Episode 3 Stargazing Live

Last night we looked at the supermassive black hole at the

centre of our galaxy, tonight we are hunting aliens.

We will be revealing, and how incredible is this, how you at home

helped us to discover a brand new planet.

I'm Brian Cox and this is Dara O'Briain, and this is Stargazing

Welcome back to the control room here in Jodrell Bank Observatory

for the third and final night of this year's Stargazing live, we are

going to be tackling perhaps the biggest question in all of science,

are we alone in the universe? are living in a revolutionary

period in a search for life beyond earth, we are now able to find

planets billions of miles outside our Solar System. They are called

exo-planets, so far we have found over 700 of them. Last month

scientists announced the discovery of Kepler 22b. A planet quite close,

about ten light years away, it is thought to be the closest one we

have come across beyond our Solar System. This is an artist

impression. It is earth-like with an atmosphere. That is because it

probably is earth-like at moss stpeers and could be a strong

candidate -- atmosphere, and could be a strong candidate for life.

can actually listen to Kepler 22b. Are we there with the co-ordinates,

I have to hit "return ", are you sure, there is a genuine note of

peril. Bingo, a monkey can do that. That will turn to face directly to

Kepler 22b. Later, as it has turned around, we can listen to it. We

will tell you about the planet at home you have found.

Last night we looked at light pollution, all the artificial light

that obscures the stars in the night sky. To tell you the light a

smallest place can create, we asked landmarks across the country to

turn their lights out. We tried to convince an entire town to switch

their lights off live on aifrplt standing by in Dulverton is Mark, -

- live on air. Standing by in Dulverton is Mark. What is

happening? It is wet here in Dulverton, the

atmosphere is electric. It is a small town. I'm here on the high

street of Dulverton, a small town with 1600 inhabitant, 800 houses,

50 shops, bars and restaurants. We have tried to spread the word to

get people to think about their lighting.

The weather doesn't look particularly good, does that mean

if the lights are out you won't suddenly see the Milky Way in all

its glory, you won't see a great show overhead? Not amazing in stars,

the clouds are looking stunning. Over the past few weeks we have had

teams working in Dulverton to spread the word. In 20 minutes time,

when the bells ring, we will find out how successful that message has

spread. As this film shows, the message or task was not an easy one.

Dulverton has 720 houses, 177 street lights, 40 shops and cafes,

three schools, three pubs, and a sports ground. That is a lot of

lights. If this is going to work, we will need to get the whole town

on board. First things first, we had to meet with the mayor. What do

you think will be the biggest challenge for us? Getting out the

word to everybody that they should do what we want them to do that is

to make the big switch off, the biggest we could ever make.

knocked on hundreds of doors, dropped leaflets through

letterboxes and spoke to as many residents as we could find. Can you

turn that off for us? Hello, what lights do you normally

have on? Maybe the upstairs light. Most of the lights, yeah.

Thank you very much indeed for your support. Thank you too.

I'm exhausted, I have been delivering leaflets all day, but

the response, I think, has been pretty positive. I just hope they

weren't telling me that to get me off their doorsteps. Dulverton is

part of Exmoor National Park, with some of the darkest skies in the UK.

Even this relatively small town generates enough life to obliterate

the skies with a fuzzy orange glow. Light pollution doesn't just reduce

the visibility of stars, light that shines where it isn't needed is a

waste of energy and money. We have chosen Dulverton as our switch-off

challenge, but there are thousands of towns and cities all over the

country that could benefit from a little less light.

Only a few days to go. This morning, one of schools in Dulverton has

allowed me to take the school assembly. I'm a bit nervous, I have

not done that since I was in school. If I can get the kids on board, I

can get the parents on board. What we need you all to do is go home

tonight, when you finish school, get all of your parents to turn off

all the lights in your house. Are you going to help us? Yeah!

What we need now is some kind of signal to make sure that all the

lights are switched off at exactly the same time. I have arranged a

meeting with the church bell ringers. Will everyone in Dulverton

hear the signal? If the wind is in the east they will hear it, if it

is in the west they won't. If the wind is blowing in the wrong

direction no-one will hear it? Crikey, this might work and it

might not. Now I have to see man about street lights. The majority

of the lights will have to be visited individually. We can't push

a red button and they all go off? Perhaps 20 years ago, but not now.

It is a big job k we do it? Yes. have visited businesses and

thousands, we have spoken to the local mayor, the police are

shutting off roads for us, posters around the town, I don't know if

this will work f it does, it will As you can see, the residents have

turned out in their hundreds to support this, including some hardy

astronomers, we have done everything we can do. In 15 minutes,

when the bells cliem chime, we will be entirely in the hands of the

good people of Dulverton. The weather isn't looking great, we

will persevere, getting those lights off will be an achievement

in itself. We will be back shortly This is turning around in its own

stately well. We gave the wrong information earlier.

Kepler 22b, is still relatively close, 600 million light years away.

You have sent us in stunners from home.

This is a photograph of a star I know well, because we talked about

it on Wonders of the Universe. There it is.

It is star called, this is the Triang ulumGalaxy, I wasn't going

to talk about that. But it is nice. This is the Rising Sun, and finally,

I think this is particularly nice, it was taken by Steve, one of the

astronomers we had out in the dark, muddy field over there on Monday

night. We do need you to keep them coming in, you will find details of

how to get them on the website -- to get them to us on the website. I

had a viewer asking for the website address. I have no idea. It is

below. I can't bear to read it out, I have read it out so many times.

You can join in on the live talk, Dr Lucie Green is standing by to

answer all guess, and on Stargazing Back To Earth following the

programme. We have questions for Brian too. We will get to the

questions for Brian later on. If you have a question,

particularly if there is anything you want to know about planets or

the search for life, you can get them to us by e-mailing the address

below, or the Twitter address. wanted you to say it!

Although we are spending a lot of time looking for life and exo-

planet, the best chance of finding life in the Solar System comes not

from the planet, but probably the moons.

We have probes all across the Solar System, the majority of the planets

we have probes, what are the best bets for finding them? This is a

picture of probably what most people think is the strongest

candidateor life beyond earth, this is Jupiter's moon, Europa, this was

taken by the Galileo Probe, it crashed into Jupiter. One of the

reasons it did that was to avoid Europa. It is thought it is just

possible we could have contaminated it if we crashed the probe in it.

Rather than landing the probe it was ditched? Yeah, into Jupiter.

The reason we are very excited by Europa, is it almost certainly has

an ocean of liquid water beneath the icey surface, there is probably

more water in the oceans of Europa, than in all the oceans of earth

combined. It is a fascinating world. The problem is the ice is probably

about 100kms thick, it would take a big drill to get through. It is a

target for exploration. The reason we know, this is a close-up of the

surface, you can see the cracks, they are very reminiscent of the

cracks in sea ice, when you model that, it indeed seems there are

cracks constantly shifting, because this ice is floating on an ocean of

lifting water. There is another of Jupiter's moons, Al-Ganzouri, we we

mentioned, -- Ganymede, it is also candidate. It has if not an ocean,

then liquid water beneath the surface. We think it probably looks

like this, this is the cross section of Ganymede, there is icey

sludge there. NASA are going to Mars later in the

year with the new Curiosity Rover, following the water and following

the complex carbon molecules in organic chepls treatment that will

specifically land in places where they need -- chemistry, that will

specifically land in places where there are water. You find mineral

deposits, this is from the Opportunity Rover, g ipsumhas been

found in Mars, it is only found in the presence of standing water, it

is probably the same on Mars, we know there was water there once.

That is from Mars, we will receive information next year, if we're

back next year we will show you the news from Mars.

Over to Liz. Welcome back to the South African

astronomical observatory. We are at the one metre telescope, British-

built in Newcastle. Normally this telescope looks at objects far

beyond our Solar System, take a look at this image it has taken of

Saturn, 900 million miles away from us. Neptune is our outer most

planet in the Solar System, another two billion miles outside Saturn.

That is not where the Solar System ends, in fact, we have still a lot

to learn about this very mysterious The Karoo desert might look more

like an alien landscape than in Britain, but this place is still

unmistakically part of our home, planet earth. Fertile soils, the

warmth from our sun, a great diversity of living things. It is

all down to our unique position in the Solar System. Where the third

rock from the sun, not too hot, not too cold, just right for life to

flourish. Of course, we are just one of a

family of planets. If my rucksack is the sun, we have rocky planets

first, Mercury, Venus, our own planet earth and Mars, then the gas

giants, Jupiter and Saturn, Uranus, Neptune and Pluto. Which has been

reclassified as a dwarf planet, it is no longer a planet. Then what

happens? What lies beyond our eight planets? And where does our Solar

System actually end? Amanda is an astronomer working here in South

Africa, she specialises in the distant objects that inhabit the

remotist regions of our Solar System.

If this is Neptune, what is going on between it and the nearest star,

over the horizon if it is four light years away or more, is it all

empty space? It is hardly empty space, we have discovered a lot of

objects out there, rocky objects, they are called the Kuiper Belt.

There are 70,000 out there we think. That sounds like a lot of objects

swimming around in the area. 70,000 are the biggest ones, if you go

down to the smaller ones we think it is billions. How wide is it?

you think of how far Neptune is from the sun, the classic Kuiper

Belt is that far from Neptune. is wide, does that mean Pluto is

officially a Kuiper Belt object? is in that Kuiper Belt, it was one

of the first objects to be discovered. If we have gone that

distance from the sun to newspaper tune again, that is the Kuiper Belt,

here it is at the edge of the Kuiper Belt, what happens here, is

this the edge of our Solar System? Not yet, we still have objects that

were discovered out here that have objected that go -- orbited that go

beyond the Kuiper Belt, we call them the scattered disc. How many

objects exist there? Maybe hundreds, a few very well known, though.

There is one called Aris, it is about three-times as far away from

the sun as Neptune is now. What does it look like? We have images

from the Hubble Space Telescope. is a bit blury? From the image you

are seeing reflected light, there are severe limitations to doing

that kind of imaging. That is the furthest object we have seen with

the telescope. When you get to the edge of the scattered disc, surely

that is the edge of the Solar System? No, there is more. Beyond

that is a structure that we have they areised called the Oort Cloud,

hundreds of thousands of objects srpbd the Solar System, two light

years away. Is that the end of the Solar System? If you want to call

it that, that is as far as we know, as far as the sun's gravitational

influence he can tends. I would say it is pretty much the end of the

Solar System. How do we know what this Oort Cloud

looks like if it is hypothetical? We have observational evidence in

the form of comets, they come from all different directions, when we

trace their orbits they come from far away, distant parts of the

Solar System. Do all comets come from the Oort Cloud? No, we had a

comet visible from here, Comet Love Joy, take a photograph here of by

one of the IT guys. Your expertise is the Kuiper Belt and the

scattered disc, you say it is difficult to get information from

the images of the objects, how do you study them further? We have to

be creative, we have the stellar augmentation. We look at the

objects passing across the scattered discs, and the shadow, we

learn about the size, properties for the atmosphere, how the

atmosphere might be changing, we combine that with things we know

and get the density. It is easy to know where the shadows are cast on

the planet? It is really hard, we spend a lot of time measuring. A

shadow Pat can come across Sutherland and we can be lucky,

there is a lot of telescopes, sometimes not, then it gets

exciting. Last year I rented a pick-up truck in Cape Town and

putting a 12-portable telescope in the back, and one of our

instruments built for the purpose, we crossed the border in Namibia,

and put all this equipment out, and looking over our shoulder all the

time for animals. You were tracking an interesting object? It was a

large Kuiper Belt object, it was a strange result, it suggests the

object is really elongateed, that is not what we would have expected.

Come back to us later, I will be finding out about superWASP-.

Discussion as it,were the edge of the solar -- discussing as they

were the edge of the Solar System, which Voyager is heading there now?

It is one of the great stories in space exploration, launched in 1977,

Voyager 1 and 2. They were launched to do the grand tour of the Solar

System. At that time you launched a spacecraft, you could visit Jupiter,

Saturn, Uranus and Neptune in one mission. It happens very rarely.

Off they went, ambitious spacecraft. I remember talking to one of the

designers, they were designed to last two or three years, four years.

It was expensive saying this spacecraft will last for 20 year,

you have to build it like a tank. I have a picture of it there. It is

about the size of a bus, or a car. It is a tiny little thing. At the

moment Voyager 1, the most distant man made object. It is 17 million

kms away -- 17 million kilometres away, 14 times the distance from

the earth to the sun. It is powered by a little battery and can be

detected now. What the Voyager 1 has done and II, is the place where

the wind from the sun meets the wind from interstellar space, they

are measuring that, the instruments are still working, and they send

the data back. The coolist thing is they do it on a tape. Most of our

viewers under the age of 20 won't know what a tape is. It is a piece

of magnetic brown stuff used to record Top Of The Pops on. It

records the data, every so often it gets its transmitters point it at a

telescope and sends the information back. NASA are saying they are

turning off some of the parts of it now to conserve energy, they think

they can keep it going until 2025? The heat has been turned off, it is

one of the coldest working things we have built, it is sending

information and should keep working until 2025. That is a brilliant

example of the things we can do when we put our minds to it. Before

we go back to Dulverton have a look at this? This is Britain on a clear

night from space. You can see the major cities, London, Birmingham,

Manchester, Edinburgh, Newcastle. It is a mess, basically. 60% of us

live in a severely light polluted area, it plays havoc with

stargazing, it is not difficult to reduce. Several iconic buildings

have been leading the way for us. This is Worcester Cathedral, they

switched off. Here is Bristol's Clifton Suspension Bridge.

Even down in Cornwall, the Eden Project, they have been dimming

their lights for us in order to get a clear view of the sky. We have

the tower in Portsmouth. There it goes.

This is BBC Media City in Salford, witching off its lights.

We want to see just -- switching off its lights. We want to see the

big difference switching off lights can make, even in a small town. It

is time for Dulverton to switch off. This is it, after months of

planning, the bells are going to ring very soon, and hopefully it

will be very dark. We need everyone in Dulverton to turn their lights

off as soon as you hear the bells ringing. I will invite my posse to

help with the countdown. I was going to say, are you ready

for this, Dulverton? I think you are.

(cheering) We are now going to start the countdown.

5-4-3-2-1. (bells ringing) This is the moment

where the bells should start ringing, instead, I want you all to

shout "ding dong". We can hear the bells, we can see

the lights going out. Except for the place beside you. So far the

lights in the street has have all gone out. It is really eerie. It is

bizarre. Look at that. It is a shame that you can't see the sky.

There it is. This is amazing, I can barely see the camera in front of

me, it has got so dark. We can't see the sky. What I would say,

eventhough it is cloudy, the sky has leapt out above our heads. We

have special night vision cameras, because there is no light around.

It looks incredible. But it is going to take a while for our eyes

to adapt to the darkness, come back in a few moments and see how we are

getting on. It is a wonderful moment that, it is easy to treat it

as a bit of a stunt, it is cloudy so you don't see the stars come out.

There is a genuine point about losing contact with the night sky.

If you think back to the time, you heard how old you are, you can't

think back to the time before electricity. But the stars were

visible, they were part of our lives. It is the foundation of

science, astronomy is the oldest science, the motivation to

understand the view that if you live in a city all your life, you

don't see it. It is a powerful thing to do.

It is very striking, we know we are doing it on bad day. We know the

weather wasn't perfect, but if they can do it for us now, there is no

reason they can't do it at a better time of year. Because it is the

last show, I usually answer the questions, but because Dara has a

degree of physics and cosmology from one of Ireland's premier

institutions. Dara will be answering the questions.

Katie asks, why doesn't planets twinkle in the sky? I always

presume it is because they were further away and more chance of

fragments of dust and other things to pass away. It is not, because

they are so far away, they are a point source of life, a single beam

of life light, when it hits the atmosphere and gets bounced around,

it gets deflected, much better than planets who have a number of points.

They are bigger, it is extended source, that is the term for it. It

is easier for them when they come into the atmosphere to remain

coherent. That is the only one we have time for. 100% record. If we

find life in the Solar System, it will only be certainly at the

microbe level. If we want to find substantial life forms, we have to

search for planets much further out in space. Take a look at this image

found by the Hubble Space Telescope, it is called Fomalhaut.

It is a star called Fomalhaut. have removed the star from the

image, the bright centre is gone, we can see around it. What you are

looking at is a very young star, a bright blue star. It is one of the

brightest stars in the sky, it is in the southern Hemisphere so we

can't see T it is a very young star. -- it. It is a very young star. You

are looking at a prime mordal disc. That is what our Solar System may

have looked like over four billion years ago. That is interesting. It

is a beautiful image. The most interesting thing about this n this

square here, it is blown up. There is a large object here. It is

actually a very large object. It is, in fact, a planet, in a very early

stages of its formation. How rare is that to see. Has it ever been

seen? No planet had been photographed before. They are

extremely faint. It was all the techniques outlined in the

programme. This shubl pays telescope image is a planet. It

wasn't moved there in -- Hubble Space Telescope image is a planet.

It is a long way out from the star. Is it gathering up and building up

dust, like the process which our planets were made. We think planets

begin very small, only a kilometer across or smaller, over time in

collisions they aggregate, the biggest ones begin to suck up all

the dust. Eventually in that system you will get a clean Solar System

like we get today. Scientists have discovered 700 exo-planets, each

and every one of these discoveries have been made in the last 20 years.

We have been looking at nebulae and planets over the years, we had to

get until 1982 for our first exo- planet, and here is why.

To understand why it is so hard to find planets orbiting distant stars,

you have to get a sense of how far those stars are from us here on

earth. If I were to build a scale model of the galaxy in the Milky

Way, starting here with the Solar System and this is the sun. Let's

say I put the earth one centimeter away. If the earth were that big,

the sun would be as big as this tea shop. Ignore that for a minute.

Let's say this is the sun and I put the earth one centimeter away. That

is known as one astronomical unit. To the outer planets of the Solar

System, Neptune, that is 30 astronomical units, 30-times

further away. On wards to the edge of the Solar System, there is the

exo-planet, Pluto. That sits around 50 astronomical units away. We have

about 50cms representing the size of our Solar System, out to Pluto.

Now, on here somewhere, on a mountain, on the earth, in Hawaii,

there is one of earth's most powerful telescope, the Keck

telescope, it took a picture of Neptune and its moon. This is the

most powerful photograph we have, and it is a featureless blob. At

its further point from the sun, Pluto is 50 astronomical units away.

That is nothing when you are building a model of the Milky Way.

Because the nearest star to our sun is 268,000 astronomical units away.

It is a star called Proximus Antori. I have to get much further out to

mark its scale. If the earth is one centimeter away from the sun in the

tea shop, then Proximus would be here, two kilo metres away, that is

the nearest star. The telescope doesn't have trouble seeing it,

although it is four light years away, it is 100-times the diameter

of Pluto, and it is a star, a giant nuclear fusion reactor, giving out

light. Imagine trying to see planet in orbit around Proximus Antori,

they are smaller than a star, they don't give out light, and they

reflect t they get lost in the glaer of the star. Trying to see a

planet around Proximus Antori, would be like trying to see a grain

of sand, 100 miles away, in the glare of a spotlight. Planets

orbiting distant stars are so far away and difficult to detect, we

discovered one for the first time, just 20 years ago.

Far too distant to be seen by any telescope on earth, it was found by

scientists who weren't looking for planets at all. They were looking

for pulsars. Pulsars are neutron stars, the

remains of dead stars. The leftovers of supernova explosions.

They are incredibly small and dense. They can be the size of a city, but

be more massive than the sun. They can spin very fast on their axis.

When they do that, you get beams of intense radiation, a spinning

around. Like a lighthouse beam. That lighthouse beam can cross the

face of the earth. So we see a series of bright, regular pulses,

and that is what gives them their name. The timing of the pulses is

so precise, that they are as accurate and reliable as an atomic

clock. But in 1992, scientists noticed something strange. One of

the pulses missed a beat. It was as if the pulsar had wobbled. Our sun

also wobbles as it spins on its axis. That is because it is

surrounded by planets. The gravitational pull of the sun keeps

the planets in orbit, but planets are also massive objects, they

exert a gravitational pull on the sun. That causes it to worbl

slightly. So -- wobble slightly. So scientists back in 1982, realised

they were seeing the same thing happening to the pulsar, those

precise rite Mick beams were being knocked out of -- rhythmic beams

were being knocked out of sync slightly by the gravitational pull

of the planet. The discovery proved there is a way to find planets too

distant to be seen. They can be detected because they cause the

stars they orbit around to wobble. Around three years after the first

one was discovered, another worbl was discovered in the orbit of the

Pegasus. It was not dead, it was a star like our sun. It was the

unmistakable sign of a planet. They named it 51 Peg. The discover of 51

Peg b was a watershed moment, it was the first time to find planet

orbiting a living star, beyond our Solar System. Today we found over

700 planets, fascinating in itself. But for me, the most interesting

thing is it takes us closer to a far more precious goal, which is to

discover an earth-like planet around a distant star, a planet

that maybe could have life. So I can see why a wobble would be

obvious in a pulsar, sending out these huge jets of radiation. A

star like our sun doesn't do that, what is this wobble? The only thing

you can do is look at the light. Stars do wobble. We have graphic

here, which shows a star, and a planet. The star, which is here,

looks as though it is orbiting as well, that is because it is. The

star and the planet orbit around what is called the common centre of

mass. The star will move a little bit. Think about the light that

star is emitting, now if the star is coming towards us, then the wave

lengths of that light become squashed, which means the light

moves to the blue bit, the shorter wavelength of the spectrum. If the

star is moving away from us, the light is stretched and the light

shifts to us a long wavelength edge of the spectrum. That is called the

Doppler shift, if you look at the spectrum of light from a star, and

can you see if it is moving towards us and back, and towards us and

back. By measuring that precisely you can infer there is a planet

around it. That wobble can only occur if the planet is making a

star? Really large planets so it is a substantial effect. The best

technique for finding smaller more earth-like planets the transit

method, which is what we have been using for our planet experiment

over the last three nights? That looks for the dips in the light

measures of distant stars. You can see it in the graphic, the planet

crosses the face of the star, as seen from earth, and the light will

drop as it leaves. 35 of the confirmed exo-planet discoveries

came from Kepler, the planet hunting telescope, it is possible

to search from earth. One of the best in the world is called

SuperWASP. It is based in South Africa. Run remotely from Britain

by scientists from Keele University. Believe it or not, by the push of a

button. Liz is standing next to it. If we press this, that will kick

off. There we go. How is that Liz? Good skills, Dara,

don't let all that power go to your head now. This is SuperWASP. Super

Wide Angle Search for Planets. When Dara isn't interfering with it, it

is run remotely from Keele University in Staffordshire. One of

their astronomers was in town earlier this week, giving it an MOT,

I caught up with him to find out how this gorgeous machine works.

So we have eight cameras here, each of which has an enormous field of

view. It images 1% of the sky. looks like a fairly simple set-up,

eight digital cameras, how do you go about finding exo-planets?

monitor the same patch of sky, 50 times a night, we continue to do

that for five months. At that point we have a measure of the brightness

of the stars over time, and we look for periodic dimming that could be

caused by a planet passing in front of the stars. We use bigger

telescopes using another technique to confirm it is a planet. One in

12 turn out to be so. How many exo- planets has SuperWASP found? 75 and

counting. The planets we find, because they are easiest for us to

find, are called hot Jupiter, planets around the size of Jupiter,

much closer to their star than Jupiter. Which one interests you

the most? One I'm fond of is WASP17b it is the first one in a

retrogade orbit, it spipbs one way and the star the other way. It is

counter to any planet known before and in the Solar System. It is

discoveries such as these which is refining planet theories and

evolution. With such confirmed exo- planets, what are the chances of

one of them keeping life? The ones found are increasingly like our

planet earth, I think the chances are very high. I think we will find

life on another planet, within our lifetime.

The reason why David isn't standing beside me right now for a bit more

of a chat, is he's on his way to Chile right now to verify another

bunch of exo-planets .5 confirmed exo-planets and counting, watch

this space. 75 confirmed exo- planets and founding, watch this

space. You saw the Lovell telescope being controlled by Dara and

pointed towards Kepler 22b. Why have we done that? Kepler 22b is

one of the best candidates for complex life outside the Solar

System. As I said at the start, it is 600 light years away, a long way

away. I don't think we will hear any signals from a civilisation.

You never know. It has never been done before. I'm quite excited.

number of our planets are in the region, we obviously are. Let me

talk about the habitable region. There is a zone around any given

star, around the sun it is the zone which the earth sits, but also

Venus and Mars sit in that zone. It is the zone where roughly speaking

the temperature will be right for things like liquid water and rich

oxygen atmospheres to exist on planets. It is not a given that

life will occur. Venus and Mars, there is no real evidence of any

major complex life on those, eventhough they are in the hab

table zone? Mars is too small, it is in the Habibi bittable zone, but,

Venus has the hottest surface in the Solar System other than the sun.

But Kepler 22b is in a similar zone around its star. Whilst you can't

say for certain it is a habitable planet, it could be like Venus,

Mars or none of the three. There is a chance that it is habitable. That

means there is a chance that telescope is pointing at a

civilisation of alien.S. Later in the show we will hear them.

We will explain what the discovery could mean, and to tell us why it

is so important is Giovanna Tinetti? It is a very exciting

planet, Kepler 22b, it is orbiting a star very similar to the sun, it

is the exact distance to the star to potentially have liquid water,

that is why it is so interesting. What's the next step, how are we

going to begin to characterise that planet and perhaps look for the

signs of life? Essentially what we are doing right now with planets

that are slightly hotter and bigger than Kepler 22b, is to use the

method to look at their atmosphere, trying to get the composition of

the atmosphere. We are looking at some light curves and preeting that

at different wavelengths. You have to wait until the planet comes back

around again and measure the light as it comes through the atmosphere?

Exactly what a challenge, we can do it for other planets now. Is there

a chance, Kepler 22b, is there a chance to map that planet out in

detail? I'm afraid Kepler 22b is probably too far away to do this

kind of measurement. We can certainly do this kind of

measurement and planets around a starch closer to us, certainly we

will do that with the dedicated space mission in the future, like

Echo. As the light goes through it, what are the tell tale signs, what

are you looking for? We look at the spectrum and look at the signature

of some molecules, if you are interested, we are looking for

molecule that is tell us something about if this planet is inhabited

or not. I would love to see liquid water, or some water vapour, and in

particular, having some signature or ozone or oxygen, like on earth,

that would be an interesting signature. In earth's atmosphere,

oxygen is only present because of the action of life in large

quantities, if you saw that in one of these planets, you would be

fairly certain there is life. We have to go back to Dulverton now,

I'm afraid. They have had 20 minutes to get used to the dark.

Usually in astronomy it takes 20 minutes for your eyes to

acclimatise. We will go back to see how different the place feels. That

was nothing more than amazing. To see the lights go out. Every single

light that I could see in the Main Street has gone out. It went so

dark. It has taken our eyes a little bit of time to adjust. It is

like being in the countryside but in the middle of a town. Joining me

is a local astronomer. What is it like having all the lights out?

is very much like how it was when I was younger. I could come out and

see the great ribbon of stars in the Milky Way, now all the fainter

stars have gone. It is a chance to get that back again. If it was

clear it would have been lovely? would have been glorious. It is

great to see the way it has worked. We're joined bit headmaster of the

local school. The entire community has come together for this? They

have, it really has company turd the imagination of the communety.

You only -- captured the imagination of the community. You

only go walk down the street and see the effort the shopkeepers have

made. Hopefully it is the start of something and we get left with a

legacy we have already been talking about forming a local astronomical

society, and having a sunnor branch based at the schools. That is in--

A junior branch based at the schools. This has shown tonight,

regardless of the fact we can't see clear stars, everyone can take

responsibility for light f we can do that and think how we are using

it we can make a difference. If you want to learn more go to the

website. You can find a link to the dark skies discovery network on

[email protected]. You can find out where the local

dark spots are and recommend your own dark sites.

I have to say, I'm just the messenger, not the person who

brings the weather, one night this week we really needed those clear

week we really needed those clear skies. At Dulverton the rain has

moved in, the same across many parts of central, southern England

and Wales overnight. The best chance to get the telescope out,

eastern England, Northern Ireland, Scotland. Cloud will vair year, but

lengthy clearer spells, even clearer spells across parts of

western Scotland. Tonight, clearer spells in the north, tomorrow we

might reverse it a little bit. Scattering of showers expected.

These will be mainly to northern and western areas. Some of those

will be wintry. Eastern Scotland, north-east England, get out early

on before the cloud thickens up. For much of England aWales, away

from the north and west, a few hours before the cloud pushes in.

Into the weekend, whilst seeing plenty of showers, across eastern

and southern parts, the air will be fairly clear at times. A cold air

mass coming down from the north, the clarity of the air should

the clarity of the air should increase as well. Happy stargazing.

I thought that showed the real spirit of stargazing, eventhough it

is cloudy in Dulverton, even the act of making it dark, the school

will be getting involved and the astronomical Society being formed,

and the schools getting involved. Try it every night of the year! We

set the dish moving at the beginning of the show, we now have

a unique chance to listen to the radio waives coming from an exo-

planet, Kepler 22b. What should we listen out for? We should listen to

what the Hubble Space Telescope usually hears, the radio waves

created into sound. This is space noise. It sounds like empty static.

That is just radio astronomy, there is data in there. Listen to this.

(knocking) If you heard that, would you think that's regular, that is

not natural. In fact, that is natural. That is the sound of a

pulsar. When it was first heard, the first pulsar was discovered,

that was named LGM1 that means "little green men 1". For a few

days it was thought how can something from nature be so regular.

If we hear that from Kepler 22b, it is a pulsar. If we hear a regular

beat like that, we would have to postpone the news. There is only

one incident where something was heard that couldn't be explained.

It is called the WOW signal. It is a picture of it. That is the

picture of the data from a radio telescope a regular strange signal

was heard, to this day it hasn't been explained. It is called WOW,

because the radio operator wrote that next to it. They have gone

back to the skies, and nothing has been heard since. It remains

genuinely unexplained. Tim comes back in, if we do hear

something you would really want to be here? Certainly. I have my

fingers crossed. Do we think we will hear anything? Tim it is

probably too far away even if it was a noisy civilisation. If they

put a beacon there. A strong enough transmitter and telescope, you

never know. This is the sound coming to us live from Kepler 22b.

(static noise) That is quiet you have now. It is quiet, that is what

we expected, of course. Tim, it sounds like a game, it sounds like

science fiction. It isn't, there is the SETI project, which this

telescope has been involved in, searching for signals. It is a

serious possibility, if you don't look you won't find anything. It is

worth having a look and listen in this case and analysing the signals

very carefully, just in case. search for exo-planets, now we can

focus where we look for possible civilisations. We may be closer

than ever to finding a planet with life, but the idea of attempting to

communicate with civilisations in the distance is not new. What would

it mean to make first contact? It is easy to find the idea of UFOs

and extraterrestrial life a bit of But for centuries scientists have

taken the idea of alien contact very seriously. Early astronomy

revealed our Solar System contained other planets, and as soon as we

thought there could be worlds like our's nearby. We couldn't wait to

tell them that we were here. We were sentient and we were dying to

say hello. If you look certainly at the 19th century, there was some

quite prominent scientific figures who had really quite practical

ideas for how you might try to communicate with alien life. So,

for example, Carl Friedrich Gauss, a very famous mathematition and

scientist, had an idea for cutting enormous geomet kal shapes into the

Siberian forest which would be -- geomet kal shapes into the Siberian

forest which would be seen from space.

He felt strongly that the sun might be a habitable place, and it might

be worth looking for life forms we could communicate on the sun.

As astronomy became clear, it was thought that aliens had to be out

joyed suer Solar System. Science had to develop enormously before

messages could be sent out to other worlds. In the 1970s NASA launched

the Pioneer and Voyager probes, sent to look at the outer Solar

System. In case they came across aliens, on board they carried

information about us. Pioneer contains a plaque which has

on it the location of the Solar System, some basic scientific

information, and most famously a picture of two naked human beings,

generally thought to be average Americans, in mellow greeting. You

know the way average Americans are this buff and hairless. At the time

of the Voyager launch, more information could be encoded,

including an entire disc of sounds of the earth, more scientific

information, and images of our history and culture. Whether of

hunting, the moment of conception, and that guy. Images of licking,

biting and swallowing, as some sort of threat, presumably. To counter

act that, we also included greetings recorded from people from

all over the world, in their own However, these messages would be

very difficult for any alien life form to find. Although the Voyager

I probe is now the fastest and distant human-made object in the

universe, it is still comparatively nearby, inconspicuous and slow.

Creatures from other worlds would literally have to bump into it in

order to retrieve the message. It won't even reach the nearest star

system for another 40,000 years. But there was another way in which

we could search for alien life, radio waves. In 1960, visionary

astronomer, Frank Drake, made the first deliberate attempt to detect

signals from other world. Scientists from around the world

soon joined the search, which became known asset at this, the

search for extra terrestrial intelligence. It dawned on radio

astronomers in the 1950s that these big radio telescopes can be

limitless in size. They are capable of enormous sensitivity. They

communicate not just across terrestrial distances or

interplanetary distances, but truly interstellar distances. The fact we

can search for messages throws up another question, what do we do if

we find one? And what if by sending a message we attract the attention

of great big extraterrestrial monsters who want to eat us. Even

if their intentions are benign, we could be opening ourselves up to

unexpected dangers. Afterall, our own history of encountering foreign

culture offers a cautionary tale. Very often they started like

Captain Cook arriving in Hawaii, with best intentions, handshakes

and smiles wall the way round. But Captain Cook still didn't survive

the encounter. Despite all the friendship and treaties, within 150

years, 90% of people in Hawaii were dead, because of diseases that were

unintentionally introduced. Even when things are all shand shake and

-- handshake and friendly there can be terrible consequences. None the

less, the SETI post detection task group is standing by, should an

alien signal arrive. Professor Paul Davies could be among the first to

receive a message from ET, his response might not use words at all.

The things we would truly share are the things that are literally

universal throughout the universe, that is mathematics and fistics,

the laws of physics are the same throughout the universe, and

mathematics are the same throughout by that definition. One could build

a broader dialogue, and after thousands of messages back and

forth we could tell them about our politics and sport. We can hope

that their politics and sport doesn't include eating us! The

truth is, whatever the price, receiving an alien message will

confirm what some of us are desperate to know, that we aren't

alone in the universe. Three nights ago we asked you to do

something very special, we wanted you to help us find a Stargazing

exo-planet. Chris Lintott is in charge. Have we found planet?

have, we think we have. We were looking for the dips in light in

the stars' brightness when planets get in front of the parent star. We

found one in particular that two people told us they were the dips,

we went back into the data and found five of the tips, each 90

days apart. We think it is planet that goes around this particular

star once every 90 days. How many people responded? Over 100,000

people, well over a million classifications, one million and

84,000 classifications. These are ordinary people, watchers of

Stargazing? They went to the website, the PlanetHunters, lock

logged on and -- logged on and did what people are still doing now

Let's see the data. I want to name it. This is Lee

Threplton, and then Chris Holmes, on the right, later on, that is 90

days later. We are looking at the light from the star, characteristic

dip of the planet crossing the face of the star. If you look to 90 days

after, that we dug into the computer. It should be noted there

were others who spotted these planets they were after Threpl to n

and Holmes. Those names down the bottom of the screen have

identified it and others too. is lots more we have got there.

More data we are put anything right now. If anyone else wants a planet

named after them they can go there. We have an artist's impression of

the planet. It is Neptune-sized. It is gaseous, it is a hot Neptune, it

goes around its star in 90 days, as close to the star as Mercury.

is the planet we are unofficially and bindingly calling planet

Threplton-Holmesb. Where is it? outside now, stair ten degrees in

the North West, between Deneb and deep Veg a. You need a pretty big

telescope but they found it on-line, but they found it. It is gas planet,

we wouldn't necessarily find life? It is too hot, it is in The Golden

Calf zone t might have a moon, you withstand on one of the moons and

look at the wonder that is Threplton-Holmes. Thank you, this

is incredible for me, our audience has found a new planet around a

distant star. And named after two guys we have never met. What an

amazing way to bring the programme to a close. Goodbye to Liz in South

Africa, we found a planet Liz, can you believe that? That is such

brilliant news. Isn't it astounding what we can achieve in this day and

age. I know we have had cloudy skies the last three nights t has

been a privilege to be here and learn about the skies in the

company of hugely inspirational astronomers, a big thank you to

them, they have been wonderful. Armed with the telescopes they are

helping us take huge leaps in our understanding of the universe,

especially in the hot topic of exo- planets. They are revealing how

much there is left to learn about the universe, not just in deep

space, but also within our very own solar siste. It is really a very

exciting time to be an -- system. It is really a very exciting time

to be an astronomer. That is all from the team in South Africa, back

to you at Jodrell Bank Observatory. That is a glorious sky, finally

seeing a good sky over South Africa. Stay with us for Back To Earth,

coming up immediately afterwards. We have many questions to raise

about the inhabitants of Threpleton-Holmes. There is warring

factions I'm sure. There is more information on the website. Find