All language subtitles for Royal.Institution.Christmas.Lectures.S2025E02.Searching.the.Solar.System.1080p.iP.WEB-DL.AAC2.0.H.264-RAWR_track3_[eng]

I've always wanted to go to Mars,

haven't you, Bruno? Well, at least

your sister rover, Rosalind Franklin,

is going to get a chance.

She's going to launch the Red Planet

and look for signs of life.

Now, in the last lecture, we were

looking at the Earth-Moon system

and finding out what it means
to be a habitable planet.

But now we're going to go
further afield,

out into the solar system.

But what are the chances
of finding life out there,

and where should we look?

Leaving Earth's orbit.

Houston, we've had a problem.

Take third exit to Mars.

WHISTLING

Mars rover collected.

Warning.

James Webb Telescope acquired.

Navigate off-road.

Voyager probe acquired.

Approaching light speed.

APPLAUSE

Welcome to the 200th Anniversary
Christmas Lectures

from right here
at the Royal Institution,

supported by CGI.

My name is
Dame Dr Maggie Aderin-Pocock,

and I'm a space scientist
and a science communicator.

Now, all my life, I've wanted
to get out there into space.

Now, I haven't quite managed it yet,

but what I do in the meantime
is build instrumentation

that help us better understand
the universe

and answer one of the most
fundamental questions of all time -

are we alone? So tonight,
we're going to continue our journey

for the search for life
from beyond the Earth,

but now out into our solar system.

The wonderful thing about our
solar system is that it's local.

And so what we've been doing
over time

is actually sending probes out

to get up-close and personal to these
planets. And so it makes our search

for life a lot easier because,
in some cases, we can land on

these planets. And we've sent
one straight towards the Sun.

Now, we've got an animation
here of this probe.

It's called the Parker space probe

and it's got very close to the Sun.

And so now I'd like to introduce
the lead scientist

for the mission, and Head of Science
at Nasa, Dr Nicky Fox.

APPLAUSE

So, Nicky, thank you so much
for joining us.

- And I know you just flew in.
Thank you.
- Yes, I did. I did, yes.

- And then out again tomorrow.
- Tomorrow? Yes.

- A whistle-stop visit.
- Absolutely.
- But can you tell us more about

- the Parker space probe?
- I would love
to talk about Parker Solar Probe.

I could talk for hours about it.
It's a mission really, really close

to my heart, because it was steeped
in sort of history and tradition.

- It was first proposed
in 1958...
- Whoa!

..when a young scientist predicted
that the Sun's atmosphere,

the corona that you see during
a total solar eclipse,

will be continually accelerated,

bathe all of the planets,

carve out a protective bubble
for us. The whole solar system,

as we are orbiting the Milky Way,

- we are protected by the atmosphere
of the Sun.
- Wow!

People didn't believe him,
and they said, no, it can't be true.

The only way we could find it
would be to send a probe right into

the atmosphere of the Sun
and actually start to see if

he was right
and, you know, what was causing it.

The Sun, as far as I know,
is quite hot, right?

- Yeah. Yeah, it's pretty hot. Yes.
- Yeah, it's pretty hot!

- Yeah.
- And so how did Parker do that?

How did you protect it
against that solar radiation?

Lots and lots and lots
of technology.

My favourite is the heat shield.

So this is a scale model of
the Parker Solar Probe.

This is the heat shield here,
on the front.

To give you sort of
a sense of scale,

this is actually about
2.4m in diameter.

It weighs about 72.5kg, and it's

about 11.5cm thick.

It's made of, like, a carbon-carbon,
like a graphite epoxy,

like you might have in a nice bike

or a tennis racket
or your golf clubs.

That's the type of stuff
that it's made of.

The important thing for us
is it keeps us cool.

So if I put on, if we can dim
the lights a little bit?

Thank you. So this is basically
like the light from the Sun.

Now, the material that
the spacecraft is travelling through

is at about 2,000,000 degrees
Celsius, which is really hot.

- Yeah, I said it was hot!
- But
fortunately, it's not very dense.

So like if you put your hand
in an oven,

if you preheated it to
200 degrees Celsius,

you don't get burnt unless you touch
a surface. Please don't try that

when you get home. You can
see here the big thing that

we have to worry about
is the light from the Sun.

The front side of this heat shield
is at about 1,400 degrees Celsius.

- The rest of the spacecraft,
about 30 degrees Celsius.
- Wow!

Now, the really big
breakthrough for us

came when Parker Solar Probe
was close to the Sun

and we were able to see
that unlike something

that you would put energy into
here on Earth,

like if you push your bike and
then you don't pedal it again,

it will slow down, solar wind

doesn't slow down.
It goes all the way beyond,

way, way out
beyond the orbit of Pluto,

way out into the very edge of
the solar system.

Yes. And I think we've got
some images

of some coronal mass ejections.

So this huge power surge,
coming out from the Sun.

- So can you talk us through these?
- Absolutely.

- This is why we care about the Sun,
by the way.
- Yes.

Because the Sun is not just
a bright point of light in the sky.

It has these big storms.

This is like a really, really

stretched slinky spring. As with

everything, if you stretch it

too much, it explodes and all

the energy comes out. Now, these

big things explode from the Sun.

They travel about, you know,

about 93 million miles between
the Sun and the Earth.

When they arrive at Earth,

they interact with our
Earth's magnetosphere,

our magnetic protection.

During those storms,
they actually caused big impacts.

I was lucky enough to be here
last year, in May,

May of '24, to see a beautiful
aurora visible over London.

- So I hope a lot of you were able
to see that.
- Wow! Because usually,

- they're much further north.
- They're much further north.

Transoceanic flights were grounded,
or had to be re-routed,

because of all of the energy
causing radio blackouts.

Things like precision navigation,

precision landing couldn't be used

for many, many hours.
So lots and lots of impacts,

all from these really,
really active storms.

- Yeah.
- So we need to be able
to predict them.
- Yes.

And so it feels as if
the Sun's out there,

many, many kilometres away,

but it does bathe our planet
with energy.

But the question is,
where does that energy come from?

Well, to answer that question,
we've got a demonstration.

So let us go back to the very

beginning of the universe.

- Ooh!
- And here it is.
- OK.

So now we're going to put on some

safety gear. Thank you very much.

So let's go back to the time

of the Big Bang.

LOUD BANG

Whew!

So, what we have here
is we've just had the Big Bang,

and this is what's left behind.

Now, most of it is white confetti,

- but we can see sort of
occasional bits of blue.
- Yup.

In the early universe,
we mainly had hydrogen,

that was the only element around,

with a sprinkling of the blue helium.

So this is our early universe.

- Now let us call for two volunteers.
- Now we want two volunteers,

because we need to sweep this up.

- Yes.
- I thought you were all going
to put your hands down then.

- It's fun, trust me.
- Yes! So,
perfect. We've got one volunteer.

- Would you like to come and stand in
the middle?
- Yes.
- And we need another

volunteer. So, yes,
would you like to come up?

APPLAUSE

So, first of all, I'd like to ask,
what are your names?

- What's your name?
- Oyinda.

- Oyinda.
- Yeah.
- Thank you.
And what's your name?
- Alec.

Alec. Perfect. So, Oyinda and Alec,
what we've gone and done

is gone back to the time of
the early universe.

And you can see here the hydrogen,

a bit of helium scattered around the
universe. But what I want to talk

about is how we formed the first
stars. So I think we're going

to need our first... Our first
star cannon is here. Perfect.

So what I need you to do is just

pick up some of this
hydrogen and helium

and put it into our first star.

- So they're going to be
our gravity.
- They are.

So could we have the gravity signs?

- Oh, perfect.
- So now you can see, yes.

Very important.
You are the gravity of the universe.

- Yes. Gathering up...
- Gathering up.
- ..the matter of the universe.

So what happened in the...
You can start.

Early in the beginning
of the universe,

so all this sort of hydrogen and

helium kind of clumped together,

just as they are doing.

- So this is all due to the force
of gravity?
- All due to the force of

gravity. Occasionally, the two
hydrogens would get kind of

forced together, lose an electron

and then fuse and form helium.

So, yeah, for a star to be a star,

fusion needs to occur.

So the star needs to get to a
critical mass before this can happen.

But then the temperatures
and pressures are high enough

that you get a hydrogen
and a hydrogen.

They fuse together to make helium.

But it's governed by this equation.

Now, I think many of you
would be familiar with this.

It was first proposed by Einstein.

But this is how stars are so bright.

This is where the energy comes from.

Because when a hydrogen and a
hydrogen come together to make

helium, what happens is you lose

a tiny amount of mass,
and that mass is converted

into energy. And so you get the mass,

you multiply it by
the speed of light,

which is 300,000,000m/s -

the fastest-known thing
in the universe -

but then you multiply it by
the speed of light again.

So tiny amounts of mass loss
converts into huge amounts of energy.

Stars are like people. They go
through sort of a life cycle.

Absolutely. And we're about to see
the end of this life cycle

because, as you said,
that fusion is going on.

- Yes.
- And then eventually, like
the pressure and the temperature

caused by the fusion is bigger
than the gravity

that's holding all of this material
together, and it's going to explode.

- It's run out of fuel.
- It's run out of fuel.

So what we're going to do is
we're going to do a countdown,

and then this star is going
to go supernova,

and let's see what happens.

So, are you ready? From three...

Three, two, one.

- Whoo!
- Whee!

- OK.
- Sorry, I shouldn't
be saying "whee!"

Now what can we see?
There's a lot more helium...

- Yes.
- ..and there's some other

- coloured paper in here.
- Actually, yeah,

I'm seeing these little pink bits.

Little pink ones. So there's still

hydrogen, but there's more
abundance of helium.

And so while this star was
undergoing that final sort of bit

before it went supernova,

the helium were actually interacting
and forming things like carbon,

- oxygen and neon.
- So what we need to do is,

that has thrown that matter out

into the universe again, but now

- gravity starts doing its work again.
- Gravity does its work again.
- Yes.

Start scooping these up, and we'll
get them into the next star.

But now we have carbon
and oxygen and neon,

and maybe a few other things,

also going in to the beginning of

the star to actually, you know,

start and kick off that fusion

- experiment again.
- Yes.

And so it just basically repeats,

but each time, it's getting more

- and more complex.
- Fantastic.
I think that's probably enough.

Gravity, I tell you,
gravity is working really hard.

Gravity is very efficient. OK.

So now we're just going to go

for another sort of
stellar evolution.

So we're going to actually explode
this star.

So I think it's your turn.
Would you like to step in?

And we will watch this star
go supernova.

Now, supernova are some of
the brightest things

in the whole of the universe.

- We can see stars going supernova
in other galaxies.
- Right.

So let's watch this happen. OK?

Three, two, one.

- Ooh!
- Ooh!

- OK.
- I just love the colours.

I know, it's great. So now

we're making more and more
complex elements.

So now you're going to have
things like sulphur and silicon.

OK. Yes. So gravity. Yes. Gravity,
you need to do your work once more.

- One more, Gravity.
- Yes.
- One more.

Yes, and so we're going for
the more complex elements.

Yes, represented here by
the different colours.

So thank you, Gravity.

Gravity, you're doing a great job.

- Yes.
- OK.
- Fantastic.

Now, you're actually
going to let me...?

Oh, yes. Now, actually, if Gravity

can stand over here, with me?

As a stellar scientist,
I think, Nicky,

you need to explode
at least one of these stars.

You know I've always wanted
to do this. OK.

- Ready?
- Right.
So I think we're ready.

Three, two, one!

Whoa!

AUDIENCE GASPS

So now we've got the hydrogen,

we've got some of those
higher elements,

but we're getting some
metallic elements as well.

And that's really important, because

as we look in our solar system,
we look at all the different bodies

that we have in our solar system,

we've actually found
eight metallic asteroids.

So we know that when our, sort of,

our planets and our Sun
was really forming,

that these elements were all around
in the environment

as the Sun formed, as the planets
were generated.

This is the stuff that
you're made of.

So you have calcium in your bones.

You have oxygen that you breathe.
You have nitrogen.

Everything in your body
comes from this early universe.

- So you guys are all
made of stardust.
- Yes.

- So we truly are part of this
amazing cosmos.
- Absolutely.

So I think a big round of applause

to our volunteers here, please.

APPLAUSE

Thank you, Nicky. I think you'll be
joining us again later?

I will, yes. I can't wait to
hear the rest of it, though.

- Thank you so much.
- Thank you
so much.
- I'll see you later.

APPLAUSE

OK, so that's talking about
stellar evolution.

So our local star plays a vital role
in life here on Earth.

But has that radiation fuelled life
on other planets?

So to find out, I think we need
to visit those other planets,

the planets of our solar system.

Now, as we visit each planet,

I'm going to give you a
few facts and figures,

but I want you to vote
as to whether you think

there might be life on
each planet we visit.

So, yeah. Yes for life,

no if there's no life,

or maybe somewhere in-between.

Now, when we go through this,

we're going to note your scores

and we're going to put them
on the planetary scoreboard.

So I've got my astro assistant,

which happens to be my daughter,
to help me do the scoreboard.

So, Laurie, if you'd like to come up?

And a round of applause
for my daughter, please.

APPLAUSE

So, let's get this journey started.

So what is the first planet out

- from the Sun?
- Mercury.

Mercury. And there it is, Mercury,

planet closest to the Sun.

Now, I think you know the drill.

What I'm going to do is I'm going
to use warp drive to get there.

So are you ready?
I'm going to do a countdown.

Three, two, one... Let's go.

AUDIENCE COO LOUDLY

I like your noise! OK.

Now, a few facts about Mercury.

Mercury is diddy. It really is

a tiny planet,
and it looks like a moon.

It's only 1.4 times
the size of the Moon.

Temperature on Mercury is about

167 degrees C,

so it has a very hot side,

when it's pointing towards the Sun,
and a very cold side.

So it's a planet of extremes.

Now, does Mercury have water,

or liquid water,
flowing over the surface?

We don't think so, because on the
day side, it will just burn off,

and on the night side,
it would freeze.

But we do believe that Mercury
probably has pockets of water,

but frozen water,
in sort of nooks and crevices

which don't ever see sunlight.

Now, just one interesting fact
about Mercury.

If you go from sunrise to
sunrise, that is 176 days,

but a year on Mercury
is only 88 days.

So a day on Mercury is actually
longer than a year on Mercury.

So that's a few facts and figures
to base your decision.

So now, Laurie,
if you can come and help me.

What I want to ask you is,
is there life on Mercury?

And remember - yes, no or maybe.

- OK, I'm seeing, like, just no.
- Actually, one or two maybes.

- I see a bit of a wobble there.
- I'm seeing just no.
- OK.

So I think it was a majority of no.

So we are concluding that there's
probably not life on Mercury.

Thank you very much, Laurie.
Let's put that up there.

So where are we going next?
What is the next

planet out from the Sun?

Venus.

Venus. OK, perfect. Let's put it up
there, Laurie, on the scoreboard.

Thank you.
And there's the Planet Venus.

So let's use warp drive to get there.

Let's go.

AUDIENCE COO

Ooh! The Planet Venus.

Now, you don't usually see
the Planet Venus like this,

because Venus actually has
a very thick atmosphere.

And one of the things that you might
not realise is that actually,

the Planet Venus,
you've probably seen yourselves,

but you might not have noticed it.
If you're up soon after sunset,

or right up early soon after sunrise,

sometimes, you see what looks like
a really beautiful star in the sky,

but it's not a star.
It's actually the Planet Venus.

So in 1970, Russia sent
the Venera 7 probe to Venus,

and it was the first probe to have
a soft landing on another planet.

We've got a demonstration here
to show what happened to Venera 7

when it landed on Venus.

Thank you very much.

So here is our space probe,
Venera 7.

Now, in this case,

our space probe is actually
made out of the metal gallium.

Yes. Now, gallium has a
very low melting point.

And this is what happened

to the Venera space probe

as it landed on Venus.

I've got a hush there. Yes.

Because we thought that
the Planet Venus

might be sort of lovely
and habitable.

It looks so beautiful
in the night sky.

But when the probe actually landed
on the surface of Venus,

it could only transmit
for about 23 minutes,

because after that,
this is what happened.

The probe started to melt.

Now, so why did it melt?

Well, it turns out that
the Planet Venus,

although it's very similar to Earth -

so it's about sort of just
under the size of Earth -

the Planet Venus
is incredibly inhospitable.

The average temperature on Venus

is 475 degrees C,

which is why it melted the probe.

Venus is actually hotter
than Mercury,

even though Mercury
is closer to the Sun.

So why is that? Well, it's because
on the surface of Venus,

it has many volcanoes, which are
spewing out greenhouse gases.

And so that means radiation
from the Sun gets trapped in

the atmosphere of Venus, and Venus's
temperature is elevated.

So... Oh, dear. It's not
looking very good, is it?

Now, I think when the Venera 7
probe landed on Venus,

it didn't quite melt as much as this,

but it did melt, and that's why

it could only transmit for
a little while.

But what we have found is

if you look, actually,
in the atmosphere of Venus,

about 60...50km or 60km up,

there, the temperature
is a nice mild 25.

So it's like sort of the UK
on a summer's day.

And so there could be life

that actually sits in
the atmosphere of Venus,

but we don't think that life as we
know it could survive on the surface.

But there's one other thing.

There was a recent detection, in
2020, of a molecule called phosphine.

Now, phosphine, we believe,
is a possible indicator

of biological life. And so the fact
that we think we've detected

phosphine in the atmosphere could be
an indication of life on Venus.

But with all these things,
we've got one detection,

and so we need to verify it
with others,

and so other people
are looking into it now.

So that is the Planet Venus.

And what I need you to do is, Laurie,
you're on scoreboard duty,

is whether you think
there's life on Venus.

- OK.
- OK.
- Seeing quite a few maybes.

Actually, I'm seeing
mainly maybes. OK.

So, perfect. It's a maybe for Venus.

So where are we going to next?

What is the next planet out from

- the Sun?
- Earth.

Ah! Earth. And so, yes. Let's put it

up on the screen. There's Earth.

We've got it on the scoreboard. So

let's use warp drive to get to Earth.

AUDIENCE COO

Ah. The Pale Blue Dot.

Our glorious planet.

Now, we know a lot about Earth,
so I won't dwell here.

But, you know, we know its size.

Average temperature on Earth,
about 15 degrees.

It has a thick atmosphere

and it's mainly made out of
nitrogen and oxygen.

And it has that magnetic field
that we were talking about earlier,

that magnetic field that protects
it from things like the solar wind.

And in terms of water, we know
it has lots of surface water.

In fact, I think four-fifths of the
Earth's surface is covered in water.

So it's a slightly
rhetorical question,

but do we think
there's life on Earth?

- So, OK, Laurie, what are we thinking?
- This isn't hard.

- This isn't hard.
- It's Earth.
- I know,

but I'm looking for the maybes.

See, I knew there would be one.
There's one person pointing down.

I think it's a resounding yes.

I think it's pretty much a yes.

So let's put a yes for Earth.
Thank you.

So where are we going next?

What's the next planet out from
the Sun?

- Mars.
- Mars.

OK, OK. Mars. And so, yes,

let's put it on the solar system map.

It's there. It's on the scoreboard.

Let's warp drive to Mars.

AUDIENCE COO

The Red Planet.

Now, it's quite interesting,
because I think Mars is

our biggest hope for finding life
out there, and we've sent many, many

probes to the Martian surface.
We are celebrating

the 200th anniversary
Christmas Lecture,

so I would first like to say

that I'm extremely honoured

to be the 200th Christmas lecturer,

because when I was a child, I used to
watch the Christmas Lectures at home,

and one of the ones that really
stands out in my mind

is watching, in 1977,
the Carl Sagan Christmas Lecture.

Now, he introduced the audience

to the latest findings
from the Viking probe,

and he invited two volunteers
to come and join him

on the stage, in a mock-up of Mars.

And this is a clip of
their conversation,

speaking about the future
of rovers on Mars.

You see, here we are, stuck

in one particular place on Mars,

and it would be nice
to go to other places.

To do that, we would have to have

a spacecraft which could move about

on Mars, which could rove. Would you

- like some milk in there, or do you
take it black?
- Yes, please.

Some milk, yes.

AUDIENCE GIGGLES

And so we have to have a spacecraft

with wheels, with tractor treads,

which could land in

the safe and dull places like here.
It's not so dull because,

after all, we're having tea.

But it is dull compared to

almost everywhere else on Mars.

- Would you like some milk?
- Yes, please.

So, fast-forward 50 years,

and we've sent six rovers
to Mars so far,

and many of them are similar
to my friend Bruno here.

Now, I would like to introduce
Charlie Roe,

who is a space engineer
and in charge of Bruno.

APPLAUSE

Charlie, what is Bruno?

So Bruno is a very early
development model

of the Rosalind Franklin
ExoMars rover.

That is Europe's first rover
and first rover to Mars,

and it's going there
to find signs of life.

Rovers already on Mars have
been coming back with data,

so what have we found out so far?

Lots of missions have been to Mars
in orbit and rovers as well.

Nasa and others have sent
rovers very successfully

to the surface of Mars.
The most recent kind of missions

have gone and found evidence

for flowing water and the conditions
we would want to find

if there was past life. Rovers
like Curiosity and Perseverance

have found evidence of riverbeds.

So you can see here
the kind of lines

where river channels may have run.

So I mentioned
Curiosity and Perseverance.

Curiosity landed in 2012,
Perseverance, in 2020.

They sent back pictures of
rounded pebbles like this,

which we would typically, on Earth,
find at the bottom of riverbeds,

where there's flowing water
and erosion.

So just to be clear, this is actually
a picture from the Martian surface...

- This is a picture from the
Martian surface.
- ..and it's showing

- water erosion?
- It's showing water
erosion, we think, on these pebbles,

that's rounded them, which is
strange, because rocks on Mars

are typically very sharp, and that's
because of the lack of erosion

- on the surface. So this is why
these really stand out.
- OK.

- So in certain areas, we see rocks
like this?
- Absolutely.
- And I guess

that's a strong indication
that Mars once had water?

- Once had water. Yep, absolutely.
- Lovely.
- And then more recently,

the Perseverance mission,
Nasa's latest rover,

still working on the surface,

found strange textures in rocks.

You can see the leopard print

- on the rock here.
- So that's
these dark, these dark bands?

That's these dark bands
that you can see there.

- Exactly.
- So what did that tell us,

or what did it give us
an indication of?

We think it's an indication of

a biosignature. So this is something

that, on Earth, we might find in

the presence where organic molecules

or elements have interacted with

the surface. So that's one way
these can be formed.

More data would be required,
but it's certainly intriguing.

Lovely. And I guess it's sort of
an area we're going to go back

- and revisit...
- Absolutely.
- Yes. ..and do more research.

- Absolutely. And here we are.
- Thank you. Yes! So thank you.

I think we're going to go on to
something else.

But if you could stay here, because
we'll be coming back to Bruno

- shortly.
- OK.
- Fantastic. Thank you.

So we were seeing there that there's
lots of evidence that suggests

we used to have water flowing over
the surface of Mars,

but the question is,
what happened to that water?

Why did the atmosphere change? Well,

to find that out, what we're
going to do is a demonstration.

Bring on...the hot cannonballs!

APPLAUSE

- Hello.
- Hello.
You've got the hot cannonballs?

I have got hot cannonballs. They
need to be in the oven a little bit

- longer.
- But I'm really hoping
they're hot.
- Oh... Oh, they're hot.

- I'm going to stay over here!
- Good idea.

So, in the early solar system,
when the planets soon formed,

they were sort of hot. But now,
as the solar system has got older,

that sort of lava stage
of the early planets,

they've begun to cool down.

So what we have in this furnace
is two cannonballs -

one representing the size of Earth

and one representing
the size of Mars.

That's right. I've got a ball that's
about twice the size of the other.

One for Earth. One for Mars.

- They're in there, so they
should be the same temperature.
- Yes.

About 800 to maybe 1,000
degrees Celsius.

I'm taking another step back! Yes.

So Dan is going to actually bring
the hot cannonballs out

and put them on those stands.
And what I want us to do is see

how the two cannonballs cool down.
Is there a difference in the cooling?

- Let's get that started. Thank you.
- I'll go for it.

So, now, if you see one cannonball
that looks cooler than the other,

I want you to shout out
the name of that cannonball.

So if you think the Earth ball is
cooling quicker, shout out "Earth".

If you think the Mars ball is cooling
quicker, then just shout out "Mars".

I'm going to stand over here
and look myself.

Mars!

I'm going to take that as a Mars. OK?

- Thank you so much.
- My pleasure.

So, we are seeing Mars... Actually,
as we bring the lights up,

I think we can see the difference
quite clearly here.

So Mars seems to be cooling down
quicker than Earth.

And this is what we believe happened
in the solar system.

So they probably started off
fairly reasonable, equal temperature,

but Mars did seem
to cool down quicker.

Now, one of the important factors
that we have on Earth

is that Earth has
a semi-molten iron core.

Now, this iron core,
as the Earth rotates,

that semi-molten iron core moves,

and that generates a current,
and that generates a magnetic field.

Now, that magnetic field protects us
from things like the solar wind.

That's what Nicky was
talking about earlier.

Now, we think that Mars used to have
a similar semi-molten core,

but because Mars is smaller,
it cooled down quicker,

so its molten core solidified
and it lost its magnetic field,

and then particles from the solar
wind just eroded the atmosphere away.

So we think about
a few billion years ago,

there was liquid water running over
the surface of Mars,

but the loss of its magnetic field

enabled the erosion
of its atmosphere.

- So thank you very much, Dan.
- My pleasure.
- The hot cannonballs.

Perfect.

APPLAUSE

So, Charlie, would you
like to join me again?

So, Charlie, you mentioned
this is the prototype

- for the Rosalind Franklin rover.
- Mm.

There have been many rovers on Mars.
We haven't found much definitive

evidence. Why would Rosalind Franklin
be different?

The main thing about this rover,
I don't know if you can all see it,

but is the black box
on the front, here.

And inside this box is
a drill that folds out,

and it allows it to drill down
to two metres.

Now, we think that about

half a metre of soil and rock

is enough to protect
the lower layers

from the really harsh
environment on Mars.

So you can see in this video
that there's a drilling demo

of what the real rover does.

So, Maggie, that environment you
described on the surface of Mars -

losing its magnetic field and
it's lost lots of its atmospheres -

- meant the surface is
very, very harsh.
- Yes.

So we think those upper layers
are just enough to protect

the lower layers and preserve
what evidence is down there.

So this drill, it drills down
to two metres.

It uses a combination of equipment

onboard to pick the perfect site.

At two metres,
it can take a sample, bring it up,

pass it onboard to the inside of
the rover. So most of

the instruments on the rover
sit inside the main body.

We call it the Bathtub, because of

how it looks. And inside there are

a suite of instruments that allow us

to analyse those samples

and search for signs of life.

Perfect. Well, thank you very much,
Charlie.

And I think a big round of applause

- for Charlie and for Bruno.
- Thank you.

APPLAUSE

So that is our current
understanding of Mars.

Laurie, we need you on the
scoreboards, and let's vote

if you believe there's life
on Mars today. Vote now.

- Ooh!
- OK.
- That's less "yes"
than I was expecting, actually.

- I'm seeing quite a few maybes.
- Yeah.
- I think "maybe".
- Maybe. Yeah.

OK, perfect. But we're not
going to stop it there,

because we also need to vote
for life, the possibility of life

on Mars past. So, again,
vote now for life on Mars past.

- OK.
- Ooh...
- That's...
- OK. Actually,
it's pretty resounding, isn't it?

- Yeah.
- Yes, OK. So I think we think
that there used to be life on Mars.

Perfect. Go ahead, my love.
Thank you.

So which planet are we going to next?

- Jupiter!
- Jupiter. Yes.

OK, let's use the warp drive.

AUDIENCE COO

I must say, your noises are
getting better and better!

So, yes, the Planet Jupiter.

The largest planet
in our solar system.

Now, there has been a probe
that has been going around Jupiter,

and it's called Juno, and it's been
sending back these amazing images.

So this is real data
from the Planet Jupiter.

And what we're doing is we're
seeing its outer atmosphere.

And you can see there's all sorts of
swirls and eddies in the atmosphere,

so it's amazingly complex.

Also, Jupiter has a strong
magnetic field. Now,

a few facts and figures
about Jupiter.

I mentioned it's the largest
planet in our solar system,

so it's actually 11 times
the size of Earth.

Average temperature on Jupiter,
about -110 degrees,

so definitely nippy. Like many of the
planets of the outer solar system,

it's about 90% hydrogen
and about 10% helium.

Now, surface water.
There's a challenge with this,

because with these gas giants
and these icy giants,

we don't actually know
if they have a surface.

We can see the outer atmosphere,
but we don't really know

what lies below. Now, we're talking
about sending a probe to Jupiter,

and we saw the wonderful images
we're getting back from Juno,

but what if we wanted to go deeper?

What if we wanted to know
what lies below the atmosphere?

Well, to talk about that,
we have another demonstration

and, of course,
I'm going to need a volunteer.

Ooh, lots of hands.

Actually, yes, I think...

Yes, would you like to come up?

APPLAUSE

- So, first of all, can
I ask your name?
- Tiwa.

Tiwa. Very nice to meet you.

Now, this is our Jupiter.

If you'd like to come in here.

So this is the layers of Jupiter.

So up here, we've got
the upper atmosphere of Jupiter.

That's what we can see from space.
But down below,

we have various layers.
And the problem is, at the moment,

we don't know what
those layers contain.

We don't actually know
what is at the heart of Jupiter.

Some people say it might be
a slushy metallic core,

and that's represented by
this shiny stuff here.

But the truth is, we don't know.

So maybe in a distant future,
we might send probes to Jupiter,

and we might send a number of
different types of probes to Jupiter,

going to the different
depths of the planets.

So let's start with a first one.
Let's say we want to go deep.

This is going to represent
our first probe.

So if you'd like to hold that.

It's quite heavy, isn't it?

Quite dense. Now, will you
hold it right at the front,

when you drop it,
and we'll see how deep it goes?

So let's drop it.
Three, two, one, drop...

Ooh! That came crashing.

And you see we get sort of
interference between the layers.

And I think that dove down
quite deep.

And I can see it just here.

I think that's where
it's got down to.

So it's gone down to the inner layers
of Jupiter.

OK, so that's quite a dense probe,
going deep into the atmosphere.

OK, so let's try another probe.

What if we want to look at
some of the outer atmosphere

and sort of going into the first
layers? So I think for that,

we'll try a ball like this.

Now, what do you think
the density is now?

- It's very light.
- Very light.

So we've got quite a large volume,
but very light, so low density.

So, again, if you could hold it

at the front and then drop it in,
we'll see where that ends up.

OK. So we've gone through
the atmosphere,

but we're just landing where it gets
a bit more dense,

which makes sense.

But finally, in the future, we may
want to send humans to Jupiter.

Now, this will be quite
a mission, but, yeah...

So what we need is something
that represents the density

of the human body, and what we have

here is a large grape. How deep

do you think this is going to go
into Jupiter's atmosphere?

So just call out some names.
So we've got sort of yellow.

AUDIENCE MEMBERS CALL OUT
We've got red.

Or will it go into the metallic core?

OK. Well, there's only one way
to find out.

Remember, hold it at the front
and let's drop it in.

Plop. Ooh... Ooh!

Blue. Actually, yeah, blue,

on the cusp of the metallic core.

Now, I must point out that we

probably wouldn't do this,

because as you go deeper and deeper
and deeper towards

the core of Jupiter,
the pressure gets higher and higher.

I think we're a long way from
the sort of technology you'd need

to protect a human body
from the crushing pressures

that you'd experience in Jupiter.

But a big round of applause
for our volunteer, please.

Thank you very much.

APPLAUSE

So that was our brief visit
to Jupiter,

but let's get on with
the scoreboards.

So please vote now. Life on Jupiter?

Yes, no or maybe?

- OK, I'm just seeing "no".
- Ooh.

OK. OK. I'm just seeing "no".
An occasional "maybe". But, yeah,

- I think it's...
- I wouldn't want
to live there, I don't blame them!

Yeah, I wouldn't want to go there.
You saw what happened to that grape.

OK, so probably no life on Jupiter.

So let us continue our journey.

What is the next planet out?

- Saturn.
- Saturn. Yes, of course, Saturn.

It's up there on the map.

It's there on our scoreboard.
Thank you, Laurie.

So let's use warp drive. Let's go.

AUDIENCE COO

Ah, Saturn and its beautiful rings.

Most of what we know about Saturn
is due to a probe called Cassini,

and Cassini sent back
some stunning images.

Now, Cassini was one of those

spacecraft that went to Saturn,

and it stayed out there for

eight years, in orbit about Saturn,

and it told us about the planet

itself. It told us about
many of the moons of Saturn.

And it told us about
the rings of Saturn.

Now, just to give you
a few facts about Saturn...

Saturn is about ten times
the size of Earth.

Average temperature,
about -40 degrees C.

Atmosphere, very much like Jupiter.

It's mainly hydrogen and helium.

Again, surface water?
We really can't tell.

Below that outer atmosphere, it's
hard to see what's going on below.

But interesting, I think one of
the interesting facts about Saturn

is its rings, because the rings
are sort of very narrow.

They're only sort of
a few hundred metres deep,

but they surround the whole of
the planet. And also, the rings are

actually made up of sort of lumps
of rock and ice, about the size of

my fist.
But they reflect the sunlight,

and that's why we see them
so clearly.

Some people think that the rings
might have been made up of a moon

that got destroyed back in the past.

So, Laurie, you're on the scoreboard

duty, and let's vote now.

Do we think there's life on Saturn?

- A few maybes.
- I think it's mainly
"no".
- I think it's mainly "no".

OK, Laurie, thank you very much.
If you'd like to apply that.

So we've been talking
about these gas giants

of Jupiter and Saturn,

and it looks as if the probability
of finding life there doesn't

seem very high. But it's quite
interesting, because

one of the things we want to do
is explore the moons of Jupiter

and Saturn's system,
because between them, they've got

about 300...well, over 350 moons
going around them.

Now, to talk about this,
I'd like to introduce

Associate Professor of
Space Instrumentation at Oxford,

Dr Carly Howett.

APPLAUSE

So, Carly, tell us more about
what you do.

So I work to explore
the outer solar system.

So anything inside of Jupiter,
not as interesting...

- Just not interested!
- No, no, no, we've been there.

- Moving on!
- So Jupiter and outside, yeah.
- OK.

Perfect. So we're going to talk
about some of the moons of

- Jupiter and Saturn.
- Brilliant.
- So what's first up?

First of all, we're going to
look at Europa, which is one of

the moons... This is Europa,
one of the moons of Jupiter.

So Jupiter has lots of
moons - over 90 moons -

but there are four
that are the big ones, OK?

And Europa is one of them. So we
also have Io, which is a bit more

rocky, Ganymede and Callisto.
But we're going to focus on Europa,

- because I think Europa is a great
place to look for life.
- OK.

Now, this seems unusual because,
I mean, we talk about planets

in the habitable zone,
but talking about moons now,

it seems like a new
sort of deviation.

It is. We weren't really sure
where life could exist. As you said,

we sort of had ideas across the
years about where they could exist.

But Europa's a great one
because there's this new idea about

- following the water, and
Europa has water.
- Ah. OK.

- So where do we have evidence
for this water?
- Well, first of all,

- the surface is water. Right?
- OK.
- What you're looking at here,

it looks like it could be rock,
but actually, it's liquid water,

and it's just incredible. Its
surface is icy down to about 30km,

and then there's 100km
of liquid water ocean underneath it.

And what I love is that we're looking
for life on some of these moons

because of something
we discovered right here on Earth.

And the deepest part of the ocean
on Earth is the Mariana Trench,

and that sits 11km below sea level.

Now, when we got there, we were aware
that light from the Sun

doesn't penetrate down here, and
so we didn't think there could be

any sort of ecosystem
that could survive down there.

But when we got down there,
we realised that there were these

thermal vents. Heat energy
that we were talking about

escaping from the centre of
the Earth,

and it's powering these
thermal vents.

And where they thought
there could be no signs of life,

this is what we saw. Can you tell us
a bit about this life?

So there's no sunlight, right?

We are seeing images here
because we took lights with us.

So where we get sunlight
on the surface,

the energy here is coming from
the core of the Earth,

through these little vents, and
that's what's powering that life.

That's that energy source.

So I think we also got
some information

from a spacecraft called Galileo?

Yeah. So Galileo went around

and it took these amazing images
of Europa,

and it gave us that first idea
of what could be going on.

And we know that Europa
is sitting so close to Jupiter.

Jupiter's enormous. It's got
a massive gravitational field.

And that's the source
of energy on Europa.

These moons are quite small, so if
they had heat, they've probably lost

that heat a long time ago.
So where's this heat coming from?

So you're right.
It's not the heat from formation.

This is energy that Europa
and its other moons are getting

as it orbits Jupiter.
So sometimes, it's closer.

Sometimes, it's further away. And
that squeezes and relaxes, squeezes

and relaxes, the core of Europa,
and energy can't be destroyed.

That energy that comes from
the squeezing and relaxing

has to be dissipated, what we call,
so it's going to be emitted as heat.

And it's maybe a little bit easier
to visualise on a squash ball.

Anyone that plays squash or
racquetball, you might be familiar.

You have to squeeze and release

that ball, in order to warm it up

before you play, and that's what's

going on in the core. The squeezing

and releasing is happening,

but to the middle of these moons,

and that's getting
then lost as heat.

So what's your favourite
moon of Saturn?

- Go on, tell me!
- Oh, I mean, everyone
has a favourite moon of Saturn,

and of course it's Enceladus. Right?
Enceladus is just brilliant.

- So it's a little bit...
This is Enceladus.
- Ah, yes.

..a little bit like Europa, in
the sense that it has an icy shell

and it has liquid water underneath.

So you're kind of getting the theme,
right? We're into water.

But unlike Europa, there's an idea
that Europa might have plumes,

but Enceladus definitely has plumes.

- And Cassini, the spacecraft, went
there and explored it...
- Ah, yes.

..and we saw images like this.
What a phenomenal image!

- Actually, to me, this is beautiful.
- It's stunning, right?

So you can see the day side,
the night side.

And then these plumes that are
coming up from the surface.

And you can see that
where this plume material

gets above the terminator,
it hits the sunlight

and then we can see it again.
So these plumes are actually

coming from fractures on the surface
that you can't see in this picture.

- Yes.
- But these are the fractures.

There are four fractures
at the South Pole,

and we call them, sometimes,
the Tiger Stripes.

And we know,
by flying through the plumes,

that the plume material is actually
ocean material.

We see things like rock, and we see

the antifreeze of that ocean in the

plume material. So we know when

we fly through the plumes, we're

sampling that subsurface ocean.

- So before you leave, I just want
to ask one more question.
- Yep.

Do you think there's life
within our solar system?

- I do, and I think if there is life,
it's on Enceladus.
- OK!

- It is your favourite, though!
- It is. I'm heavily biased,

- I acknowledge that.
- Well, thank you.
A wonderful round of applause

- for Carly.
- Thank you so much.
Thank you, everyone.

CHEERING AND APPLAUSE

Now, Carly mentioned Enceladus,
one of the moons of Saturn,

but one of MY favourite moons
of Saturn is actually a moon

called Titan.
Now, Titan, we have actually visited,

and Titan was part of a mission

for the Cassini-Huygens space probe.

So I mentioned Cassini earlier
as one of the missions

that went in orbit around Saturn,

but as well as Cassini,
there was Huygens.

Now, Huygens was designed
to land on the moon Titan,

and this is what it saw.

But not only is it what it saw,
it's what it heard.

LOW RUMBLING

Because what it turns out

is that Titan has an atmosphere
rich in methane.

And so you can hear that rumble.

That's actually as the probe fell
through that methane atmosphere.

And what we saw as we actually
landed onto this moon

was, sort of were mountains,
river tributaries,

all sorts of amazing features
on a moon.

So we saw these river tributaries
and we were thinking, you know,

so this is a long way
away from the Sun.

Out here, it's pretty cold.

So what is causing these rivers?

And it turned out
that it's liquid methane.

Way out here, the temperature is

cold enough that methane is a liquid.

So now, what I want you to do

is have another demo
to introduce you to liquid methane.

Oh, I love it when
they come on bubbling!

- Fantastic. So, Dan,
what have we got here?
- So,

I've brought you a balloon of
methane gas.

Oh, I see. OK, so methane gas
is the sort of thing we have in our

gas cookers, but what we're going
to do is we're going to liquefy it.

- We are.
- So how are you going to
do that?
- So in here, I have some

liquid nitrogen, which is extremely
cold - about -196 degrees Celsius.

Yes. And do we know at
what temperature methane liquefies?

It's around, if I remember rightly,
about -188.

- OK.
- So a little warmer than
that is cold.
- OK. Lovely.

So if you put the methane gas
into the liquid nitrogen,

it should turn into a liquid.

So let's give it a go.

Now, as it sort of condenses down,

we're going from gas to the liquid,

so the balloon's getting smaller

and smaller and smaller. And in a
second, what we'll do is take it out

and see that liquid methane.

If it makes all of the methane into

a liquid, there won't be any gas,

and the balloon should...

- ..suck itself inside.
- Yeah!

Yeah. I'll try and get it out
before it breaks.

- Got it.
- OK, perfect. Lovely.
So we've got the liquid methane,

but we need a means of
getting rid of it.

So what we're going to do is pour
that liquid methane into this tray

and set it on fire,
so we can just get rid of it safely.

So, here we go. Liquid methane.

Just got to warm it up a little bit,
get it back to gas.

- There we go.
- OK. So, yes.

So a blue flame, just like we have
on our gas cookers at home.

Whoa!

AUDIENCE COO

Wow!

- Thank you very much.
- Thank you very much.

APPLAUSE

So do we believe there might be life
on the moons of Jupiter and Saturn,

especially Europa, Enceladus
and Titan? Let's have a vote.

Yes, no or maybe.

- Oh.
- Oh, yeah. So what are we
thinking?
- I'm seeing a lot of

- yeses and a lot of maybes.
- So shall we say a tentative "yes"?

- We could do both.
- I like your style! OK.

So we're going to do yes or maybe,
because we don't know.

But the thing is, before
we'd discovered that life in

the Mariana Trench, we wouldn't
have even been considering this.

So it's just another possibility
of finding life in our solar system.

Thanks very much, my love.
And so, yes,

let us continue our journey to
the outer parts of the solar system.

Next stop is Uranus. Are you ready?

Let's use the warp drive.

AUDIENCE COO

OK. Warp drive has taken us
to Uranus and Neptune.

Now, it's quite interesting here,
because we're seeing...

This is the Planet Uranus,
and you can see two things about it

which are slightly odd.
Firstly, that it has a ring.

Now, it's quite interesting because
when we think of ringed planets,

we think of Saturn, but all the
planets of the outer solar system -

so Jupiter, Saturn, Uranus
and Neptune - all have rings.

Now, this is an interesting fact
about Uranus.

When you look at the spin of Uranus,

it's actually spinning on its side.

The atmosphere of both Neptune

and Uranus is mainly methane,

and that's what gives it
the blue colour.

But let's talk about a little bit
about Neptune as well.

One of the things that is
quite interesting

is how these planets were detected.

These planets, unless you really know
what you're looking for,

you can't really see them
with the naked eye.

So we know the planets of
the inner solar system,

the Ancients knew about
Jupiter and Saturn,

but Planets Neptune and Uranus,

people didn't know very much about.

So, how did they detect them?

Well, I've got another demonstration
to show you how this works,

and for this, I need a volunteer.

Oh, gosh. Yes. Blue top,
in the middle, with the hoodie.

Yes. Do you want to come on down?
APPLAUSE

Thank you. So, first of all,
what's your name?

- Ela.
- Ela. Very nice to meet you.

Now, what we're going to do
is imagine this

is our backdrop of stars. So this is
the outer parts of the solar system.

Now, what I want you to do is I'm
going to give you a piece of chalk,

and what I'd like you to draw is,

if I'm going to come over here

and put this ball on the ramp

and it's going to roll down,

draw me the path you think
the ball is going to take.

So from there, it's going to follow,
I think,

pretty much a straight line

and go all the way to the bottom.

OK. So that's perfect.

So now I'd like to give you
the ball.

And if you stand here,

right at the end, I'd like you to,

when I say... Actually, we'll say
"three, two, one",

and then you release the ball
and let's see what happens.

So, are we ready?

- Three, two, one.
- Three, two, one.

Release the ball!

Whoa!

OK. Well, now, we're scientists,
so I think we should just do that

one more time. Maybe there was
sort of something on the surface

or something disturbed it.
So let's just do that one more time.

- Three, two, one.
- Three, two, one.

Whoa!

So there's quite a deviation there.

So, thank you very much. I think a
round of applause for our volunteer.

APPLAUSE
Thank you very much. Thank you.

And what we need to do now
is analyse what just happened.

So I mentioned that Neptune

and Uranus are very hard to spot
with the naked eye from Earth.

And Uranus was detected using large

telescopes, scanning the skies, and
they realised there was something

out there. But Neptune, no-one really
had any idea that it was out there

until they started doing experiments
like this. Because what they were

doing is they were looking at
the orbit of Uranus,

and they realised that
the orbit of Uranus

sort of had a bit of a kink,
a deviation.

And so what they realised is

that thing that was causing a
deviation - a gravitational pull -

was probably another planet.

So thank you very much,
and I think it's time again, Laurie,

to do the scoreboard. Thank you.

I've only got Uranus up there.

- Yes.
- There we go.
- Now, what I want
you to do is vote on whether

life is out there.

- Ooh! That's resounding.
- That's a no.
- Yeah, actually, yeah,

I don't think I can see any maybes.

OK. So let's put that on
the scoreboard, my love.

OK. So now we've travelled
through our solar system.

There we have the playground,

and this is where
we've been searching for life.

And I think out there, we also,
of course, have the Planet Pluto.

Yes. Now, Pluto,
we're not going to stop there,

because it isn't actually
officially a planet.

Yeah, when I was a child,
Pluto was a planet,

but of course, now it's not.
So we won't dwell on Pluto.

But now it's quite interesting,
looking at our scoreboard,

these are the sort of places
we've been looking for life,

and we've got one or two indicators.
I mean, I think Earth is a bit of

a cheat. We're pretty convinced
there's life there. We think maybe

on Mars and possibly on some of
the moons of Jupiter and Saturn.

Now, the Voyager spacecrafts

were launched in 1977,

and there were two spacecrafts -
Voyager 1 and Voyager 2 -

and they travelled out
into the solar system.

And so what I'd like to do is invite
the Head of Science at Nasa

back to the stage, Dr Nicky Fox.

APPLAUSE

So, Nicky, can you tell us a bit more

- about the Voyager missions?
- Oh,

I'd love to. So obviously, there's
two of them. They were launched

nearly 50 years ago.
Launched in 1977, separately.

They were designed for
a five-year mission,

to fly past those four outer planets

that you've just been talking about.

They send back all that
spectacular, spectacular data,

and then they continued onwards.

- Ah.
- So, you know, after passing,
sort of, passing Neptune

and that orbit,
they then became what we think of

as like an interplanetary mission,
and now they're an

interstellar mission. And just to
give you an idea of the distance,

it takes light eight minutes

- to travel from the Sun to the Earth.
- Yes.
- About this time next year,

the Voyager 1 will be one
light-day away from Earth.

So that means when we send a signal,
when we want to send a command,

we'll send it, it will take a full
day for the light to travel out.

And it sends a message back to us,
and that's another day for that

- to come back.
- And that's travelling
at the speed of light,

300,000,000m/s, and it still takes
a day to get there.

It will take a day to get there.

- Voyagers are just wonderful.
- I know, I know.

And the thing is, they have
transformed our understanding

and given us a better understanding
of the scale of our solar system.

Absolutely. Also, the fact that
that boundary between

where the Sun stops
and interstellar space starts,

it isn't just like a point.
It moves.

So the space weather we talked about
at the beginning,

the Sun, it actually causes kind of

the heliosphere to sort of move
and breathe as well.

And we had to watch the data
and really sort of predict what

the boundary would look like. Every
day, we would get data sent back

from Voyager 2. The actual tape
recorder on Voyager 2

doesn't work any more, so we only
get it when we're listening

- to it. So you can imagine...
- The fact that it's a tape recorder

- I think really dates it.
- It does.
It does. But we were, you know,

just sitting together,
watching the data come in every day

and waiting for that to go to zero.

And when that went to zero,
the cosmic ray population -

- which is what's outside the solar
system - shot up.
- Yes.
- And we could

- actually put our finger and say,
that's the moment.
- That's the mark.

- But I think they took that data and
converted it into sound.
- They did.

- And I think we actually have
the sound.
- Wonderful.

- From the plasma wave instrument.
- Yes.
- Yep.
- This is from Voyager 1.

STEADY, FUZZY STATIC

So, yeah, the plasma wave.

- And we're hearing the sound.
- Yep.

HIGH-PITCHED WHISTLING

And that's the actual sounds

coming from the very edge of
the heliosphere.

- How cool is that?
- So, yeah,
that is the sound of the edge of

the solar system, in translation.

- Absolutely. Yeah.
- Yes. I have to ask

a question. Do you think there's life

- within our solar system?
- I do.

One of our core objectives

is searching for life
elsewhere in the universe.

You know, you've already heard
the wonderful stuff about Enceladus

and about Europa.
We're sending missions to Europa.

We're also sending Dragonfly.
You said Titan was your favourite.

- Yes.
- So we are sending Dragonfly,
which is like a large drone

that will sort of land and then
fly over Titan, looking for, like,

the ingredients of life.
For me, it's getting used to maybe

- not life as we know it,
but life as we don't know it.
- Ah.

How about life out there?
Because that's where we're heading.

We're in interstellar space now,
heading out beyond.

- Will we find life out there?
- It will take us a long time

to actually do in-situ measurements
there, but we have spectacular

astrophysics telescopes.
So, yes, watch this space.

- That was a yes!
- Watch this space,
literally.
- Perfect. Yes.

So thank you, and a big round
of applause for Dr Nicky Fox.

- Thank you so much.
- Thank you.

APPLAUSE

So we were just speaking
with Nicky there

about how we can convert
Voyager data into noise, into sound.

But I want to speak to you now

about someone who's
taking that a step further,

because he has taken Voyager data
and converted it into music.

So I'd like to introduce scientist

and composer Domenico Vicinanza.

APPLAUSE

- Lovely to see you.
- Thank you.
- Thank you.

So, yes, we were looking there
at how we've converted

Voyager data into just a sound,

- but you've converted it
into music.
- Yes.

So the piece I've written is
a celebration

of the 40th anniversary

of the launch of Voyager 1.

- OK, lovely.
- And so what I did was,

using an instrument
that is onboard Voyager 1,

that is able to count the amount of
tiny charged particles

- that are around Voyager 1.
- Yes.

And what I've done is converting
that measurement into melody.

So 23 - C. 24 - C Sharp.

- 25 - D.
- Ah, OK. Yes.
- So the larger
the number, the higher the pitch.

- Right.
- The lower the number,
the lower the pitch.

We can think about this measurement

- as the amount of special cosmic dust
around Voyager.
- Ah.

- OK, perfect.
- So when Voyager is travelling from,

let's say, Jupiter to Saturn,
pretty empty.

Not much dust. Low number,

- low note. Really low.
- Yes.

When Voyager is approaching a planet
like Jupiter or Saturn,

- the melody rises because the amount
of dust...
- More particles.
- Exactly.

- Lovely.
- And finally, when Voyager
leaves the solar system,

we are going to hear
at the very, at the very end,

that at a certain point, the music
goes really high and stays high,

and that's because in the
interstellar space, there's a lot of

- very special dust, galactic dust.
- Oh!
- So by listening to this,

- we can actually have an idea about
the story of Voyager...
- Oh, perfect.

..going through the solar system,

- shooting into
interstellar space.
- Yes.

We're going to listen to
the piece of music now,

but at the same time, we're
going to see the puppeteers

of our circus theatre

performing to that piece of music.
So let's take a seat over here.

CLASSICAL MUSIC PLAYS

APPLAUSE

So we've made it to the edge of

our solar system,
and what a fitting way to end.

And we haven't found any life here,
but now we're going to start a new

journey into interstellar space.

And this is our new playground.

Our galaxy, the Milky Way.

APPLAUSE

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CHEERING AND APPLAUSE