Episode 1

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:00:38. > :00:44.Welcome to a rainy Jodrell Bank Observatory in Cheshire on the day

:00:44. > :00:49.we discovered we are only one of the 17 billion Earth-like planets

:00:49. > :00:53.in our Milky Way galaxy which is one of 350 billion galaxies. Of all

:00:53. > :00:56.those, we will be focusing much closer to home. We will take you on

:00:57. > :01:03.a journey to the surface of Mars, to join one of the biggest quest in

:01:03. > :01:13.all of science - the hunt for life. I'm Brian Cox. He is Dara O Briain.

:01:13. > :01:38.

:01:38. > :01:42.We may be insignificant... And wet! Yes, welcome to a damp night here

:01:42. > :01:46.in Cheshire. Come with us inside, into the control room of Jodrell

:01:46. > :01:50.Bank. It's the jewel in the crown of British astronomy. Scientists

:01:50. > :01:55.tracked Sputnik from this site. They also performed the early

:01:55. > :02:00.detection of the first extragalactic radio signals. And

:02:00. > :02:07.were instrumental in discovering Pulsars. 2012 was a huge year for

:02:07. > :02:13.astronomy. We had the transit of Venus. And also we celebrated the

:02:13. > :02:19.lives of three men - Neil Armstrong, Sir Patrick Moore and Sir Bernard

:02:19. > :02:25.Lovell. Tim O'Brien is here, the associate director of Jodrell Bank.

:02:25. > :02:35.A sad year for Jodrell. But in other ways a great year. I have

:02:35. > :02:35.

:02:35. > :02:42.noticed new buildings? This is the global design headquarters for the

:02:42. > :02:48.Square Kilometre Array. How big is that? The Square Kilometre bit is

:02:48. > :02:53.the overall area of this telescope. It is 220 times the area of that

:02:53. > :03:02.dish. It is thousands of individual receivers spread over hundreds or

:03:02. > :03:07.thousands of kilometres. This is the base for - the British design

:03:07. > :03:11.base is here. Yes. So many exciting things are happening. What we want

:03:11. > :03:21.you to do is to prepare to journey with us to the stars. This is what

:03:21. > :03:24.is coming up this series: We will be exploring some of the

:03:24. > :03:27.biggest questions in science. We will be investigating the entire

:03:27. > :03:32.history of the universe, the formation of the Solar System and

:03:33. > :03:39.the origin of life itself. We will be looking at our own crowded

:03:39. > :03:43.corner of the Cosmos. We are live from NASA this year.

:03:43. > :03:47.The birthplace of scores of space probes that are scattered across

:03:47. > :03:50.the Solar System. We will watch the next space

:03:50. > :03:54.missions being prepared and we will be communicating with the Curiosity

:03:54. > :03:58.Rover which is exploring Mars as we speak.

:03:58. > :04:04.Closer to home, we are building our own version of one of the most

:04:04. > :04:08.important telescopes in the history of astronomy. We will find out how

:04:08. > :04:13.photography helped us to plot our position in the universe.

:04:13. > :04:21.As ever, we will be telling you what to look out for in the skies

:04:21. > :04:28.above your head. We don't want you to be passive

:04:28. > :04:33.consumers. If you have a question, then e-mail it to us at

:04:33. > :04:41.stargazing@bbc.co.uk. Or tweet us - @bbcstargazing. We want to see your

:04:41. > :04:48.best astro photographs. The website is bbc.co.uk/stargazing. You will

:04:48. > :04:55.also be able to join in our live webchat. Last year, you, the

:04:55. > :04:59.viewers, discovered a brand-new candidate planet. Amazing

:04:59. > :05:05.achievement so we thought we would ask you once again for your help.

:05:05. > :05:09.This time we are going to search on the surface of Mars. Join in with a

:05:09. > :05:16.mass participation experiment to explore a totally uncharted area of

:05:16. > :05:21.the Red Planet. Dr Chris Lintott will be here with the details later

:05:21. > :05:27.on. As always, to tell us what is visible tonight, Mark Thompson is

:05:27. > :05:29.standing outside in a muddy field. How is it looking? Yes, I'm here

:05:29. > :05:37.with the Liverpool Amateur Astronomical Society. How you

:05:37. > :05:43.doing? CHEERING It has been a cloudy, wet day. The rain has

:05:43. > :05:47.stopped so we do remain hopeful, don't we? ALL: Yes! So we will see

:05:47. > :05:53.how it goes. If the skies are clear where you are, you will have missed

:05:53. > :06:01.your chance to see Mars tonight. You can see it just after sunset,

:06:01. > :06:07.ten degrees above the south-western horizon in the constellation of

:06:07. > :06:11.Capricorn. If you want to see it, you will have to get out there

:06:11. > :06:15.soon! If you are luckier than us and the skies are clear, there is

:06:15. > :06:22.plenty still to see tonight in the south-eastern part of the sky. We

:06:22. > :06:28.have Taurus rising up in the sky. Jupiter is shining bright just

:06:28. > :06:33.above us. Come back to us later. On the day that David Bowie

:06:33. > :06:43.released his first single for 11 years, we are going to be asking...

:06:43. > :06:47.

:06:47. > :06:53.# Is there life on Mars? # In August, NASA landed this, and it

:06:53. > :06:57.didn't work! This would have been a picture of the Curiosity Rover. Its

:06:57. > :07:03.mission is to help answer some of the biggest questions in science.

:07:03. > :07:09.Has Mars ever had an environment that was able to support life?

:07:09. > :07:13.Bonnin has travelled to NASA's Mission Control. Welcome to NASA's

:07:13. > :07:19.Jet Propulsion Laboratory. Ever since the first American space

:07:19. > :07:23.mission in 1958 with Explorer 1, JPL has sent out over 100

:07:23. > :07:28.spacecraft throughout our Solar System and this is Mission Control

:07:28. > :07:31.for its latest explorer, the Mars Curiosity Rover. These are the

:07:31. > :07:36.engineers that monitor her every move and get the very first glimpse

:07:36. > :07:39.of all the data she is sending back. Tonight, I will be meeting the team

:07:39. > :07:43.that put Curiosity Rover on Mars. We will find out what she has

:07:43. > :07:46.taught us so far about the Red Planet and I will be meeting her

:07:47. > :07:51.twin here at JPL. We are exciting to be coming live

:07:51. > :07:56.from NASA tonight. NASA are just as excited. A load of their staff are

:07:56. > :08:01.watching it on their lunch break! Good afternoon to NASA! We will get

:08:01. > :08:08.a wave off them once... There we go! Fantastic! Lovely stuff. This

:08:08. > :08:17.makes me more scared! Good afternoon, NASA! What do you do for

:08:17. > :08:23.a living? You work at NASA. Good for you! They are all over Mars at

:08:23. > :08:31.the moment. Yes. I think a few facts about Mars. Mars is our

:08:31. > :08:35.closest neighbour. The last of the rocky planets. And in some ways its

:08:35. > :08:41.best days are behind it. Its volcanoes are the highest in the

:08:41. > :08:47.Solar System. It has river beds so it must have had water. It had an

:08:47. > :08:51.atmosphere but it has now lost it. Yes. Also very interesting for

:08:51. > :08:55.amateur astronomers. You can see the surface of it which you can't

:08:55. > :08:59.say for Venus. We have an image which we took last March when Mars

:08:59. > :09:08.was in opposition which means when it was at its closest point in its

:09:08. > :09:15.orbit to Earth. We used a 14-inch reflector for this. You can see the

:09:15. > :09:21.Red Planet. You can see detail at the pole, I think. It is a planet

:09:21. > :09:26.that an amateur can observe, sketch and see things on the the surface.

:09:26. > :09:29.Our special guest tonight is a keen amateur astronomer, also a

:09:29. > :09:35.professional astronomer in some ways, Dr Brian May. Thanks for

:09:35. > :09:40.joining us. Dr May, how are you? Very good. Welcome to Jodrell Bank.

:09:40. > :09:45.Thank you. When was the last time you were here? 1968. As a new

:09:45. > :09:50.graduate I came here for a job. Sir Bernard Lovell interviewed me and

:09:50. > :10:00.offered me the job. To my shame, I didn't take the job. I went back to

:10:00. > :10:01.

:10:01. > :10:05.Imperial College. You went through a phase... Other things happened.

:10:05. > :10:15.Something happened musically! the band happen mid-way through the

:10:15. > :10:19.

:10:19. > :10:29.PhD? Did you ditch that? The PhD got tired and music called me.

:10:29. > :10:32.

:10:32. > :10:37.that happen to you? That is you in 1971? Yes, in Tenerife. You got

:10:37. > :10:41.your PhD. Mars, the planets. You are a particular fan of gazing at

:10:41. > :10:47.the planets? Yes. Mars is difficult. I wouldn't make out that it is too

:10:47. > :10:54.easy. You have to have patience. Eventually, you might see the polar

:10:54. > :11:00.ice Caps, which is a thrill. If you go to Saturn, it will be a big wow!

:11:00. > :11:10.You do it in London? I have a telescope in the country. I much

:11:10. > :11:14.prefer my telescope on my roof in town. People laugh at me and say,

:11:14. > :11:20."You won't see anything." It doesn't matter. You can see stuff

:11:20. > :11:24.fine in London. Our knowledge of Mars has been revolutionised thanks

:11:24. > :11:28.to the extraordinary work of scientists at places like NASA.

:11:28. > :11:31.They have sent 15 missions to the Red Planet and it has transformed

:11:31. > :11:40.what we know about the landscape and conditions there. Let's take a

:11:40. > :11:49.look at what they have managed to achieve in that time.

:11:49. > :11:54.In 1964, we got close to the Red Planet for the very first time.

:11:54. > :12:04.NASA's probe sent back pictures of the surface, inspiring a generation

:12:04. > :12:10.

:12:10. > :12:15.of Martian explorers to go back and find out more. In 1971, the first

:12:15. > :12:19.spacecraft went into orbit around another planet and sent back

:12:19. > :12:23.detailed pictures of Mars' volcanoes. NASA's Viking landers

:12:23. > :12:30.touched down on the planet's surface by the middle of that

:12:30. > :12:37.decade. # The boys are back in town. #

:12:38. > :12:42.Their cameras beamed back pictures of a rocket desert.

:12:42. > :12:45.20 years later, the NASA Pathfinder mission returned to the surface

:12:45. > :12:55.with a rover, a mobile laboratory that drilled into the rocks to

:12:55. > :13:01.learn the secrets of Mars' past. Meanwhile, in the skies above, a

:13:01. > :13:08.new generation of NASA orbiters captured detailed birds eyes views

:13:08. > :13:13.of the entire surface. In 2004, the European Space Agency's Mars

:13:13. > :13:19.Express photographed the planet in 3D giving us a stunning new

:13:19. > :13:23.perspective on Martian landscapes. In the same year, two new NASA

:13:23. > :13:28.rovers travelled for miles across the surface, exploring cliffs, sand

:13:28. > :13:36.dunes and craters during their journey of discovery. Spirit kept

:13:36. > :13:41.going for six years. Opportunity is still on the move to this day.

:13:41. > :13:46.Nearly 50 years of exploration has told us more about Mars than we

:13:46. > :13:56.could have ever dreamt and with the Curiosity Rover, the stage is now

:13:56. > :13:59.

:13:59. > :14:04.set for a new era of Martian discovery.

:14:04. > :14:07.Let me show you that picture of the Curiosity Rover on Mars. It is

:14:07. > :14:10.spectacular. This is a self- portrait. The Curiosity Rover

:14:10. > :14:15.landed in the Gail Crater. The landing site was chosen because

:14:15. > :14:23.this is a place where we are sure that water existed at some point in

:14:23. > :14:29.the past and it's - I saw a lot of noise about this on Twitter. It is

:14:29. > :14:34.a self-portrait of a free-standing rover. Who took the picture? To

:14:34. > :14:39.prove that NASA are on Mars, I thought I would show you a picture

:14:39. > :14:46.from Viking. This proves that NASA did land on Mars and there was no

:14:46. > :14:49.funny business going on! Curiosity Rover has a much more profound

:14:49. > :14:56.mission than just exploring the landscape. Its goal is to search

:14:56. > :15:00.for evidence that Mars was habitable in the past. To tell us

:15:01. > :15:10.all about the mission and how they managed to get that enormous thing

:15:11. > :15:14.

:15:14. > :15:20.This is the room where NASA scientists controlled the landing

:15:20. > :15:30.on to Mars. It is very calm right now, but on sixth August last year

:15:30. > :15:32.

:15:32. > :15:38.it was a very different place. One of the very excited people you saw

:15:38. > :15:44.is the man in charge of landing the Rover. Thank you for coming, Adam.

:15:44. > :15:51.You will never forget that day, is that save to say? Yes, the best day

:15:51. > :15:55.it ever. The rovers were bounced onto the surface of Mars with their

:15:55. > :16:01.backs, to put it crudely, but when you think about Curiosity, your

:16:01. > :16:05.team have to have an audacious plan to land the thing. Talk me through

:16:06. > :16:11.this animation. We let go of the parachute onto rockets, we have

:16:11. > :16:18.done that before, but we have not done the next step. Because she was

:16:18. > :16:23.so big, the team had to lower her on Cables, Lundin her gently on her

:16:23. > :16:27.wheels. Every time I see this, I can't believe what you achieved.

:16:27. > :16:32.You also have to deal with something called the seven minutes

:16:32. > :16:36.of terror - of what were they? takes seven minutes to get from the

:16:36. > :16:43.top of the atmosphere to the surface safely, and during that

:16:43. > :16:49.time everybody on earth is the Spectator, waiting to see if

:16:49. > :16:53.Curiosity makes it safely to the surface. Terrifying! With something

:16:53. > :16:58.as challenging as this, and with the options you might have had in

:16:58. > :17:03.your head, when you came up with this, did you ever say I am having

:17:03. > :17:09.second thoughts? Every day. Throughout the whole process, you

:17:09. > :17:14.are worrying about it and a lot of other people worrying if this is

:17:14. > :17:19.the right thing. All the way to the head of NASA, the administrator. He

:17:19. > :17:24.said it looks crazy, but he thought it might be the right kind of crazy.

:17:24. > :17:29.It doesn't do justice to say this to you, but well done. Another

:17:29. > :17:36.thing that NASA is very good at is maximising its chances of success.

:17:36. > :17:41.For every mission it does. When it comes to Curiosity, it even made an

:17:41. > :17:49.exact copy here at JPL to put through its paces so I have to

:17:49. > :17:53.check it out. The job for the earthbound twin is to practise

:17:53. > :17:59.moving in this replica of the Martian landscape. It may not look

:18:00. > :18:05.much, but these variations of sound on stone are the best guess of what

:18:05. > :18:10.Curiosity might encounter. It is so exciting to see it in action.

:18:10. > :18:17.are standing right up close to this thing, which is taller than you.

:18:17. > :18:22.Even though it is moving slowly, it is kind of scary. It has a laser so

:18:22. > :18:27.it could shoot you. That is not even funny. Scott Maxwell drives

:18:27. > :18:31.the real Curiosity. His job is to avoid steering a multi-billion

:18:31. > :18:37.dollar vehicle into a Martian ditch so the meticulously planned

:18:37. > :18:43.rehearsals with this twin are crucial. Right now it is trying to

:18:43. > :18:48.navigate what it thinks are the sloping sides of the Martian Valley.

:18:48. > :18:54.With the rotating camera, it takes three still pictures which helps it

:18:54. > :19:03.to plot the safest route. Then it powers forward a few centimetres,

:19:03. > :19:09.and begins the process again. A love the way the wheels move. It is

:19:09. > :19:15.going this way. It is so clever. The record of the painstaking

:19:15. > :19:25.rehearsal was then sent to the twin on Mars. How fast can the Rover go?

:19:25. > :19:25.

:19:25. > :19:35.So nothing like 0.1 of a mile per hour. The reason for that is the

:19:35. > :19:40.

:19:40. > :19:47.Rover has a mass of about a ton. Why so little energy? There we have

:19:47. > :19:52.a chunk of radioactive plutonium and a device that turns the heat

:19:52. > :19:59.into electricity. It is a trade-off to get as much power into the Rover

:19:59. > :20:04.without being too heavy. Meanwhile, about 140 million miles away on

:20:04. > :20:12.Mars, communication is not good enough for video so NASA has

:20:12. > :20:17.created simulations to help visualise the journey. Curiosity

:20:17. > :20:24.await instructions. We e-mail a package of stuff, the to-do list

:20:24. > :20:29.for the day, and when we sleep the Rover spends the day carrying out

:20:29. > :20:33.those commands, then e-mails back. On a good day those packages look

:20:33. > :20:39.the same, the things you wanted it to do are the things it actually

:20:39. > :20:46.did. A on a bad day? On a bad day, they are different. So far we have

:20:46. > :20:53.never driven the Rover over a cliff. She is packed full of science

:20:53. > :20:59.instruments. Curiosity can locker rocks up to 12 metres away and fire

:20:59. > :21:02.them with the laser, and look at the Weber, the light spectrum of

:21:02. > :21:06.the vapour and determined properties and mineral content of

:21:06. > :21:12.the rocks to understand whether she wants to investigate more

:21:12. > :21:17.completely. We have got an ability to drill into rocky material and

:21:17. > :21:21.take out powdered samples, sort them by the size of their grains,

:21:21. > :21:25.and distribute them into science instruments in the body of the

:21:25. > :21:33.Rover. Have you had a moment when you thought we should have put this

:21:33. > :21:38.on it as well, or so far so good? So far so good, Curiosity blows out

:21:38. > :21:44.of the water anything we have done on Mars today. Can you believe they

:21:44. > :21:50.have allowed me in here? This is the operation centre for the Deep

:21:50. > :21:58.Space Network, and they communicate with everything from brogue to

:21:58. > :22:03.telescopes to all voters in here. This is the chief scientist, John

:22:03. > :22:08.Grozinger. It is such a privilege to be in here. It is 21 minutes

:22:08. > :22:15.past eight in the UK, what time is it on Mars right now and what is

:22:15. > :22:19.the Rover doing? It is slightly after 2 o'clock in the morning, and

:22:19. > :22:26.Curiosity has just finished processing some of its data and it

:22:26. > :22:30.is sending some back to earth. has already sent back tens of

:22:30. > :22:36.thousands of images, some of which are extremely exciting. Can you

:22:36. > :22:46.talk me through this one? This is one of my favourites, the foothills

:22:46. > :22:47.

:22:47. > :22:52.of Mount Sharp, which has almost five kilometres high. The mountain

:22:52. > :22:57.is made out of layers, which allows geologists to read it like a book.

:22:57. > :23:03.You can turn the pages and understand the early environmental

:23:03. > :23:08.history of Mars. This other images even more interesting for other

:23:08. > :23:15.reasons. Talk me through what we are looking at. The so something we

:23:15. > :23:21.found literally where we landed. You don't need a higher degree to

:23:21. > :23:27.understand this kind of science. We have rounded pebbles, some gravel

:23:27. > :23:31.that accumulates on earth here, and the difference is this one comes

:23:31. > :23:36.from 3 billion years back in time we know we had an ancient flowing

:23:36. > :23:42.river. You are also looking for evidence from the sedimentary

:23:42. > :23:46.layers as well, right? Yes, they tell us that these could be the

:23:46. > :23:54.kind of places were micro organisms could have lived. That is

:23:54. > :24:01.incredible. Thank you so much. I will be checking out Curiosity's

:24:01. > :24:05.twin, and finding out the future of NASA's Mars mission. John mentioned

:24:05. > :24:15.water being a key component of the search for evidence of past life,

:24:15. > :24:16.

:24:16. > :24:21.so why water and nothing else? is the basic physics behind it.

:24:21. > :24:29.Dara will be charging that rod, and I will be filling this with water.

:24:29. > :24:37.I will not tell you what you are supposed to see. Carry on talking,

:24:37. > :24:44.please. Water... Can you see how that is bending? Slightly towards

:24:44. > :24:50.the charged rod, and that is because of the poll molecules.

:24:50. > :25:00.There we go. Water it is responding because of the electric field from

:25:00. > :25:02.

:25:02. > :25:08.the rod. Imagine my fist. Oxygen once electrons. It wants to drag

:25:08. > :25:14.electrons around it if it can, so it drags the electrons from the

:25:14. > :25:19.hydrogen and leaves the protons, which are positively charged. The

:25:19. > :25:23.net result is that you get a positive charge up here, a negative

:25:23. > :25:28.charge down here, and that is why water molecules respond. In some

:25:28. > :25:32.ways it is like a bar magnet. like that, but that has an

:25:32. > :25:37.interesting effect when you look at the structure of the liquid. It

:25:37. > :25:41.looks like the simplest thing in the universe, this is a picture of

:25:41. > :25:50.a representation of some of what the water molecules do it in the

:25:50. > :25:56.liquid. They come up because the oxygens can bond to the hydrogens

:25:56. > :26:02.from other molecules. You can create this lattice of H2O

:26:03. > :26:07.molecules linking up. They look like ice but they are passive

:26:07. > :26:14.structures, structures that come and go in the liquid called

:26:14. > :26:17.hydrogen formeds. Water is like scaffolding, and biological

:26:17. > :26:22.molecules like proteins can be orientated in the right way by the

:26:22. > :26:26.water because of that complex structure of water and the way that

:26:26. > :26:31.proteins in complex carbon molecules are relying, there is key

:26:31. > :26:35.to our biochemistry. Also because of that polarity, the water

:26:35. > :26:40.molecules can get inside other things and it is one of the best

:26:40. > :26:45.solvents that we know of. Also, it is liquid across a vast range of

:26:45. > :26:50.temperature. If you look at hydrogen sulphide, sulphur with

:26:50. > :26:58.hydrogen bonded to it, that boils at minus 60 so you wouldn't have

:26:58. > :27:03.hydrogen sulphide as a liquid on earth. Because of the polarity, the

:27:03. > :27:09.fact you can polarise these things, they'll loose living together as a

:27:09. > :27:15.structure, but they are also liquid at temperatures that other liquids

:27:15. > :27:25.are not. Yes, and that is why most biologists would say that water is

:27:25. > :27:26.

:27:26. > :27:32.a pre- requisite necessary for the existence of life. On Mars, we know

:27:32. > :27:37.there is no water at the moment. What various NASA missions has

:27:37. > :27:44.discovered is that evidence liquid water used to flow on its surface.

:27:44. > :27:52.If you take a look at an image like this, this is from 2003, a river

:27:52. > :27:57.valley. It obviously looks like that. I want to show you the polar

:27:57. > :28:01.caps on Mars. A proportion of that is certainly water ice. What

:28:01. > :28:07.happened to that water? Birth is next door and we are covered in

:28:07. > :28:12.liquid water, so what makes these two planets so different? Our next-

:28:12. > :28:17.door neighbour is known as the Red Planet, a rocky, lifeless world

:28:17. > :28:23.covered in dust, but Mars has not always been a desert. Billions of

:28:23. > :28:33.years ago, we think liquid water flowed here, perhaps even enough

:28:33. > :28:34.

:28:34. > :28:41.for an ocean. Where did the water go? When did Mars die? In the early

:28:41. > :28:45.solar system, debris came together to form the inner planets so Mars

:28:45. > :28:49.and the Earth are made from the same material. At the heart of each

:28:50. > :28:57.is a metallic core, something which is key to the difference between

:28:57. > :29:02.the planets today. In the earth, the outer core is Malton, and as it

:29:02. > :29:09.spins an electric current is produced generating magnetic field

:29:09. > :29:18.that extends into space. It is the effect of this magnetic field which

:29:18. > :29:24.could explain why we have the water and Mars does not. When charged

:29:24. > :29:30.particles leave the sun, they head towards us as solar wind, but are

:29:30. > :29:37.magnetic field deflects them, protecting our atmosphere. The

:29:37. > :29:45.situation on Mars is very different. Being smaller, Mars had less heed

:29:45. > :29:50.to begin with, and also lost it to space more quickly. Its outer core

:29:50. > :29:54.began to solidify, weakening its electric currents, so by 3 1/2

:29:54. > :30:01.billion years ago, its magnetic field had almost completely shut

:30:01. > :30:07.down. Without it protection, the solar wind blasted much of the

:30:07. > :30:16.atmosphere into space, leaving it 100 times less dense than our own.

:30:16. > :30:20.That had a devastating effect on On the Earth we have ice at the

:30:20. > :30:26.poles, water vapour across our skies and liquid water in the

:30:26. > :30:30.oceans. Water exists in three states - something that is possible

:30:30. > :30:36.because we have a thick atmosphere thanks largely to the protection

:30:36. > :30:41.given by the magnetic field. But in today's thin and cold Martian

:30:41. > :30:45.atmosphere, while we find both ice and water vapour, there's barely

:30:45. > :30:53.any liquid water at all. It's probably been that way ever since

:30:53. > :31:00.Mars lost its magnetic field. So the challenge now is to look for

:31:00. > :31:05.signs of liquid water in Mars' distant past before it disappeared.

:31:05. > :31:13.Perhaps billions of years ago life may have exploited a brief

:31:13. > :31:20.opportunity to flourish when the Red Planet was blue.

:31:20. > :31:25.The good parallel comes if you look at frozen carbon dioxide here on

:31:25. > :31:31.Earth. That is the block of frozen dry ice there. If you heat it up,

:31:31. > :31:37.it doesn't turn liquid at all, it goes to vapour. You are loving your

:31:37. > :31:44.demos! I love this. The interesting thing is that is how water would

:31:44. > :31:50.behave on Mars. We tend to think of Earth as unique because we have

:31:50. > :31:55.liquid water on the surface. It is a rare commodity, but if you

:31:55. > :31:58.include ice and vapour, water is abundant throughout the universe.

:31:58. > :32:04.Oxygen is the third most abundant element and hydrogen the most

:32:04. > :32:12.abundant element in the universe. Let's welcome back Tim O'Brien. Tim,

:32:12. > :32:17.I want to start with a picture that will be familiar to every

:32:17. > :32:24.astronomer, the Orion Nebula. are pointing our second biggest

:32:24. > :32:31.telescope here. It is called the Mach II. There it is. Does that

:32:31. > :32:38.cable go to the field? It travels to the focus of that telescope.

:32:38. > :32:43.What you are seeing here is radiation coming from water vapour

:32:43. > :32:52.molecules in clouds in the Orion Nebula. What is this? Radiowaves?

:32:52. > :32:56.Yes. What are we looking at? It is a bit like a laser. It's spinning

:32:56. > :33:01.water molecules in space that are radiating, beaming these radiowaves

:33:01. > :33:07.towards us which is why it is so bright. This is a signal of

:33:07. > :33:13.spinning water molecules in space?! That is wonderful! I'm impressed

:33:13. > :33:19.you get to see that amount of water vapour. We have to see through our

:33:19. > :33:25.own atmosphere with all those rain clouds. How much is there? Probably

:33:25. > :33:34.about 100 times the mass of the Sun in the Orion Nebula. I want to show

:33:34. > :33:41.this of the Chandra X-Ray of the Quasar - what are we looking at

:33:41. > :33:51.here? Quasar is the most distant detection of water we have ever

:33:51. > :33:51.

:33:52. > :33:56.made in the universe. This isn't the earliest detection of water?

:33:56. > :34:02.The light from this thing has taken 12 billion years to reach us.

:34:02. > :34:08.is fascinating. At least one generation of stars has lived and

:34:08. > :34:12.died to produce the oxygen. billion times the mass of the Earth.

:34:12. > :34:16.Water is everywhere. Earth isn't the only place in the Solar System

:34:16. > :34:21.where you can find liquid water. There might be more of water on the

:34:21. > :34:27.moons of other planets than there is here. Liz is standing by with

:34:27. > :34:35.Linda Spilker from Cassini, the NASA mission that first discovered

:34:35. > :34:40.water on Saturn's moons. Thank you for joining us. It has sent us back

:34:40. > :34:44.some spectacular images of Saturn's moons. Can you talk me through

:34:44. > :34:50.Enceladus. There are features which point to liquid water? These are

:34:50. > :34:53.cracks or fractures in the crust of Enceladus at the South Pole.

:34:53. > :34:59.Cassini instruments have measured the temperature deep inside these

:34:59. > :35:08.cracks. It is warm enough to have liquid water underneath the tiger

:35:08. > :35:12.stripes. This comes out and freezes and forms this comet-like plume.

:35:12. > :35:17.When it comes to Titan, this is a very recent image from Cassini. It

:35:17. > :35:22.is a river system flowing into an ocean. This is liquid methane.

:35:22. > :35:26.Scientists were talking about the possibility of methane-based life

:35:26. > :35:31.forms. Is there evidence of liquid water on Titan? There is evidence

:35:31. > :35:36.of liquid water on Titan, but not on its surface. It is too cold

:35:36. > :35:43.there. Titan is deformed by Saturn's gravity as it orbits

:35:43. > :35:50.around. It can't be frozen solid. There has to be a liquid water

:35:50. > :35:55.ocean underneath Titan's icy crust. It points to the possibility of

:35:55. > :35:59.life, doesn't it? It is a fascinating possibility. Thank you

:35:59. > :36:04.so much. Next, we will be finding out about the future of Mars'

:36:04. > :36:09.missions here at NASA. See you soon. It is not just Titan, there is

:36:09. > :36:16.another candidate for liquid water, that is Jupiter's moon, Europa.

:36:16. > :36:23.This is a picture of Europa taken by Galileo. What you are looking at

:36:23. > :36:28.is a surface of water-ice. We know that because of a spectoscropy.

:36:28. > :36:34.There are a lot of cracks on the surface. If we zoom in to another

:36:34. > :36:41.picture, of those ridges on Europa, what you are looking at there is

:36:41. > :36:48.ice sheets but moving against each other. Over the years, the Galileo

:36:48. > :36:54.saw those ridges shift. That looks like - it's the same way water-ice

:36:54. > :36:58.behaves in the Antarctic or the Arctic. Also, the way Europa

:36:58. > :37:01.interacts with Jupiter's magnetic field. It tells us there is an

:37:01. > :37:05.ocean beneath the ice. There is more water in the ocean of Europa

:37:05. > :37:10.than there is in all the oceans of the Earth combined. Liquid water

:37:10. > :37:20.within that, but it is a long way away from the Sun. Where it is

:37:20. > :37:24.

:37:24. > :37:32.getting its heat from? It is. Because it is eliptical, the Moon

:37:32. > :37:37.gets stretched, that is what melts the ice. If there are clear skies

:37:37. > :37:41.above where you are, it will be easy to observe Europa and the

:37:41. > :37:46.three largest moons of Jupiter after the show tonight. If you do

:37:46. > :37:52.observe them, you will be following in the footsteps of one of the

:37:52. > :37:56.greatest scientists of all time. In 1610, Galileo Galilei became the

:37:56. > :38:01.first person to observe the four largest moons of Jupiter. He

:38:01. > :38:06.tracked their movement with the telescope and found they were

:38:06. > :38:10.orbiting around the gas giant. At the time, the widely accepted view

:38:10. > :38:15.was that all celestial bodies orbited the Earth, that we were at

:38:15. > :38:19.the centre of the universe. His discovery shattered this belief.

:38:19. > :38:25.They are known today as the Galilean Moons and they are easy to

:38:25. > :38:34.observe. Anyone can get a glimpse of these distant worlds. Even a

:38:34. > :38:37.simple pair of binoculars or a small telescope will reveal

:38:37. > :38:42.Jupiter's companions. Finding Jupiter is really easy at the

:38:42. > :38:47.moment. Simply look due south around 7.00pm. The moons can't be

:38:47. > :38:53.seen with the naked eye. Look through a decent pair of binoculars

:38:53. > :39:03.and they are suddenly revealed. They are even more impressive

:39:03. > :39:03.

:39:03. > :39:06.through a telescope. Each moon is a distinctive world. Even through a

:39:06. > :39:13.telescope, it is difficult to identify which is which. This is

:39:13. > :39:17.because they are so far away they appear small and faint. The four

:39:17. > :39:23.moons have different orbits so working out which one you are

:39:23. > :39:27.observing can be tricky. You may not see all of them all of the time.

:39:27. > :39:32.One or two may be behind Jupiter when you are looking. Fortunately,

:39:32. > :39:39.there are free reference charts online and affordable apps to help

:39:39. > :39:43.you identify them. I can see all four Galilean moons. I'm using an

:39:43. > :39:53.app to help me identify which is which. The moon I can see on the

:39:53. > :39:58.

:39:58. > :40:08.far left is Ganymede, the largest moon in the Solar System. The tiny

:40:08. > :40:08.

:40:08. > :40:13.dot to the left of Jupiter is Io. It is covered in hundreds of

:40:13. > :40:19.sulphur-spewing volcanoes. To the right of Jupiter, the first moon I

:40:19. > :40:27.can see is Europa. This is the moon that scientists seeking life are

:40:27. > :40:37.most interested in. Images taken by the Galileo mission have shown us

:40:37. > :40:39.

:40:39. > :40:49.it is a frozen world. Last but not least we come to Callisto. It is

:40:49. > :40:53.believed to have the oldest solid landscape within the Solar System.

:40:53. > :40:57.Thanks to their constant dance around Jupiter, observing the moons

:40:57. > :41:02.can be different every time. It is a spectacular sight. Learning about

:41:02. > :41:12.these diverse worlds makes seeing them with your own eyes more

:41:12. > :41:16.incredible. It is possible to see all four of

:41:16. > :41:21.Jupiter's moons tonight, but it is still cloudy! I have been joined by

:41:21. > :41:26.Brian May. Bryan, the British weather, don't we love it?! It is

:41:26. > :41:29.rubbish for astronomy. What is it that makes us keep coming back for

:41:29. > :41:37.more? I guess we just love it. There is a passion for knowing what

:41:37. > :41:41.is out there. We still do it. We still do it in England. We get a

:41:41. > :41:46.low percentage of nights where we can see something. We were lucky

:41:46. > :41:50.enough to capture some footage of the moons of Jupiter last night. It

:41:50. > :41:58.was clear for us during the rehearsal so you can see in this

:41:58. > :42:02.video footage the belt of Jupiter and you can see the tiny dot of

:42:03. > :42:07.light is Europa. Now, the planets are really quite spectacular for

:42:07. > :42:10.most of us. Do you remember the first time you saw a planet and do

:42:10. > :42:19.you remember how you felt? first gasp was Saturn. I still feel

:42:19. > :42:28.the same about it. I think I was like Galileo. "My God, what is

:42:28. > :42:34.that?" I wasn't educated. We had a telescope and it looked like two

:42:34. > :42:39.circles next to each other. It is breathtaking. You never get over

:42:39. > :42:43.Saturn. It is quite amazing. I have a lot of keen astronomers here.

:42:44. > :42:48.What is your top tip? For people who are starting - you know what

:42:48. > :42:56.you are doing - I would say keep it simple. Get something which is

:42:56. > :43:02.rigid and doesn't flap about but is simple. My favourite telescope is a

:43:02. > :43:09.Dobsonian. There is no electronics or whatever. You have the find on

:43:09. > :43:14.it and you go, "I want to look at that." Learn your way around the

:43:14. > :43:18.universe. Yes. Of course, if you want to find out if it is clear

:43:18. > :43:26.tonight - we are unlucky here - if you want to find out if it is clear

:43:26. > :43:28.where you are tonight, here is Nina where you are tonight, here is Nina

:43:28. > :43:33.Ridge with the weather. You are stuck underneath the cloud

:43:33. > :43:42.there. There are some places where we will begin to see some breaks in

:43:42. > :43:45.the cloud. A weather front has been moving south, taking the rain.

:43:45. > :43:50.However, to the north of that system, that is where we will see

:43:50. > :43:53.some breaks in the cloud, certainly Northern Ireland, North East

:43:53. > :43:59.England, Eastern Scotland. Here we will see some clear skies through

:43:59. > :44:03.the night. Later on, the risk of patchy mist and fog forming. These

:44:03. > :44:12.look like being our best spots for tonight.

:44:12. > :44:15.Thankfully, the Moon isn't going to rise until later on in the night.

:44:15. > :44:20.Eastern Scotland, North East England and Northern Ireland is

:44:20. > :44:25.where you will see some breaks coming and going. Tomorrow night is

:44:25. > :44:28.coming and going. Tomorrow night is looking cloudier.

:44:28. > :44:32.Last year we teamed up with the Zooniverse Citizen Science Project

:44:32. > :44:40.and asked for your help to find a new planet outside of our Solar

:44:40. > :44:43.System. It was a huge success. It resulted in the discovery of a new

:44:44. > :44:50.planet. We want your help again. Whilst the Curiosity Rover is

:44:50. > :45:00.exploring the geology, we want your help. Here is Dr Chris Lintott.

:45:00. > :45:03.

:45:03. > :45:07.Curiosity is exploring one tiny piece of Earth, which is like

:45:07. > :45:13.exploring Earth by sitting in Trafalgar Square. We have taken

:45:13. > :45:18.images from the spacecraft called the Mars reconnaissance or bitter,

:45:18. > :45:23.and these are images that no one in history has seen at this level

:45:23. > :45:30.detail. They have been sitting on a hard drive, and nobody has looked

:45:30. > :45:36.at them. This is near the South Pole. What is the resolution here?

:45:36. > :45:41.The is small back things are probably maybe 100 metres across.

:45:41. > :45:46.In this resolution, you can see things this sort of size. If you're

:45:46. > :45:52.dining room table was on here, we could see this. We can see these

:45:52. > :45:56.appear every spring time, and they disappear over the course of the

:45:56. > :46:02.summer. We don't know what causes these, we have ideas, but this is

:46:02. > :46:07.what we want people to look for. You will give people a patch of

:46:07. > :46:14.ground to look at, and what sort of things should they be looking for?

:46:14. > :46:18.You can see these spider things, known as Marsh and spiders. Imagine

:46:18. > :46:28.you were standing on a sand dune, you hear rumbling underneath you,

:46:28. > :46:35.

:46:35. > :46:42.and suddenly this geyser erupts. This shows that Mars is not a dead

:46:42. > :46:47.world. You yes, this is a dramatic event, and it tells us about the

:46:47. > :46:54.cycle that happens every year on Mars. We want people to do this, go

:46:54. > :47:02.to the website, where there is a full tutorial. Go to

:47:02. > :47:07.bbc.co.uk/stargazing and click on the box that says Explore Mars.

:47:07. > :47:12.Searching for life on Mars is not a new idea. Ever since we have been

:47:12. > :47:20.able to observe the planet with telescopes, scientists have been

:47:20. > :47:24.theorising about what Martians might look like. William Herschel

:47:24. > :47:30.used his 20 ft telescope to produce some of the first detailed images

:47:30. > :47:36.of Mars. From observation after observation, he recorded the

:47:36. > :47:46.surface with patches of light and dark areas. But then he went beyond

:47:46. > :47:47.

:47:47. > :47:56.simply observing. He speculated that those dark patches could be

:47:56. > :48:01.oceans, and if there are at oceans there could be life. In 1783,

:48:01. > :48:06.William Herschel published his findings on the philosophical

:48:06. > :48:10.Transactions of the Royal Society. He says, "and that Canada has a

:48:10. > :48:16.considerable atmosphere so that its inhabitants probably enjoy it the

:48:16. > :48:22.situation, in many respects, similar to ours". He is making an

:48:22. > :48:32.assumption that people live there. That assumption live on for the

:48:32. > :48:34.

:48:34. > :48:38.best part of 100 years. Then, in 1919, they made contact. The

:48:38. > :48:45.inventor of the wireless was experimenting with his radio at sea,

:48:45. > :48:49.and thought Mars was signalling to him. In a way, I suppose this was

:48:49. > :48:56.the beginning of what we think of as modern radio astronomy and it

:48:56. > :49:04.turned out that what he detected when not signals from Mars. What he

:49:04. > :49:08.actually picked up were natural signals generated in the atmosphere.

:49:08. > :49:18.But the world's imagination was caught, and science-fiction authors

:49:18. > :49:23.eagerly turned the inhabitants from Mars from humans into monsters. The

:49:23. > :49:27.Martians were born. They were all bent on interstellar domination.

:49:27. > :49:34.This could be the beginning of the end for the human race. Hollywood

:49:34. > :49:41.film-makers chose to show Martians hidden inside Cyclops like machines.

:49:41. > :49:49.Even NASA was at it. On Mars, deadly radiation from the sun

:49:49. > :49:54.penetrates to the surface. Mars may have silica cells to protect it

:49:54. > :49:59.from this radiation. It was hoped the speculation would end once and

:49:59. > :50:05.for all when NASA sent probes to Mars. Some still thought life would

:50:05. > :50:09.be found. We have just had some amazing photographs sent back from

:50:09. > :50:12.Mars, and you can see some of the darker areas which may be

:50:12. > :50:18.vegetation, and at the bottom you can see the white polar cap which

:50:18. > :50:26.has always been thought to be a frosty deposit. Alas, it turned out

:50:26. > :50:32.to be a dead planet full of craters. So, was that the end of the

:50:32. > :50:38.Martians? No, actually. The search for life has continued, but the

:50:38. > :50:48.Martians just got smaller. Instead of little green men, we are now

:50:48. > :50:58.

:50:58. > :51:04.Joining us now is and astrobiologist. To sum up what we

:51:04. > :51:09.have learned, I think we should ask the question - speculate, what

:51:09. > :51:16.could be fined on Mars? The best we can possibly hope for from Mars,

:51:16. > :51:26.given what we have seen about its environment, is for committed

:51:26. > :51:33.bacterial life, similar to what we find in harsh environments on Earth.

:51:33. > :51:37.This is a sandstone from Antarctica in the dry valleys. In these cold

:51:37. > :51:42.environments on Earth, we use it to study our techniques for finding

:51:42. > :51:50.life, and if you look at the inside of this rock, just underneath the

:51:50. > :51:55.surface you can see this layer of green, it is colonised in the rock

:51:55. > :51:59.to protect it from the harsh environment outside. We could

:51:59. > :52:06.imagine organisms like that existing on Mars? That is exactly

:52:06. > :52:11.what we are trying to look for, yes. Would it be the same biochemistry,

:52:11. > :52:20.similar even down to DNA? If it were different, what would that

:52:20. > :52:24.suggest? The fundamentals, water- based or carbon-based, seems to be

:52:24. > :52:28.the best bet. If we look at the specifics of how the cells are

:52:28. > :52:33.built, perhaps something like DNA would be too specific, they might

:52:33. > :52:39.be alternatives that might be able to store the information and pass

:52:39. > :52:47.it on to the next generation. life on Earth is based on DNA.

:52:47. > :52:56.Would be more exciting to find DNA or not? Let's say the probes we are

:52:56. > :53:03.sending to Mars are successful and we find life on the surface of the

:53:03. > :53:09.planet, and they are DNA based like us. It might be that that is how

:53:09. > :53:16.life works, or it might be that way are the same thing and we have the

:53:16. > :53:26.same origin. The en email asks, "how do we know that we did not

:53:26. > :53:26.

:53:27. > :53:35.A good question. We could have been transferred by a meteorite during

:53:35. > :53:40.the early solar system, or it could be that life got started on Mars

:53:40. > :53:46.first and got transferred to Earth. It might be that we are the

:53:46. > :53:55.Martians. A what are the next steps for the exploration of Mars? Back

:53:55. > :54:01.to Liz. To answer that question, I am back with Curiosity's twin. This

:54:01. > :54:08.is another indoor facility, where they can carry out testing. We are

:54:08. > :54:13.joined by a Dr Fuk Lei, the manager for the missions in NASA's Mars

:54:13. > :54:23.programme. Can I ask about the latest news that finally we will be

:54:23. > :54:30.using the last tool in the Rover's kit, the drill, is that right?

:54:30. > :54:35.we can drill into the rocks, turn them into powder, and we are

:54:35. > :54:40.excited to test out this equipment. When it comes to the future of Mars

:54:40. > :54:45.exploration, you have an Orbiter mission to investigate the thin

:54:45. > :54:50.atmosphere, and another Rover mission in 2020, but the one I am

:54:50. > :55:00.interested in is the one that is sending samples back to Earth.

:55:00. > :55:01.

:55:01. > :55:06.many scientists believe the most important thing we can do is to

:55:06. > :55:11.return samples that are worth, but it is more ambitious. A extremely

:55:11. > :55:18.challenging, but ultimately do these lead to one thing - to put a

:55:18. > :55:23.man on Mars? Of it is my personal opinion, but we all have an innate

:55:23. > :55:27.spirit to explore. We went to the South Pole and all that, and I

:55:27. > :55:34.believe that spirit will drives people into the solar system beyond

:55:34. > :55:41.the Earth, and one-day humans will be on Mars. When? I don't know, I

:55:41. > :55:46.hope one day soon. There is it from us at JPL today, but tomorrow I

:55:46. > :55:51.will be finding out more about the Deep Space Network at NASA and its

:55:51. > :55:54.deep space missions, and also I will be finding out about the

:55:55. > :56:01.biggest space telescope ever built, which might finally answer

:56:01. > :56:05.questions about our very origins. Join me then. Back to you guys.

:56:05. > :56:15.next generation Rover is not from NASA, it is a joint European Russia

:56:15. > :56:15.

:56:15. > :56:24.and mission run by ESA, the European Space Agency. This is a

:56:24. > :56:28.prototype. I am here with Abigail Hutty, can you give an overview?

:56:28. > :56:33.this was built to demonstrate ability to build the Mars Rover

:56:33. > :56:40.project. It is different from Curiosity in that we are looking

:56:40. > :56:46.for life, not just the conditions for life. Can I just say, this is

:56:46. > :56:52.fully functional and I have been given the complex control device.

:56:52. > :56:57.These are presumably the similar rocks you will use, because they

:56:57. > :57:04.are very authentic-looking. I know we were talking earlier, and in

:57:04. > :57:08.many ways this is better than Curiosity at somethings. One of a

:57:08. > :57:14.big development is the autonomy system, so we can give our all

:57:14. > :57:21.Rover a destination. It doesn't have to be in the field of Duke of

:57:21. > :57:30.the Rover. It can mark in 3D, form an elevation Mark, and plan a route

:57:30. > :57:36.towards its goal, driving unaided by people on Earth. I am just going

:57:36. > :57:41.to bring in Lewis, the astrobiologist, and Brian May who

:57:41. > :57:47.wants to play with it as a toy. This is what I have been waiting

:57:47. > :57:54.for! The drill, we will get down two metres. Why would we want to do

:57:54. > :58:00.that? We have this trail on the front of the Rover. Where Curiosity

:58:00. > :58:05.is only managing to take a sample from the surface, we have a two me

:58:05. > :58:09.to drill, and it will be protected from the cosmic radiation

:58:09. > :58:18.environment so if there is any life still on Mars, that is where we are

:58:18. > :58:22.likely to find it. Is there life still on Mars? Certainly. I hope so.

:58:22. > :58:26.We can discuss this at greater length, but first we are going to

:58:26. > :58:31.see how Mark is doing in the field. Three astronomers have gone indoors

:58:31. > :58:35.now for the start of Back To Earth in a few minutes, but if you have

:58:35. > :58:42.been inspired to learn about this guy, there was a lot of

:58:42. > :58:46.downloadable resourced on our website. Just go to

:58:46. > :58:56.bbc.co.uk/stargazing, and if you want a more detailed guide, you can

:58:56. > :58:58.

:58:58. > :59:07.stay tuned. If you are looking for hints and tips on how to get

:59:07. > :59:13.started in astronomy, then you should checkout this year's Star

:59:13. > :59:17.Guide. Put together by the BBC and Open University, it'll help you get

:59:17. > :59:21.the most out of the night sky, wherever you are in the UK. Keep