:00:10. > :00:15.After last night's cloud cover, the sky is completely clear tonight.
:00:15. > :00:18.The stars are out and Jupiter is shining. Last night we searched for
:00:18. > :00:21.evidence of life on other worlds. Tonight we will try and explain how
:00:21. > :00:25.everything came to be here in the first place by looking up at the
:00:25. > :00:29.night sky. We have one hour to tell you the entire history of our
:00:29. > :00:32.universe. Hold on to your hats. By the end of this programme Brian
:00:32. > :00:38.will try to answer the question more of you have asked him than
:00:38. > :00:48.anything else - what happened before the Big Bang? I'm Brian Cox.
:00:48. > :01:10.
:01:10. > :01:17.He is Dara O Briain. And this is Welcome back to Jodrell Bank. We
:01:17. > :01:19.were unlucky with the weather last night. This is the second night of
:01:19. > :01:25.Stargazing. Thank you for your questions and photographs that you
:01:25. > :01:30.have already sent us. We have been inundated. There are some
:01:30. > :01:40.incredible images. Here is the first one. It is a beautiful image
:01:40. > :01:52.
:01:52. > :02:01.This one, the Milky Way over Trusk Lough. Finally, this is the Flame
:02:01. > :02:07.Nebula in Orion. Wow! The star in the belt is just below there. That
:02:07. > :02:10.is the star that lights up this nebula. The dark patches are dust
:02:10. > :02:13.lanes across the glowing gas. Fabulous stuff. We want to see more
:02:13. > :02:23.of these. More questions. More photographs. We will cover them in
:02:23. > :02:24.
:02:24. > :02:28.this show or in the later show, Back to Earth. E-mail them to us -
:02:28. > :02:35.stargazing@bbc.co.uk. Send them on Twitter to @bbcstargazing or go to
:02:35. > :02:40.the website - bbc.co.uk/stargazing. Ed Copeland is waiting to join in
:02:40. > :02:44.with our live webchat as well. bet you say that in your sleep!
:02:44. > :02:51.Anyway, tonight we will try and take you on a tour of the history
:02:51. > :02:55.of everything. Take a look at this image. This was taken by the Hubble
:02:55. > :03:02.Telescope. In this image there are some of the most distant galaxies
:03:02. > :03:10.we have ever seen. The interesting one is this one. You can't see it
:03:10. > :03:16.there. It has 11.9 next to it. That is 13.35 billion light years away
:03:16. > :03:21.from Earth. That means that light has taken 13.35 billion years to
:03:22. > :03:28.travel from that into the Hubble Space Telescope. The universe is
:03:28. > :03:32.only 13.75 billion years old. That light has been travelling
:03:32. > :03:36.throughout the history of the universe pretty much. You have seen
:03:36. > :03:43.a galaxy there that formed only a few hundred million years or so
:03:43. > :03:49.after the Big Bang. What we see is a snapshot of what that galaxy was
:03:49. > :03:54.like at the moment its light left on the long journey to us. Mark is
:03:54. > :03:56.in a field. It is great to be back here again
:03:56. > :04:03.with the Liverpool Amateur Astronomical Society. ALL: Hello!
:04:03. > :04:10.They are quite cheery. We have clear skies at the moment. Earlier,
:04:11. > :04:16.we did manage to get some footage of the Pleiades star cluster,
:04:16. > :04:24.otherwise known as the Severn Sisters. It is a billion million
:04:24. > :04:27.miles away. It takes its light 4 40 million years to get to us. Most of
:04:27. > :04:32.the stars are in the Milky Way. There are a couple of objects which
:04:32. > :04:37.you can see which aren't in the Milky Way such as the Andromeda
:04:37. > :04:42.Galaxy. We have a live image now of the galaxy. It is an object which
:04:42. > :04:47.is 15 quintillion, which is a billion billion miles away. The
:04:47. > :04:53.light has been travelling for 2.5 million years to get to us. The
:04:53. > :04:57.image is just under three million years old. That means if anybody is
:04:57. > :05:02.on a planet inside the Andromeda Galaxy looking back on us, they are
:05:02. > :05:06.seeing us as our ancestors were starting to walk on two legs which
:05:06. > :05:11.is crazy! Great objects to look at. Try and get a look at them if you
:05:11. > :05:20.can. For now, back to you in the studio. Do you understand those?
:05:20. > :05:25.Quintillion, I have never heard that. It's a million million
:05:25. > :05:29.million million - I should have put the brakes on one million ago!
:05:29. > :05:36.to the ten or something. Anyway, the deeper into space you can see,
:05:36. > :05:40.the further back in time you are looking. A lot of our greatest
:05:40. > :05:44.questions have been answered by sending incredibly complex
:05:44. > :05:48.instruments into space. Many were built in the room where Liz Bonnin
:05:48. > :05:55.is now. Welcome back to NASA's Jet
:05:55. > :06:00.Propulsion Laboratory here in California. This is High Bay One
:06:00. > :06:04.where they built Voyager and also the Mars Curiosity Rover that we
:06:04. > :06:07.saw last night. Not only that, but this is the room where the wide
:06:07. > :06:11.field planetary camera of the Hubble Telescope was built. The
:06:11. > :06:15.camera that has given us the deepest view into our universe to
:06:15. > :06:20.date. Tonight, I will find out how that camera has improved on that
:06:20. > :06:26.image and I'm also going to show you Hubble's successor, the biggest
:06:26. > :06:33.Space Telescope ever built. Come back to me soon.
:06:33. > :06:37.The telescope is in space, it looks for light. The light we see is only
:06:37. > :06:43.a tiny proportion of the light that exists in the universe. I will
:06:43. > :06:48.expand on that idea in the old- fashioned way with a piece of chalk.
:06:48. > :06:56.Visible light - light is an electromagnetic wave. It has a
:06:56. > :07:01.wavelength. It is the distant from peak to peak. Visible light has a
:07:01. > :07:08.wavelength of 500,000 millionths of a metre. That is visible. That is
:07:08. > :07:13.what our eyes can see. If you go to longer wavelengths, first you move
:07:13. > :07:19.to infrared light. We can't see that. We can feel it. You feel it
:07:20. > :07:26.as heat. You go further to longer wavelengths, we go through
:07:26. > :07:32.microwaves which have a wavelength of five centimetres. Then into the
:07:32. > :07:36.radio part of the spectrum. Jodrell is detecting wavelengths of 20
:07:36. > :07:41.centimetres. You can have radiowaves out to hundreds of
:07:41. > :07:46.metres. Go to the other end, the wavelengths start getting shorter
:07:46. > :07:51.and shorter. Beyond the visible there is ultraviolet. That is the
:07:51. > :07:56.stuff you can't see but gives you a suntan. Shorter wavelengths we get
:07:56. > :08:06.out to x-rays which pass through your skin which is why you can see
:08:06. > :08:10.
:08:10. > :08:14.your bones. Finally, to the low- wave radiation. Different
:08:14. > :08:24.telescopes have been designed to cover all parts of that spectrum.
:08:24. > :08:27.
:08:27. > :08:37.We have images from them here for example. This is the Nova Cygni.
:08:37. > :08:41.
:08:41. > :08:47.This is why you are seeing super- high-energy photons. The Chandra X-
:08:47. > :08:57.Ray Total scone. Pillars of Creation. Visible light is one of
:08:57. > :09:03.
:09:03. > :09:07.the few pieces that's affected by our atmosphere. -- Chandra X-Ray
:09:07. > :09:16.Telescope. We have mike wave telescopes, this
:09:16. > :09:20.is from the Planck. This is the Helix Nebula. That is very
:09:20. > :09:23.beautiful. It is material coming off a dying star. In there, the
:09:23. > :09:28.elements of life have been spread out into the universe. Collectively,
:09:28. > :09:32.these have allowed us to piece together the grand story of our
:09:32. > :09:42.universe. First, we need to try and give you a sense of timescale. When
:09:42. > :09:46.
:09:46. > :09:50.did everything start? How long will The rhythms of the natural world
:09:50. > :10:00.have an eternal quality to them. Perhaps that is why our earliest
:10:00. > :10:02.
:10:02. > :10:10.theories of the universe picture it as unchanging and everlasting. Over
:10:10. > :10:16.the last century, that picture has been transformed. Our current best
:10:16. > :10:23.model of the universe is called the Big Bang Model. That says the
:10:23. > :10:27.universe is 13.75 billion years old which means that it began 13.75
:10:27. > :10:34.billion years ago. So if the universe had a beginning, does that
:10:34. > :10:38.imply that it will also have an end? To answer that we need to
:10:38. > :10:44.understand how the universe evolved with time. That is something that
:10:44. > :10:49.was discovered in the 1920s when astronomers measured the movement
:10:49. > :10:56.of distant galaxies relative to the Earth. If you look at galaxies
:10:56. > :11:00.beyond the Milky Way, what you find is all the galaxies appear to be
:11:00. > :11:10.rushing away from us. Imagine all the dots of the galaxies and I blow
:11:10. > :11:11.
:11:11. > :11:16.up the balloon - as the balloon expands, every dot, every galaxy
:11:17. > :11:20.moves away from every other galaxy. The interpretation of the
:11:20. > :11:24.measurement that virtually every galaxy is rushing away from every
:11:24. > :11:32.other is the same. They are doing that because the universe is
:11:32. > :11:35.expanding and it's been doing that since the Big Bang. The cause of
:11:35. > :11:43.this expansion is not fully understood. But in the billions of
:11:43. > :11:52.years since the Big Bang, space has continued to expand. There are also
:11:52. > :11:55.other forces at work on the galaxies in the universe. All those
:11:55. > :11:59.galaxies out there across the universe have one thing in common
:11:59. > :12:04.which is that they are massive, they have mass, they are made of
:12:04. > :12:11.solid objects. Now, Isaac Newton told us there is a force that
:12:11. > :12:17.exists between objects that have mass, the force of gravity. It acts
:12:17. > :12:22.to pull things together. If I drop this shell, then due to the force
:12:22. > :12:25.of gravity it meets the earth. Think about what that means for the
:12:25. > :12:30.expansion of the universe. It is full of these galaxies, a great
:12:30. > :12:34.deal of matter, a great deal of mass, all attracting itself
:12:34. > :12:39.together, so the mass in the universe acts as a brake on the
:12:39. > :12:46.expansion. The mass in the universe acts to slow the expansion of the
:12:46. > :12:51.universe down. For much of the 20th Century, scientists believe that
:12:51. > :12:55.the balance between these two effects, the initial expansion and
:12:55. > :13:03.the breaking effect of gravity, would determine how the universe
:13:03. > :13:08.might end. In this old theory, if gravity won the battle, then the
:13:08. > :13:16.expansion might not just slow down, it might even stop and reverse so
:13:16. > :13:20.the universe could one day begin to contract. That scenario is called
:13:20. > :13:25.the Big Crunch. It means every galaxy in the sky will start
:13:25. > :13:29.rushing towards every other galaxy and eventually the entire
:13:29. > :13:33.observable universe would shrink back to the size of a single atom,
:13:34. > :13:38.hot and dense. It would be an incredibly violent end to the
:13:38. > :13:43.universe. Just over a decade ago, when astronomers measured how space
:13:43. > :13:49.has been expanding over time, they discovered something unexpected
:13:49. > :13:54.which completely changed how we think the universe might end. Five
:13:54. > :14:03.billion years ago, the expansion of space actually began to speed up as
:14:03. > :14:07.if something had given it fresh momentum. So what is this
:14:07. > :14:11.mysterious thing that is stretching the very fabric of space itself?
:14:12. > :14:17.Well, the best answer I can give you is that we don't know. It is
:14:17. > :14:22.one of the great mysteries in physics. It does have a name. It is
:14:22. > :14:26.called "dark energy" and that is all that everybody can agree upon.
:14:26. > :14:33.There are theories about what this dark energy is and where it comes
:14:33. > :14:39.from. But so far, nothing quite seems to fit. What we do know is
:14:39. > :14:43.that its presence in every cubic metre of space, here and out beyond
:14:43. > :14:49.the edge of the Solar System, beyond the Milky Way, and out to
:14:49. > :14:53.the edge of the observable universe, space contains dark energy. The
:14:54. > :14:58.universe, so far as we can tell, will continue to accelerate faster
:14:58. > :15:03.and faster. The galaxies will get further and further away.
:15:03. > :15:13.Ultimately, that dark energy will dominate and our best guess is that
:15:13. > :15:15.
:15:15. > :15:21.the universe will continue to We have lots and lots of questions
:15:21. > :15:26.coming in. Loads of the has asked - - have asked a version of this. How
:15:26. > :15:32.do we know the universe is expanding? It is one of the most
:15:32. > :15:36.important measurements in astronomy. If you look out to distant galaxies
:15:36. > :15:41.and you can pick up stars in those galaxies, then what you see is that
:15:41. > :15:45.they emit light but that light is stretched and what you find is that
:15:45. > :15:51.the further away the object is that you look at, the more stretched the
:15:51. > :15:55.light becomes. How do you measure distance? There are certain objects,
:15:55. > :15:59.supernova explosions, where we know the brightness and we understand
:15:59. > :16:02.the physics were enough to know how British should be and then it is
:16:02. > :16:08.quite simple. You look at how bright it looks and you can look at
:16:08. > :16:12.the distance. -- you know how bright it should be. This then
:16:12. > :16:16.tells us the universe has been stretching. If you can imagine a
:16:16. > :16:24.wave of light that has been travelling from some object for 1
:16:24. > :16:28.billion years. The universe has been stretching for 1 billion years
:16:28. > :16:33.and him when it is 2 billion light years it will be stretched to
:16:34. > :16:38.billion years. And if you run the clock backwards, you start drawing
:16:38. > :16:42.it in and it reduces down the universe. That is it. So you
:16:42. > :16:46.reverse it mentally. The universe is contracting and contracting and
:16:46. > :16:49.at some point you find something is on top of everything else and that
:16:49. > :16:55.is what we call the Big Bang, and that is what we will be talking
:16:55. > :17:03.about later. Lucy has asked on behalf of her class, how can space
:17:03. > :17:08.never end? It is a very difficult concept. And that is if indeed it
:17:08. > :17:15.never ends. It was born in the neck so I hope that is the answer.
:17:15. > :17:21.we happy with batons are? Yeah! We of fine! We have an update on the
:17:21. > :17:26.Mars sedge. We have pictures that have been picked out by you. We
:17:26. > :17:34.have 60,000 people taking part already. 450,000 images of Mars
:17:34. > :17:40.have been explored by you in 24 hours and we should make it well
:17:41. > :17:48.over one million tonight. It is three-quarters the size of Wales,
:17:48. > :17:53.the area. We have gone from Cyprus to three-quarters of Wales. Can we
:17:53. > :17:57.make it all of Wales this evening?! This is an interesting feature
:17:57. > :18:05.never before seen, picked out by a few were. These are geological
:18:05. > :18:11.features. What is that? What are those bright bits? Is it the sun
:18:11. > :18:19.catching it? It is fascinating. had some discussions last night
:18:19. > :18:27.with folks like Brian May. What if aliens landed? We will give you a
:18:27. > :18:33.patch of Mars that you can look at if you want to join in. The people
:18:33. > :18:38.of Wales are locked on Mars! We are trying to find them! If you find
:18:38. > :18:46.Elvis, we will give you a price! How did we begin to work call of
:18:46. > :18:52.his out? I will show you this one image. If -- work all of this out?
:18:52. > :18:59.This is the 20 ft telescope built by William her sure. You had to
:19:00. > :19:06.stand on it to make observations. You could see the two moons of
:19:06. > :19:10.Uranus and Oberon. And another moon that we think may be home for life.
:19:10. > :19:19.We like a crazy project on this show and we decided to recreate and
:19:19. > :19:23.rebuild her -- the Herschel Telescope.
:19:23. > :19:29.To find out just how he made his 20 ft telescope, I have come to the
:19:29. > :19:34.Royal astronomical Society in London where his observations have
:19:34. > :19:39.been collected. I guess the important question to build this,
:19:39. > :19:44.have you got any plans I can take with me? Not directly. We do not
:19:44. > :19:51.have a lot of detail. Just the sketches. So I only have pictures
:19:51. > :19:59.to work from? Fabulous! It is a brilliant structure. It has to go
:19:59. > :20:04.up and down and a new track and let the sky rotate in front of you. He
:20:04. > :20:08.wants to fathom what he calls the length, breadth, depth and
:20:08. > :20:13.profundity of the universe. And so he built bigger and bigger
:20:13. > :20:20.telescopes to see further out? Exactly. It looked quite cumbersome.
:20:20. > :20:26.How did it work? The whole structure could rotate. You would
:20:26. > :20:29.have needed some big strong beefy chaps down here. Lots of polls,
:20:29. > :20:36.ropes and chains. A bit of ingenuity and we can probably
:20:36. > :20:39.cricket! I hadn't quite appreciated how much effort he had gone into
:20:39. > :20:43.building this. And there is a lot of stuff I have to think about. So
:20:43. > :20:48.for me to get it working safely, it is going to take quite a bit of
:20:48. > :20:51.planning. I will also need a lot of help so I have come to the
:20:51. > :20:54.University of Derby, who have agreed to house the telescope, to
:20:55. > :21:02.meet the crack team who are going to help make this happen. So
:21:02. > :21:05.hopefully I can see what he saw. The university's staff and the
:21:05. > :21:13.local astronomy Society are going to run and manage how it is built
:21:13. > :21:20.and they have a but you'd have questions. Are we going to keep it
:21:20. > :21:24.in wood? If you want to see a perfect image in the sky you want
:21:24. > :21:31.tea the telescope to be sealed and not distorted. As you wind it up it
:21:31. > :21:36.will become unstable. How will you stop it sagging in the middle?
:21:36. > :21:40.how stable will it be in terms of higher winds? It looks like a have
:21:40. > :21:43.a bit of thinking to the engineers have come up with a design that
:21:43. > :21:47.looks a bit different to the original. Instead of wood, we are
:21:47. > :21:51.going to build it out of scaffolding poles revolving around
:21:51. > :21:56.a central pivot. The telescope will sit in a cradle to support it and
:21:56. > :22:00.it can be winched up and down. Although remains dated, it remains
:22:00. > :22:06.true to the principles. Now I am against the clock to get this ready
:22:06. > :22:15.Surrey solid base of the telescope is first on my list. -- so a solid
:22:15. > :22:19.base. We need to plot true North first so the local astronomical
:22:19. > :22:26.Society is here to find it a proper way, with an astronomical clock and
:22:26. > :22:34.the sun. At local noon, a shadow is thrown by a perpendicular stick
:22:34. > :22:40.showing North. And with some nifty maths, they can workout East, West
:22:40. > :22:50.and the degrees in between. He if you are South, give me a wave!
:22:50. > :22:54.help it get marked out in style, the local primary school are here.
:22:54. > :23:02.They are painted in bright colours. Who is looking forward to the
:23:02. > :23:12.telescope? Me! We need clear skies, don't we? Yes. What planets have we
:23:12. > :23:18.got here? Uranus and Sutton. you remember who discovered Uranus?
:23:18. > :23:27.William Herschel. Now the base is down and looking beautiful, it is
:23:27. > :23:31.time to put the construction plan into action. Now, this is no
:23:31. > :23:35.ordinary scaffolding job. Inaudible the telescope to work, all
:23:35. > :23:45.measurements have to be totally precise. -- in order for the
:23:45. > :23:49.
:23:49. > :23:54.telescope. I am trusting you all. Shall we get started? Yes. To see
:23:54. > :24:03.the whole night sky, William Herschel needed a panoramic view so
:24:03. > :24:08.that team attaches 12 kneels to the base so it can rotate. -- wheels.
:24:08. > :24:14.The original fellow over two or three times at first, I think, so
:24:14. > :24:19.that won't happen to us, will it? No. We have taken on board all of
:24:19. > :24:24.the issues and accommodated them. We have made sure it is safe to use
:24:24. > :24:29.and we have no concerns. We Dicky layers of scaffolding and plays it
:24:29. > :24:33.is time to add the specially crafted cradle for the 20 ft long
:24:33. > :24:39.telescope tube which will hopefully stop its sagging in the middle.
:24:39. > :24:43.Well, it fits! And as it is put in position, you start to get a feel
:24:43. > :24:50.for William Herschel's ambition and the sheer scale of what he was
:24:50. > :24:54.doing. There is just one thing missing - the actual telescope. I
:24:54. > :24:59.have no idea whether the drawings are going to give me enough
:24:59. > :25:07.information to actually see what he saw through it, so there is still a
:25:07. > :25:10.lot to figure out. Mark, that didn't look too easy?
:25:10. > :25:17.it was and! I still find it amazing the amount of effort William
:25:18. > :25:21.Herschel went through. -- it was not! We understand as much as we do
:25:21. > :25:26.about these amazing stars behind me offence to him. But the setting up
:25:26. > :25:30.of the mound was a bit easier than I expected. The optics was a bit
:25:30. > :25:33.more of a challenge but you will see a bit more about that tomorrow
:25:33. > :25:37.and after the show I will be heading down to derby of the
:25:37. > :25:41.weather is clear and I will be showing you what you can see
:25:41. > :25:46.through the telescope. If this is important things up. The lesson
:25:46. > :25:50.here is that there is an interaction between engineers and
:25:50. > :25:55.inventing new instruments a more we can learn about the universe and
:25:55. > :25:59.William Herschel discovered Sutton's Moon. You go for 100 years
:25:59. > :26:03.and you get to Edwin Hubble and we have learned a lot about that, with
:26:03. > :26:08.the Hubble telescope. I am going to show you something now. The Hubble
:26:08. > :26:16.constant. I am going to use my Black Hawk! I am going to remind
:26:16. > :26:22.back through the time of television backed Izzy 1970s! This is what he
:26:22. > :26:28.measured. He used a bigger telescope. So what could he see
:26:28. > :26:33.what that? He was the first to see stars in distant galaxies.
:26:33. > :26:37.Initially in the Andromeda Galaxy, so he was the first to show it as
:26:37. > :26:43.not some kind of nebula in the Milky Way but an external island of
:26:43. > :26:47.stars. He went on in 1929 by making hundreds of measurements with high-
:26:47. > :26:52.precision telescopes to work out this number, which is the Hubble
:26:52. > :26:58.constant, named after him. It is 70 kilometres per second per
:26:58. > :27:05.megaparsec. Now, this is a strange thing. It is a distance measure.
:27:05. > :27:11.You will know what it is if you one astronomer. It is 3.2 something my
:27:11. > :27:14.ears or so. So this number maps and encodes the expansion rate in it of
:27:14. > :27:19.the universe and it says if you go about 3 million light years over
:27:19. > :27:23.there and look at the galaxies and average out their motion, then on
:27:23. > :27:27.average they are moving away from the Milky Way at 70 kilometres per
:27:27. > :27:32.second, pretty slowly. A my favourite thing about this is a
:27:32. > :27:36.little mathematical trick and we're going to do this at home for those
:27:36. > :27:40.of you were so minded. If you have got them to be the same unit, they
:27:40. > :27:47.kind of cancel each other out and you are left with a number which
:27:47. > :27:53.has just in units of one over a second. Yes. Send us a tweet as
:27:53. > :27:59.soon as you have done it. Turn megaparsec into kilometres and they
:27:59. > :28:02.will cancel out. Invert that number and you will get an age of the
:28:02. > :28:11.universe which is something in billion years. Send it in on
:28:11. > :28:15.Twitter. The first one IC, I will buy you a pint! You flip the number
:28:15. > :28:20.over and you get the age of the universe! What I love about it is
:28:20. > :28:26.it is a measurement. A simple measurement. This is how we first
:28:26. > :28:29.deduced or measured the age of the universe. It is a beautiful thing.
:28:29. > :28:39.It is how they measure the first space Telegraph... Sorry!
:28:39. > :28:39.
:28:39. > :28:49.Telescope! Let's go back to Liz by -- and she will tell us more.
:28:49. > :28:50.
:28:50. > :28:59.you. We are at the Deep Space Network and it is from here that
:28:59. > :29:05.they, and Nasser -- at NASA, do many of their measurements. One of
:29:05. > :29:11.the most famous has to be Hubble's of the early stars and galaxies.
:29:11. > :29:14.Thank you very much for joining us. This iconic Deep Field Image that
:29:15. > :29:23.we know and love so well has recently been improved. Is that
:29:23. > :29:28.right? Yes, it is the most recent image we have and we are looking
:29:28. > :29:33.back 90% back to the Big Bang. The objects highlighted here are the
:29:33. > :29:38.most distant images and galaxies known. The one on the left in red
:29:38. > :29:42.is the most distant we have seen and it has been seen for 380
:29:42. > :29:47.million years after the Big Bang. That is amazing! Can we now say
:29:47. > :29:50.these are the earliest galaxies? That is it? No. We already know
:29:50. > :29:54.from the colours of these stars that the stars have chemical
:29:54. > :29:57.elements in them which have been enriched with and galaxies
:29:57. > :30:01.themselves so there are even earlier galaxies be on the depth of
:30:01. > :30:06.this image. Hubble has probably looked back as far as it can but we
:30:06. > :30:10.now know there are earlier object so it has set the stage for further
:30:10. > :30:20.exploration of even earlier object with more powerful facilities.
:30:20. > :30:20.
:30:20. > :30:27.need a bigger telescope! Hmm! And will -- and to uncover all of those
:30:27. > :30:37.stars and galaxies, NASA or were doing the work and I was lucky
:30:37. > :30:38.
:30:38. > :30:45.enough to go and see the latest The plan is to solve the mystery of
:30:45. > :30:50.how the very first stars were formed. They are believed to be 300
:30:50. > :30:56.times the mass of our Sun. A telescope here is planning to
:30:56. > :31:03.change all that. These are the plans for NASA's most
:31:03. > :31:10.formidable Time Machine yet conceived. Called the James Webb
:31:10. > :31:14.Telescope, its 6.5 metre diameter mirror will let us see objects far
:31:14. > :31:18.fainter than Hubble can. It will be the biggest telescope ever sent
:31:18. > :31:23.into space. They have been building it for a decade. The mirror is too
:31:23. > :31:28.large to fly into space on any of today's rockets so it folds up into
:31:28. > :31:38.three sections. Each of the 18- mirror segments are precision-made
:31:38. > :31:41.
:31:41. > :31:45.and are coated in pure gold. Today, two more are just arriving.
:31:45. > :31:52.Critical spaceflight hardware. Don't you just love it?! I would
:31:52. > :32:01.not want to be the guy manoeuvring this right now. Far too nerve-
:32:01. > :32:11.wracking. Just don't drop it! Like everything else, these mirrors have
:32:11. > :32:12.
:32:12. > :32:15.been designed to be as light as possible, by Nobel Prize Winner Dr
:32:15. > :32:21.John Mather. We have made it lightweight because that is the
:32:21. > :32:26.only way to get it up into space. We need to go much higher so we are
:32:26. > :32:35.going up on a European rocket and it can carry 6,000 kilos, which is
:32:35. > :32:40.about half what the Hubble was. So it has to be much lighter.
:32:40. > :32:45.Each mirror weighs 20 kilograms and they will be assembled in a clean
:32:45. > :32:50.room so nothing can contaminate their 1.32 metre diameter surface.
:32:50. > :32:56.It is not just its size that will give it the edge over Hubble, it is
:32:56. > :33:01.the light that the Webb Telescope is designed to see that will make
:33:02. > :33:05.all the difference. On its journey towards us, the light from the most
:33:05. > :33:09.distant stars and galaxies has changed. It is still travelling at
:33:09. > :33:14.the speed of light. Because the universe is expanding the
:33:14. > :33:18.wavelength of that light has become longer, from visible to infrared
:33:18. > :33:24.wavelengths. So to be able to detect that light you need a
:33:24. > :33:29.telescope that is sensitive to infrared. The Webb Telescope can
:33:29. > :33:39.pick up the radiation from a bumblebee the distance of the Moon.
:33:39. > :33:44.By giving the telescope's sensitive infrared eyes we are on the brink
:33:44. > :33:49.of viewing our deepest origins in the birth of the first stars.
:33:49. > :33:55.Though for Dr Mather, the most exciting discoveries will be those
:33:55. > :34:01.that we can't even begin to imagine. Every time you build a big
:34:01. > :34:05.telescope, we get a surprise. Nature seems to be like that. Our
:34:05. > :34:11.imagination, no matter how imaginative we are, there are
:34:11. > :34:14.things out there that we will never guess.
:34:14. > :34:19.Richard, you have been working on this area all your life. How
:34:19. > :34:23.important is it that we find those very early stars? It is very
:34:24. > :34:28.important. This moment when the universe was bathed in light for
:34:28. > :34:32.the first time - we call that Cosmic Dawn - it is an important
:34:32. > :34:37.landmark in the history of the universe. What are the implications
:34:37. > :34:40.if Webb does find those stars? we know when this moment is, we can
:34:40. > :34:44.start to come backwards to the present day and start to piece
:34:44. > :34:50.together how stars enriched the galaxies with the chemical elements,
:34:50. > :34:53.how they grew in size up to the majestic systems we have around us
:34:53. > :34:58.today. How does your research follow on? There is lot more to do.
:34:58. > :35:03.We have to understand the physics of what is going on. You are not
:35:03. > :35:07.out of a job(!) No. Thank you. Join me later when I find out about some
:35:07. > :35:11.other NASA missions that are helping us to understand star
:35:11. > :35:16.evolution in much greater detail. See you in a bit.
:35:16. > :35:20.Thanks, Liz. Until the James Webb is launched, the deepest image of
:35:20. > :35:23.the galaxies we have is from the Hubble Space Telescope. We should
:35:23. > :35:30.be able to see the same patch of sky outside with Mark now. Which
:35:30. > :35:34.patch of sky is the Hubble looking at? It was in a position in the
:35:34. > :35:39.constellation of Fornax. It is just below the trees, ten degrees above
:35:39. > :35:47.the southern horizon. We have a video which shows what it would be
:35:47. > :35:54.like if you were to take a journey in that direction. The final image
:35:54. > :35:58.was a combination of 2,000 individual images. Stunning. It is.
:35:58. > :36:04.We can see back to the formations of the first galaxies. We can't see
:36:04. > :36:10.to the first moment of the Big Bang. It took light a while to get going?
:36:10. > :36:13.Yes, imagine when every galaxy you can see in the night sky, the whole
:36:13. > :36:18.universe was crammed into something the size of your head. That is
:36:18. > :36:25.large enough! Very dense! Yes! universe has expanded and cooled
:36:25. > :36:27.ever since. So it gets cooler and cooler, at a point around 400,000
:36:27. > :36:37.years after the Big Bang, the universe had cooled down so much
:36:37. > :36:41.that electrons were able to go into orbit around the nucleus to form
:36:41. > :36:44.atoms. Light could travel through the universe and we can take an
:36:44. > :36:48.image, we can see that light now travelling from that place all
:36:48. > :36:58.those light years away. We have taken a picture of that image and
:36:58. > :37:03.
:37:03. > :37:09.it is this. It is called the Cosmic Microwave Background. This is the
:37:09. > :37:15.first light we are seeing there? That's right. In universe terms,
:37:15. > :37:20.that is a baby. It is the earliest light we can see. It was taken by a
:37:20. > :37:25.NASA probe which measured this faint glow of light that bathed us
:37:25. > :37:29.in all directions. It's been travelling to us for 14 billion
:37:29. > :37:33.years. What are we seeing here? There's a lot of features in this?
:37:33. > :37:38.The colour tells you its temperature. The temperature is
:37:38. > :37:42.almost the same everywhere. With probes like this, we have managed
:37:42. > :37:46.to find, tease out the tiny variations across the sky. Where it
:37:47. > :37:50.is red, it is ever so slightly hotter than average. Ever so
:37:50. > :37:57.slightly? It is a millionth of a degree. The light we are measuring
:37:57. > :38:02.is really cold. It is minus 270 degrees. We are measuring tiny
:38:02. > :38:07.variations. The measurement is the temperature fluctuations. What do
:38:07. > :38:13.they correspond to? You have these ripples in temperatures. They trace
:38:13. > :38:17.out tiny lumps and bumps in space. The space was almost completely
:38:17. > :38:21.smooth. There were these tiny lumps and bumps. They are origins of all
:38:21. > :38:25.the stars in the galaxies that we see now. We think they grew over
:38:25. > :38:29.millions of years until the lumps got big enough to form the very
:38:29. > :38:35.first stars. This image is the entire sky? So every direction you
:38:35. > :38:39.look? Unwrapped on to a flatscreen. We are looking at the seeds of the
:38:39. > :38:46.galaxies. Without these fluctuations, we wouldn't exist?
:38:46. > :38:52.That's right. There is another mission, the Planck Mission? That's
:38:52. > :38:57.right. We have learnt a lot about what the universe is made of, but
:38:57. > :39:04.the Planck Mission has been operating beautifully. It is
:39:04. > :39:08.working at higher resolution. This is a map of it right now. This is
:39:08. > :39:14.our Milky Way galaxy in the purple. You are getting in the way - this
:39:14. > :39:18.is what we want to see at the edges? Exactly. We have to filter
:39:19. > :39:24.out the Milky Way? Exactly. question is what is that going to
:39:24. > :39:28.tell us? What is the origin of those fluctuations? Exactly. We
:39:28. > :39:33.have this crazy idea about what happened in the first trillionth of
:39:33. > :39:37.a second. The first one trillionth? Yes. The universe expanded
:39:37. > :39:44.incredibly fast, faster than the speed of light, blowing up bits of
:39:44. > :39:48.space that are smaller than the nucleus of an atom in a trillionth
:39:48. > :39:52.of a second. That is what made our universe the way it is today. We
:39:52. > :39:56.are not sure if that is what happened or not. I find that
:39:56. > :40:03.remarkable that we make a measurement that you can link back
:40:03. > :40:07.to events that may have happened a trillionth of a second after our
:40:07. > :40:12.universe began. It is phenomenal. You can trace it through to 400,000
:40:12. > :40:15.years where we see this light and all the way through to today and it
:40:15. > :40:20.is making so much sense. We are finding out what the universe is
:40:20. > :40:25.made of. It is really a wonderful thing. We will talk to you after
:40:25. > :40:29.the show. Thank you very much. We will see you again. If you are
:40:29. > :40:37.hoping to get out after the show, you will need some clear skies. So
:40:37. > :40:47.over to Su San Powell in the BBC Weather Centre. -- Susan Powell in
:40:47. > :40:55.
:40:55. > :41:04.If you are planning on casting your eyes skywards, you better get on
:41:05. > :41:12.with it! Further north, you are up against some fog so the best places
:41:12. > :41:15.might be North Wales and the North East of England. Better prospects
:41:15. > :41:21.tonight than tomorrow night. Tomorrow, a lot of cloud across the
:41:21. > :41:23.UK. An old weather front in the east, a fresh one to the west. The
:41:24. > :41:29.clearest of the skies will be between those two weather fronts.
:41:29. > :41:32.It will be limited so your best chances are this evening. Perhaps
:41:32. > :41:39.tomorrow, not quite so great. I will be back tomorrow to give you
:41:39. > :41:43.Thank you. If you do have clear skies, get out there and take a
:41:43. > :41:48.look after the show. Even if all you are doing is gauging it with
:41:48. > :41:56.the naked eye, there is a still a lot you can work out about the
:41:56. > :42:02.history of the stars above us. Here is Mark to explain.
:42:02. > :42:11.On a clear, dark night, thousands of stars can be seen twinkling
:42:11. > :42:16.above our heads. To the untrained eye, it is easy to assume they are
:42:17. > :42:20.all the same. Tiny white specs light years away. In fact, many
:42:20. > :42:24.stars aren't white at all. Our nightly companions are many
:42:24. > :42:30.different colours and those colours give us a clue to their life
:42:30. > :42:34.stories. Most stars appear white to us on Earth because they are so far
:42:34. > :42:38.away they are too faint to stimulate the part of the eye that
:42:38. > :42:48.lets us see in colour. If we could see as well as a powerful telescope,
:42:48. > :42:50.
:42:50. > :42:55.our view of the sky would turn technicolour. When you know what
:42:55. > :43:01.you are looking for, picking out the colours of stars is fairly easy
:43:01. > :43:07.to do. Many are bright enough to be seen with just the eye. Let's start
:43:07. > :43:12.by looking at Orion. It rises nice and high so it is easy to spot. We
:43:12. > :43:19.start by looking for its famous three-star belt which you can see
:43:19. > :43:26.just over my left shoulder. Move upwards to find a star called
:43:26. > :43:29.Betelgeuse. To the naked eye, it is one of the most colourful. You
:43:29. > :43:34.can't see this with our special low-light black-and-white camera so
:43:34. > :43:43.here is what it looks like through our telescope. As we go out of
:43:43. > :43:47.focus, its stunning red colour becomes really prominent. If we go
:43:47. > :43:54.back to the belt stars and start at the top star and drop a line down
:43:54. > :43:58.towards the lower right-hand corner we spot another bright star called
:43:58. > :44:05.Rigel. This is Rigel out of focus. You can see it is a vivid blue
:44:05. > :44:11.colour. Both Rigel and Betelgeuse are known as super-giants. They are
:44:11. > :44:20.amongst some of the brightest stars in the night sky. Why is one red
:44:20. > :44:25.and the other blue? The colour of a star can tell us how hot its
:44:25. > :44:30.surface temperature is. We think of hot things as red and cold things
:44:30. > :44:36.as blue. The hotter a star is the bluer it looks. The cooler the star,
:44:36. > :44:42.the redder it glows. So Betelgeuse is colder than blue Rigel. With a
:44:42. > :44:48.simple chart like this, we can tell how hot the stars are. I would say
:44:48. > :44:52.Rigel is more of a Bluestar than "a bluey"-white star which means its
:44:52. > :44:56.temperature is 10,000 K which means it is a burning furnace with
:44:56. > :45:06.phenomenal amounts of energy. At the other end of the scale is
:45:06. > :45:07.
:45:07. > :45:17.Betelgeuse. It is less than 3,700 K. One of my favourite colour for
:45:17. > :45:17.
:45:17. > :45:22.objects to observe is a map in Andromeda. To find and, --
:45:22. > :45:32.Andromeda, we need to get to Pegasus. At this time of year, it
:45:32. > :45:37.
:45:37. > :45:46.is directly above our heads. Stop around 13,000 Kelvin. If we move
:45:46. > :45:53.upwards, we which another bright star. It is more orange. If we
:45:53. > :45:57.continue higher, we reach the last. If we look at this through a
:45:57. > :46:07.telescope it is transformed into one of the most stunning objects in
:46:07. > :46:11.the night sky. It is a double star, made of a hot blue star orbiting
:46:11. > :46:16.with a larger, cooler golden companion, and when you see them
:46:16. > :46:19.together it makes their contrasting colours all the more striking.
:46:19. > :46:24.Observing the colours of them can take a bit of practice but it is
:46:24. > :46:27.well worth the effort. And the more you discover about the colour and
:46:27. > :46:37.other characteristics, the more they will reveal their secrets to
:46:37. > :46:39.
:46:39. > :46:42.I'm here with some of the younger members of the Liverpool astronomy
:46:42. > :46:48.Society. Do you remember the first time you saw the colour in the
:46:48. > :46:54.stars? Yes, it was a star low on the horizon flickering from red to
:46:54. > :47:00.blue. That is what started me on the road to learning about them.
:47:00. > :47:05.And it looked beautiful. Yes. do you remember? It was really cool
:47:05. > :47:09.because I thought all stars were white and then I realised they were
:47:09. > :47:13.different colours depending on their age and their temperature.
:47:13. > :47:19.And that is the case, it is the temperature which affect it. Of
:47:19. > :47:27.course there are other things. Have you seen any colour in the Planets?
:47:27. > :47:32.I saw Jupiter. It has got orange, brown and white. It has got a white
:47:33. > :47:37.dot and it is a volcano. Yes. A big storm on Jupiter. Thank you for
:47:37. > :47:41.that, guys. We will let you get back to observing. Back to the
:47:41. > :47:46.studio. A big debate going on here as to
:47:46. > :47:56.what the colour means - does it mean temperature? First of all,
:47:56. > :48:05.Mark, it is that a budget. She was correct. The reason why. -- it is
:48:05. > :48:10.the temperature. This is part of a triple star system. This is red and
:48:10. > :48:15.that is because it is cool on the surface. That is because it is very
:48:15. > :48:20.small, around a tenth of the mass of the sun. The pay up is that it
:48:20. > :48:26.will burn for many, many, many billions of years. But here's
:48:26. > :48:31.another famous red star. Can you believe I have mess this up again?!
:48:31. > :48:38.This picture you cannot see now and has become faded in! There it is.
:48:38. > :48:43.This is Betelgeuse. This is red for a different reason. It is a very,
:48:43. > :48:49.very, very large star indeed, many times larger than the sun. You
:48:49. > :48:54.could fit most of the solar system in there and you can even see sun
:48:54. > :48:59.spots on the surface. It has only been alive for less than 10 million
:48:59. > :49:07.years. It is burning is feel so voraciously. The surface is cold
:49:07. > :49:12.because it is very large so it is a long way away from the core.
:49:12. > :49:17.things might get more dramatic for that star at any point? Yes, it is
:49:17. > :49:21.already burning helium and it will run out of fuel building the
:49:21. > :49:25.heavier elements to its core and then it will collapse. This is an
:49:25. > :49:29.artist's impression of what that would look like in our skies. And
:49:30. > :49:35.quite honestly, this could happen tomorrow. Betelgeuse is on borrowed
:49:35. > :49:39.time now. That will look like a second sun in the sky. How long
:49:39. > :49:45.will we have this in the sky? will go for about two weeks like
:49:45. > :49:49.that and it will be the most spectacular sight. What you are
:49:49. > :49:55.seeing is the distribution of the elements of life. Because we are
:49:56. > :50:02.overdue a supernova in the Milky Way? Yes, because on average you
:50:03. > :50:09.get one in each large galaxy per century. What was the fame has one
:50:09. > :50:14.we had? This was the Crab Nebula. So this was seen by Chinese
:50:14. > :50:19.astronomers. That Furnace was basically where the heavier
:50:19. > :50:22.elements were built? Yes. It is a spectacular and beautiful thing in
:50:22. > :50:29.the sky but what we are looking at... Well, we have an image we
:50:29. > :50:32.took early on tonight. There it is. That is a small telescope. What
:50:32. > :50:36.you're looking at it is the elements of not only carbon and
:50:36. > :50:40.oxygen that were cooked in the heart of the star, but elements
:50:40. > :50:48.like gold. Anything heavier than I am cannot be made in the centre of
:50:48. > :50:53.a star. It is only made for a few minutes each century each galaxy
:50:53. > :51:00.and that is why they are so expensive, those elements -
:51:00. > :51:02.platinum, gold. Because they are only made out there. So you can see
:51:03. > :51:08.what this teaches us about the origins of the stars and galaxies
:51:08. > :51:13.and it tells us ultimately how we got here. Liz is with some of the
:51:13. > :51:23.pioneering scientists leading this research. At thank you.
:51:23. > :51:30.
:51:30. > :51:35.I am with Professor Fiona Harrison, principal investigator with the
:51:35. > :51:40.NuSTAR telescope with NASA. Camped -- am I right in saying this is the
:51:40. > :51:45.only telescope that could get us this image? You snack. It is making
:51:45. > :51:55.images more than 10 times Chris Pratt and sensitive, by hundreds of
:51:55. > :51:55.
:51:55. > :52:00.times, than anything we have seen previously. -- images are more than
:52:00. > :52:07.10 times more precise. It was created in a foreign nuclear
:52:07. > :52:15.explosion. In particular, 44Ti, which could end up in our bones.
:52:15. > :52:18.And does this give us a better understanding of how stars explode?
:52:18. > :52:24.Yes, the distribution is very sensitive to whether the explosion
:52:25. > :52:34.was spherical or oxide did. And that tells us how stars explode.
:52:35. > :52:36.
:52:36. > :52:42.Thank you very much. A telescope that has communicated with the Deep
:52:42. > :52:47.Space Network is the Spitzer Mission telescope. Thank you for
:52:47. > :52:52.joining us. It can peer through all of the dust and gas of newly-formed
:52:52. > :52:58.stars so when the supernovae begin to form into stars, it can give us
:52:58. > :53:03.images like this. Tell us what we are seeing here? We are seeing a
:53:03. > :53:06.helium cauldron where dust and gas are being thrown back and forth by
:53:06. > :53:16.young stars and massive stars are being formed. You can see a bubble
:53:16. > :53:18.
:53:18. > :53:22.be -- being formed. So we are learning a lot more about how that
:53:22. > :53:29.process comes about. What about planets coming into formation
:53:29. > :53:34.around a star? Can it tell us about that? It can tell us about planets
:53:34. > :53:42.because they are warmed by the star light. The team yesterday found a
:53:42. > :53:49.second asteroid belt around the second brightest are in the North
:53:49. > :53:54.sky. We have an inner and an outer belt sculpted by the planets.
:53:54. > :54:00.Fascinating. Thank you so much, Neil. These are teaching us so much
:54:00. > :54:04.more about the cycles of star death and birth and how all of that works
:54:04. > :54:08.together, to understand how our universe is shaped. We will also
:54:08. > :54:12.find out a lot more about how our own solar system came to be made
:54:12. > :54:19.and how we came to be made of staff stuff. Tomorrow, we are leaving
:54:19. > :54:26.this place, heading deep into the desert to this. This part of the
:54:26. > :54:32.Goldstone at work. And I will be finding out how scientists are
:54:32. > :54:37.tracking asteroids. Or we gave you is a bit of an
:54:38. > :54:47.approximation. It should have come out at 15 billion. You opines to
:54:47. > :54:56.Guy and Andrew Murray. -- you owe a drink too. We should probably leave
:54:56. > :55:01.the last final bet to Ed. Yes, Professor Ed Copeland. The question
:55:01. > :55:08.is, what is the fate of the universe? I don't know. OK, thanks
:55:08. > :55:12.for coming along, Ed! The best you can do, because you need to look
:55:12. > :55:16.into the future and for that you have to base it on whatever models
:55:16. > :55:20.you have, and we have a series of models which are consistent with
:55:20. > :55:28.the data so you can project thenceforward so we have three
:55:28. > :55:36.scenarios I can come up with. You had a thing about Doc energy and if
:55:36. > :55:39.you imagine that being constant. -- dark energy. It is a nightmare for
:55:39. > :55:46.particle physicists. If it is driving the universe than the
:55:46. > :55:49.universe is accelerating so distant galaxies are accelerating a part
:55:49. > :55:54.and these galaxies will disappear before us over many billions of
:55:54. > :56:01.years and gradually it would just look like an empty universe with
:56:01. > :56:10.these things all spread out. you would see no stars in the
:56:10. > :56:14.skies? Well, probably. And the other one is, imagined the dark
:56:14. > :56:19.energy is increasing, so it is getting more and more dominant, and
:56:19. > :56:25.then things are more dramatic. data doesn't suggest it should be
:56:25. > :56:31.like that. If it is, acceleration is even more rapid and then not
:56:31. > :56:35.only do the galaxies move apart but they split apart and then the
:56:35. > :56:39.constituencies split apart and the atoms split apart and then you get
:56:39. > :56:46.the fundamental parts thrown across the universe like an angry child
:56:46. > :56:50.throwing their toys across the universe! Again, not wonderful!
:56:50. > :56:55.There is a happy ending and that is in the case were the dark energy is
:56:55. > :56:59.a transient feature and so it is driving the energy now but maybe it
:56:59. > :57:03.is changing with time, and it actually decays. A bit like the
:57:03. > :57:08.early inflation you describe but the beginning of the programme. And
:57:08. > :57:11.what will happen there is the energy stored in the dark energy
:57:11. > :57:17.goes to create particles and radiation and the universe read
:57:17. > :57:24.Keats again. And now we are back to his scenario with a much lower
:57:24. > :57:29.energy scale. -- it heats up again. Another curvature of the universe
:57:29. > :57:36.becomes important in determining the ultimate fate of the universe.
:57:36. > :57:43.So that is the most palatable? It is still not entirely palatable!
:57:43. > :57:50.is the least likely. At the moment it looks like... We are going to
:57:50. > :57:55.talk about a lot more of this next time. For now, let's go outside to
:57:55. > :57:58.Mark for the last time. Everybody has gone indoors now but if you
:57:58. > :58:06.have been inspired to look up at the sky, we have lots of resources
:58:06. > :58:11.you can look up on the website. If you want to get hold of race
:58:11. > :58:13.stargazing guide, then the details are on the screen. They are in
:58:13. > :58:19.conjunction with the Open University and it is well worth
:58:19. > :58:23.getting one of those. OK, that is the Star Guide. At the
:58:23. > :58:28.beginning of the show a promise to answer the ultimate question, what
:58:29. > :58:33.happened before the Big Bang? -- I promised. Well, the universe may
:58:33. > :58:36.have existed for an infinite amount of time before the Big Bang or time
:58:37. > :58:46.may have begun at the Big Bang, so the answer is either the universe
:58:47. > :58:48.
:58:48. > :58:52.has been here forever or it hasn't. Fantastic, isn't it? That is why we