Original subtitles

On Christmas Day 2021, the largest space telescope ever built

was launched into space.

This was the James Webb Space Telescope.

It does amazing things.

It looks at the formation of galaxies.

It looks at some of the earliest stars

and also the planets going around those stars.

But most crucially, it's probably our best tool

for finding alien planets,

and possibly the aliens themselves.

So we're going to continue our journey

from the Solar System, through our galaxy

and out to the known universe

as we continue asking the question,

"Are we alone?"

Leaving Earth's orbit.

Houston, we have a problem.

Take third exit to Mars.

Mars rover collected.

Warning.

James Webb Telescope acquired.

Navigate off-road.

Voyager probe acquired.

Approaching light speed.

APPLAUSE

Welcome to the 200th anniversary of the Christmas Lectures

from right here in the Royal Institution,

supported by CGI.

Now, my name is Dame Dr Maggie Aderin-Pocock,

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

Now, I've built instrumentation

that help us to better understand the universe.

Now, going back to that Christmas Day in 2021,

my daughter, who was then 11, was opening her presents.

I was distracted.

All I wanted from Santa was the safe launch

of the Webb Telescope into space -

a huge global project in which I played a small part.

Now, the main feature of any telescope is, of course, its mirror.

And of course, the bigger the mirror,

the more light it can gather.

Now, this is the size of the Hubble Space Telescope.

It is 2.4 metres in diameter.

You can see it's a lot taller than me.

Now, Hubble sits in low Earth orbit -

about 500km above sea level -

and from there, it's taken some fantastic images of the universe

and transformed our knowledge.

But this...

..is the Webb Telescope,

and this is actual size -

18 segments all put together to make this fantastic mirror.

Now, James Webb is detecting infrared light,

and infrared radiation has a much bigger wavelength.

But the challenge is this -

how do you get something this size,

along with a heat shield, into space?

Well, to explain that, we use origami and inspiration from nature.

So this is the James Webb Space Telescope,

and as you can see, it's unfurling here.

So there's the mirror.

This is the giant heat shield,

protecting it from radiation from the Sun and Earth.

And what it's doing is deploying all these mechanisms

so that it can be ready to detect infrared light out there.

The final bit's the mirror coming into place,

just as we've done here.

Thanks, guys.

Now, unlike Hubble,

Webb sits 1.5 million kilometres away from Earth.

But why go to the trouble of sending a telescope

out into space, so far away?

Well, Webb's location is needed

partly because it needs to be up above the atmosphere.

The atmosphere absorbs infrared light,

so we need to get it up above the atmosphere

so Webb can do its work detecting that light.

But my favourite thing about James Webb

is the wonderful pictures it takes.

And here are my top three pictures.

Coming in at number three - this is the first image,

and it's actually of the planet Neptune.

But one of the things we can see is one of the rings around Neptune.

Now, many people don't realise but all the outer planets,

from Jupiter onwards, they all have rings.

We know about Saturn's rings,

but we don't often see the rings of the other planets.

But using this infrared light, we suddenly see a familiar planet

but in a detail that we're not used to.

OK. Coming in at number two - it's this image.

Now, this image is looking back through time.

So this is showing us sort of ancient galaxies.

So, many of these galaxies no longer exist,

but what we're seeing here is a number of different stars,

and this is some of the earliest galaxies that ever formed.

But my favourite picture is called the Pillars of Creation.

Now, this was first photographed back in the 1920s

by a scientist called John C Duncan,

and he used a black-and-white photographic plate.

Now, the image we have here

is actually taken by the Hubble Space Telescope.

But now, this is the Hubble image,

so we're looking at invisible light,

but let's fade that

into the James Webb Space Telescope image,

and suddenly we're seeing a lot more stars.

So, see, these stars are giving out lots of infrared energy.

Also, I'm going to come around this side

because these are the Pillars of Creation.

And up here and here, we've got these red areas,

and these are known as stellar nurseries.

These are where new stars are being born.

So that's the joy of it -

with the James Webb Space Telescope,

we're looking at our universe but in a slightly different way.

So these images are absolutely glorious,

but what if you could transcend our atmosphere

and experience first-hand that view from space,

just as Hubble and Webb do?

Now, to hear from someone who has actually made that journey,

I would like to invite to the theatre

the astronaut Tim Peake.

CHEERING AND APPLAUSE

Hello, Maggie. How are you?

- Hello, Maggie. - Hello, Tim.

Now, what we've got going on behind us,

- because it's nearly ten years to the day... - Yes.

- ..since you launched into space... - Yes.

..and last time you did a Christmas Lecture...

Because you've done one before!

But last time you did a Christmas Lecture,

you actually did it from the International Space Station.

- That's right. - Is it good to be here in the theatre now?

Oh, it's fantastic to actually be back down on Earth.

But I have to say, I did enjoy my time up in space,

and that was so exciting to be able to come down in 2015

and join you from the International Space Station.

Now, one of the things that I've heard when I speak to astronauts

is that when you're living on the International Space Station,

one of the places that people love to go

is something called the Cupola.

- That's right. - Yeah. Now, can you explain what that is?

Absolutely. So this is the International Space Station,

and this is the front of it.

So imagine that the Space Station is flying towards us out the screen.

But if we rotate this 90 degrees,

we'll look down the length of the Space Station.

And actually, this thing's about the size of a football pitch,

so it's quite big.

But whenever you get any free time at all,

all the astronauts, we like to grab a camera

and go to this cupola window here.

- OK, so that's that nodule there. - That's right.

If we turn it a bit more, we'll see it a bit more clearly.

And the reason being is, as the space station orbits the Earth,

we constantly pitch down like that.

- So this cupola window, it's always facing planet Earth. - Ooh!

And so when we go there,

you can fit your entire body into that window, actually,

and just look down and see the stunning view beneath you.

It's constantly changing, by day, by night.

We never get bored.

And by the daytime, you just see all of Earth's geology -

the deserts, the mountains, the cloud formations,

the stunning colours of planet Earth.

And then by night-time, it's so easy to see that

we live on a planet of... inhabited, you know,

people who've discovered electricity because we see the cities,

the motorways, the lights and everything.

And also, we see thunderstorms, we see the aurora,

the Northern Lights, the Southern Lights,

- and it's utterly magnificent. - Oh, yes.

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

So just that description... Just, whoa!

Do you think it changes your perspective

to see the universe spread out in front of you like that?

Oh, it completely changes your perspective of our planet,

because you see it against the vast black backdrop of space,

but also it changes your perspective of, "Is there life out there?"

When you see that abundance of stars in our galaxy,

it does make you think, you know,

there has to be life out there somewhere.

So you're a believer,

you do believe there's life out there?

I am a believer, yes.

I love it. Optimism - that's what we need.

Thank you so much, Tim.

- And I think you'll be joining us again later. - Excellent.

- Thank you very much. - So we'll see you shortly. - See you in a bit.

- Bye-bye. - Thank you.

CHEERING AND APPLAUSE

So Tim went to the International Space Station,

which sits about 500km above sea level.

But on our hunt for alien life,

we're going to need to go much, much, much further.

And so our new playground is our home galaxy, the Milky Way.

So bring on the galaxy!

And here it is.

Our home galaxy, the Milky Way.

Now, we call it the Milky Way

but if we look back at other cultures and back through time,

other people have called it other names.

In the Kalahari Desert in Africa,

it was known as the Backbone of the Night.

Now, the name Milky Way actually stems from

a Greek legend which was about Hera,

a goddess who was breast-feeding the infant Hercules.

And what happened is Hercules came away from her breast

and the breast milk spilt across the sky,

and they say that's what formed the Milky Way galaxy.

But it is actually gorgeous.

And it is a collection of many, many, many stars.

One of the questions is, where are we in this Milky Way galaxy?

And I think I've got... Thank you very much.

And I think I've got a little "you are here" sign,

and that sits about here.

So we are in one of the spiral arms of this amazing galaxy.

Now, how do we know that?

And one of the things is we believe that the galaxy looks like this,

but we've never actually taken an image of our whole galaxy.

That's because the galaxy is so huge,

we can't travel far enough away from it to take the whole picture.

But what we can do is we can look out into space

and see other spiral galaxies,

and we're pretty convinced that this is the view.

We are in one of the spiral arms of our galaxy.

Now, humans have mapped the stars for thousands of years -

from the ancient Babylonians, who'd draw pictures,

to the last century where we were using photographic plates.

But now we know more about the galaxy than ever before,

thanks to a spacecraft called Gaia.

So Gaia has been out there in space for 12 years now,

and it's created the most detailed 3D map of the Milky Way

that we've ever made before.

Now, to find out more about this

and discover what Gaia has found out so far,

I'm thrilled to invite to the stage

my Sky At Night co-presenter

and galactic scientist, Professor Chris Lintott.

CHEERING AND APPLAUSE

Hello! Hello!

How are you?

- Good crowd, good crowd. - Good crowd!

Nice spaceship!

- Hey...! - Careful!

CHUCKLING

This is great.

- You should stay here all the time. - I know!

- Actually... Yeah, this is my home away from home now. - Good, OK.

- Good, good. - You can come on board whenever you like. - Fab.

Thanks, Maggie.

So tell us a bit more about Gaia.

First of all, how does it work?

Actually, sorry - just to start with,

this is the Gaia spacecraft sitting out there in space.

Yeah, so the magic thing about Gaia is it's only

a small telescope, but it does a really clever thing.

It measures the distance to stars,

and I can show you how it does that

with nothing more complicated than your finger.

- OK. - So if everyone in the audience and everyone at home gets a finger,

and I want you to line it up with something in the background,

and then I want you to shut one eye

and then switch to the other eye,

and you can go back and forth,

- and what you see is the finger jumps from one side to the other. - Yeah.

- So the background seems to change quite radically. - That's right.

Exactly. And then if you move the finger further away,

so at arm's length, and you do the same thing -

so one eye, then the other eye, and then back -

what you see is that the finger still moves but a bit less.

OK, lovely. OK, so let's go to the ultimate distance.

I'm standing here on the stage, and if you look at me

and then shut one eye, and then the other eye,

you can see that the distance is now quite small.

The background hardly seems to move behind me.

So that means by measuring that shift,

if you observe something from two different positions,

you can get a distance, and that's what Gaia does.

- Now, the trouble is, the stars are a long way away. - Yes.

So the shift is really small.

And so it uses not two eyes but two sides of the Earth's orbit.

So it observes the same stars six months apart,

and then we get the distance.

So we get a three-dimensional map of the galaxy,

- but we can also measure how the stars are moving. - OK.

So we can see the velocity of things as well.

Lovely. So that's it.

So Gaia has been out there for 12 years.

So what's it been telling us?

Well, my favourite thing is that we can predict the future.

- Ooh! - So this is a map of the million nearest stars in the Milky Way.

And we can show you the next 1.6 million years.

- OK. - So this is the future of the night sky,

- because the galaxy is changing. It's evolving. - Oh!

So we think of the stars of the night sky as static,

but this is projecting into the future.

That's right, and my favourite thing is,

- you can see these fast ones that zip around. - Yes, nip round.

They're popping in and out of the pancake of the Milky Way.

- So they're rather special stars. - Oh!

- But because we can do this forwards... - Yes.

- ..we can also go backwards. - OK.

And so we can plot the past of all the stars in the Milky Way,

and that's told us that our galaxy is assembled violently.

- It eats other galaxies. - What?!

And we see these streams of stars,

which are like the leftover dessert.

So they're remnants of galaxies that our galaxy has consumed.

And they've got brilliant names, these old galaxies that we've eaten.

There's one called the Kraken, which is a sea monster.

My favourite is one called the Gaia-Enceladus-Sausage,

which is just lovely.

- But there's something special that happened 5 billion years ago. - OK.

So this is the Sagittarius Dwarf Galaxy.

- This is a simulation. - So this is a cluster of stars.

Yeah, and 5 billion years ago,

or 6 billion years ago, it came close to the Milky Way.

The Milky Way sparkles,

and this thing gets flung out.

It stretches out into this beautiful stream.

And then, 2 billion years ago, it comes close again.

And today we see it in the Gaia data

- as these long streams of stars. - Yes.

But what's special is that...

- I said 5 or 6 billion years ago. - Yes.

Now, that's the time that the Sun was forming,

and this encounter with this tiny galaxy

may have kick-started a lot of star formation in the galaxy

and it may be the reason that we're here.

Our sun might have formed in a burst of star formation

that was formed by the Sagittarius Dwarf.

So that's the spark we saw earlier.

So what I want to ask you is, in the current time,

how many stars do we think are in our galaxy?

Gaia's looked at 2 billion stars.

- Right, yes. - And that's a fraction of the whole.

So we think our galaxy has got between

- about 100 billion... - OK. - ..and 400 billion.

- We're very bad at counting the small ones... - Yes.

..but let's say at least 100 billion stars

- and you won't go wrong with that. - OK. Lovely.

So I'm going to take as our baseline 100 billion stars,

and that's in our galaxy,

and so that is a heck of a lot of stars.

- It is. - Thank you, Chris. You're going to join us later,

but thank you so much for joining me now.

See you soon. Thank you.

APPLAUSE

So we settled on the number of around,

you know, give or take, 100 billion.

And so that is quite a mind-boggling number.

But now what we're trying to do is detect exoplanets,

planets going around the distant stars we see in the night sky.

And of course, if they are reflecting

the light from their local star,

we can barely make out the star -

how are we going to see that reflected light?

So we need another way of detecting exoplanets,

and we need to get clever.

So, first of all, I'd like to introduce another method,

and we call it the wobble method,

and I think you'll see why.

And so, for this, I need to call down a volunteer.

OK, perfect. I think, yes, would you like to come up?

Yes, please.

I just love your hat.

APPLAUSE

So, first of all... Yes.

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

- Liam. - Liam. Thank you very much, Liam.

Now, what we're going to do is we're going to try

and detect exoplanets.

But first of all, if you'd like to stand in front of this star.

So what we have here is a star.

And it's a star, a distant star,

trillions of kilometres away from us.

So we can't see the exoplanets going around the stars,

but we can see the stars themselves.

Now, first of all, we've got this star

and it hasn't got an exoplanet around it.

Now, I don't know... See how it's hooked there?

What I'm going to do is we're going to give you a countdown,

and then - after three, two, one - I want you to unhook it

and we're going to see what happens to this star.

OK. So are we ready?

Three, two, one...

Ah, yes. You have to... Yes.

OK, so just like our star,

this star is spinning on its axis.

But as you can see, there's not much movement there.

It seems to be spinning on its axis and we're not getting much wobble.

So that is a standard star without an exoplanet going around it.

But of course, we have exhibit two.

Now, this is a star

but now we have an exoplanet in orbit around this star.

And what we want to do is compare the movement of this star

with the movement of that star.

So, are we ready?

OK. So...

Three, two, one...

It's fiddly, but here it goes.

And so now, do you see what's happening?

The star is wobbling and gyrating

because of the presence of the exoplanet.

It makes it unstable

and so it sort of moves around in this way.

And now, we can't see the exoplanet from space,

but we can see the star wobbling because we do see the stars.

And so this is what we're looking for -

the wobbling of stars -

and that indicates that there might be an exoplanet in orbit about it.

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

Thank you very much.

CHEERING AND APPLAUSE

So this seems like a great way of detecting exoplanets,

but the problem is we can only detect the larger exoplanets

and so we're talking about sort of Jupiter-mass exoplanets

and in tight orbits around their star.

But that's not really what we're looking for.

We're looking for Earth-like planets with sort of a broader orbit,

because they will sit in the habitable zone.

And so we have another method,

and that's called the transit method.

And funnily enough, we have a demonstration for that, too.

So now, once again, we have our star in the middle,

and now, I think, back here, you might be able to see

we have an exoplanet in orbit.

And what I'm going to do, if I press the right button..

OK. Our exoplanet is orbiting around the star.

Now, imagine that we are back here on planet Earth,

and we're looking up at this exoplanet in space.

The star itself is giving out a lot of light,

but what we have here is a meter sitting on planet Earth.

OK, yeah, so we're just going to dim all the lights.

And this is actually reading out what this light meter is detecting.

So, at the moment, it's about sort of 37, 38,

but when the exoplanet goes between the star and us,

we should hopefully see the light signal dip down.

So, there we go. Did you see it?

It went down to 15 and then it came back up again.

And so we can detect exoplanets this way, using this transit method

as the exoplanet goes in front of the star.

And this is actually closer to the data we really get.

We actually have what we call a light curve,

and it shows how the light changes as the exoplanet goes in front.

So here it is. So that's without the exoplanet.

That's the exoplanet going in front of the star.

And then the light level goes back up as it comes out the other end.

And so that is the transit method.

But using the transit method,

we can tell a lot about what we're observing.

And so, as the exoplanet goes in front of the star,

depending on how much starlight is blocked out,

we can actually get an indication of how big that exoplanet is,

how big its orbit is around the star.

We can tell a lot of things about it

just by looking at this light curve.

And using this technique,

we have found many thousands of exoplanets.

So, to date, we've got about sort of 6,000 in the bag.

OK.

So, using the transit method, one of the questions

we're trying to ask is, "Are they habitable?"

And so how do we find that out?

Well, it turns out that the transit method can help us with that, too.

And for this, we've got another demonstration to show you.

It's all based on something called spectroscopy,

because what we can do is actually,

as the starlight passes through the atmosphere of an exoplanet,

it's a tiny, tiny fraction of starlight,

but we can actually look at that starlight

and analyse what elements are in the atmosphere

of an exoplanet trillions of kilometres away.

So what we're doing here is mimicking

that transit method that we discussed earlier.

So what we have here is a bright source,

and that is representing the local star

that the exoplanet is going around.

Then here, we have the atmosphere of the exoplanet.

OK. Then, over here, what we're doing is we're taking the light

from the star that's passing through the exoplanet's atmosphere

and we're analysing it.

We're using this technique called spectroscopy.

So let's dim the lights.

Let's set that atmosphere alight.

OK.

So now, here we have our spectrum of colours.

So, as it passes through this piece of equipment called a grating,

it is stretching the light out into its component colours.

And we can see that on the board here.

Now, Fergal, what you're going to do is you're going to add

a compound to that atmosphere, aren't you?

- Yep. - And it's going to burn.

So what compound are you adding?

So this is sodium bicarbonate.

- Sodium bicarbonate. - The same stuff you would put in cakes.

Now, what happens is, as we add that to the atmosphere,

some of the starlight will pass through the atmosphere,

but with the sodium bicarbonate,

because it's a sodium-based compound,

we will actually get absorption.

And so, as Fergal adds the sodium bicarbonate,

we get a dark band.

Now, that is known as an absorption band.

OK, yeah, I don't know if you can see it just there.

And so, as you can see, the flame is burning very yellow.

Sodium compounds sort of absorb that yellow light,

and that's what we're seeing here -

the absorption of that sodium band.

So, thank you very much, Fergal.

So that's what's happening in the atmosphere.

The starlight of the distant star,

it passes through the atmosphere of the exoplanet,

and depending on what sort of compounds are in that atmosphere,

some of the light will be absorbed,

and we can actually see that here.

And this is what we were seeing.

So I don't know if you noticed the band was sort of in the yellow,

and so that's probably the yellow sodium doublet there.

But other compounds sort of also produce these absorption bands.

And so we've got sodium there, we've got nitrogen.

Here's hydrogen.

And these are where the absorption bands occur.

So when we look at an atmosphere,

we get a distinct fingerprint of these absorption bands, and that

tells us the chemical composition that that atmosphere has.

Now, remember, these are exoplanets

trillions of kilometres away from us,

and yet we can actually do some remote-controlled chemistry

and work out what the composition is.

Thank you so much, guys.

Now, analysing the atmosphere of exoplanets

can tell us whether they might be habitable,

but can it actually detect life itself?

Well, not exactly, but it can give us an indicator.

There are certain molecules that occur on exoplanets

and right here on planet Earth

that are what we call biosignatures.

Also, they're quite unstable, so they break down quite quickly.

So when we see one of these molecules in an exoplanet

far, far away, the question is, have they been generated by life?

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

from the University of Cambridge, Professor Nikku Madhusudhan.

CHEERING AND APPLAUSE

- Now, Madhu, if I may... - Yes. - Thank you.

Now, tell me about....

Because you made the headlines earlier this year.

You made the headlines because of a planet called K2-18b.

Now, this is an exoplanet,

and what you detected was, I guess, a biomarker.

So can you tell me about this?

So this planet, K2-18b, is about nine Earth masses in mass.

- So, quite big. - It's quite a big planet,

and two-and-a-half times the size of the Earth.

So, two years ago, we had already made the first detections

of carbon-bearing molecules in this planet -

methane and carbon dioxide.

So we think this is what is known as a Hycean world,

it is the possibility, that it's

an ocean-covered surface with a hydrogen-rich atmosphere,

and that it could be habitable.

- OK. - In other words, the conditions in the oceans

could be conducive for life.

So, already, two years ago, we saw a tentative hint of this molecule

called dimethyl sulphide in the atmosphere of this planet.

We weren't sure at that time, but this year, what we published was

a second observation with a different instrument,

- where we continue to see tentative hints of this molecule. - Oh, OK.

Now, DMS is interesting because it's

a molecule produced primarily by life.

- Now, on Earth, this is, I guess, plankton. - Right.

OK, so these are microscopic organisms

that live in the ocean, and they produce the molecule DMS.

- That's right. - And the fact that we found this compound

on another planet, it does seem incredibly exciting.

One of the questions we have asked throughout time - "Are we alone?"

- And this is getting closer to answering that. - That's right.

The excitement here is that

even though we are at the very early stage

and it's too early to claim that we have detected life,

the fact that we are seeing molecules like this

means we have the technology

to be able to detect biomarkers in exoplanets.

This particular planet is hundreds of trillions of miles away.

So the fact that we're able to detect even a tentative hint

of such a planet from such a distance is immense.

And that leaves the door open to

what else we can discover on such planets.

Yes, and the fact that these observations

are coming through the James Webb Space Telescope.

This is the best piece of equipment we have out there.

But of course, we have other things in the planning,

and so maybe these sort of detections

might be easier in the future.

Yeah. The search for life is such a fundamental quest

that no amount of observation time is going to

satisfy our curiosity to look for what else is out there.

So, thank you very much, Madhu.

- But don't go yet. If you'd like to step this way. - Yes.

We have a little bit of fun for you in the audience

because we've talked about

the possibility that sort of life is out there,

but what would creatures like that look like?

Would we just find biological organisms or something very simple,

or what would alien life actually look like out there?

And so what I want you to do is join me in a game show,

and the game show is called

Draw That Alien!

OK.

Thank you very much.

CHEERING AND APPLAUSE

Thank you.

This is me getting into game show host mode.

Now, first of all, I'd like to invite Tim Peake back to the stage.

Come on down, Tim!

- CHEERING AND APPLAUSE - Thank you very much. - Thank you.

So, Madhu, please, you're going to be part of the hosts for

Draw That Alien!

OK. So, first of all, we are going to break up

this lecture theatre into three parts.

You, middle section, you are my section.

Tim, this is your section.

And Madhu, this is your section.

Now, what I'm going to do for each section,

I'm going to give you a real exoplanet,

and I'm going to tell you the tentative information

that we have about each of the exoplanets.

And so what I want you to do is, when I describe this planet,

I want you to draw that alien! OK.

Now, let's start with my section.

Our planet is K2-18b.

Now, it's a water world.

So start drawing the alien.

What sort of alien do you think might be on a water world?

Now, what do we know about this planet?

Well, the information is a little tenuous,

but we think its size

is somewhere between Earth and Neptune.

So it's like a super-Earth

or sort of a Hycean planet, as we mentioned.

It has an atmosphere, probably, which is thick in hydrogen,

and it's mostly completely covered in water,

and the average temperature is probably about zero degrees.

Tim, were coming over to your section. Perfect.

Now, you have TRAPPIST-1e,

- one of the planets of the TRAPPIST system. - Yeah.

OK. Now, TRAPPIST-1e is a rocky planet.

And let me give you a bit more information about this.

Now, its size is quite similar to Earth,

so this is looking quite promising.

- It sits in the habitable zone of its stars. - Excellent.

But unfortunately, it has a violent star.

This means extreme radiation.

OK. Madhu, over to your section.

Now, your planet is LHS 1140 b.

Now, this is an ice planet.

Now, this is called a super-Earth

because its diameter is about two times the size of Earth.

We think it's got an icy surface,

but it is very, very windy.

But it has a light, puffy atmosphere,

mainly made out of hydrogen and helium.

Now, in the meantime, I'm going to come and see my section.

So I'm coming up here.

So, how are your pictures coming along?

What have we got?

OK. Lovely. I can see...

Ooh, gosh!

I can see a lot of artistic interpretation here.

Now, what I need to do is select...

So can you hold them up so I can see them?

Fantastic. Ooh!

OK. Oh, my goodness!

I've got to choose one as an example to bring down.

Ooh, my! Ooh!

Actually, I quite like that one.

Yes, with the two googly eyes.

Thank you. Can you pass that up?

Thank you very much. Very artistic.

Fantastic. Thank you.

So, in a minute, I'm going to cause a halt,

but I'm going to take this one down.

Tim, how are you doing?

- We're doing great over here. - OK. - Thanks, Maggie.

- Yeah. - I think your time is almost up. Select your alien

- and bring it on down. - OK.

Yeah. Let's go for this one.

There we go. Thank you very much.

Madhu, how is your section doing?

- Lots of choices here. - Lots of choices.

LAUGHTER

I know. It is very hard.

- My apologies. - Very, very, creative.

Yeah, that one. Yeah.

OK, yeah. Pass it along, please. Thank you.

So, guys, thank you so much

for participating in Draw That Alien!

OK. Let's look at the results.

- OK. - So, Tim, I think we'll start with you.

- Right. Are we ready? - Show me the alien on your planet.

TRAPPIST-1e.

Here we go. There we are.

We've got an alien that clearly has

to protect itself from radiation.

- Yes. - So it's already developed

this complex life form that has shelter.

OK, yes. Built-in umbrella.

Has the ability to walk on the rocky planet, obviously,

and support its own body weight on that planet as well.

- Fantastic. - So there we have it, TRAPPIST-1e. - So there we have it.

Yes, that is the alien.

And Madhu, what do you have?

So we have a simple tardigrade-like planet.

You want to go simple on this planet.

- We didn't want to make too many guesses... - OK.

..too much complexity.

- So I'm happy with that, yeah. - So you've gone... Yeah...

- Simple life form on an ice-covered planet. - Yes.

OK, perfect. And water.

And we've heard that tardigrades can survive sort of very extreme...

Harsh conditions, yes.

OK. And this is what I got from my group.

Let's get it the right way.

Very good, I think, artistics here.

And I'm going to put that in.

And what do we have here?

So we have a sort of bulbous alien with a number of tentacles.

I love the eyes.

And the eyes are quite spread out,

and so it gives it sort of a good viewpoint.

So I think those are wonderful examples

of alien life on other planets.

So I think a round of applause for everybody who drew an alien.

APPLAUSE

But first of all, I wanted to say

that now each of you is an astrobiologist,

because astrobiology is the science of trying to work out

what kind of alien life you'd find on these exoplanets.

So pat yourselves on the back.

You're astrobiologists now.

But now, this is the bit I've been waiting for most

because I think, Tim, you, and you, Madhu,

have drawn your own alien, and I must admit, I've drawn mine, too.

- So, Tim... - OK.

..let's put these down,

and could you get out the alien you drew?

So this is an alien living on your planet.

Yes, yeah. So this was my alien on TRAPPIST-1e

that I drew earlier.

Fantastic. Madhu, what have you got?

So this was actually drawn by you, wasn't it?

We tried!

HE LAUGHS

- So do you want to put it in the stand? - Er, yeah.

With all the courage I can muster.

Actually, this is your worst nightmare, wasn't it?

- Happy as scientists! - It was indeed.

Science is the easy part.

THEY LAUGH

Maggie, did you draw one?

Oh, me? Well, actually, I didn't have much time.

- Right. - So I just threw something together.

- Oh, OK. - But I've just got it here.

And, um, yeah, so it's a bit rough.

- So, yeah, apologies. - Oh!

- Yeah. - Oh, right. - Right, right.

This is just something I threw together.

Not much time. Let's just put that there.

OK. So if we were going to vote, I wonder whose would be best.

Did you really...? Did you draw that?

I think that's enough of that!

Thank you so much for participating.

I think that's enough of Draw That Alien!

APPLAUSE

Thank you.

I'd better not be a game show host any more!

So, thank you both, guys.

- Thank you very much. - And I think I'll be seeing you again later.

- Thank you. - Thank you. - Thank you.

So we've been talking about the search for alien life out there,

looking at what compounds might be found in an atmosphere

of an exoplanet far, far away.

But what if we wanted to actually go out and find these aliens?

Now, our nearest exoplanet is Proxima b,

and it's actually a rocky world,

and it's about sort of 4.2 light years away from Earth.

Now, that sounds like it's worth a visit,

but just how far away is that?

So a light year is actually the distance

that light will travel in one year.

And that turns out to be

9.5 trillion kilometres.

So that's 9.5 with 11 zeros after it.

So, there it is.

So the distance to our next-door neighbour star

is 40 trillion kilometres.

So what if we wanted to travel there?

Until recently, the fastest we could travel in space

was about 1,600 metres per second.

It's nowhere near the speed of light,

but it's still pretty quick.

Now, if we could travel at that speed,

and travel out towards Proxima Centauri,

that journey would actually take

76,000 years.

And that's just going from our star to the next-door neighbour star.

So what we need is a faster way to travel.

Now, there's actually a project going on right at the moment,

and it's called Breakthrough Starshot.

Now, instead of carrying heavy fuel on board the spacecraft,

what they need to do is make it light and agile.

What we do is we use a massive solar sail.

Now, I've got a little demonstration to show you how this works.

Fantastic. Aha! I have the water.

Fantastic. Thank you.

So what I'm going to do is I'm going to pour some water

in here, without making a mess.

Whee!

And then what we're going to do is add our boat.

There's the water, and there's our boat.

OK. Now, we've actually used this technology,

and in the past we've used light from the Sun

to accelerate things through space.

But what we want to do now is, we don't want to just use light,

we want to generate our own light.

We want to use lasers.

What we're doing is we're distributing balls

throughout this section.

Now, each one of these balls represents a photon of light.

So this is laser light.

So what we need is a sail,

and so what we're going to do is get a solar sail.

Bring on the solar sail!

And here it is.

So this is our solar sail.

And what you'll see is it's made out of very, very light plastic.

So now what we have here is our solar sail.

Now, remember, what we have here in the audience -

each one of these balls represents a photon of light.

And now I want you to throw them towards the solar sail.

So...

First of all, I'm getting out of the way. OK.

And so what I want to do is I want to count three, two, one,

and throw them at the solar sail.

- So, are you ready? - Yeah!

Three, two, one...

Throw your photons!

OK!

OK. So your photons hit the solar sail.

OK. We've still got incoming photons.

I thought this would be a problem!

But, yeah, apart from getting bogged down,

look, our solar sail has made its way,

all the way across, out beyond our solar system

to the other end of the trough.

And so this is the plan for Breakthrough Starshot.

Up here, I've got a picture of a real solar sail.

So this is what we're designing.

This is the solar sail,

and you can see it is very much like this sheet of metallised plastic,

but it sits in space and it is absolutely ginormous.

Now, as I said, in the past

we've used light from the Sun to accelerate them,

but what we need to do now is use these photons of light, this laser.

So we will send a pulse of laser light into space.

Now, you only need a pulse of laser light,

because once you accelerate the solar sail,

because we're in the vacuum of space,

there's nothing to slow it down.

So you accelerate the solar sail,

and we have very tight pointing accuracy,

and we point it towards Proxima b.

Now, we can actually set this up and we can point it towards Proxima b,

but we have no means of slowing it down.

So, as it approaches Proxima b, it will fly past,

but what we want it to do is take photographs.

So, as it flies past Proxima b,

it will take photographs of that exoplanet

and it will bring those photographs back to Earth at the speed of light.

So, even then, it will take 4.24 years

to get those images back.

But if we do this, we might be able to get closer to the answer of,

"Are we alone in the universe?"

But there's a few things to say.

If we can get this technology to work,

then we can actually accelerate this solar sail

to about a fifth of the speed of light.

Now, I'm a Trekkie, so that's warp factor a quarter.

But the probe we can send can weigh no more than one gram,

because if it's any heavier, it has inertia,

and so then we'll need more energy to accelerate it.

If we actually get up to a fifth of the speed of light,

that journey of 40 trillion kilometres,

it won't take 76,000 years.

We'll be able to do it in just 20 years.

Thank you very much. And a round of applause for our volunteers.

CHEERING AND APPLAUSE

So, with a solar sail, we can get something very small and lightweight

out to an exoplanet and take photographs

and bring them back to Earth.

But my dream has always been literally to travel to the stars.

So what if we wanted to get something a bit more massive,

something like me, out to the stars?

Well, there is also a new way of thinking about it.

We're talking about the Alcubierre drive.

And this is a theoretical way of travelling into space,

and it's been developed by Miguel Alcubierre,

a Mexican physicist,

and what he's suggesting is that we actually...

Well, we manipulate space and time itself

to travel out into space.

So, now, for this, I'm going to need another volunteer.

I always hate doing this. OK.

Actually, would you like to come up?

A round of applause for our volunteer.

APPLAUSE

Thank you for joining me.

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

- Bukayo. - Bukayo. - Yeah.

Very nice to meet you.

Now, what we've got here is my Alcubierre drive.

Now, if you can put your feet just on the edge there.

This is planet Earth,

and at the other end of the carpet is Proxima b.

Now, this carpet represents space and time.

And that's something that Einstein came up with -

the idea that we can take three-dimensional space and time

and smoosh them together.

So this is the space-time carpet.

And out there, yes, that is Proxima b,

and we want you to travel there.

Now, first of all, what I want you to do

is just take one step and get to Proxima b.

So give it a go.

Yeah, that's... Whoa!

SHE LAUGHS

That's big, but not big enough!

OK. So do you want to come back here?

Thank you very much. I'm just going to sort of straighten up

space and time. Just even that out.

OK. So, now, travelling conventionally,

it will take quite a while, as we've worked out,

to get to Proxima b.

But what if we can actually manipulate space and time?

So what we're going to do is we're going to

scrunch up space and time in front of you.

So this is the principle behind the Alcubierre drive.

Rather than trying to take that big leap,

what we do is we concertina up,

or scrunch up space and time.

So, now, when you take your step,

it's quite easy.

So, because we've manipulated space and time, scrunched it all up,

we have effectively brought Proxima b towards you.

But that's not all we do,

because we've scrunched space and time up in front of you,

but what we need to do now is elongate it behind you.

So, now, this is it. With the Alcubierre drive,

we scrunch it up before you

and we elongate it out behind you.

So there we have it.

You have travelled from Earth to Proxima b in just one leap.

So a round of applause for our volunteer, please.

Thank you.

APPLAUSE

So this is something that's been worked out mathematically.

Mathematically, the Alcubierre drive seems to be

a feasible way to travel in the future.

But there are a few caveats.

One of the things is, actually, to scrunch up

space and time like that and elongate it behind you,

you need huge amounts of energy.

And that energy, we just don't have access to at the moment.

But maybe in the future, we'll find ways of making that energy

and we'll be able to travel these vast distances in space.

Let's assume that we've made it to another planet

and there is some kind of life out there.

But what are the chances of finding civilised life, intelligent life?

And what is the probability of just finding bacterial slime

or something a little more sophisticated?

Well, to make this discussion,

I'm going to call back Professor Chris Lintott.

APPLAUSE

Now, back in 1961, Frank Drake came up with an equation,

and it was trying to work out the probability of finding

civilised life - and we'll define that in a minute -

within our galaxy.

Now, for this, we've got seven volunteers,

but I think they've already been pre-selected,

and so would our seven volunteers please stand up?

And will you all get out your whiteboards, please, and your pens?

Now, also, each of the volunteers here in this line represents

a parameter from the Drake equation.

So this is the Drake equation here.

Yeah, so this is how you calculate...

We're not going to think about probabilities,

we're going to try and calculate the number of alien civilisations

in the Milky Way galaxy that are there right now

- for us to talk to. - OK. - So, when we're looking for

alien life in the galaxy, this is what we need to know.

- Are we going to stumble across aliens wherever we look... - Yes...

..or is it going to be really rare and difficult?

- So, that's what this equation calculates for us. - OK.

Drake developed this equation back in 1961,

and then, some of the parameters weren't known.

But what we're going to do is actually go through each parameter

and write down what you think.

Now, Chris, I hate to say this, but you're a bit of a Grinch,

- aren't you? - I am at this, yeah.

I think... I'm going to be a pessimist today, I think.

So let's see what the odds are, even if we think we might be

a little lonely in the galaxy.

- OK. - But we know the first few terms, though, so we can start with

the number of stars in the Milky Way,

- and we know that from Gaia. - We spoke about that earlier.

So we think there are 100 billion stars in our galaxy.

So, please, for the first term - so, you are N* -

could you write down "100 billion"?

- So, that's 100 with nine zeros behind. - That's right.

- OK. - Yeah, and we know that pretty accurately,

at least for astronomers,

there might be a factor of two in there or something.

- Yes, but ballpark, ballpark. - Yeah, exactly.

And that's what this is about, OK. So, let's go on to the next.

So, what's the next term?

- So the next one is, how many of those stars have planets? - OK.

And when I was growing up watching the Christmas Lectures,

- we didn't know that at all. - Yes. - But we now do.

We know that the Milky Way likes making planets.

So, we can more or less assume that every star has a system

of planets going around it.

So, this is function FP.

Yes, so it's the fraction of stars that have planets.

- We're going to say one. - OK. - All of them do, more of less.

OK, so, yes, some might have more, some might have less.

So, could you put one on your scoreboard?

Thank you very much. Thank you.

OK, so what's our next priority? We've got NE.

Yeah, so this is the number of those planets that are capable

- of supporting life. - OK.

So we could argue about what you need to support life,

but maybe we think our kind of life.

So you need water, maybe a rocky planet.

Well, these are quite common, we've found out recently.

So we know Earth-like planets are common,

so we might as well put one here, as well.

So I reckon every star that has planets, on average,

will have one planet capable of supporting life.

So that's a one, as well.

- OK, but now we're going into what we don't know. - Yeah.

We're going from the modern science to future science.

So the next thing we need to know is this FL.

- So if we've got a planet that can support life, does it? - Yes.

- OK. - What fraction of planets have life?

And here, this is where my pessimism,

my Grinch-like tendency comes in.

So I think we haven't found life anywhere but Earth yet,

- and we've been looking. - Yes.

So I reckon life must be pretty rare, so -

this is a guess - let's say one in 1,000 of those planets.

- So, one in 1,000. - Yeah.

So, can you write that on your screen?

- One divided by 1,000. - Then the next term... - FI.

Yeah, so that's the fraction of those planets that have life

where you get intelligence.

Yes, OK, so intelligent life.

Yeah. Now, again, there's just us.

- If we're... - But are we intelligent?

Well, we're as good as it gets, Maggie, as far as we know,

you and I, and this wonderful audience.

And I think... You have to think, it's taken five billion years

of the Earth to get to here, and we've only just made it.

- So I reckon intelligence must be rare, as well. - Ooh, OK.

So I'm going to say one in 1,000 - one divided by 1,000

- for this, as well. - OK, can we put that on the...?

On the case already, this is good.

Lovely. And can you hold it up when you've written it out? Thank you.

OK, so, now, what's the next thing?

Well, this is FC.

- So this is the fraction of planets that have intelligent life... - OK.

..that are capable of, and willing to talk to us.

- Oh, OK. - So, one way of thinking about this is maybe,

do they have radio?

- Have they developed radio? - Ah!

- So, for example, if you think about the Aztecs or the Romans... - Yes.

..past civilisations, they were intelligent

- but they wouldn't be in this category. - Yes, and so it's the

- technological capability to actually communicate. - Exactly.

So I'm going to use my recent argument again -

we've only just, in the last maybe 100 years, started to do this.

I reckon it's going to be rare.

- Let's...let's say one in 1,000 again. - OK, one in 1,000. Thank you.

- Let's get that... - I want to point out, I could be more grumpy

about all of these, as well.

One in 1,000 I think is quite generous,

so hopefully, we'll get some aliens at the end.

OK, so that's one over 1,000 again, OK.

And then we're coming to the last term, FL.

Yeah, this is the most unknown term.

- So this is how long you last as a civilisation. - Oh, yes.

So... Well, we've got at least 100 years,

because we've been transmitting radio waves for about 100 years.

So maybe I'll be generous - let's say we'll last

- at least twice as long. - OK.

So, 200 years for the lifetime of our civilisation.

But the Earth will exist for about ten billion years in total.

- OK, cos we're about halfway through the life, OK. - Yes.

So that's 200 divided by ten billion.

- Oh, OK. - So, that's a really small number.

So can you write 200, and then divide by ten billion?

- So we get more ignorant as we go along... - OK, yes.

..but we can guess all these numbers,

and then we can put them together and calculate the number of

civilisations there are for us to talk to.

- So, let's do just that. - OK.

- Can you send all your sheets to this end? - Shall I go and get them?

Yeah, and Chris, if you can go and get them.

So, if you pass them up, what we're going to do is put them into

the Drake Equation calculator.

Oh, is that what that thing is?

- Yeah! - OK, good.

MAGGIE LAUGHS

- Was it expensive, Maggie? - Incredibly.

- OK. - We blew our budget on this, but I think it's worth it.

Excellent. And we're not going to ask how this works.

MACHINE BEEPS

- Ooh. - I know!

SHE GIGGLES

So, OK, I think we're ready.

I'm going to press the red button, and we'll get an answer.

I'm going to stand back.

- OK, so, three, two, one! - ..two, one!

Let's see if we can get an answer.

- Whoa! OK, that's not good. - Is it supposed to do that?

- Yes. - OK! - That's what I'm going to go with, yes. - All right!

- Oh, hang on! - Oh, it's doing its calculation.

CHRIS LAUGHS

Ooh, OK!

- So we have a scroll, and let's see what's on here. - Of course we do!

- Fantastic. - So, this will be... - Ooh, more smoke!

..our calculation of the number of civilisations in the galaxy

- that we can talk to. - OK, so let's get this the right way round.

OK. So, Chris, if you hold the other end...

- So, the number is... - OK, so it's less than one.

We've got...

- It's not very many. - It's not very many at all!

Do you think you might have been a little over-pessimistic here?

Well, I think I was quite generous, actually, all those 1,000s.

But this is the point, so in this situation,

if we're right about those numbers, we're it!

We're almost certainly the only civilisation in the galaxy.

You could multiply this by a million,

and there'd still only be two civilisations.

So, yes, so if you took every star in our galaxy and multiplied it

by a million times,

there'd only be two civilisations in our galaxy -

so us and someone else to speak to.

And, of course, they could be far, far away,

so we can't actually communicate.

So, if you believe the numbers that we put in,

then you have a world, a galaxy in which civilisations appear

and then disappear pretty quickly and they never talk to each other.

- Yes. - It's very festive! - Well, not very festive at all!

- I feel quite depressed! - No. - I think I would be really...

I don't want to be alone, and that makes me feel very,

- very lonely, Chris! - No, I should say,

even if this is true, we should look anyway,

- because you never know. - OK! Yes.

Because there were things in there that we didn't understand.

- But, of course, you can also change the numbers... - Yes!

- ..and think differently about things. - Lovely.

So, Chris, if you'd like to step over here,

what I want to do is, I want a slightly more optimistic approach.

Now, when I think of optimism,

I think of someone who's travelled out there into space.

Tim, would you mind coming down again?

- A round of applause for Tim! - Hello, Maggie. Hi.

APPLAUSE

- Good to see you again, Tim. - You, too.

Now, that answer was a little depressing to me.

A LITTLE depressing? God! Only 100 years left to go!

- Goodness me! - Wipe-out, yes.

So, Tim, what I'd like you to do is offer some alternative numbers.

- Right. - OK, first of all, so you've got 100 billion... - OK. 100 billion.

- Yes, and then it was one and one. - One and one. - OK.

So, if you put those on your boards and hold them up.

So 100 billion takes a little longer to write.

And that gets us to the fraction of planets that could support life.

- Yes. - OK. - So we agree on that. - We're on FL. - Yeah.

And I actually think the raw materials are abundant

in the universe for life.

- Water and ice is everywhere, organic compounds. - Yes.

And on planet Earth, as soon as the conditions became

favourable for life, life evolved.

- And so I'm going to go for one for FL. - OK.

So, if life can exist on a planet, it will.

- That's what you're effectively saying. - Absolutely. - So, perfect.

Let's put a one there on the board, and let's hold it up, please.

- OK, so we've got one. - Right.

OK, so go on to the next parameter now.

So, FI - intelligent life.

And I do understand Chris's point of view here,

but, given enough time, I think life finds a way.

It's always going in one direction.

- It's evolving! - And that's becoming more complex, evolving.

- Yes. So what are we going to put on this? - I'm going one.

- I'm all in. - OK, one, OK. I love the optimism!

- OK. - Right, FC. - FC, yes.

Will that intelligent life communicate?

Again, I'm taking the positive view that intelligent life,

at some point, will ask itself the question,

"Am I alone in the universe?"

and "I'm going to try and communicate with other intelligent

"species out there" - so that, for me, is a definite one.

OK, perfect. Lovely, so let's put one on the board

- and turn it around. - I suppose we exist and we've done it,

- so I guess there's a logic there. - We're not that intelligent, so, yes!

THEY LAUGH

- OK, so, then, the last one. - FL.

- Yes. - So I'm going to take Chris's rather depressing 100 years...

- Oh, yes! - ..and say, actually, as a species and intelligence,

you know, it solves problems,

and our technology is getting better and better,

our life expectancy is improving.

- Yes. - We're able to overcome problems.

- Yes. - Our medicine is getting better and better.

There's every indication and every potential that

if we collaborate and work together,

we'll last as long as this planet can maintain us here.

Which is about 4.5 billion years into the future. I like this.

Absolutely, and so that will be half of the entire

- Solar System's life. - Yes, perfect.

- So we're going to have to put 0.5 for our final one. - OK, 0.5.

So what we need to do is gather these results up and put them in

- the Drake Equation calculator. - OK.

- Thank you, if you can bring these down. - All right,

- can I have these ones, please? - This is a lot more positive.

- Maggie, I'm going to stand over here. - OK. - Thank you.

I'm going to let you and the astronaut be next to that thing.

THEY LAUGH

I do my science at a computer, I don't use those things.

- Yes, the smoke was a bit worrying, that's all I can say. - Yeah.

- It's perfectly safe! - All right, Maggie. - Fantastic. - Here's the

- more optimistic version. - Fantastic. Now, let's put this in,

put them all together.

Let's slot them in. Thank you. MACHINE BEEPS

OK, we are getting the calculation.

So, let's hit the red button.

So, let's count down.

Three! Two! One!

What's the answer?

Ooh, OK, we're getting the smoke again. We have a Pope!

LAUGHTER

Ooh! So we're getting the scroll.

Oh, hey! What's this?

THEY LAUGH

Ooh, this is looking promising!

I like the look of this. OK, so let's take this.

OK, I've got the magic scroll. LAUGHTER

- OK, so let's put this down here... - OK.

- ..and let's check this out. - Let's see what we've got here.

Are we ready? This is the number of civilisations

in the Milky Way galaxy.

Yeah, and this is just our galaxy, the Milky Way galaxy.

So, OK, we've got five, sort of....

- OK, 50... Oh, OK, 50. - Oh, wow!

- One, two, three, four, five, six... - Wow.

OK, so that is 50 billion.

- OK! - You've got a galaxy full of life!

That's a bit more optimistic.

That is very, very much more optimistic.

Well, first of all, a round of applause for our volunteers.

Please, take your seat, and thank you very much.

And thank you, a round of applause for our wonderful contributors,

to the both of you. Thank you, guys.

I'll let you keep it. Thank you. APPLAUSE

And so we came up with some interesting answers there.

It was never actually going to give us a definitive answer,

because we just don't know,

we don't have the right information accessible yet.

We think that there must be life out there -

but the problem is it might be far, far away.

So, if you could find the aliens, the question is,

what sort of thing would we like to say to them?

Now, we've been polling people who have come in to the studio,

and this is the result of what they want to ask aliens.

Do you like to sing? Do you like to dance?

I mean, cos if you like to dance,

we could have a competition. Yeah!

If you're thinking of coming on holiday to planet Earth,

I don't know if it seems big or small to you,

but there is huge variety

so you're going to need to take a while.

What do you look like?

And is there other planets out in the universe

that human beings do not know?

Do you have any hobbies that we don't know about here?

Is there any materials that are undiscovered to Earth?

Where do you live and what's it like?

And are you carbon-based?

Do they get hungry? Do they ever eat for pleasure?

Is water really necessary for life?

I think that's one of the big questions that we're

grappling with here on Earth.

Hi. What's your planet like?

And what's your favourite things on your planet?

What sort of wildlife do you have?

And do you speak English, or do you speak Spanish?

Or do you speak any other language?

Um, I want to know, ooh, what your plants are

and if you can breathe.

Yeah, we're a beautiful planet, we're diverse.

It's humans and animals, plants, and that's great.

But so much has changed, and I think actually, we would learn

so much from meeting another off-world civilisation.

Do you guys have a fascination for outer space as much as we do?

Aliens! Please come to my home!

APPLAUSE

So, yes, these are the messages we'd like to get out to aliens.

Now, this has actually been done before,

because there were two spacecraft called Voyagers,

and they travelled through our solar system and went out beyond.

And this is the golden discs that were actually put on board

the Voyager spacecraft.

So, Voyagers were launched in 1977,

and they have travelled through space for over 50 years now,

and they've gone out into interstellar space.

And yet, on board, they had these records - and these records,

they're actually... So they were very much of their time,

this is 1970s, so these are records,

and we sent them out into space

but we also included instructions of how to play the records.

And on this, they included all sorts of things,

but they included a map of where we sit in our solar system.

They included sort of the laughter of children,

sort of children of the Earth saying hello,

and sort of the music of Beethoven, and many other things.

Now, because this is the 200th Christmas Lecture,

I thought it would be wonderful to do the same thing.

So what we've done is collected all those messages

and put them on this disc.

And now, I haven't got the capability, and we haven't got

the budget to send this into space,

so what I'd like to do is,

please welcome the Director of the Royal Institution,

Katherine Matheson.

APPLAUSE

Now, Katherine, what I'd like to do is give you this disc

that we've created, our own Golden Disc,

and hopefully it can join the archive here at

the Royal Institution.

- So, thank you very much. - Thank you so much, Maggie,

and thank you to everyone who has contributed to this amazing record.

It's a real privilege to have it here at the Royal Institution.

It's a really special year.

As you know, it's 200 years since the Christmas Lectures

were started by Michael Faraday to share the joy and wonder

of science with young people,

and that goal feels just as relevant and important then,

in 1825, as it does now.

So, thank you very much to all of you,

and especially for being our 200th Christmas Lecturer.

- Thank you, Maggie. - Thank you very much.

And a round of applause for Katherine, please!

So that brings us to the end of this lecture,

and I must admit, I'm tearing up a bit because,

as I said, I used to sort of always want to come and see

the Christmas Lectures.

I never got the opportunity, but it is...

I feel so honoured to be here with you tonight.

Now, as a child, I was at the back of the class,

I wasn't considered very bright.

I went to 13 schools, and I have dyslexia and ADHD,

so I never thought I'd be standing here in front of you.

But I think this is the key.

Have a big, powerful dream

and see where it takes you.

All my life, I have been reaching for the stars - literally.

I have wanted to get out there.

And in this lecture, we have done just that.

We have gone to the very edge of the Solar System.

What I hope for in the future, and especially for you young people,

is that as we make that journey, we do it in the right way,

we do it for the benefit of all humanity,

and we learn from our past mistakes and make sure we actually go out

into space in an essence of unity.

So thank you very much for having me here,

and thank you all so very much for support from CGI.

And for that, that's it from me,

wishing you all a very, very merry 2026.

Thank you very much, and goodnight!

CHEERING AND APPLAUSE

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