was
around after the big bang,
hydrogen gas, until it ignites.
And that is a star.
Sounds simple? It isn't.
Don't try this at home.
It is a job for the
professionals.
The chamber will briefly use more
power than a city like Birmingham.
And the ignition countdown
begins 100 metres away
in the relative safety
of mission control.
We're now approaching the T-minus
one minute mark. T-minus one minute.
I'm joining star maker-in-chief,
Professor Steve Cowley.
- Steve, hello. - Hello.
I haven't touched anything
and I promise not to
because you're effectively
creating a star here.
Yeah.
This looks amazing!
This looks like
I'd want it to look.
Is it running now?
We're about to fire it up,
and for a few seconds,
we'll reach the temperature of
round about 100 million degrees.
100 million degrees!
What if it goes wrong, Steve?
I mean,
it's kind of extreme, isn't it?
If something goes wrong,
and it does do,
the physicist in charge,
she's got a red button, basically,
and she will press
the red button
and it will abort the shot.
The amount of energy in there...
This isn't that far from my house,
is where I'm going.
- I live 50 miles away.
- But it does have a wall that's two metres, so...
- - What's that?
It's the panic button.
You have to run now.
I'm not going to bother running.
Really, what would be the point?
If something really did go wrong,
you could cause a lot of damage.
Right.
And I'm being allowed to
give the trigger command
to turn it on.
So, what I'm going to do now is
trigger the creation of a star,
briefly, on Earth.
Um, ahem.
Er, trigger, please.
Can you accelerate, please?
Okay. Thank you.
Start.
- It's starting up now.
- All right.
Electrical current
going through it.
I'll be honest,
I'm faintly nervous.
How many times a
day do you do this?
...eight,
seven, six, five, four,
three, two, one, zero.
There it is. - Right.
Oh, look at the instability,
it's shaking.
This is mind-blowing.
Inside the chamber is hydrogen.
It was pretty much the only thing that
existed in the darkness after the big bang.
This machine heats and
squeezes the hydrogen
with such force that it ignites,
creating a star and light.
So,
what's happening in that chamber right now,
there, that is...
That is a star on Earth.
What's remarkable is the
process of making a star
doesn't just create light.
It also makes brand
new ingredients,
and this is going to help
me build our universe.
There's little white specks,
which is exactly
what stars are doing.
It's turning
hydrogen into helium.
They start with hydrogen
and they make helium
and then they get helium
and they make carbon,
then they make oxygen.
All the things you're made of,
right, and they're made bit by
bit by bit in the centre of the star.
- Was that it?
- That's it.
And was that the abort button there,
you had all the... Whoa...
Within a star,
these different elements are made...
- Yeah.
- But how do they then...
They've got to get elsewhere.
So, if it's a big enough star,
it explodes,
that's a supernova explosion,
and it spews all that stuff,
all those things you've made,
all the carbon,
all the iron, all the nickel,
all the whatever, right, spews it out
into the universe as dust,
as particles,
as this, that, and the other.
These elements
are created within it
and then, boom,
it's all over the universe.
Stars not only give us light,
they are the element factories
to build everything else.
Back at my tower,
I can now make light
and create all the stuff to
build the rest of our universe.
We just need a
star to go supernova.
A supernova is the
biggest explosion there is,
and for us,
it's an essential stage
in our construction process
because it takes all those
elements created in big stars
and scatters them everywhere.
Just one note of caution though,
when I say "big," I do mean,
"Really, really big."
And that supernova
has now scattered all
the ingredients we need
to build everything.
Floating around the tower,
we've now got carbon,
oxygen,
iron,
and all the other elements
we're going to need
to make the planets,
and even us.
In that sense,
everything really is stardust.
You, me,
everything you've ever seen or touched,
or ever will.
All of it created from the
birth and death of a star.
It's mind-blowing.
And that cloud of gas and dust,
called a nebula,
also provides the
ingredients for other stars.
So we can now build
our own star from it.
We'll call it the sun.
The real one took around
50 million years to form.
Here, we've done it in seconds.
And orbiting it is the
dust and gas we'll need
to make all the planets
in our solar system.
The first planet to
start forming is Jupiter.
But something's
not going to plan.
The young planet is
starting to hoover up
way too much of
the gas and rock.
And this process
is slowing it down
causing it to fall
inwards towards the sun.
Which is a problem
because this is the very stuff
that's going to build
all the other planets.
It's bad. What do we do
to stop Jupiter gobbling up
all our planetary
building materials?
Well, fortunately,
I'm told there is a man who knows.
This is Professor
Alexei Filippenko.
And this is a Fresnel lens.
A simple enough device,
but surprisingly powerful.
- Hi, Richard.
- So, how do we get rid of our rampaging Jupiter problem?
Oh, well, look. Let me show you
a little demo that'll help illustrate it.
Declan,
why don't you tilt it there?
- It's on fire. Right away!
- It is on fire!
But what's that got to
do with Jupiter? It's a bit of wood?
Yeah, well, what's happening
is there's all these photons,
all these little energetic particles
of light coming from the sun
and they're being
focussed here on this wood,
heating it up,
causing it to burn.
In the case of the
early solar system,
the sun was much
brighter than it is now
and it acted for hundreds of thousands,
or millions of years.
So the photons were hitting
the particles of dust and
gas and heating them up,
causing the atoms to
actually evaporate away,
to be blown out of
the solar system.
That meant that
Jupiter was no longer
slowing down and
spiralling into the sun.
Two things. One,
there's a small fire over there.
- Yeah!
- Two,
the stuff in the way of Jupiter,
slowing it up,
wasn't wood.
Yeah, I know,
but look how powerful the sun is.
Here's a rock. Why
don't you put it right there?
I don't want to get
zapped with your machine.
Well, Declan isn't going to zap
you while you're putting it there.
And, yeah, we need to have
some safety glasses on because
it's going to get heated up so
much from the trillions of photons
hitting it that, er, it's actually
going to snap, crackle and pop.
Little pieces are going
to come flying out.
You've got more safety than me.
Well, you know,
my eyes are more important.
- I'm an astronomer, okay?
- Okay.
So let's put the
rock in there...
I can't argue with that, can I?
- I can't argue with that.
- I think you're okay.
Oh, hang on, that is the rock.
Yeah,
that's the rock flaking off
because of all the
energetic photons hitting it.
I am properly
impressed with that.
That is in seconds.
It's heating up to 3,000
degrees Fahrenheit, okay?
Now, over millions of years,
the material is being blown
out of the vicinity of Jupiter,
so it's not growing any more and
also it's not spiralling into the sun.
So that saves us.
Turn it off, Declan,
I'm terrified.
So this is another one of
those events that had to happen
at the right time, in the right place,
and to the right extent.
Too much of this for too long
and there's nothing left to
make your inner planets from.
Yeah, that's exactly right.
Okay, a plan.
I'm going to use light from the
sun to clear a path for Jupiter
to stop it slowing
and spiralling inwards,
gobbling all the building
materials for our other planets.
So,
let's crank up the light from our sun
and get those photons pumping.
Jupiter's way is now clear.
But luckily for us,
the perfect amount of stuff
is left behind to build the
rest of our solar system.
So we've got Jupiter.
Now,
how do we make our other planets?
To find out what planet formation
was like in the early solar system,
I need the help of the
Texas Roller Derby.
Excuse me. Sorry.
Of course I do.
Sorry, ladies,
excuse me. Can I join?
- Oh! Do I really need that?
- You need it to protect your head.
Yeah? Right. Well,
I'll pop it on. Thank you. Er...
What's your skate name?
Your name on the track,
your alter ego?
Hamster. Yeah, it's a long story.
- What about Slamster?
- Slamster!
- Oh! I'm loving that!
- Yeah, that's good.
What sort of injuries can
you acquire doing this?
Broken... Everything!
- Broken ankles. - Broken teeth.
Hands, arms...
I am really scared!
You should be.
Now,
I know what you're thinking.
Actually,
I've no idea what you're thinking.
But bear with me. This is a
genuine scientific demonstration
of what happened in
the early solar system.
See you out there,
girls. Oh, scared!
I should say,
I'm not what you'd call a regular skater.
Imagine the sun in the centre
of the track providing the gravity
to pull around a whole host
of rocks of different sizes.
Go, go, go!
These wannabe
planets are known as planetesimals.
Stop.
Some of these
planetesimals were large,
some very small,
some moving in crazy orbits.
All of them were affected
by one another's gravity.
So there were huge collisions.
Potential planets were
flung out of the solar system.
And some wannabe
planets were destroyed.
Others had huge
chunks ripped off them.
What happened over
just a few million years
was a sort of planetary carnage.
Oh! This is really difficult!
Whoa!
Eventually, some of the larger,
more stable planets emerged
and took the
outside orbital lane.
Whilst closer to the sun,
smaller planets jostled for position.
The remnants of
this orbital tussle,
the dead and never-to-be
planets didn't just disappear.
They still exist.
A graveyard of broken worlds
now orbits the sun
as a ring of debris
known as the asteroid belt.
So here we are.
Our solar system.
There's Jupiter and alongside it,
the asteroid belt.
And then the rest of the
planets in our solar system.
There's Mercury,
nearest the sun.
Its atmosphere has
already been burnt away.
Then Venus,
a big bash early on
has reversed its spin.
And Mars,
there's an enormous
volcano here,
Olympus Mons.
Three times higher than Everest.
Then Jupiter,
bigger than all the planets put together.
Saturn, with its amazing rings.
So light,
it could float on water.
Further out, Uranus, where summers
last 21 Earth years, as do winters.
And finally, Neptune.
Freezing cold with hurricane
winds of 1,000 kilometres an hour.
Of course,
there is one planet missing, ours.
And exactly where
it goes is critical
because we need it to support
one very fragile thing, life.
Earth is unique amongst the
planets in our solar system.
It teems with life.
Life which comes in
countless different forms.
So what is it that
makes Earth so special?
What do we need
for life to exist
when we're building
a solar system?
To find out,
these scientists are attempting to reach
one of the most inhospitable
and extreme places on Earth.
Sandro...
How far is it to the lake?
Where
they're heading is so toxic,
it is like an alien planet.
If they can find
life down there,
it'll help us understand the most basic
requirements for life in our solar system.
Okay, I'll follow you.
Be careful.
To get there, they must
risk a perilous three kilometre-descent
into eastern Italy's
Frasassi cave system.
Caves like these contain some of
the last unexplored frontiers on Earth.
Here I come.
Oh!
The expedition is led by
astrobiologist Professor Jenn Macalady.
Stay left, it's really tight.
If you go to the right you're
going to get stuck for sure.
I'm not far behind.
Use your feet.
Yeah, I am. It's, er, tight.
Breathe out.
Yeah, that's it.
You got it? - HAMMOND: Yep.
You're through! Awesome.
The things I do for science!
After six hours,
they're approaching the final descent.
At the bottom, Jenn's hoping to shed light
on the minimal conditions required for life.
- Aldo, coming down. - Okay!
This is the Crystal Lake.
Wow, it's beautiful.
Okay, I'm going down.
Deep below its surface
is home to what Jenn is looking for.
Long way down, folks.
Down here, all the normal things
you need to support
life have disappeared.
Shall I come all the way down?
There is no light.
No animals or
plants to feed off.
And where they're going,
there's no oxygen.
We made it.
The water is even poisonous,
but Jenn is hoping
to find life there.
The hunt will involve
one of the most dangerous
dives on the planet.
Preparing to make the 80-foot plunge
is ex-Navy diver Alejandro Crocetti.
Perfetto.
His dive
time is strictly limited.
Any kind of
cave diving is very dangerous,
because if there's a problem,
you can't just pop up to the
surface. You have a long way to go.
But also, in this particular case,
the water is actually toxic.
So the chemicals that are dissolved
in the water come through the skin,
so that if you stay in that water
for a while, then you become sick.
You start to have symptoms
that prevent you from
making good decisions.
Very quickly,
the passages become tighter and tighter.
There is no room to manoeuvre.
As soon as you move,
you suspend all the
sediment that's on the bottom
and the visibility goes
to zero very quickly.
Fish would die instantly here.
Very quickly, the water
will become sulphidic and more cloudy,
and more difficult
to navigate through.
We're not meant
to be there really.
It's a place where we can
stay only for a few moments.
Finally,
they find what they've been looking for.
These weird alien
fingers are alive.
They are bacteria,
living on nothing more than
rock dissolved in toxic water.
Wow!
Wow!
Look at that.
This is beautiful.
Were there a lot like this?
- Molti? - Si.
- Amazing sample, bravo.
- Grazie.
This is life that
we don't really understand yet.
It's from water that's toxic,
it's hostile, there's no oxygen.
Where we've lost all the light,
almost nothing to live on.
All that's left, really,
is water and rocks,
and yet there's
this beautiful form
just full of interesting,
weird, strange life,
and it's extraordinary,
because it represents something new
that will help us explore
for life on other planets.
One of the things that we can
learn from a sample like this is that
wherever we have
rocks and water,
then, somehow,
the water is going
to allow life to thrive
because it allows things to mix.
It allows the rock
to interact with life.
So water is really,
as we understand life,
the most essential ingredient.
Life as we know it
can't exist without water.
But it must be liquid.
Water, of course,
comes in several different states.
And where it is in our
solar system is key.
Too close to our sun,
and water boils away.
Too far away,
like in the rings of Saturn
and water freezes
as hard as iron.
Where we place our planet,
then, is critical
if we want to have liquid water.
But how much leeway do we have?
What about here, near Mars,
about 142 million
miles from the sun?
Well,
to find out if Mars is suitable
for liquid water, and for life,
first you've got to get there.
Mars.
And NASA's rover,
driving on the surface.
Well,
as close as you can get to its surface
in Houston, Texas.
Don't look at the bulldozer,
that gives away
that it's not Mars.
Just so you know,
that's not there!
Or those cars.
- - It spoils the effect!
And my guide is NASA astronaut,
Mike Gernhardt.
- Would it look anything like this?
- Yeah.
NASA wants to put humans on
the Red Planet in the next 20 years.
Their goal is to find life.
Problem is, despite there being
hundreds of old river beds on Mars,
all images show that the liquid
water has vanished from the surface.
So, what's happened to it?
NASA is developing the kit to
take us to the Red Planet to find out.
This is Building Nine.
A place I dreamt of as a kid
and as an adult.
You do have the coolest
garage in the world. It's...
Yep,
we got some really cool stuff.
So this thing is
called the Robonaut.
This is actually on the International
Space Station at this point.
This is called the Space
Exploration Vehicle.
This would be going to an asteroid,
or possibly
a moon of Mars like Phobos.
Then with the reaction-controlled jets,
we can hop.
And an astronaut is on
the end of a robot arm
and we can have that on Mars,
or the moon,
or whatever planets
we end up going to.
All of this really informs us how to
support these deep space missions.
It's... Talking to you is just
like going through a movie plot,
constantly, it's so...
Right, that all makes
perfect sense. If you're you.
We're now
approaching the T-minus one minute mark.
T-minus one minute.
T-minus one minute.
And this is how we
might get to Mars, the Orion spaceship.
- Earth... - Are we getting in?
We're going to get in.
- Oh! I so want to get in.
- So...
A born astronaut, me.
Here I go! Right,
climbing across.
You could bang your head
on many things in here.
Yeah. Oh, yeah.
Ooh! Yeah.
I am so in.
All right, good job!
T-minus 20 seconds and counting.
Having been to space,
Mike's going to take me through
what a Mars launch would be like.
So, you climb in here.
- Ten, nine, eight...
- You're strapped in.
Ignition sequence has started.
Then there's check
lists you go through.
Five, four...
The countdown clock hits zero...
Two, one, zero...
...and, all of a sudden,
you have this big thrust in your back.
And you're going up into space.
We have ignition
and we have lift-off.
We're going to be going
faster than we ever have before
so it's going to be a,
you know, a real sporty ride.
Sporty,
that's a good word. Vigourous.
Lift-off...
- So, four of us in here? - Yep.
- Mars. - Mars.
- It's not a short trip, is it?
- It isn't.
Generally think of it
as a nine-month trip out.
Nine months?
What if somebody
snores? I snore.
I have actually flown in space
with a guy that snored so loud
that it kept me awake
for days actually.
Were you not just tempted to,
you know, let him out?
Nah, you can't do that.
Okay, Houston, go in 30 seconds.
Mark one bravo.
Having reached the Red Planet,
we now need to get out
and search for Mars' water.
So, I'll need one of these.
Can I just say, this is an
amazing privilege to get to do this.
This is the Z1,
next gen prototype.
Besides me,
Bruce Willis is the only non-astronaut
who's ever been cleared to
wear a real spacesuit. Oh, yeah.
It's kind of like
putting on a big onesie.
Do I look faintly ridiculous?
- Yes! - I know!
Wow! That's a glove and a half.
That is serious.
- Wow! -
The NASA team are
now putting me through
a full Mars atmosphere
suit simulation.
...and that'll go all
the way up until we get to 4.3,
which is operating pressure.
- Okay. - Sound good?
- Yes. - Okay.
I'm waiting for a massive
burst of claustrophobia.
The atmosphere on Mars is incredibly thin,
just 1% of Earth's,
so we need to pump up the suit,
like inflating a tyre,
to hold my body together.
- Swallowing.
- Doing okay?
You're looking
worried. I'm fine!
Great. You're starting to
look a little more muscular now, you know.
- No, I actually am, I'm actually flexing.
- We're at three.
3 psi. 3 psi.
Four, one.
Four, one. Popping ears.
- We're at operating pressure.
- Operating pressure. Wow!
So, the arms are a little
bit long for you in the suit
but that's as small as they go
- -because
you're at the small end...
This is like every shopping
trip I've ever been on!
"The legs are a bit long on the jeans,
sir,
"but that's the shortest
we have." All right!
- Yeah, it's... - Okay!
Why did I know it
wasn't going to fit?
So the next thing, we're going to
release you from the donning stand.
I only have short legs,
so the bigger steps thing...
It had to happen. I told you,
'70s moves, there they are.
I am super impressed.
My daughters will be just cringing,
"Dad, don't dance!"
I'm dancing, yeah. See,
look, girls, there it is.
Suddenly,
I feel like doing this a lot.
Oh, yeah, moonwalk!
Were I on Mars right now,
the atmosphere on the other side
of this suit would be very different.
- What's it like?
- Yeah, it's basically almost no atmosphere.
As we stand here,
we're at 14.7 pounds per square inch,
on Mars the pressure
is roughly ten torr,
which is, like,
one-hundredth of this.
What would happen to
me if I didn't have this?
You'd be dead pretty
soon. You'd probably have
a couple to three minutes, and then,
that would be it.
Clearly that's bad. Well,
thank heavens for this thing then.
Mars is relatively
close to Earth,
yet we certainly
couldn't live there.
So, for life,
what's wrong with the Red Planet?
Well, Mike's going to show us
with just a glass of water
and a pump.
So that's a pump and you're
just pumping the air out of here
- until you're creating a vacuum in there.
- Exactly.
It actually won't
be a pure vacuum,
it'll be the same pressure
as we have on Mars,
which is very low,
but not a complete vacuum.
So you're
just taking the air out
- to lower the pressure.
- Exactly.
- There it goes.
- There it goes.
So there's no
extra heat in there,
that isn't at 100 degrees C?
In fact that could be
at zero degrees C.
This is why you
should always be careful
- with your spacesuit on Mars.
- Exactly.
- You don't want that happening to your blood. It's bad news.
- Exactly.
And that's why,
so far as you know,
- there isn't any liquid water on Mars?
- Right.
The atmosphere is so thin
that if there were
any liquid water,
it would just
evaporate like that.
So, suddenly,
holding on to your atmosphere becomes
critical to keep your water along with it,
how do you do that?
So you need the right
combination of things
and one of them
is the planet's size
because that
affects the gravity,
and if you don't
have enough gravity
then the atmosphere
that was there
will eventually go away.
And then,
as the atmospheric pressure drops,
then the liquid water goes away.
So there's this
optimal size planet
and Earth just happens
to be one of those,
so you need all these things
to line up just, you know,
shoot through the holes
of the Swiss cheese
in order to get the right
combination to have life.
- And no liquid water, no life?
- Yeah.
Complicated things to build,
planets that you can live on,
as it turns out.
So there are a couple
of things to think about
when positioning our planet.
The best place to put our planet
for us is exactly where we are,
93 million miles away from the sun,
third rock along,
in the part of space that we've
called the "Habitable zone,"
where we get just enough
of a slug of the sun's energy,
not too much or too little.
It's a zone where water
doesn't instantly freeze,
but also doesn't boil away.
Both Earth and
Mars are in that zone.
But even then,
as we've discovered with Mars,
a planet has to be big
enough to hold on to its water
with an atmosphere to
stop it escaping into space.
So our planet has to be not
only in just the right place,
it has to be just the
right size to support life.
Where we place our planet
needs to be precisely right.
It must go between
Mars and Venus,
bang in the middle
of the habitable zone.
So there we are.
All our planets in place
around what scientists call
a middle-aged yellow dwarf,
our sun.
We've built our solar
system! Wonderful.
We started with a supernova
which created light
and the ingredients
to make our sun.
Then we made eight planets,
including one just like ours.
In the perfect
place to support life.
Except, that's not all.
Can you imagine the Earth
without stars in the sky? Miserable.
We need more than that one star,
we need a whole galaxy of them.
Still, that's easy. Build one star,
you've built them all.
We've made over
300 billion stars
and put them all
together into a galaxy.
Just like the one we live in,
the Milky Way.
And we've put our sun with
its solar system right out here,
in a sleepy backwater
on the outer edge.
Astronomers have even
given it a galactic address.
Seriously,
anyone can reach us at the local fluff,
inside the local bubble at the
Gould Belt of the galaxy's Orion arm.
I don't know what number.
Anyway, it's a good job we
are out in the galactic sticks
because we wouldn't
want to make the mistake
of being too close to
the centre of things.
Because that is where lurks
a supermassive black hole.
Yep, they really do exist.
These are once-giant stars that
have collapsed in on themselves,
pulling in millions of
other stars around them.
They sit at the centre
of most galaxies,
including our own Milky Way.
Their gravity is so strong
that not even light can
escape its violent pull.
I think it's best we stay
well away from that.
Where we are is exactly
where we want to be.
This galactic neighbourhood
really works for us.
But if we're
building a universe,
we need more than one galaxy.
We need a whole ocean of them.
Some spiral, some spidery,
some lens-shaped,
but each of them
beautiful and unique.
And scientists have
calculated that to fill our universe
we need more stars
than grains of sand
on all the beaches on Earth.
But all is not well in
the universe we've built.
The galaxies are flying apart.
I'm missing something
that holds them together.
What have we forgotten?
Our universe is
missing a vital ingredient.
It's something that produces
a massive gravitational force.
Without it,
the universe would disintegrate.
Below my feet,
is a lab full of people
all trying to find the stuff that
holds the universe together.
Which is why I'm heading
1.3 kilometres underground.
Scientists have worked out
that what glues the
galaxies together
is the most common
stuff there is.
It makes up a staggering
85% of everything.
They named it "dark matter."
Problem is,
it's totally invisible
and undetectable.
But that may be about to change
thanks to scientists like
Professor Rick Gaitskell.
No music?
Well,
they did actually put some in
- once upon a time. - And?
Nobody could agree
on what to play!
Okay.
We also had a light in here at one point,
it was all mod cons.
Rick's built a dark
matter detector that's so sensitive
he's had to protect it
under 1.3 kilometres of rock.
- Why have we stopped here?
- I think this is it.
These are scientists,
not miners.
I have a desperate
urge to sing...
* Hi-ho, hi-ho!
I'm not going to.
And they've spent $100 million
to look for something
you can't see,
you can't touch,
and we haven't even found.
And this is what they've
spent their money on.
So, is that it?
Yep,
that's the dark matter detector.
Or rather,
this is the water tank
that surrounds our
dark matter detector.
I'm not being funny,
but it's like being in my loft,
except I bet there's no
dead pigeons in there.
- It's a pretty specialised environment.
- It's got to be very clean.
The water inside this
tank is extremely pure
and it isolates our detector
from all the radioactivity in the rock,
and even you.
And in terms of
search instruments,
this is one of the biggest
in the world? Or best?
This is the most sensitive
dark matter detector in the world
and we're running it right now.
- It's on? - It's on.
So, how does the detector work?
Well, suspended inside it
is a capsule of a special gas
called xenon.
It's the same stuff
that's in this novelty toy.
It's very nice,
it's a pleasing distraction,
but why are you
holding that thing?
We've filled this
plasma ball with xenon
and we're exciting
it using electricity.
As you can see,
light is being generated.
The dark matter detector works
on exactly the same principle.
We filled it with xenon,
and when a dark
matter particle comes in,
the particle directly
excites the atoms,
and the atoms emit light,
which we then detect.
So that's the event you're waiting to
observe. It's not a giant one of these,
but that's to illustrate the idea
of seeing these interactions.
That's right,
and the particle
events we're looking for
are extremely infrequent.
We're operating this detector
for weeks, months, years,
looking for very, very
occasional dark matter particles
to interact with the xenon
and we'll see the
light coming from it.
It sounds complicated,
and it is.
Rick's been searching for dark
matter particles for 23 years.
But scientists
know it must exist
because they can see
the effects of its gravity
holding galaxies together.
If they can detect it,
they'll have solved one of the
greatest mysteries in science.
Rick, would it ruin millions
of pounds worth of research
and years, decades in fact,
of your own work if I turn the lights on?
Don't touch any
one of those buttons.
That's six months' delay.
I won't touch anything.
Hands in pockets.
The first live results
have started streaming in.
So, any of these spikes,
that spike, that could be it,
one of greatest
moments in science ever?
That spike could be it,
the event you're looking for?
- That's right.
- So, if that one was it,
- proof of the existence of dark matter, and I'm here?
- Yep.
Will I get my name on it?
Well, I was
here. If that's it, I was here just then.
If it is that event,
we'll name it after you.
Every day you enjoy your unusual
commute a mile under the ground.
If that happens,
if that's the day
that those spikes occur,
it's a big deal!
It will be an amazing feeling.
I think you'll hear
the celebration,
um, even though we're a mile
underground. It will be quite a roar.
I'll hear
the champagne corks open!
But I haven't got time to hang
around talking about champagne.
I need to head back to the tower
to add some elusive dark
matter to the cosmic mix right now.
And it's working.
The gravity of the dark matter
is pulling our
galaxies back together.
Disaster averted.
Scientists have
crunched all the numbers
relating to dark matter
through a supercomputer
and come up with
a way of seeing it.
And for the first time,
we can show you what that looks like.
Each of these points of light is a
galaxy made up of billions of stars.
They're held together in
a vast gravitational web,
created by ribbons
of dark matter.
Adding that missing matter
to a map of the universe
means we can actually see
how we, here on our planet,
really are connected
to even the remotest star.
And it's...
It's kind of beautiful.
This vast web of dark matter
holds the entire
universe together.
As you look up on a clear night
at that band across the sky,
you're looking into the heart
of the Milky Way,
a tiny part of
the great web of galaxies.
We are connected to it all
because we are made
of the same stuff.
And if anything
had been a bit different,
the Earth a bit too small,
the sun too bright,
the other planets too big,
or the solar system in the
wrong place in our galaxy,
then we simply wouldn't be here.