:00:27. > :00:31.Welcome, ladies and gentlemen, welcome toback to earth, our
:00:31. > :00:37.discussion programme where we'll have more time to flesh out the
:00:37. > :00:47.questions you've asked. Brian is still with me, and we're joined by
:00:47. > :00:48.
:00:48. > :00:56.Tim O'Brien, the associate director of Jodrell Bank. And Dr Lucie Green,
:00:56. > :01:02.a solar astronomer joins us, and Andy Nyman, a comedian and
:01:02. > :01:06.illusionist. Are you a fan of astronomy? Oh, yes. Absolutely,
:01:06. > :01:12.especially after the show. The gravitational stuff on the beach
:01:12. > :01:21.blew me away. I could have talked to Captain certainon for ever. I've
:01:21. > :01:26.got his phone number now, I'm going to phone him back. So, half an hour
:01:26. > :01:35.of questions that you've sent in and photographs that you have sent
:01:35. > :01:43.in as well and some other surprises. One thing I want ed to ask, one
:01:43. > :01:52.question from two young stargazers in Dublin. They can, through the
:01:53. > :02:02.telescope see the Jovian moons, but what others can you see? You can
:02:03. > :02:04.
:02:04. > :02:09.see Saturn's moons and and you can see the rings and Titan. Stuart
:02:09. > :02:15.says why are all planets and moons in our solar system the same shape.
:02:15. > :02:20.Well, they're all spherical, if you're big enough, that is what
:02:20. > :02:28.gravity will shape you into it. It's the lowest form of dust and
:02:28. > :02:38.ice and rock. But some are not spherical because they're very
:02:38. > :02:39.
:02:39. > :02:46.small the two moons Phobos and Deimos, so they're too small to be
:02:46. > :02:51.made spherical. Now, some asteroids are grabbed by
:02:51. > :02:58.gravity? They can be captured bits of space debris or formed at the
:02:58. > :03:06.same time as planets, or, like our moon, probably formed in a
:03:06. > :03:13.collision between two planets. So there is a whole spread of ways
:03:13. > :03:18.moons can be formed. We have Keaton over there, who is taking in e-
:03:18. > :03:25.mails as they arrive, so we'll have more of those. Lucie, you're an
:03:25. > :03:30.expert. Solar astronomy? That's right. I'm looking at emissions
:03:30. > :03:38.that come out from the sun and impinge on the moon. What I look at
:03:38. > :03:44.coming from the sun has an effect throughout the whole solar system.
:03:44. > :03:50.And Helium-3 is from the sun? That's right. And the moon lass
:03:50. > :03:58.this great history embedded in its surface.
:03:58. > :04:03.Andy, we have a scratch and sniff card of the moon. Scratch it
:04:03. > :04:11.anywhere on there. Is this a school-boy prank? No, it's not
:04:11. > :04:16.cheeky. There was an Artist who took testimony from those who
:04:16. > :04:23.visited the moon and they smelt the dust off their suits. It smells
:04:23. > :04:30.like the moon! You know what it smells a bit like...cap guns, I
:04:30. > :04:34.loved that when I was a kid. That's what the astronauts said, they said
:04:34. > :04:41.the moon smelt a little bit like gun powder. Really? I nailed that.
:04:41. > :04:48.That was a lucky guess. Wow! I'll be doing this for the whole show.
:04:48. > :04:54.want to ask what, if any changes we've seen on the surface of the
:04:54. > :04:59.moon. Meteors regularly bombard the earth. Do they really? Tonnes and
:04:59. > :05:03.tonnes. It's a huge amount. Mostly small bits that come into the
:05:03. > :05:08.atmosphere, but sometimes satellites. In the absence of an
:05:08. > :05:12.atmosphere that burns them up, like we have here, those collisions will
:05:12. > :05:20.be changing the surface of the moon all the time. Oh, yes. It is
:05:20. > :05:30.thousands of tonnes per year. of tonnes per day of dust. And will
:05:30. > :05:31.
:05:31. > :05:40.that eventually remove those footsteps that we see of the Apollo
:05:40. > :05:46.mission s? I think the sun dying will remove them now. It's
:05:46. > :05:52.disconcerting how you say that with a beaming smile. Look on the bright
:05:52. > :05:58.side. It will get brighter and brighter. So we can look after a
:05:58. > :06:04.tremendous summer! How long before that? About five billion, well,
:06:04. > :06:08.attitudely less. Lucie about 1.5 billion? Yes, the sun will get much,
:06:08. > :06:15.much brighter and it will swell up and there will be more surface for
:06:15. > :06:21.the light to come out. So we've only got about a billion years
:06:21. > :06:27.before it will get unmanagably hot, so get a move on. How far will the
:06:27. > :06:33.sun swell up? It will come into the inner planets. So it will be
:06:33. > :06:40.approaching the earth. I'm not sure whether the earth will get burnt up.
:06:40. > :06:47.I don't know whether that is any comfort! We're not going to survive
:06:47. > :06:53.it any way? No, it will be too hot long before it reaches the earth,
:06:53. > :07:00.so we'll have to move before that. I get asked this a lot and there
:07:00. > :07:04.are a lot of stars out there at different stages of their lives.
:07:04. > :07:09.Beetle juice is a star right at the end of its life, it's getting
:07:09. > :07:15.brighter and dimmer all the time and it could explode tomorrow,
:07:15. > :07:24.literally, or it could explode in thousands of years. It could
:07:24. > :07:33.explode on December 21, 20126789 that like when you say we are
:07:33. > :07:40.coming to the end of our life? it is running out of the fuel core
:07:40. > :07:47.so it is coming to the end of its life and roughly the sun will look
:07:47. > :07:57.like that in..? Four billion year. So how bright exactly do you think
:07:57. > :07:57.
:07:57. > :08:03.it will be? Will it be like a second moon in the sky? When that
:08:03. > :08:13.one explodes? It will be so bright you can see it like a star in the
:08:13. > :08:19.
:08:19. > :08:28.day. And the last one? 1607 was the last superNova in our day.
:08:28. > :08:34.beetle juice is ten times closer than something that was seen in
:08:34. > :08:42.1054 that was painted like a crescent moon and that was seen by
:08:42. > :08:49.the Chinese and the people in next co-all that time ago. But it won't
:08:49. > :08:59.do anything to us, it's not part of the apocalypse.
:08:59. > :09:04.
:09:04. > :09:11.Let's go to Skype. Hello. They are frozen? Can you hear us? Yes.
:09:11. > :09:21.question would you like to ask our panel? Have we lost them
:09:21. > :09:32.
:09:32. > :09:40.completely? (sound breaks up) We've lost it. Do you believe
:09:40. > :09:48.keeneos are the answer to time travel? It's a question about the
:09:48. > :09:51.certain experiment in Cerny. Where it looked at newt Renos. And the
:09:52. > :09:58.experiments still say that they travelled faster than light by
:09:58. > :10:03.quite a large amount. If that is correct, and most think it is
:10:03. > :10:09.incorrect ct but nobody has yet found out what the problem is in
:10:10. > :10:16.the calculations. So people are saying we have something that
:10:16. > :10:26.travels greater than the speed of light and you keep Einstein's
:10:26. > :10:26.
:10:26. > :10:31.theory of relativeity, then you could build a time machine. No
:10:31. > :10:37.physicalist thinks you can build a time machine, but it means that our
:10:37. > :10:46.picture of time -- and we should go back to the experiment. If that
:10:46. > :10:53.experiment bears up to scrutiny we'd have to throw all of the past
:10:53. > :10:58.calculations away. And the pulsars are a test. Yes, when we observe
:10:58. > :11:06.these remnants of dead stars, the size of cities, because they're so
:11:06. > :11:11.big they spin very stably, they almost tick. So we have two
:11:11. > :11:17.spinning and orbiting each other like two clocks and for us that's
:11:17. > :11:27.the best-ever test of Einstein's theory of gravity and we've been
:11:27. > :11:27.
:11:28. > :11:37.able to show it is 99en 7% correct of the theory, which isn't bad for
:11:38. > :11:43.
:11:43. > :11:51.a theory that old. And the thought of two spinning stars the size of
:11:51. > :11:57.cities spinning round each other can show that that theory is
:11:57. > :12:03.correct is amazing. So, if we're wrong about this, e-mail us from
:12:03. > :12:07.the future! This is our most amazing
:12:07. > :12:12.stargazers' board. Over the next three nights we want you to send in
:12:12. > :12:18.as many pictures of the night sky as you can, and the best ones we'll
:12:18. > :12:24.put up on the board. This is the sun, if the sun was really this
:12:24. > :12:31.size, I have to stress this is not to scale, because if the sun was
:12:31. > :12:34.that big the earth would be a marble outside. But it's too cold.
:12:34. > :12:41.So we'll put the best pictures up on the board.
:12:41. > :12:45.We have a few. This is a picture of the moon that was sent in by Julian
:12:45. > :12:52.Cooper. A brilliant picture taken by 40 individual pictures of the
:12:52. > :12:57.moon through a modest six- inch telescope. You can see beautiful
:12:57. > :13:05.detail along the line of light and dark.
:13:05. > :13:15.And the next picture -- also stuck to the first one! This sticky stuff
:13:15. > :13:23.
:13:23. > :13:33.This image was taken over one hour and 24 minutes. And finally, we
:13:33. > :13:35.
:13:35. > :13:42.have the great Andromeda galaxy. That was taken in Belgium. And it
:13:42. > :13:49.was a long exposure about two-and- a-half hours and made up of 47
:13:49. > :13:54.individual pictures. Keep the pictures coming in, e-mail them in,
:13:54. > :14:03.stargazing@bbc.co.uk and the best ones we'll put on the board. There
:14:03. > :14:13.were ex poshs there, how long? hour and 24 minutes. And that sky
:14:13. > :14:13.
:14:13. > :14:18.is moving? Nigh yes, the earth is spinning. But the point is that man
:14:18. > :14:22.wasn't slowly rotating in order to allow for that, it's all through
:14:23. > :14:29.the equipment he has as well? That's right. The earth rotates to
:14:29. > :14:38.give us a day, and the camera rotates in the opposite direction
:14:38. > :14:45.to the earth's spin, so it freezes what it is viewing. And what is
:14:45. > :14:52.incredible, is that those pictures are real. Is that on the equipment
:14:52. > :14:58.that you showed in the show? That's right. This is all amateur
:14:58. > :15:02.equipment. And it's relatively cheap, that is what is amazing,
:15:02. > :15:12.because you expect it to be thousands and thousands of pounds
:15:12. > :15:16.
:15:16. > :15:23.and then you see the quality of those. It's stunning. We've been
:15:23. > :15:30.talking about the moon and we mentioned some of the pseudo
:15:30. > :15:35.scientific elements, like the apocalypse. But it fastates on many
:15:35. > :15:41.levels. We've seen these tremendous pictures, which is the raeplt
:15:41. > :15:45.reality of what's out there and I know you do a lot of work on
:15:45. > :15:49.Victoriania. And you have an atmosphere around exploration, what
:15:49. > :15:58.is it that captures our imagination? I think one of the
:15:58. > :16:03.things that is fascinating, there was a name that grabbed me, the
:16:03. > :16:08.Transylvania effect. We laugh at it, but the wear wolves and the idea
:16:08. > :16:13.that the pull of the moon, as it is pulling the waves, also, the theory
:16:13. > :16:20.comes from the idea that because the brain is the moistest part of
:16:20. > :16:28.the body, that it is being pulled and affected by the moon. It's one
:16:28. > :16:37.of the great misconceptions. The tides apply to rock as well, but it
:16:37. > :16:47.makes weird sense. Well, it makes fantastic sci-fi sense, as opposed
:16:47. > :16:50.
:16:50. > :16:58.to logical sense. One researcher said, no, the skies were brighter
:16:58. > :17:06.so people could see on those nights, so crime was higher. That's right.
:17:06. > :17:12.And now people who they believe were Bi-polar, were affected by it,
:17:12. > :17:17.but it's not, it's the sleep deprivation. So it's mythology,
:17:17. > :17:25.backed up by consign science -- science.
:17:25. > :17:32.Now, Lucie, you're hoping to send something to the moon? Yes, I've
:17:32. > :17:36.brought it with me. It's being led by UCL, but Leicester are involved
:17:37. > :17:43.and imperial College are involved. So this is a British mission we
:17:43. > :17:48.want to send to the moon. It needs a little Union Jack on it. It does.
:17:48. > :17:53.This is nice and simple and relatively small, so it is quite
:17:53. > :17:57.cheap. And we would drop them from a British satellite around the moon
:17:57. > :18:02.and they will land on the surface of the moon and bury themselves.
:18:02. > :18:08.This will land at 300 metres per second, so it has to survive. And
:18:08. > :18:14.then you can search for things like search for quakes on the moon. The
:18:14. > :18:18.moon is tectonicly active and has quakes. So if you send these to
:18:18. > :18:28.different points you can detect them. Which might mean possible
:18:28. > :18:31.
:18:31. > :18:36.human habitation on the moon. part of a probe has been sent to
:18:36. > :18:42.the moon? That's right, a part of the probe was blasted on to the
:18:42. > :18:48.moon to look for water on the moon. Again a really important question
:18:48. > :18:54.if we want to send humans to the moon. This was sent into a big tub
:18:54. > :19:00.of sand to simulate landing on the moon and the sand has scraped away
:19:00. > :19:05.the surface. And that's completely sarned, we have to test it before -
:19:05. > :19:12.- standard, we have to test things we're going to send to the moon.
:19:12. > :19:15.And one of the prerequisites to build a moon base for potential
:19:16. > :19:19.human habitation, I know you worked on the physical effects of space
:19:19. > :19:23.travel and going to the moon. Can you speak a little about the
:19:23. > :19:30.difficulty of living in space for humans? The main problem is you
:19:30. > :19:36.just have to take everything you take for granted down here, the
:19:36. > :19:41.light, water, the atmosphere, and take it with you to space. And it
:19:41. > :19:47.has to be wrapped up and parked out there. And keeping people healthy
:19:47. > :19:53.is enough of a problem, but you have to consider what happens if
:19:53. > :19:57.something goes wrong and you need a doctor or a hospital. It is tricky.
:19:57. > :20:03.I remember you told me that the Americans had an operating theatre
:20:03. > :20:07.in space, and the Russian response to that? Yes, at the start, the
:20:07. > :20:12.Americans literally thought they would take the kitchen sink up
:20:12. > :20:18.there, and the space module had an operating theatre in it, and the
:20:18. > :20:22.Russians said, "We just send healthy astronauts into space!"
:20:22. > :20:32.We're going to go back to a few more questions, but firstly, a
:20:32. > :20:35.
:20:35. > :20:43.short quiz for you. Patrick Moore here. Nice to be
:20:43. > :20:48.talking to you. Have a look at this little chap, Buzz Lightyear. Has he
:20:48. > :20:54.really been into space? Fact or fiction?
:20:54. > :21:03.OK, the question simply is, is it fact or fiction that Buzz Lightyear
:21:03. > :21:13.has really been in space? That, I know is fact. Oh! I disagree, it's
:21:13. > :21:13.
:21:13. > :21:18.fact. Your sense of drama. There's a wonderful video. You can go on
:21:18. > :21:23.the web and look at it. And it's about all the space shuttle
:21:23. > :21:29.launches. And in one of those there is a rotating picture. Do you think
:21:29. > :21:35.we wouldn't have looked for that! Are you going to show the answer
:21:36. > :21:44.now? Of course we are. This is the way quiz shows work. Oh, I thought
:21:44. > :21:51.I was going to get a mug or a prize. Buzz Lightyear, has he been in
:21:51. > :21:59.space? We say, Sir Patrick Moore, it is fact. Are we correct? Yes, he
:21:59. > :22:07.has actually been in space. He has been one year and over 15 months
:22:07. > :22:11.orbiting the earth and seemed to enjoy the experience. Do we have
:22:11. > :22:21.the footage? There's the space station and there he is. Look at
:22:21. > :22:23.
:22:23. > :22:30.that! That's sweet, isn't it? great. We are getting questions
:22:30. > :22:37.about the moon base. If we went up there, it's not like going to an
:22:37. > :22:46.tafbgtia or underwater, there is been been Antarctica, or underwater,
:22:46. > :22:54.there is a deteriorating effect, isn't it? Yes, going into space, it
:22:54. > :22:59.is like going to Everest, or Antarctica, you waste away and you
:22:59. > :23:03.come back feeling like you've had the hell kicked out of you, even if
:23:03. > :23:11.everything went right. So it is like going to places we have
:23:11. > :23:15.explored in the last century. calcium definite see, isn't it?
:23:15. > :23:21.Your bones and muscles become weaker. Yes, everything, the heart
:23:21. > :23:29.itself, which is a muscle. And your hand co-ordination is impaired. No-
:23:29. > :23:34.one knows how long enough is enough. The longest in human missions is
:23:34. > :23:40.478 days, which was undertaken by a Russia, because the Americans
:23:40. > :23:45.weren't crazy enough. That's the longest anyone has been in space.
:23:45. > :23:50.How noticeable on the depletion those things were on the astronauts
:23:50. > :23:54.after that period of time? Russians know more about long-
:23:54. > :24:00.duration space flight than any other country in the world. And
:24:00. > :24:08.when they bring their crews home they just lie them out on a couple
:24:08. > :24:15.of lilos and bring out a packed lunch and let it all wash over them.
:24:15. > :24:21.They don't try and do interviews. You feel dreadful. And there are
:24:21. > :24:26.some stories of astronauts coming back from space and going to
:24:26. > :24:31.banquets in Russia and basically throwing up all over the table. You
:24:31. > :24:36.feel pretty beaten up. And if we go to Mars that will happen the entire
:24:36. > :24:42.journey if you're travelling in weightlessness? That's the problem.
:24:42. > :24:46.The moon is just a few days out. Mars is six to nine months out-
:24:46. > :24:51.bound journey and all that time you're wasting away and then you
:24:52. > :24:58.get there and have to do a heroic landing, with all that muscle
:24:58. > :25:04.wasting and impairment of hands and eyes. And we are' wondering whether
:25:05. > :25:08.we can use the far side of the moon for a telescope. That is a
:25:08. > :25:14.fantastic idea because you're shielded from the atmosphere on the
:25:14. > :25:18.far side, so it would be a great place to set up telescopes and not
:25:18. > :25:23.have the interference of mobile phones going off from the earth.
:25:23. > :25:28.And gravity is lower so you can make physically larger structure
:25:28. > :25:33.than here on earth, so they wouldn't collapse. So that would be
:25:33. > :25:39.useful for us. Yes, absolutely. obviously want you to go and look
:25:39. > :25:44.at the stars yourselves, and Mark has set up a star cast to help you.
:25:44. > :25:51.If the sky is clear where you are after the programme, look to the
:25:51. > :25:56.north-east and you'll see the seven stars that make up the plough,
:25:56. > :26:06.sometimes known as the saucepan and at this time of night it is stood
:26:06. > :26:08.
:26:08. > :26:12.on its handle. But it is the back and tail of Ursa Major. They point
:26:12. > :26:22.to Polaris. If you can see this star then you know you're facing
:26:22. > :26:23.
:26:23. > :26:28.north. Polaris is the brightest star in another bear constellation,
:26:28. > :26:33.the little bear. If you don't think it looks much like a bear, blame
:26:34. > :26:43.the ancient Greeks because it's been called that for over 2,000
:26:43. > :26:51.years. If you swing round 90 degrees to the west, there are nine
:26:51. > :26:59.stars that make up Pegasus, but be quick, as it sets around ten
:26:59. > :27:05.o'clock. Move another 90 degrees round and Orion is in the south.
:27:05. > :27:13.Above Orion is another easy one to spot, Taurus the bull. The clue to
:27:13. > :27:20.finding Taurus is a distinctive V shape on its side. And above Taurus
:27:20. > :27:24.is Auriga less well known, the Kharioteer. It's supposed to look
:27:24. > :27:30.like a helmet. Throughout the night, these constant layings move towards
:27:30. > :27:35.the west as the earth spins and around 2am, if you look to the east,
:27:35. > :27:40.the moon will be rising on the eastern horizon. It should be half
:27:40. > :27:44.full tonight so look along the line between light and dark and you'll
:27:44. > :27:49.see some fantastic detail. All that to see in the sky tonight.
:27:49. > :27:56.This is the perfect time to do it because the weather is particularly
:27:56. > :28:02.good. Tonight. It may not be as good over the next couple of nights.
:28:02. > :28:08.Thank you very much to all our guests for coming in. Kevin, Tim,
:28:08. > :28:14.Lucie, and Andy, I hope you have enjoyed your visit. I've smelt the
:28:14. > :28:20.moon, what can I say! Tomorrow, we're into black holes. Yes, we're
:28:20. > :28:30.stepping away from the solar system and talking about black holes. The
:28:30. > :28:38.strangest prediction of ice and galaxies relativeity. Do they have
:28:38. > :28:44.a role? Physical -- physicals is odd around black holes. It's a
:28:44. > :28:50.paradox, how do you see a black hole? No light can escape from them,