All language subtitles for Royal.Institution.Christmas.Lectures.S2025E01.Destination.Moon.1080p.iP.WEB-DL.AAC2.0.H.264-RAWR_track3_[eng]

If you look across the globe
and back through time,

every culture has looked up
at the night sky and wondered,

are we alone?

And with the possible detection
of signs of life on a planet

far beyond our solar system,

we are getting tantalisingly close
to finding an answer.

As a space scientist,
I explore the universe,

and I'm more and more convinced
that there is life out there.

So in this series of lectures,
we are going to look

and ask the question,
is there life beyond the Earth?

Leaving Earth's orbit.

Uh, Houston, we have a problem.

Take third exit to Mars.

WHISTLE

ROBOT BEEPS

Mars rover collected.

Warning.

James Webb Telescope acquired.

Navigate off road.

CRAFT BEEPS

Voyager probe acquired.

Approaching light speed.

APPLAUSE

CHEERING

Welcome to the 200th anniversary
of the Christmas Lectures

from right here
in the Royal Institution,

supported by CGI.

Now, let's go back 4.5 billion years

to the time soon after the birth
of the solar system.

That was quite a tumultuous time.

Things were moving around
all over the place,

and sometimes there were real
cataclysmic crashes.

What we just saw there was
the formation of the moon.

I'm Dame Dr Maggie Aderin-Pocock,

and I describe myself
as a self-certified lunatic,

because I am just mesmerised
by the moon.

So in that early solar system,

we think that a body
about the size of planet Mars

crashed into the early Earth
and sent dust and debris

up into the atmosphere.

That coalesced to form our moon.

Now, this is the Earth
as we know it now -

but back then the Earth
was like a molten rock,

and the moon was also a molten rock,
but in orbit about it.

But I would always like
to travel back to that time,

because the moon was much closer
to planet Earth,

and it must have been like
a golden orb in the sky.

Quite magnificent.

So all my life I have been
absolutely fascinated by space,

and I think the first trigger
for me was actually my father.

So this is a picture of my father.

Unfortunately, he's passed away,

but he actually got that sort of
that spark of interest in space,

because he used to tell me tales
about when he was a child,

because he was born in Nigeria -
and living in Nigeria,

he used to actually have to travel
12 miles to get from home to school,

and that journey was on unlit roads,

and so when the moon was up,
it would light his way,

and so the moon
was my father's friend.

So if it was my father's friend,
it was going to be my friend too.

Now, in inner city London,
there was lots of light pollution.

So when you look up at the night
sky, you don't see many stars -

but what you can see is the moon.

As a child, I used to always love
looking at the moon.

So when I was about six or seven,
I dreamed of getting into space.

Now, I co-host a television show
called the Sky At Night,

and it's the longest running science
show in the world -

but my predecessor was a chap
called Patrick Moore,

and he'd say, you know,
if you have a telescope,

this is what you can see
in the night sky.

And so I decided then
that I would build my own telescope.

And so this was when I was about
your age, I was about 14.

So to show you how I did that,
I'm going to need two volunteers.

Oh, I love the way the hands
go shooting up.

OK! Perfect. OK.

Both of you. Yes, with your matching
Christmas jumpers.

Please come on down.

APPLAUSE

First of all, to start off,
what are your names?

- What's your name?
- Sophie.
- Sophie. Very nice to meet you.

- And what's your name?
- Emma.
- Emma.

Sophie and Emma, thank you.

So you're going to be part
of this demonstration.

Now, Sophie, what I want you to do

is I want to show you
how I made my own telescope.

And, Emma,
if you can come over here,

we'll be doing a demonstration
on that in a few minutes. Thank you.

OK, now, first of all,
I've got a powder in here.

So what this is,
it's like an abrasive powder.

And what I'm going to do
is I'm going to sprinkle

that abrasive powder

on this piece of glass.

So this is just a plain
piece of glass.

And then what I'm going to do
is I'm going to add some water,

and I'm going to smoosh that around.

But what I'm doing is making
an abrasive paste.

And I'm going to put this piece of
glass on top of that piece of glass.

And then what I did, I spent many,
many months sort of grinding.

Now, OK, you give it a go.

OK. So what you're doing
is you're actually grinding

that piece of glass to shape it.

Now, I'm going to leave you
doing that.

In the meantime, what I want to do

is talk about the history
of the telescope.

Now, the first person to apply
for a patent for their telescope

was a chap called Hans Lippershey.

Now, he was a Dutch spectacle maker.

This is about in 1608,
and spectacles were all the rage

and they'd just been invented -

and so now if you step over here,

what he realised is if you put
a lens which you use for reading

and a lens that you use
for distance viewing together

and you move them around,
what you get is magnification.

Now, Emma, I don't know if you can
see at the back of the room -

yes, someone
is holding a sign there.

Now, I can see
"my favourite planet is."

Now, can you read the bottom word?

I think it starts with an M,
but I'm not sure about the rest.

OK. So it's a bit blurry. OK.

Now, what I want to do is do exactly
what Hans Lippershey did.

So move these lenses around
and see if you can actually see

that image up there.

So if you can, can you look through?
OK. Perfect.

Can you read it through here?

- Mars.
- Ah, OK.

But that's what Hans Lippershey did.

He effectively put these two lenses
together and got magnification.

So thank you. A round of
applause for our volunteer.

APPLAUSE

Thank you.

So that is what Galileo did.

He took a telescope like that...
Oh, lovely.

..and made it into something
like this.

So this is effectively
a Galilean telescope.

And so you've got a lens at one end,
a lens at the other,

and then you can actually sort of
adjust the focus,

just as we were doing there,
with this bit here.

Don't forget we're going back
to 1608 -

and if you've ever seen
any old buildings

and the glass in the
windows of those old buildings,

it's not very good quality glass.

And so the question was,
could you still get magnification,

but without passing the light
through the lens?

Well, that brings us back
to this demonstration.

Now, do you want
to give it another grind again?

Ooh! See, with that abrasive paste,
can you feel what's happening?

- Yes.
- Yeah. Because I think you're
actually grinding away the glass.

Yeah.

And what actually happens is...
Oops.

..the one on the bottom
becomes convex,

and so it's like a hill,

and the one above becomes concave.

- So it's like you scrape out
the glass.
- Yeah.
- Yeah!

Now, when you are grinding,

that results in a shape
that is a spherical surface.

Now, the problem with a sphere
is it doesn't bring light

to a nice tight focus,
because what we're trying to do

is have a mirror that takes light
from a very, very distant object,

it hits the glass mirror, and then
we bring it down to a focus.

Now, unfortunately,
a spherical surface can't do that.

But what we can do is continue
working the telescope mirror

to form something called a parabola,
which is a different shape,

but it brings light
from a distance to a sharp focus.

And so that's just what we did.
So thank you very much.

I think a round of applause
for our volunteer again. Thank you.

APPLAUSE

Perfect.

So what we actually need is to coat
that glass

with something like
aluminium or silver

to get a really shiny surface.

And that's what we've got in here.

So this is the basis
of a new telescope.

Now, the person who came up
with the idea of this telescope

was Sir Isaac Newton,

and Sir Isaac Newton realised that
you could actually get magnification

by using a mirror.

But the light path through this
is very different -

and I can show you
with smoke and lasers.

So thank you.
If you put the lasers on.

MACHINE WHIRS

Ah. See? Smoke and mirrors,
that's what it's all about.

Ooh!

Now, at the moment, these lasers
are representing the light

from a distant object -

so maybe a star or a galaxy
that is a long, long, long way away.

So the light comes in
in nice parallel lines,

and then what happens is that light
will travel through the telescope

and it will hit
our reflecting mirror.

And then that mirror, as we said,

is designed to actually bring
that light to a nice tight focus.

So it throws the light back up
towards this flat mirror here.

Now, this flat mirror
you can buy off the shelf -

and what that does is,
if I take the cap off...

..and a bit more smoke,

you might be able to see the laser
light coming out through the top.

Can you see the laser light
coming out of the top?

So that light has travelled
from a distant star,

travelled through the telescope,
reflected off our primary mirror,

it goes up to this secondary mirror,
and then it is sent out to our eye.

Now, these days we have
very good quality glass,

but the challenge is,
if you actually want to make

a really big telescope, imagine
sort of getting a lens that big

and grinding and polishing -
it's really quite hard.

And so, now, for the bigger
telescopes that we use

right here on the ground, we
actually use the Newtonian method.

And what I was making was
a Newtonian telescope,

because it's quite a simple design.

And so now we have some
amazing telescopes out there,

telescopes like the VLT.

Now, VLT stands for
Very Large Telescope.

That is truly the name
of this telescope - the VLT.

So you saw the mirror at the
back end of this telescope,

the primary mirror
of these telescopes

is eight metres in diameter.

It's not just one
very large telescope,

it's four very large telescopes,

each one with a primary mirror
of eight metres.

But the VLT is getting quite old,
it's been out there for 25 years,

and so now they're building the
next generation of space telescope.

And we simply call that the ELT -

the Extremely Large Telescope.

And this is it.

The ELT actually has a primary
mirror 39 metre in diameter.

And so, now, this isn't a
single block of glass,

it's made actually of a number
of sections which are put together

to make this glorious telescope.

So the ELT will probably
be coming online

in about the next
two or three years.

We'll point it up at the night sky
and get glorious images -

but the telescope I hope to see
in my lifetime,

we simply call the OWL.

And that stands for the
Overwhelmingly Large Telescope.

Truly, I am not making this up!

And so this is a picture of
the Overwhelmingly Large Telescope.

If we build this telescope,

this telescope will have a primary
mirror of 100 metres in diameter.

So we're talking about a mirror
the size of a football pitch.

And, of course, with a telescope,
the bigger your mirror,

the more light you can gather, and
so the fainter objects you can see.

Now, I mentioned that I sort of
ground and polished

my own telescope mirror
when I was about 14 years of age,

and when I actually got
the telescope together,

I was so excited.

And I kept on thinking,
so what do I want to have a look at?

What is my first object in the
night sky that I want to look at?

And so, of course,
the first thing was the moon.

Now, it turns out I was following
in some very good footsteps,

because one of the first things
that Galileo did

is he also looked at the moon -

and these are the images he took.

This is Galileo looking through
the telescope

and making a drawing of what he saw.

You see all sorts of craters

and all sorts of things
on the moon's surface.

Before that, people thought
the moon's surface

was just a round sphere -
but now there was details on it.

Details you could see
with the telescope.

And so some people started
speculating, you know,

perhaps some of those darker patches
are sort of large oceans

on the moon's surface.

And if you have oceans and mountains
and things like that,

maybe there is life on the moon.

And so what I'd like to do is invite
someone who actually works here

at the Royal Institution -
Charlotte New.

APPLAUSE

So Charlotte, you work here
at the Royal Institution -

and I think you've got something
from the archive here to show us.

I have, yes. So first we have
this wonderfully old book

that was first published in 1638.

- 1638.
- 1638,

and it was published by and written
by a guy called John Wilkins,

who was a clergyman and a scientist.

Ah! Yes.

And it details information
about the moon,

so it has a very interesting
title piece.

OK, lovely.

And so this is "a discourse tending
to prove that 'tis probable

"there may be another habitable
world in the moon."

- In the moon, yeah.
- Oh!

So I think, inspired by things like
Galileo's pictures

and pictures that people
were taking with telescopes,

from seeing that surface
and realising that it's not smooth,

people started to speculate as to
whether there's life on the moon.

- They did.
- But I think they went
further as well, didn't they?

They did - and he even goes on
to say on another page here...

..that you can get there by means

"of a flying chariot."

DR ADERIN-POCOCK LAUGHS

So they were talking about taking
a flying chariot to the moon

- and hopefully, I guess,
to meet the Moon People.
- Indeed.

OK, perfect. And so that
was the current state of technology.

We started using the telescope,
we were looking at the moon

and thinking that there might be
life out there.

So the next important breakthrough
was, I guess, photography.

- Photography, yes.
- And we've got an example here.
- Yes.

So this is a wonderful glass plate
taken by Warren De La Rue in 1859,

and it's one of the first
full pictures of the moon.

- OK. And so we've moved on
some 200 years now.
- Yeah.

So photography was quite new
at this stage.

- Yes. So it's actually announced here
in 1839.
- Oh, right.
- Yes.

- Part of our history.
- Part of our history. Lovely.

But I think this is
a glorious image.

I see, looking up there, I would
like to have a projection like that

in my room -
as a self-certified lunatic,

- that would be lovely to have.
- Indeed.

So thank you so much, Charlotte.

- It was lovely to see these exhibits.
- Thank you very much.
- Thank you.

APPLAUSE

So that's what I find
most interesting,

is the advent of photography
in terms of astronomy

was a major leap forward -

and for many, many years we were
using photographic plates

to capture images of the night sky,
but in glorious detail.

Then we started taking photographs
of what we saw through a telescope.

But then the next step forward
was actually to get out there.

What if we could get closer to
the moon, not through a telescope,

but actually getting
physically closer to the moon?

And one of the first probes to do
this was actually called Luna 3.

Now, Luna 3 was made
by the Soviet Union, the USSR,

and it actually went on a journey
out there into space

and went and orbited the moon
and came back home.

Now, one of the things
you might not have realised

is we only see one side of the moon.

That's because
as the moon orbits the Earth,

the moon spins on its axis,
but as it orbits,

the same side of the moon
is always pointing towards Earth.

And so people got quite excited.

Maybe that's where
the Moon People lived,

on the far side of the moon,
which we couldn't see from Earth.

Now, we don't have any pictures
taken by Luna 3,

because that was quite
some time ago -

but I'd like to show you
this picture.

Now, this picture is actually
a real picture

and it shows us
the far side of the moon.

So there is a probe
with a camera on it,

and it's looking towards the moon
and towards the Earth.

First thing to say about this image
is the Moon People are not there.

But I think this picture
is quite amazing

because it shows you the moon
and it shows our planet Earth,

and so it just sets the scale.

As I say, this isn't photoshopped,
this is a real image.

So again, we've gone through
that journey.

We look at the moon
with the naked eye,

we look at the moon
with a telescope,

we take photographic plates,

we actually journey out to the moon
and then come back -

but the next step, of course,
was landing on the moon,

and that happened in 1969,

with Neil Armstrong stepping out
onto the moon's surface.

Now, the moon landings
were very much driven by a race.

It was what they called
the Space Race.

So it was the USSR against the USA,

and they were both trying to show
that they were the better nation

or they were the better people,

and so they had this
technological battle in space.

But since then, we've been working
in an era of collaboration

where different nations actually
pool their resources in space.

Space is incredibly expensive,

and so in 1975, you get things
like the formation

of the European Space Agency -

so the countries of Europe
putting their money together

to go further into space.

Now, I am incredibly excited,
because in the theatre today,

we are going to be joined by
the latest generation

of ESA astronauts, and they're going
to come into the theatre here.

And this is Rosemary Coogan,
Meganne Christian and John McFall.

Please come in.

CHEERING AND APPLAUSE

I can't help it. I always smile
when I see astronauts. Ooh!

So thank you very much
for joining me today.

Now, Rosemary,
I'd like to start with you.

Now, we were talking about
international collaboration,

like the formation
of the European Space Agency.

Why is that important,
and what does it mean to you?

Yeah, it's so important.

I absolutely love with working
with people from all over the world,

all over the planet.

It really started for me
when I was in my 20s,

the first time I lived abroad,
and it was completely life-changing,

because for space, it is
so important -

to get to space, to live there
is incredibly difficult.

It's something we can't do alone

and so we need the countries
to work together.

We achieve so much more
when we do that.

- Yes.
- And it also gives this platform
for countries to work together

towards a shared goal at times
where I think we really need it.

Yes - and that's what I really like.

From space, you don't see countries,
you don't see barriers,

you just see planet Earth.

And I think it's really lovely
that space can unite like that.

Perfect. Thank you.

Now, Meganne, why is it still
important to send humans into space,

and especially when we're looking
for signs of life out there?

Well, we are doing a really good job
with robots on Mars, right?

We have rovers.

But rovers can only
go so far and so fast.

So we really need humans there
as well,

because humans can do things faster,

humans have a kind of intuition

and are really good
at problem-solving.

So if we want to speed up our search
for life elsewhere,

we need to send humans there
to do it.

I'm happy to be that human!

So are we!

THEY LAUGH

It's slightly more likely for you,
I think.

Now, John, I'd like to ask, what
does it take to be an astronaut?

Well, typically astronauts come from
a test pilot background

or a science background, usually.

Now, all of us actually here
come from a science background.

Me, in particular, I'm a doctor,
a medical doctor,

an orthopaedic surgeon.

But what's interesting
about astronauts,

is we are not brilliant
at any one thing -

and the thing about
being an astronaut,

is you actually have to be good
at many, many different things.

So not just have a
scientific background

or a test pilot background,
but be good communicators,

be resilient, problem solvers,

self-aware, all sorts of stuff.

- So you need a broad,
broad set of skills.
- Lovely.

Now, John, I believe
you're the first person

with a physical disability
to actually be certified

for life on the
International Space Station.

Absolutely, yes.
I'm a leg amputee.

I lost my leg on a motorcycle
about 25 years ago,

and I use a prosthesis.

And a couple of years ago, the space
agency, European Space Agency,

wanted to see if it was possible
to clear the path to space

for an astronaut with
a physical disability.

And at the beginning of this year,
actually, I was the first person

with a physical disability, as you
say, to be medically certified

to fly to the
International Space Station.

- This is a world first.
- Yes, I know -

but I find it really exciting,

because it is opening up
sort of that life in space

to more and more people.

So thank you very much.

Now, John, if you could stay with me
and Rosemary and Meganne,

if you could take a seat
on the hot step,

I think you'll be
joining me again later.

APPLAUSE
OK, big applause. What the heck?

Thank you so much.

Now, John, we were talking
about earlier

what it takes to be an astronaut.

- And so I effectively want to put you
through your paces.
- Oh, dear.

Yes!

THEY LAUGH

- But on top of that, I want to give
you a bit of competition.
- Oh, OK.

OK. So now I need a volunteer
from the audience -

but, but, I need someone
who is good on fair ground rides,

who doesn't mind you know getting
spun around and things like that.

OK? Oh, OK.
That is a classic Christmas jumper.

Come on down.

APPLAUSE

Lovely to meet you.

Now, first of all, what's your name?

- I'm George.
- George.

Now, if you'd like to come up here,
this is your challenge.

And so what we have here
is a dexterity test.

So I'm going to hold up
one of these.

Each one of these pegs
has a planet on the outside,

the name is also written here,

and that needs to match
a planet on this board with holes.

And so what we're going to do is I'm
going to get you to put these in.

Now, they're quite a tight fit, OK?

And so now, John, I think you've
done something like this before.

We do some reaction stuff
and sort of perceptual speed,

- this sort of stuff in the selection,
yeah.
- OK.

- So you're on home turf here.
- Mmm... Yeah, maybe a little bit.

Maybe. OK.

But to make it a little bit more
interesting, what I want to do is,

well, let's just do it.

Bring on the Chairs of Doom!

THUNDERCLAP

APPLAUSE

Unfortunately,
I think due to budget cuts,

the Chairs of Doom
actually got a bit cut down -

but, please, take a seat.

So what we're going to do here,
we're going to spin you around

for 20 seconds,
so you'll be a bit disoriented.

Then I want you to get up
and go and put the pegs in

as quickly as you can.

And we're going to give you
15 seconds to do that.

OK. Yes!

- And, now, John, if George wins,
he's the new astronaut.
- Yeah.

- You're leaving with this on.
- Yeah.

THEY LAUGH

OK, start the clock.

OK. So 19, 18... OK.

We're spinning quite fast, actually!

I'm glad I'm not doing this.
I don't think I'd survive!

John, you're going into orbit.
Come back.

Am I going to still going to be in
the theatre by the end of this?

I know! So how are we doing?

Oh, six, five, four...

..three, two, one.

OK.

- OK.
- Whew!

OK, so now, John and George, I will
be marking you on accuracy as well.

So we've got to count down.

So nine, eight, seven...

..six, five, four,

three, two, one.

Put your pegs down. John, John.

That was sneaky.

- Right to the line.
- Right to the line!

Make the most of every second. OK!

Ooh. I don't know
what happened to Jupiter there!

OK. So how did you find that?

George, let's start with you.

It was quite difficult
because I was still spinning.

Reeling? Yes, yes, from the chair.

And so let's see. OK.
You've got one, two, three, four.

Four, I think that's a good effort.

OK, but now over to
the trained astronaut.

OK, how many we've got?
One, two, three, four, five, six.

OK.

I'm sorry, you don't get the suit.
SHE LAUGHS

Well, thank you so much -

- and a big round of applause for
George, please.
- Well done, mate.

APPLAUSE

Thank you so much, John.

We've put you through your paces -
and you've survived.

So if you'd like to go
and sit on the astronaut seat.

And, Rosemary, would
you like to come up?

APPLAUSE

Now, Rosemary, one of the things -
you haven't been into space yet,

but you're in training and you're
training for a mission to the ISS.

- Is that correct?
- Yeah, that's right.
- Lovely.

Now, let's see what the ISS is.

- The ISS is the
International Space Station.
- Yes.

So this is the
International Space Station.

It's kind of as it sounds.

- It is a station, a laboratory
that is flying through space.
- OK.

So it's flying above us 250 miles
above the surface of the Earth,

and it's going 18,000 miles an hour.

So it's going very, very quickly,

and it goes round and round
the Earth

- every one and a half hours.
- Oh!

So, so, so every 45 minutes
you get a sunrise and sunset.

Yeah. 16 times a day on orbit

you will see a sunrise and a sunset.
If you're awake all day!

Of course, if you're awake all day.
And so we've got the solar panels,

we've got the
International Space Station.

- And also we've got these
different modules.
- Yeah, exactly -

and, you know, we have modules
at the front from NASA,

- from ESA, from JAXA.
- Japanese space
agency.
- Yeah, that's right.

- We have Roscosmos at the back here.
- Russian.

So there's five different space
agencies all contributing to this.

We've got 23 countries
already within ESA,

so it's loads and loads
of countries.

It really is international.

And essentially it's a place
to do science,

because we have microgravity,
or weightlessness,

when we're on the ISS,

and we can learn so much
in this environment

that we can't learn on Earth.

So the majority of these modules
are laboratory, scientific modules,

but we do have a few that aren't.

So right in the middle,
we've got the cupola here

where we see these iconic views,

and just above it
is what we call Node 3 -

and this is where we have the gym,
we have the toilets,

and just next door to it is Node 1,
where we do our food preparation.

OK. And speaking of food, I think
we've prepared a snack earlier.

THEY LAUGH

So, yeah. So we brought in
some space food,

just because I thought it was
kind of interesting

to see the different types of food
that we can eat in space.

So this here is a
space chocolate bar.

And it actually says on the back,

"the healthiest chocolate bar
in the universe,"

which I thought was really fun.

- That's quite a statement!
- You can
just unwrap this and eat this.

And then we have lasagne, which just
gets put straight in the oven.

And this is macaroni cheese,

- which has been completely
dehydrated.
- Ooh.

So you use this opening here to put
in hot water from the machines

and in five to ten minutes

it will become beautiful macaroni
cheese again.

When you say beautiful,
have you tried any of this food?

I haven't tried the macaroni cheese,

but I've had some other space food
and I thought it was great.

- And, you know, sending it up
like this...
- She has to say that!

- ..is much, much lighter.
- OK, lovely.

But after a number of processes
in the body,

I guess food has to come out.

- Yes.
- Now, going to the loo in space,
I was told, was...challenging,

I think that's the best way
to put it.

Yeah - and it's something we
get asked about a lot,

and it's something that I wouldn't
have really thought about,

you know, before being in this role,

but actually when you go
to the toilet on Earth,

everything kind of goes down.
You know where you're going

and it's easy and simple.

But in microgravity,
you go to the toilet,

- things can start floating around...
- OK, I'm backing away now.

- ..and you need to stop that
happening.
- Yes!
- Exactly.

So actually they've got
a great system.

So to go for a wee in space,
you have a funnel

attached to a long hose that has
an air flow going through it.

And when you wee in there, you know
exactly where you're aiming.

- OK, lovely.
- And everything is simple.

- And it gets sucked away?
- Exactly.
- Yes!

- Sucked away and recycled...
- Oh, recycled.

..into fresh drinking water.

So let's just think about that
for a moment.

So pee and other things
go through the system

- and they get recycled.
- Yeah.

- Recycled into drinking water?
- Yeah.

All of the water on the ISS -
so this is the sweat,

the water we use to wash with,
the water vapour in the air

we breathe out and our urine,
it all goes and gets cleaned

and turned back into drinking water.

So it's an amazing technology

that we'll need as we go
further and further afield.

OK. Perfect.

You're slightly putting me off
the whole situation now!

Oh, no! It's a great system.

It works really well!

So fantastic. So that's food
and going to the loo.

But also, the International Space
Station is getting a little old now,

it's about 25 years old.

And it's been a glorious
collaboration, as you say,

of countries across the world.

So what's coming next?

Yeah. So as you say, I mean,
actually the ISS

has had humans living on it
permanently

for more than 25 years now,
which I think is really impressive -

but in the next few years it is
going to be decommissioned.

But there's still a lot
to look forward to

in terms of stations going around
the Earth.

We'll either have a new station
or several stations

almost replacing the ISS,

and beyond that,
we actually have a collaboration

between ESA and NASA
going back to the moon.

- Ooh!
- And this is
the Artemis mission.

So I know you've just been talking
about the moon, so it's a hot topic.

- Yes.
- And we're really building
upon what Apollo has taught us.

It's more than 50 years
since we've been to the moon.

And this time, as we go back,
we're going to be having Europeans

go to the moon and around the moon
for the first time.

We're going to have a space station
that goes around the moon...

- Orbits the moon?
- ..instead of going
around the Earth.
- Yes.

The first crewed mission of this,
of Artemis

is, actually, our American
and our Canadian colleagues

are training for that
next year already.

- So it's happening really,
really soon.
- And I must admit,

this is something which would be
a dream come true for me.

But we do actually have amongst us

- someone who has been to the moon.
- Ah!

So I think he's with his handler.

So no photography please,
but here he is.

This is Shaun the Sheep.

Thank you very much. Thank you.

Yes. This is Shaun the Sheep.

Now, so this actual model of
Shaun the Sheep has been into space,

has been in orbit around the moon.
Is that the case?

Yeah, exactly.

This Shaun the Sheep actually did
the first Artemis mission,

Artemis I, just a few years ago.

He very bravely tested out all
of the systems

because there were no other
astronauts on board to help him.

And he has returned safely.

And I had the pleasure
of meeting him, actually,

just after his mission for the first
time a couple of years ago.

And he's a great ambassador for it.

- Well, he doesn't look frazzled
by the whole journey.
- He doesn't.

- He looks pretty cool.
- He looks really chilled.

In fact, I'm sure he looked like
that before he went, but, yes...

And so I have to say it,
it does feel like one giant leap

for lambkind.

AUDIENCE GROANS

OK, OK. I'll go!

So much for the career
as a stand-up comic.

And now, thank you so much
for joining us -

and I think a round of applause
for Rosemary, please.

APPLAUSE

To find out more about plans of
actually setting humans on the moon,

I'd like to recall Meganne
to the stage, please.

Thank you. Meganne.

APPLAUSE

Now, Meganne, what are the plans
for Artemis II?

Artemis II, there are going
to be humans on board,

and so they're going to be testing
all the systems

for an eventual moon landing
from Artemis III onwards.

- OK.
- So, yeah, so Artemis II is
going back to a bit like Apollo 8,

the first mission where we
had humans going around the moon.

Now, it's quite interesting
talking about a moon base,

because as far as I'm concerned,

we've been talking about
moon bases almost forever,

since before we actually went
to the moon.

But it is a very exciting prospect
for me.

But it has got its challenges.

I think the temperature on the
moon's surface, for instance -

on the day side of the moon where
the sunlight is hitting it directly,

I think it's about plus 150 degrees,

but on the night side,
where the sunlight isn't hitting it,

it's about minus 150 degrees.

And so we need to make sort of
habitation and things like that

on the moon's surface that can
survive these extreme conditions.

And this time with the
Artemis mission,

we're going back to stay.

Now, I guess one of the challenges,
if we can send resources

- to the moon, that's going to be
expensive.
- Yeah, that's right.

I mean, think about it, you have
to take everything with you

to the moon. The moon doesn't have
an atmosphere, you can't breathe,

you can't go and stand
on the surface of the moon

and breathe what's there.

So you have to take all that
oxygen with you.

You have to take all your water
and all your food with you -

and that gets really, really heavy,

and it's already hard enough to get
to the moon by yourself.

So we want to be able
to use the resources

that are already available there.

So we've found that there is
actually ice inside the lunar dust,

the regolith,

and so perhaps we can use that.

- OK.
- We can use the resources
available on the moon to support us.

OK. That sounds very exciting -

and so now, to actually demonstrate
this in a little more detail,

what I'd like to do is actually
ask for a volunteer.

Any volunteers in the audience?

OK. I've got a chap with a
red jumper and a white shirt.

Yes, you.
Do you want to come on down?

Oh, look. It's you.

APPLAUSE

- Thank you.
- Thank you.
- Oh, pleasure.

So, first of all, what's your name?

- Nakul.
- Nakul?

- Very nice to meet you, Nakul.
- Nice to meet you too.

SHE LAUGHS

So what we're going to do
is we're talking about utilising

those lunar resources.

Meganne mentioned that on
the moon we have discovered water.

Now, what is the chemical make-up
of water? Does anyone know?

Actually, shout it out if you know.

H2O.

Good old H2O.

And so that translates
to hydrogen and oxygen.

Now, Meganne, you mentioned
that on the moon's surface

it has no atmosphere and so we need
to take our own supply.

Now, what we're taking
from our atmosphere is oxygen,

and that's what we need to breathe -

so the fact that water contains
oxygen is really useful.

But then we also
talk about hydrogen.

Now, hydrogen we can actually use
to fuel rockets,

and one of the nice ideas
about having a moon base

is we can use it as a staging post

to go to other parts
of the solar system.

The moon is smaller
than planet Earth, it has less mass,

so launching things from the moon's
surface should be cheaper

once you've got the base.

And so what we're going to do is try
and do a demonstration of that.

So we have actually some water
in this tube.

So what's going on here is a process
called electrolysis.

We're passing a current
through the water

and it's splitting it up
into hydrogen and oxygen.

And that's what you can
see bubbling out of this tube.

So what I want us to do
is launch our own rocket.

There is your rocket, and we're
going to launch it into space.

Now, I'm going to fill up the rocket
with fuel,

the oxygen and the hydrogen.

Then I'm going to put it
onto the launchpad.

Then what we need you to do
is actually launch the rocket.

Now, you do that by pressing
that red button,

but it's a press and a hold, because
I think many people realise here

that hydrogen and oxygen
are both flammable.

So you will set out the spark,
so you'll hold it down

and you'll have a spark,
and that will ignite the fuel

inside the canister
and whoosh to the stars.

So that's the plan.

Now, I'm going to give you some
ear defenders and also some glasses.

So I'll put these on too. Perfect.

- Now, for health and safety, you're
going to be the key operator.
- Yes.

So what we're going to do is, first
of all, I need to fuel our rocket.

So this is the rocket.

Now, it turns out that hydrogen
is lighter than air.

So if I take this out,
what I'm going to do

is count for ten seconds
to fill up the rocket with fuel.

So one, two...

..three, four,

five, six, seven,

eight, nine, ten.

OK, put that back in there.

Now, I've got to get on the
launchpad quickly

because I don't want
that gas escaping.

Ah, yeah, that's a reassuring click.

And then what I'm going to do
is I'm going to step back

and then what we're going to do
is count down from five,

and then you're going to press
and hold and we'll see what happens.

OK. So five...

..four, three,

two, one.

LOUD BANG

Whoa!

APPLAUSE

That's wonderful.
I'm just going to take this off.

So thank you so much. That was a
brilliant launch, very successful.

And congratulations -

and a round of applause
for our volunteer, please.

APPLAUSE

Thank you.

Thank you to all the astronauts.

Thank you so much for joining us and
sharing your experiences with us.

So I think an extra big round
of applause for our astronauts.

CHEERING AND APPLAUSE

Now, it's quite interesting
because I think many people

might not be aware, but every time
we do a Christmas lecture,

one of the things we do
is have a Youth Summit.

Now, there was someone here in the
audience that was actually at that,

one of those Youth Summits.

Now, Ella, I'm going to come up
and see you.

So excuse me. Oops!

Now, Ella, first of all,
can I ask you, how old are you?

So I am 17 years old.

- 17 years old.
- Yeah.
- OK.

- So you were at the London
Youth Summit, I believe.
- I was.

- You were speaking at it?
- I was
speaking at the Youth Summit, yeah.

Lovely. And so, what were you
talking about?

So I was talking
about the space economy.

It started off with governments,

- governments were running
the space industry.
- Yes.

And it wasn't until we
had billionaires,

that there were people who could
afford to ask that question of,

how do we turn this
into a business opportunity?

- OK.
- So we have Richard Branson,
who has founded Virgin Galactic.

They are looking at space tourism.

- So any of us could,
in theory, be a space tourist.
- Yes.

You also have Jeff Bezos,
CEO of Amazon

and now founder of Blue Origin.

One of Blue Origin's missions
is taking all infrastructure

- and heavy industries up
off of Earth and into space.
- Wow.

And so effectively
that would give us a greener future.

On the flip side, you have
Elon Musk, founder of SpaceX.

He is looking at
sending humanity to Mars.

He really created a shift
in this industry

because he developed
reusable rockets.

That is what caused the shift,

- because now millionaires
could access this industry.
- Ooh.

And there are a lot more
millionaires

than there are billionaires.
This is a transition period.

- This is the new space age.
- Fantastic.
- Yeah.

- Well, lovely to speak to you.
- It was nice speaking to you, Maggie.

And I wish I was doing this sort
of thing you're doing when I was 17.

- Well, yeah, maybe.
- Lovely to speak to you.

- And a round of applause.
Thank you.
- Thank you.

APPLAUSE

So we're exploring how we
utilise a moon base

to actually travel further
into the solar system -

and it just makes so much sense.

And so we're going to go
on in our journey,

but I think before we can understand
a sort of a life on another planet,

we need to get an understanding
of life right here on Earth.

And the thing is, we have a variety
of life here.

We have life up in the air,
we have life on the land,

we have life in the oceans,
a variety of life.

Now, what I'd like to do now
is to invite some people in

from the Natural History Museum -
Srishti and Chris.

APPLAUSE

Now, I'm quite excited by this,

because I'm usually talking about
things far away, the big universe -

and now we're going to...

We've got a microscope,
so that makes me very excited.

Now, Srishti, you've been going
around cemeteries

- and collecting samples.
- Yeah!

This makes me slightly worried.
So what have you got in the jar?

So this is moss from
Tower Hamlets Cemetery.

- So this is just normal moss?
- Just regular moss that we've...

Well, I did get them from
gravestones, but, you know.

We won't ask too many questions,
I think.

It was very easy, you just kind of
pick it up, yeah. It's not hard.

But why have you got this?
Why is this of interest?

So we were looking at moss
because there are actually animals

and other organisms living in this
moss that are very, very cool.

And you might not think, you know,

you can't really see much
in this right now,

but if you use a microscope,
you can actually see a whole world

of animals just living in it
that are just really tiny.

OK, lovely.

Chris, you're operating
the microscope,

and so you've got a sample
that was taken from this

- in the petri dish underneath.
- That's right.
- Fantastic.

So what are we seeing
in this microscopic world?

- So most of the life you can't see,
it's single celled organisms.
- Ah.

Too small even for this microscope.

- But we can see that there
is some life.
- Oh, yeah.

- So you see that little writhing,
snake-like form there?
- This one?

- Yeah. That one, yeah.
- So that's called a nematode.

This is a group of organisms that
occurs on all parts of the Earth,

wherever there is even a
little bit of liquid water,

bottom ocean, top of high mountains.

They've been found miles
beneath the Earth's surface.

So these things are
in that petri dish?

- From literally this exact moss,
as well, so...
- Yes!

There's another creature there
just creeping out of view.

Let's see if I can follow her.

Oh, yeah. There's our movie star.

So these are organisms
called tardigrades,

or, if you like, a more cuddly term,
water bears.

Water bears? Yes!

Why are they interesting?

They're really,
really cool creatures.

So moss has this property
where it dries out

and then it gets wet again,
and it goes through these cycles.

Animals like tardigrades are
specialised to be dealing with that,

so they can also dry out
and be completely fine.

And then when they're rehydrated,
they go back to normal.

- Can they go into more extreme
conditions?
- They really can -

and in fact they have been studied
for that purpose.

They were sent up to space, lots of
animals have been sent to space,

but these were the first ones
to be sent into a vacuum

and come out just fine, which is...

- Vacuum means that they
can't breathe.
- Yeah.

Lack of oxygen, extreme radiation,

weird temperatures, all of it.

So they are able to withstand very,
very difficult environments

which we would not be able to.

- Do we know how they survive
these environments?
- Yeah.

So they've got some specialisations
in the proteins that they make,

which are very specific to them,
that helps protect their cells,

and they have other proteins and
other methods

in which they can repair DNA damage,

which would happen when you have
a lot of radiation

or a lot of cold
or any of these things.

They enter this thing called a
tun state where they curl up,

they hide all their legs, they hide
their head in their cuticles

of their shells,
they sort of completely dry out.

And once they are in an environment
that's safe for them,

they rehydrate, they fix up all
the problems that they've had

and they carry on with their lives.

In fact, when they're
in this tun state,

they become so light
and so shrivelled up

that they become able to travel
vast distances by air

- so they can be blown away.
- Yes.

And that's why we find tardigrades
in lots and lots and lots

of different environments.

Maybe we could find them
in space one day

- just because they've blown up there.
- Yeah! Wow.

So, yeah, a fascinating world
going on around us

- that we're just not even aware of.
- Mm-hm.

Well, thank you so much,
Chris and Srishti.

But now what I'd like to do is
introduce another type of creature.

Ooh!

DR ADERIN-POCOCK LAUGHS

So, hello. Who is this?
Who am I addressing?

- Samara.
- Samara.

And so tell me a bit more
about Samara.

- And can I hold her?
- Yes, of course.
- Oh, gosh.

She's a nine-year-old
albino Burmese python.

She's weighing in about,
coming under seven stone.

Seven stone? Oh, my goodness.

- And just under 17 foot.
- 17 foot. OK. Which is why...

You've got about three foot,
we've got the rest of it.

OK. Lovely. Yes!

Fantastic.

And so... Wow, she's lively!

- She's warm.
- She's warm. Yes.

OK. Sorry, sorry!

Um, OK.

AUDIENCE LAUGHS

OK. Can you tell me more about her?

And, oh, she has adaptations.

She isn't trying to eat me, right?

- No. Absolutely not. She's just
giving you a lovely cuddle.
- Aw.

- I can uncurl her if you want me to?
- Oh, no.

No, no, I think I'm quite happy.

Yes, so tell me a bit more about her
and her adaptations.

Well, she's, they see a lot
in infrared.

- OK, lovely.
- Small amounts of infrared.

So, like, in the audience,
for example, there's lots of

red dots everywhere. That's what
she's detecting as food or prey.

OK. Don't worry, don't worry.

Detecting that, which she uses
with the pits in the nose,

which are all the little
sensors there.

- So eyesight is not 100%.
- Ah, yes.

- They more rely on the
heat signatures.
- Oh, lovely.

So, yeah, infrared energy
is heat energy,

- and she can detect those?
- Yes.

And any other adaptations?

SHE LAUGHS

- She's very good at holding
on to you.
- I know!

I do like a hug.

They certainly rely on the safety of
being able to hold on to something

- so they don't fall on the floor
or fall off a tree.
- Yes.

You know, they like to be relatively
high up because they feel safer.

Now, it's lovely to show you all
these different examples of life.

OK, I think I need to get
myself unwound.

And I think a round of applause
for our animal handlers.

APPLAUSE

So we are trying to search
for life out there -

but one of the things is,
we are finding planets

but what are the chances of life
actually emerging on another planet?

So one of the questions
we need to ask

is how did life start
right on this planet?

Now, to answer this question
and help me find out,

I'd like to invite
from the Natural History Museum

a cosmic mineralogist,
Professor Sara Russell.

APPLAUSE

Hi, Maggie.

LOUD ALARM WAILS

I'm sorry, I'm sorry.

OK, we weren't expecting that,
so please stay in your seats.

We'd better go up here.

LOUD BANG

Ooh.

So I think we can go
and investigate.

So, Sara, I think this
is more your domain than mine.

We've had a meteor strike
right here in the lecture theatre.

I can't see the hole
where it came in from,

but we'll worry about that later!

So, yes, this is sort of
the RI meteorite.

So I think what we're going to do
is going to lift it up

- so we can explore.
- OK.
- But this is
what you spend your time doing.

Absolutely. This is my day job.
I look at meteorites

which are any
natural extraterrestrial rock

that falls to the Earth

and survives its fall
through the atmosphere.

And, yeah, so meteorites can come
from anywhere,

- but most of them come
from asteroids...
- OK.

..and a few of them are from
the moon and a few are from Mars.

So they can tell us about all sorts
of environments beyond Earth.

- Lovely. So let's go in closer.
- Yes, OK. Great.

- I don't know if any of yours
do this?
- Ooh! No.

- You see, a flip top meteorite.
- Yes! They haven't had that upgrade!

OK, so now I've got a few things
inside which I'm going to show you.

- OK.
- Now, first of all,
I'm going to start with this.

- Now, the label says silicates.
- Silicates.

And to me it just looks like
a bit of sand.

Yes. Well, silicates are
what nearly all rocks are made of,

and so silicates make up most
of the Earth and also the moon.

Also, most meteorites
are made of silicates.

OK. So perfect. Let's see what else
I've got in here.

OK. I wasn't expecting this. It says
iron, but this is just an iron bar.

Have you found many
of these in meteorites?

- I'm going to put that on the table.
- Right.

None that look exactly
like an iron bar, I have to say -

but iron, as well, is a very
common ingredient of meteorites.

So on Earth, in its early history,
it melted,

and all of the iron
and other heavy metals went down

to form the Earth's core.

And that melting and
differentiation process

also happened on many asteroids,

which means that sometimes we can
sample their iron-rich core -

and that's exciting because we
can't actually dig down

and reach our own Earth's core,

but we can learn about what it's
made of by using meteorites.

Lovely.

I think we've got a few
other things in here as well.

- And so I've got something here,
I think that's a glycine.
- OK.

- And so these look like molecules.
- Yes, they are.

On a bigger scale than usual.

- Alanine.
- Alanine, yes.

- Now, these are something familiar.
But what actually are they?
- Yes.

So these are a very special kind
of molecule called amino acids.

- OK, lovely.
- So again these have been
found in meteorites.

So, yeah, not all meteorites,

but a very unusual type of meteorite
called a carbonaceous chondrite

can have a lot of organic material
in it.

And so molecules like this,

the amino acids are the building
blocks of proteins.

We find all sorts of organic
material in meteorites

- that could be the building blocks
of biological systems.
- Lovely.

So there is this theory
that life started out there,

and it was actually seeded on Earth
by things like this - meteorites.

Yes. That the ingredients
for life were in space

and then came to Earth
where life could begin.

Lovely.
OK, this is rather on a grand scale,

- but I think there was a meteor
strike right here in the UK.
- Yes.

- Not that long ago.
- Not that long ago.

Yes. So this was in February 2021.

This was in the middle
of the Covid lockdown,

if any of you remember that,

and on a clear night in February...

There's a fireball there.

..this massive fireball
was seen across the sky -

and this was witnessed
by over a thousand people.

So this image, what was...

- So that's a camera?
- Yes.

So this was a camera
that was actually designed

to look for exactly
this kind of event.

We have a network of cameras across
the UK looking up at the sky

all the time,
looking for this sort of thing,

because if we get observations
from several cameras,

we can work out two things.

- We can work out where this object
came from in space...
- OK.

..and also, if it's going
to be a meteorite,

we can work out where it's landed
so we can go and hunt for it.

So I can understand
where it's landed,

but you can actually
extrapolate backwards?

- You can backtrack, exactly...
- Oh, my goodness.

..to see what its trajectory was.

So this particular meteor originated

in the outer part of the
asteroid belt, out towards Jupiter.

Fantastic. OK, so this is sort of
professional footage

with dedicated cameras,

but I think there was footage
taken by other cameras, too.

Yes, absolutely. So this was a
really widely seen event

and several door cams, so these days
people have door cams...

- If you look at the corner.
- Oh, yeah.

They also caught
the meteor going, as well.

- So we have a huge amount of data.
- Lovely.

So you were saying you were sort of
using triangulation

and sort of looking
at the trajectory.

- So where did this one land?
- Yes.

So we worked out that this one
was going to land in the Cotswolds.

So it landed in a town called
Winchcombe, just outside Cheltenham.

- Hence the name.
- OK, lovely.

Meteorites are always named
after the place where they landed.

And I was expecting some sort
of impact crater, I guess.

- This is the result.
- This is the result.

So I don't know if you can see
what we're looking at here,

but the next morning,
the family opened their curtains,

the Wilcock family, and they saw
this big splat in their driveway.

THEY LAUGH

And this is where the meteorite
had landed -

and they very kindly donated both
the meteorite to our museum,

the Natural History Museum,
but also their driveway, which is...

- A section of their driveway?
- Yes.

It's just like a metre squared
section of their driveway.

Perfect. But, Sara,
before I say goodbye,

- I just wanted to ask one question.
- Yes.

Do you believe
that there's life out there?

You know, Maggie, I'm pretty sure
there is life out there,

because I think that meteorites
like Winchcombe

are relatively common
throughout the solar system,

and if they were impacting
the early Earth

and bringing ingredients there, they
would have also been impacting Mars

and other parts of the solar system,
as well.

And so I think it's out there.

OK, perfect.
Well, thank you very much.

And a round of applause for Sara,
please.

- Thank you.
- Thank you very much.

APPLAUSE

So we want to know if there's life
out there beyond the Earth -

and what we've discovered
over the last 30 years

is that one of the best places
to look is at planets

orbiting the distant stars
we see in the night sky.

We call these exoplanets.

To find out more, I'd like
to introduce my colleague

from the Sky At Night and planet
huntress, Dr George Dransfield.

APPLAUSE

So, George. You are... I called you
a sort of a planet huntress there.

- Is that an official title?
- Yeah, absolutely.

And this is what I do
for my day job.

I search for new planets
outside the solar system

orbiting any star
other than the sun.

OK. When I was at university,

we thought that there might be
exoplanets out there,

- but these stars are
trillions of kilometres away.
- Yeah.

So how do we go about actually
trying to search for life

on these exoplanets?

So, I mean, one of the key
indicators that we have right now

is trying to probe whether they have
an atmosphere or not,

and if there are signs in that
atmosphere of biological activity

- on the surface.
- OK. Lovely.

So to actually explore this
a bit further,

I want a bit of
audience participation.

If you look under your seats
you will find a piece of card,

and on that piece of card
there is an exoplanet on board.

So what I want you to do
is hold the exoplanet up,

the picture of the exoplanet,
so it's facing outwards,

but just have it up there
on your lap.

OK. Oh, gosh, that's quite amazing
actually.

We're just getting a wide array.

Now, each one of these is a true
exoplanet. Is that not the case?

Absolutely. This is a small subset
of the over 6,000 exoplanets

that we've discovered so far -

and I'm seeing some lovely
familiar names out there,

some of my favourites in the room.

You've got your exoplanet picture
in the front,

but on the back I think
you can see a table.

Now, what is this table telling us?

So one of the things that we do
when we want to select planets

to investigate and do a deep dive
and figure out

if they could maybe host life,

is we look at an archive
of planets that we have,

and we start to rule them out
based on certain parameters,

certain characteristics
that we've measured for them.

So we just try and say,
"OK, these ones, not a chance."

We just rule them out immediately
and we don't waste telescope time

- investigating them further.
- Yes.

So now, you've all got,
you're holding up your exoplanet.

What we're going to do
is we're going to start eliminating

exoplanets where we don't think
life is likely to be.

- So let's start
with our first parameter.
- Yeah.

So here we have Star Type.

That's the first one in your table.
So Star Type, what does that mean?

So one of the ways that we can
classify stars

is on a thing called
the spectral type.

So the spectral type tells you stuff
like how big the star is

and how hot the star is,
what it's made of, stuff like that -

and what I would never do
is search for life

on a planet around
an O, a B or an A-type star.

OK, so we've got O, B or A.

So if you have O, B or A
as your star type,

please put your card down
into your lap.

You have been eliminated,
unfortunately.

We think it's unlikely
that you'll find life there.

OK, so I think that's all been done.

So we've lost a few -
but not that many.

Actually, we've still got a good,
healthy population

- to continue the search for life.
- Yeah, absolutely.

And the thing is, you know,
these stars,

they're actually hard
to form planets around anyway.

They're very, very young,
they're very hot,

they wouldn't be a great
environment.

So next we have Eccentricity.
What does that mean?

So eccentricity tells us something
about the shape of the orbit

- as the planet orbits its star.
- Lovely. OK.

If your eccentricity
is greater than 0.7,

then please put your cards down. OK?

OK. We're seeing some going down.

OK, we've still got quite
a healthy population.

So why are we eliminating
these planets

if their eccentricity
is greater than 0.7?

So eccentricity, like I said before,

it tells us something about
the shape of the orbit,

and so we're thinking about
how squashed out,

how elongated is the shape
of the orbit.

So the value can be
from zero to one.

If it's zero,
it means it's a perfect circle,

but the bigger the number,
the more stretched out it'll be -

and what that means is that
sometimes the planet

will be really close to its star,

and sometimes it'll be
really far away.

So you get huge variation
in temperature,

which means that it's difficult
to get the stability you need

for life, as we know it at least,
to develop.

So let's see what we have next
on our criteria.

So now we have Planet Radius. OK.

So this is quite simple.

This is the size of the planet
compared to Earth.

OK. Lovely. And so now,
we need to see the criteria. OK.

So anything greater than
2.5 times the size of Earth.

So anything two and a half times
bigger than Earth

we're going to eliminate.

So will you put your cards down

if you're two and a half times
bigger than Earth?

- OK. OK.
- So when we're thinking
about, again, life as we know it,

we believe that life as we know it,
so far at least,

requires liquid water. So we've got
to think, what are the chances

of there being liquid water
on the surface of this planet?

And so things that are bigger
than two and a half times the size

of Earth, we think they're most
likely going to be gas dominated.

And so we think that this is now
challenging

- to host life as we know it.
- OK. Lovely.

OK. So we've got one more criteria -

and I must admit I don't
recognise this word - Insolation.

Yes. So insolation
or insolation flux -

and this tells us how much energy
the planet is receiving

from its host star. Again,
we measure it compared to Earth.

So let's have the criteria. Yeah.

Yes. So the criteria
is less than 0.4

or greater than 1.5.

So if you're less than 0.4
or greater than 1.5,

please put your cards down.

OK. Oh, gosh. That was quite
a decimator, wasn't it?

Yeah. That one knocked out a lot.

- OK, lovely.
We still have a few left.
- Yeah.

OK, so tell me a bit more
about this.

So this is the amount of radiation
actually reaching the Earth?

Yes, exactly. So we're looking now
at the kind of the nitty gritty.

This is what's called the
optimistic habitable zone.

So the habitable zone is this kind
of area that we define around a star

that tells us whether it could be
the right temperature

on the surface of the planet
to have liquid water.

So if your planet receives

between 0.4 and 1.5 times
the insulation of Earth,

it means that you are
in the optimistic habitable zone

of your star.

So congratulations. You maybe have
some liquid water on the surface.

But I do want to give
a shout out to a planet up here.

- So this is another one...
- Why is this one special?

This one is very special to me.

It's called TOI-715 b.

It's about 137 light years away -

and the reason I love this one

is it's because it's the first
habitable zone planet

that I led the discovery of.

- Oh, right!
- Yeah. So this one has my
name on the paper for the discovery.

- So why isn't it George's Planet?
- Oh, I wish!

But, no, we actually have a
convention for naming planets

where it's the star name followed by
a lowercase letter, starting with b.

But it's a lovely little thing.

It's about one and a half times
the size of Earth,

and like I said,
137 light years away,

which in astronomical terms
is really, really close.

- So it's a great candidate to search
for life.
- Thank you, George -

but before you go,
the question I keep on asking,

do you believe
there's life out there?

Oh, absolutely. I mean, one of
the things that kind of guides

our understanding of the universe
is that the laws of physics

apply the same
all over the universe,

so there is nothing special
about this place and time,

and therefore life must
have happened elsewhere.

OK, fantastic.

- I think around a round of applause
for our planet hunter.
- Thank you.

APPLAUSE

In the next lecture, we're going to
be exploring our own solar system,

looking to see if there could be
life on the planets

orbiting our local star - the sun.

Now, we don't have a star to bring
in here into the lecture theatre,

but we have the next best thing...

BLOWTORCH HISSES

..a traditional
Royal Institution demo

created using burning phosphorus -

and it's known as phosphorus sun.

Let's stand back
and bask in its glow.

Thank you very much.

APPLAUSE

Think you've got what it takes
to run a space mission?

Step into command
with the Open University's

interactive experience and meet
the experts that make it happen.

Scan the QR code on the screen

or visit connect.open.ac.uk/ri2025