Original subtitles

It's one of the biggest questions in science - is there,

somewhere out in the cosmos, life waiting to be discovered?

And what will it be like?

But what's less reported is the work being done to determine what happens

if we do discover aliens.

How could we communicate with them? What should we say?

And, most importantly, should we talk to them at all?

This month, The Sky At Night team are investigating

the controversial world of extraterrestrial communication.

We follow one of astronomy's most contentious figures, Doug Vakoch,

on a research trip to the UK...

This isn't the ordinary kind of signal.

I think they're trying to get our attention.

..to meet experts in animal and alien communication.

We can say that any alien civilisation that has technology

must have a language.

Exoplaneteer George Dransfield

discovers how we listen for messages from outer space.

Something out there has made that technology to produce that signal

and therefore, we're going to assume that's an intelligent,

extraterrestrial civilisation.

And Pete Lawrence tells us how to see this month's supermoon

and Perseid meteor shower.

Welcome to The Sky At Night.

This is Professor Doug Vakoch.

He's an astrobiologist and he's trying to communicate with aliens.

I have no doubt that aliens have to exist somewhere out there.

If there's no-one else out there it would be a miracle

and I don't believe in miracles.

Vakoch spent much of his career working at the SETI Institute,

an acronym which stands for the

Search for Extraterrestrial Intelligence. But in 2015,

he decided to stop waiting for the aliens to come to us.

The SETI organisations that exist have avoided the controversy

of sending messages into space.

And yet, maybe that's what we need to do to make first contact.

And so that's how METI International came to be.

He's now the president of METI International,

which stands for Messaging Extraterrestrial Intelligence.

They use a powerful transmitter to send a signal out into space

in the hope that aliens will find it and respond.

The goal of METI is to establish first contact.

We've always assumed the aliens will take the initiative.

Maybe it's the audacious young civilisation like earthlings

who have to reach out to make first contact.

Vakoch collaborates with like-minded scientists,

linguists and philosophers around the world

to answer crucial questions. And that's why he's here in the UK.

The Sky At Night have been invited to follow some of these meetings

to gain a better understanding of the world of METI.

I want very practical answers to questions that seem very esoteric -

how to communicate with aliens.

I want to figure out how to create a message that might actually

be understood and then how to remember that message

in case, centuries from now, we get a reply.

But if we can't even communicate with our nearest animal relatives,

what chance do we have with an alien?

First stop on his trip is a slightly unusual zoologist.

I mean, if you go to his website, University of Cambridge,

Dr Arik Kershenbaum - "animal vocal communication

"and the evolution of language

"and xenolinguistics and the search for extraterrestrial intelligence."

This is a zoologist I need to meet.

Dr Arik Kershenbaum, from the University of Cambridge,

specialises in the communication of wolves and dolphins.

He's also a member of the Cambridge Institute for Exo-Language.

How does a zoologist come to get interested in aliens?

I think that what zoologists do is understand mechanisms.

We're always thinking evolution.

What is it that made this, gives this an advantage?

I don't know exactly what

a creature on another planet is going to look like.

But I can make general predictions

about how evolution will always work out - that they will need food,

they'll need to search for energy.

So you would expect from that,

them to live in groups with related individuals.

How about something like language or communication?

Do you have to have that?

Well, all animals on Earth communicate, all of them,

every single one. And that's not a coincidence.

It's nothing special about Earth.

Is there any reason to think that aliens would talk with one another

in a way similar to what we're doing?

We can say that any alien civilisation that has technology,

the kind of technologies that we're familiar with,

must have a language because there needs to be something like language

to allow them to say to each other, "Give me the screwdriver,"

or, you know... And if you can't say, "Give me a screwdriver,"

you're not going to build a radio transmitter, a radio receiver.

Exactly. So these are the aliens we're interested in.

At least, I'm interested in, the ones I can talk with.

If we're talking about an intelligent, technological,

alien civilisation that's looking for us, just like we're looking

for them, hopefully they'll be trying to teach us their language,

just as we should be trying to teach them our language.

Arik records animal vocalisations

in the search for patterns that could be universal.

So, this is an example of a dolphin whistle. And I'll play this.

DOLPHIN CLICKS AND WHISTLES

If you compare that to a wolf howl...

So, this is an example of a wolf howling.

WOLF HOWLS

That very typical rise in pitch and then fall.

Played at normal speed, dolphins and wolves sound completely different.

But Arik believes that their communication

is much more similar than we might think.

This, on the left, is the same dolphin whistle

but slowed down by about 30 times. It sounds like this.

SLOW, LOW-PITCHED WAIL

So they're using the same method, that varying of the frequency,

varying of the pitch, high pitch, low pitch,

to send messages over long distances.

It's a very reliable way to send information in a noisy environment,

and it's constrained by the physics of the world they live in.

So, if you go to another planet, the details of the planet

may be different, but the physics is going to be the same.

The physics is the same. And that means that the constraints

on the evolution of these animals are the same.

The constraints that determine,

should this animal have words and sentences,

should this animal have continuous howls going up and down in pitch?

So there's hope of understanding alien...if not language,

at least vocalisations. I think there's hope of understanding

whatever language we might encounter, wherever it is.

I came into our conversation wondering whether our attempt

to send human greetings into space is completely meaningless.

But what I'm getting from you

is that if we look at the physics of sound,

that's something that we might be able to communicate to an alien,

and they should be able to figure out

that it's a language of some sort.

Doug Vakoch and his METI colleagues

are not the first to attempt communication with aliens.

These messages have taken on a variety of forms over the years,

a record of us shouting into the cosmos.

The first transmission intended for aliens was sent in 1962

by Soviet scientists

who aimed a radio transmitter at the planet Venus.

It contained three words spelled in Morse code.

"Mir" - which is Russian for peace or world -

"Lenin" and "USSR".

The aliens didn't reply,

presumably because they don't understand Morse code.

A decade later, Pioneer probes 10 and 11 carried small metal plaques

showing our location in the galaxy

and, perhaps because it was the '70s, naked human figures.

It's a rather narrow view of humanity, a gesture to the cosmos

made by a white man, hardly representative of life on Earth.

This project, like so many attempts to communicate, ends up telling us

more about ourselves than whoever or whatever is out there.

Then in 1974, Carl Sagan and Frank Drake

used the upgrade of the Arecibo telescope, in Puerto Rico,

to send a radio message of binary code to M13.

But M13, the target cluster, is nearly 25,000 light years away.

So even if the Arecibo message is received by aliens,

we'll have to patiently wait 50,000 years for their response.

In 1977, Sagan and Drake teamed up again to place the Golden Record

aboard Voyager 1 and 2.

The ambitious international time capsule contained music,

a greeting in Welsh, a selection of whale song and some more Morse code.

Voyager 1 is currently the furthest away human-made object in space,

and it would be nearly impossible for another civilisation to find it.

But as Carl Sagan said,

"The launching of this bottle on the cosmic ocean

"says something very hopeful about life on this planet."

And then there were the more recent attempts to share popular culture

with outer space.

In 2008, NASA broadcast The Beatles song Across The Universe

to the star Polaris.

And in the same year, the ice cap radar on Svalbard

was used to transmit a powerful, deliberate signal

to hungry extraterrestrials in the Ursa Major constellation.

It was an advert for Doritos.

One reason to think about messaging aliens is that THEY might call US.

Finding signals from space is the work of SETI,

the Search for Extraterrestrial Intelligence.

Exoplaneteer George Dransfield

is at the Jodrell Bank Observatory to investigate.

In my work, I search for potentially habitable exoplanets,

that is, planets outside the solar system

that could possibly sustain life.

However, while I am hunting for these brand-new worlds,

there's a whole other set of astronomers

who are listening to them, searching for potential signs

of advanced civilisations out there in the universe

that could maybe be looking down at us.

Professor Tim O'Brien

is Associate Director at the Jodrell Bank Centre for Astrophysics.

The radio telescopes here have been used to search for aliens.

What kind of telescopes around the world are focusing

and working on SETI right now? Yeah, I mean, it's a sort of golden age

for SETI, I would say. I mean, it started... It began, really,

in the early 1960s with just a few sort of pioneers.

And now we've actually got a major effort, the best SETI programmes

we've ever had, particularly the Breakthrough Listen programme,

which is using telescopes in the USA.

It's also using the Parkes telescope, in Australia.

We're part of that programme as well.

SETI scientists like Tim are looking for technosignatures -

signs of distant, advanced civilisations.

Technosignatures is a... In our case, a radio signal

that's produced by technology.

So of course, one of the reasons SETI people would be interested

in that is because we think, if we detect such a signal

coming from distant space, something out there has made that technology

to produce that signal and therefore, we're going to assume

that's an intelligent, extraterrestrial civilisation.

All objects in space that emit energy, emit radio waves.

Most of these signals are naturally occurring,

but certain types could be a sign of alien technology.

How can you distinguish between technosignature

and radio signatures produced by nature?

The key difference really is that natural radio signals

tend to produce radio waves across a really wide part of the spectrum

the very broad band signals,

whereas technosignatures from technology

are often very narrow lines in the spectrum.

And I've got a sort of example here,

this very bright feature that runs down the middle,

that's actually a natural signal,

that's actually a broad line from hydrogen in space.

But you might also spot, just sitting in the background... Yeah!

..there's some little faint spikes.

Now, those are some sort of interference,

which is basically a technosignature,

but likely from nearby. Right. From the Earth, effectively.

The challenge is distinguishing a technosignature from outer space

from technology here on Earth.

How do you know that they're not going to be false positives

if you find them in space? Yeah, this is a classic problem.

Modern world, full of technology

producing these sorts of radio signals.

And you've got to distinguish a so-called sort of alien signal

from a human-made one.

And so there's a number of sort of clever ways we can do that.

One way is to look at the exoplanet direction you're interested in

and then shift your telescope off to one side and just do that

sort of on-and-off sequence. Yeah.

If there's something local around us

that's producing this technosignature

it would also be in the off direction.

And if it's just coming from the exoplanet direction,

you only see it in your own data.

Another sign of a technosignature is random patterns,

but these can also be misleading.

What if you find something that looks exactly like

a technosignature, as you'd expect it to be,

how do you know that there's nothing in nature that can produce it?

Yeah. I mean, the pulsars were an interesting case.

I mean, discovered in 1967 by Jocelyn Bell.

What they saw was a signal that went on and off repeatedly and, you know,

that seemed unnatural.

And they did call that first pulsar

LGM-1, where LGM stood for Little Green Man.

The scientists soon realised that the signal

wasn't little green men, it was a pulsar.

This can occur when a large star collapses in on itself

at the end of its life.

It starts to spin, shooting out powerful beams of light.

This is a recording we made with the Lovell Telescope here,

and here we go. Wow, yeah.

So, these are the repetitive flashes,

about three a second, something like this, in this case.

So, this is a dead star the size of a city,

spinning around something like three times a second,

which is pretty, pretty incredible.

I mean, you can see why when you first find that,

you would think that that is not natural. Yeah.

Tim might listen for messages from outer space, but he is less keen

on actually sending one from Earth.

I wouldn't send out messages deliberately.

I mean, some people will say that they'd not be keen because

why would you advertise your presence so deliberately

to a potential extraterrestrial civilisation when you have no idea

what they might be like?

So you might end up with an Independence Day scenario

or some such thing where you are... Mars Attacks! Mars Attacks! indeed.

For me, it's more to do with what to say. Yeah.

Is it just people like me who happen to have access

to a big radio telescope who speaks on behalf of the planet? Yeah.

We're speaking on behalf of the planet... Of course, yeah.

..in these sorts of situations. Yeah. So what you say matters.

I think that's an interesting challenge

because we're in that situation now. We have the technology

and we'll probably very soon have the potential targets.

So, Tim's told us that we are now entering a golden age of SETI.

My hope is that, in the next few decades, we might find some sort of

technosignature from one of the many, many exoplanets

that people in my field are so keenly looking for.

Astronomers are still searching for the man on the moon.

But in the meantime, The Sky At Night's stargazing expert

Pete Lawrence is here to tell us

why it looks particularly impressive in July.

This month, we're talking about a special full moon

and a dramatic meteor shower that could be breathtaking.

We get a full moon when it's on the opposite side of Earth to the sun.

When it's in position closest to Earth,

it's called a perigee full moon,

sometimes referred to as a supermoon.

A perigee full moon occurs several times a year,

and the next one will happen on the evening of the 31st of July

into the morning of the 1st of August.

As we move towards mid-August, the full moon will be slimming down,

ensuring perfect conditions

for the peak of a spectacular meteor shower, the Perseids.

I've been observing the Perseid meteor shower since 1977.

It's one of my favourite showers.

Now, the climb to maximum is pretty steep, and that occurs

on the nights of the 12th, 13th into the 13th, 14th of August.

Now, the best time to look out for them is from 1:00am BST -

that's midnight GMT - because after that time, the Earth has turned

to face the particles which form the meteor trails head on.

The Perseids are one of the more plentiful showers.

They have a peak zenithal rate of around 100 meteors per hour.

The particles in the Perseid stream

originate from comet 109P/Swift-Tuttle.

The small area of sky that the meteors appear to emanate from

is called the shower's radiant.

The Perseid shower gets its name because when it's most active,

its radiant is in the constellation of Perseus.

The location of the radiant moves over time,

activity beginning when it's in Cassiopeia.

As it moves into Perseus,

it reaches the peak.

But shortly afterwards

it slips into neighbouring

Camelopardalis,

a faint constellation

representing a giraffe.

It's not difficult to set up a camera to photograph meteors.

The tricky part is pointing the camera at the right area of sky

at the right time to catch a bright meteor trail.

That's down to luck, I'm afraid.

If you want to try your hand at capturing the Perseids,

check out our guide on The Sky At Night website for my top tips.

If you manage to get any photographs of a Perseid meteor trail

or even the perigee full moon, we'd love to see them.

Upload them to our Sky At Night Flickr

and we'll pick our favourites and showcase them in next month's show.

Since our last episode, we have been receiving

your amazing images of the sun

and its incredible surface.

Scientists from around the world are waiting and listening

for a message from aliens. But in the meantime,

others are already making the first move.

In 2017, Professor Doug Vakoch and his fellow METI scientists

worked with the EISCAT antenna, in Norway,

to send an interstellar message in binary code.

At METI, we identify a couple of principles

that we want to communicate -

things like time, things like radio signals -

and then explain them in great depth.

We sent our message to a little red dwarf star called Luyten's Star,

12 light years from Earth.

And it means, in 24 years, we could get a message back.

BEEPING

But who should speak for Earth? And what should they say?

Vakoch's next appointment is trying to figure this out.

I'm excited to meet with Paul because he may just have the answer

to one of the biggest challenges we face at METI -

to create a message

that is really, adequately representative of humankind.

This is Paul Quast. He's a researcher on the council

of a charity called the Beyond the Earth foundation.

I want to learn about this project

that you've had going on for a while.

We are currently trialling a project which we call

The Companion Guide To Earth. We're looking at

this small physical time capsule that we're hoping

to attach with bolts to a geosynchronous satellite.

And who do you hope will receive this?

If extraterrestrials are coming to Earth long after humans have left,

What would posterity need to know about here and now that might be

of some benefit to them?

Paul's Companion Guide To Earth

is very different to previous messages we've sent into space.

A lot of the messages that we've sent out have been

greetings from Earth, they have been shining portraits.

What we're documenting is some of the more left-out subjects

that are of pertinent interest for those people

who will one day inherit this world.

So how does the content of your archive

compare with the messages that we've sent out into space?

We've branched into two different segments.

One is "do not go" and the other one is "need to know".

So, in terms of "do not go" - things like pollution histories and such.

"Do not go to this nuclear waste site."

Ideally, "Do not go dig up this ground.

"Do not go into these landscapes

"because there's still some radioactive isotopes there."

The "need to know" side of the guide is slightly more positive.

It includes information about long-term science experiments

that aliens or future humans might want to continue.

Another key component is an archive of the messages

we've sent to extraterrestrials in the past.

So, we sent out a message to a nearby exoplanet.

You have a case where it takes ten, 20, 100 years for a round trip

of light to reach there and back.

And how do we remember what we even sent?

Indeed. I've developed The Profile Of Humanity Catalogue.

It's documenting well over 70 signals.

I'm impressed by what you're doing. I don't know of anyone else

who's taking this seriously. And if I may, I would love to give you

a copy of the message that METI sent out in 2017.

And so, here is the date that we hope to get a reply back.

It is the summer solstice in 2043.

And there's one thing you have to promise me, though,

you're going to upload that, because 20 years from now,

no-one's going to be using a thumb drive like that. Very true.

Past messages we've sent out have whitewashed human history.

Paul emphasises, we need to talk about some of the things

we're not as proud of, so we need to take the next step

and explain something about what makes us human.

An increasing number of individuals and organisations

are getting excited about contacting extraterrestrial intelligence.

But many scientists, including Stephen Hawking,

have expressed their concerns.

And I have to say that I remain unconvinced.

The idea of communicating with aliens,

of deliberately sending messages out into the cosmos, is controversial.

Some people think it might be dangerous,

that it might attract hostile attention. Others, like me,

think the universe is so vast

that the odds of succeeding have to be low.

Before Doug heads back to the US,

I've asked him for a chat in one of our earthling cafes.

Why do you want to talk to aliens? Because, so far, we have been

locked into just talking with other human beings,

so we really have a narrow perspective on the world.

To me, talking with aliens is like going to another culture

here on Earth. You learn different ways of doing things,

you have to call into question,

my way of doing things isn't the only way.

So, why haven't we found this kind of message

from another civilisation? Why are they so hard to find?

That's been the hope of SETI,

in fact, that maybe they've heard we're here and now they're going

to say, "Welcome to the galactic club." Yeah, yeah, yeah.

My problem is, maybe to get into the galactic club,

you actually have to apply and pay your dues. Right.

So that's what we're doing with the message. I mean, my big fear is that

aliens are going to be kind of like my cat.

I mean, they know we're here, they just really don't care.

But there are these ideas around, aren't there,

particularly in recent science fiction, you know, things like

the idea of a dark forest of a galaxy where you don't want to

draw attention to yourself

because there may be predators lurking out there between the trees.

Does that worry you? I think it would be a nice illusion

to think that somehow we can kind of curl up and protect ourselves.

Sorry, the cat's already out of the bag.

We have already been blasting our existence into space

by radio and TV signals for the last century.

And so, what do you think of those efforts that have been made already

to send messages out? For the most part, they've been symbolic.

NASA sent a message to the North Star

to celebrate its 50th anniversary, Across The Universe.

The Beatles song. The Beatles, yeah, yes. But to really have a chance,

we have to do it over and over and over again, cos it's probably not

going to be in the North Star or any individual star.

It could be that we have to transmit to hundreds or thousands,

maybe millions of stars.

So, how do we anticipate who we're talking to?

How do we craft a message for an unknown audience?

What if they don't like The Beatles? If they don't like The Beatles,

we need to send them some other stuff.

I like the idea of a selection. We can just do,

"Press one if you want to hear greetings from humanity. Press two

"for a selection of music."

That's the enticement to get them to send back again.

"Yes, we would be glad to send you more of that.

"Send us some of your favourites."

But I think the biggest inhibition is, are we willing to take the risk

of listening and listening and waiting for century after century

and hearing absolutely nothing?

And I think we do, because what that will tell us is, you know,

all this time we've been looking for an advanced civilisation,

someone that we can learn something from,

but eventually we're going to realise that, you know,

by doing this project of transmitting and listening,

we've turned into the civilisation

we were looking for out there all along.

For METI to make sense, you need to believe in Doug's vision

of a galaxy filled with benevolent,

technologically advanced civilisations just sitting out there

waiting for us to call them.

Personally, I don't know how likely that is, but if they are out there,

it's good to think that there are people here trying to talk to them.

That's all we've got time for this month, but join us next month

when we'll be taking a deep dive into black holes. Goodnight.