:00:11. > :00:14.Over 100,000 of you have been working hard scouring an unexplored
:00:14. > :00:18.area of Mars. Your efforts have paid off. You have made an
:00:18. > :00:21.incredible discovery on the surface of the Red Planet. We will be
:00:21. > :00:31.revealing all tonight. I'm Brian Cox. He is Dara O Briain. This is
:00:31. > :00:56.
:00:56. > :01:03.Welcome back to a very foggy Jodrell Bank Observatory. So foggy
:01:03. > :01:07.we can hardly see the big dish. Not a great night for stargazing. It is
:01:07. > :01:10.the third and final night of this year's Stargazing Live. Thank you
:01:10. > :01:17.for your questions. We have some remarkable viewer photographs that
:01:17. > :01:27.I want to show you. This is the Orion Nebula. We saw it on the
:01:27. > :01:28.
:01:28. > :01:36.first night. This is a picture - it is taken with a 4.5 inch reflector.
:01:36. > :01:45.26 30-second exposures. This was taken last night. This one,
:01:45. > :01:54.California Nebula. Is it because it's the shape of California?
:01:54. > :02:04.It was taken on the 9th. This one is the jewel in the crown in many
:02:04. > :02:14.ways. It may not look like it. It's - we now know - a comet. It was
:02:14. > :02:18.
:02:18. > :02:25.discovered, or the photograph was taken by Nick Howes in the States.
:02:25. > :02:29.On Monday night, the stargazers at the school - this is now a comet.
:02:29. > :02:33.That is a genuine discovery. As we mentioned, we have made some
:02:33. > :02:37.interesting discoveries on the surface of Mars. Chris Lintott will
:02:38. > :02:41.be back later in the programme to reveal all. There is much more to
:02:41. > :02:45.stargazing than these TV shows. There are over 500 events taking
:02:45. > :02:49.place up-and-down the country for you to get some hands-on with
:02:49. > :02:55.astronomy. I have some pictures. I want to show you what everybody has
:02:55. > :03:01.been doing. Here is one. This is the Canterbury Star Party. 1,200
:03:01. > :03:09.guests turned up to Canterbury on Tuesday 8th. This is them showing
:03:09. > :03:19.how to make rockets with a vitamin tablet. This is the Eden Project.
:03:19. > :03:20.
:03:20. > :03:25.1,500 guests on 8th January. Finally, this one - that is nice.
:03:25. > :03:31.Where was that? Birmingham. This is people from Birmingham University
:03:31. > :03:38.explaining how gravity works. One last picture. This one was sent in
:03:38. > :03:43.by Private Eye. There is Dara O Briain looking very handsome and
:03:43. > :03:50.Buzz Lightyear! To find an event near you, go to
:03:50. > :03:56.bbc.co.uk/stargazing. We will be going to see how Mark got on with
:03:56. > :04:01.the Herschel Telescope. Among his many claims to fame, Herschel
:04:01. > :04:07.coined the term "asteroid". It means star-like in Greek. In five
:04:07. > :04:11.weeks' time an asteroid 45 metres wide is going to pass between us
:04:11. > :04:21.and the Moon, coming closer to Earth than some of our satellites.
:04:21. > :04:22.
:04:22. > :04:32.In March, the comet Panstarrs will streak by in the sky followed by
:04:32. > :04:43.
:04:43. > :04:50.Ison. This was taken on 9th. Ison will pass very close to the Sun. If
:04:50. > :04:58.it survives that encounter with the Sun, it could break up, it will
:04:58. > :05:05.sweep out in January 2014 - it could be one of those comets that
:05:05. > :05:10.you see in a tapestry! Fantastic. We are going to pass through the
:05:10. > :05:13.tail of that later in March. It may give us a meteor shower. Fantastic.
:05:13. > :05:19.We have had lots of questions. "What is the difference between
:05:19. > :05:26.asteroids, comets and meteors?" We have to keep on explaining this.
:05:26. > :05:29.Comets are large dirty snowballs. Yes. They are icy with some rock
:05:29. > :05:36.mixed in. They come from distant regions of the Solar System. We
:05:36. > :05:42.will see that later on in regions called the Kuiper belt and the Oort
:05:42. > :05:48.Cloud. The comets are spectacular. We have some fantastic footage.
:05:48. > :05:54.This is a beautiful shot from the International Space Station. Looks
:05:54. > :05:58.like some kind of computer graphic. That is Comet Lovejoy. Lovejoy was
:05:58. > :06:02.discovered in December 2011 by Terry Lovejoy in Australia. Here it
:06:02. > :06:12.is passing behind the Sun. Remarkable piece of footage. Here
:06:12. > :06:16.is another video. This is from the Solar Observatory. The thing about
:06:16. > :06:21.comets - you tend to think of them streaking along. The tail is blown
:06:21. > :06:26.by the solar wind. The Sun is heating the comet up. You are
:06:26. > :06:32.getting gas and dust erupting. it is moving away from the Sun, it
:06:32. > :06:38.follows its own tail? Yes. Asteroids are more like rocky
:06:38. > :06:43.fragments of planets. Yes, this is the first asteroid we encountered
:06:43. > :06:48.in space. This is not a video. This is Eros. It's about 34 kilometres
:06:48. > :06:52.long, which is about the size of the thing that - if it hit us, it
:06:53. > :06:58.would be the size that killed all the dinosaurs. It doesn't cross the
:06:58. > :07:05.Earth's orbit at the moment. It crosses Mars' orbit, though.
:07:05. > :07:11.Because it continually crosses the orbit of Mars, it could be
:07:11. > :07:16.perturbed by Mars. We landed on the surface of that asteroid. When we
:07:16. > :07:26.talk about meteors and meteoroids, they interact with our atmosphere.
:07:26. > :07:28.
:07:28. > :07:33.Meteors are when they burn up. Meteor showers. What are they?
:07:33. > :07:38.is a meteor shower in December. The reason for that is that they were
:07:38. > :07:45.created by a comet. They are the remains of the tail of a comet.
:07:46. > :07:49.you think about what a comet does. It orbits the Sun. So they leave an
:07:49. > :07:53.ellipse of debris and that will sit there in orbit around the Sun in
:07:53. > :07:57.the place where the comet tracks around. The Earth passes through it
:07:57. > :08:00.at the same point in its orbit every year. And that is why you
:08:00. > :08:10.always see them coming from the same place. That is how meteor
:08:10. > :08:11.
:08:11. > :08:16.showers are named. So one of the things we want to
:08:16. > :08:20.talk about is the big asteroid coming our way very soon. It is
:08:20. > :08:28.called Asteroid 2012 DA14. On Friday February 15th it will pass...
:08:28. > :08:32.Here it is. That is how close it is going to come! These are our
:08:32. > :08:37.satellites. The green blobs are the satellites. It will come well
:08:37. > :08:41.within the orbit of the station. will pass on 15th February. This is
:08:41. > :08:50.going to be more pressurised Valentine's Day so do something
:08:50. > :08:58.good on the 14th February! It will miss us by a mile! How can we be so
:08:58. > :09:03.sure that this trajectory is so right? Liz Bonnin is standing by
:09:03. > :09:13.for us at the Goldstone Observatory. Welcome to Goldstone in the Mojave
:09:13. > :09:18.Desert. This is the Mars Antenna, part of NASA's Deep Space Network.
:09:18. > :09:27.Now, I'm inside the base of the antenna and presently, it's
:09:27. > :09:31.tracking the New Horizon's Mission to Pluto. Marina, you are one of
:09:31. > :09:36.the scientists that does that work. How does tracking an asteroid work?
:09:36. > :09:43.It is simple. You point it to the asteroid and you bounce on some
:09:43. > :09:48.mike waves. This allows you to get its location very precisely --
:09:48. > :09:54.microwaves. This allows you to get its location very precisely.
:09:54. > :09:59.were tracking Apophis last night. Scientists thought it was going to
:09:59. > :10:02.hit us. What is the latest? Well, we have been tracking it since late
:10:02. > :10:07.December and what you are seeing here are the images from this
:10:07. > :10:12.morning. Is that Apophis? What you are looking at, this is a 300 metre
:10:13. > :10:16.diameter object that is 14.5 million kilometres away and we have
:10:16. > :10:22.the detection. Radar data that we have collected have completely
:10:22. > :10:29.excluded any chance of impact. We are safe. That is good news.
:10:29. > :10:36.Furthermore, we can now precisely predict its trajectory decades into
:10:36. > :10:40.the future. Fantastic work. As well as tracking, you get a good
:10:40. > :10:47.resolution from these orbits. This is Toutatis. This is a prime
:10:47. > :10:55.example of what radar can do. This is 4.6 kilometre-long asteroid. It
:10:55. > :10:59.was 7.5 million kilometres away from Earth. We are getting
:10:59. > :11:02.resolution to resolve surface boulders. Wonderful technology.
:11:02. > :11:06.Scientists are also getting a better idea of the composition of
:11:06. > :11:11.asteroids with their latest work. What is clear is that there are
:11:11. > :11:19.many more different types than previously thought. Amy Mainzer,
:11:19. > :11:27.another NASA scientist, taught me how to make my own.
:11:27. > :11:34.We have asteroids that are solid lumps of metal. Take some of this
:11:34. > :11:39.dirt and spoon it in. Step one - all asteroid also have some type of
:11:39. > :11:44.dirt? That's right. You have silicon in here, all kinds of
:11:44. > :11:50.heavier elements and that's going to be the basic constituent of most
:11:50. > :11:55.asteroids. We will pour some of that water in and make a big mess.
:11:55. > :11:59.One theory about why there's so much water on Earth is that some
:11:59. > :12:09.arrived here aboard comets and asteroids. That's not the only
:12:09. > :12:14.
:12:14. > :12:20.familiar substance found in them. Let's take some of this molasses.
:12:20. > :12:23.How much? That's pretty good. This one is carbon-rich! Now we need a
:12:23. > :12:32.squirt of another ingredient that has been found in the remains of
:12:32. > :12:38.asteroids that have landed on Earth, ammonia. Then we add our final
:12:38. > :12:43.ingredient - dry ice. At minus 78 centigrade, it will mimic the
:12:43. > :12:50.freezing conditions of the Solar System. Sprinkle that in there. We
:12:50. > :12:59.will freeze it up good. Let's take a look and see what we have ended
:12:59. > :13:03.up with. Amazing! That is what we got. In true asteroid-style, it is
:13:03. > :13:09.beautifully irregular. It is not completely round. Oh my goodness!
:13:09. > :13:14.This asteroid is a very particular kind, a randomly active main belt
:13:14. > :13:19.object. A Rambo, would you believe?! It is special. We have
:13:19. > :13:23.discovered in the last ten years or so this very unusual class of
:13:23. > :13:27.asteroid that becomes active. Active in what way? These things
:13:27. > :13:32.exhibit huge clouds of gas and dust coming off the surface. What
:13:32. > :13:37.happens is when the Sun hits the objects, we use this bright lamp to
:13:37. > :13:43.represent the Sun, what we think happens is that a smaller asteroid
:13:43. > :13:48.may strike the surface and scrape off some of this dirty outer layer
:13:48. > :13:51.and it may expose some of the ice. Look at that jet coming out from a
:13:51. > :13:54.tiny little hole and you can't see any of the ice exposed? That's
:13:54. > :13:58.right. This is a really good example of what we think happens.
:13:58. > :14:04.If we were orbiting the Sun, this object would have a big tail around
:14:04. > :14:07.it. And a big halo following it. Almost two years ago, the Hubble
:14:07. > :14:13.Space Telescope photographed a Rambo which grew a tail when it was
:14:13. > :14:18.heated by the Sun and just there is its X-shaped impact scar. Closer to
:14:18. > :14:24.home, what is the worst that could happen to the Rambo we have made?
:14:24. > :14:28.This is a good sized lump of rock. How can this really cause that much
:14:28. > :14:32.damage? Well, something this small obviously can't. If something were
:14:32. > :14:36.the size of a building, like 30 or 40 metres in diameter, it would be
:14:36. > :14:41.large enough to make it through the Earth's atmosphere. Now you have
:14:41. > :14:45.something that can cause a great deal of damage because if it is
:14:45. > :14:53.travelling at 10 kilometres a second or more, it packs an
:14:53. > :14:58.enormous punch. Amy has now joined us at Goldstone. You use Space
:14:58. > :15:02.Telescopes to find out potentially dangerous asteroids. Tell me about
:15:02. > :15:07.the project? It's a Space Telescope that used infrared light to
:15:07. > :15:11.discover and track near Earth asteroids. Infrared is heat. We are
:15:11. > :15:13.sensing heat. It gives us an idea of the size of the object. We can
:15:13. > :15:18.tell the difference between something that is really large but
:15:18. > :15:21.dark, like a piece of coal, or something that is much smaller, but
:15:21. > :15:30.highly reflective. OK. Getting the size is important for understanding
:15:30. > :15:35.We sampled some of the population and used it to look at what is out
:15:35. > :15:39.there. What have you come up with? For objects that are larger than a
:15:39. > :15:44.kilometre, like the dinosaur killing object, 90% of these have
:15:44. > :15:48.been found. What about the other 10%? We don't know where they are
:15:48. > :15:53.yet. There's another piece of not so good news which is that for
:15:53. > :16:00.objects larger than 100 metres, we've only discovered 25% of those.
:16:00. > :16:04.They can cause great damage. Absolutely. You need to continue
:16:04. > :16:11.this surveying work. We have a lot more work to do. What happens if a
:16:11. > :16:18.big one is coming at us? Ideally we will find an object 20 to 30 years
:16:18. > :16:21.before it will happen. If we have time like that, we can design
:16:21. > :16:26.strategies that would use explosives to push the asteroid
:16:26. > :16:31.aside or break it into pieces or maybe even devised technology to
:16:31. > :16:37.target out the way. How? A either gravitationally or attaching solar
:16:37. > :16:44.sails. Astonishing. Thank you. Come back to us when we talk about
:16:44. > :16:48.emissions and more about asteroids and comets. Standing by it on our
:16:48. > :16:55.live block is Don. He is head of NASA's near earth objects
:16:55. > :16:59.department. He will be informed if an asteroid is heading our way for
:16:59. > :17:03.a start -- he will have to inform the President. He can take your
:17:03. > :17:08.questions at bbc.co.uk/stargazing. A lot of people are asking where
:17:08. > :17:15.these objects originate from. We have a model for you. All of the
:17:15. > :17:19.asteroids we ever encountered... Everything comes from three places.
:17:19. > :17:25.We have an animation that shows just the asteroid belt ter, between
:17:25. > :17:27.Mars and Jupiter and it is the Mars and Jupiter and it is the
:17:27. > :17:34.green area. Every point is a map position of an asteroid. This is
:17:34. > :17:38.what it looks like. It is a bit of a mess, which is why we get impact.
:17:38. > :17:44.The asteroid belt is packed with Rocky objects, including this one.
:17:45. > :17:51.This is called Vesta. I have an image of it. It is quite a big rock.
:17:52. > :17:59.It is about 350 kilometres in diameter. The remarkable thing
:17:59. > :18:05.about Vester is I have a piece of it here. This came from there. The
:18:05. > :18:11.mystery will be revealed later. It mystery will be revealed later. It
:18:11. > :18:18.is beautiful. This is the Kuiper belt. Faces a region of IAC, rocky
:18:18. > :18:22.object. This is where Pluto lives. It was demoted because it turn
:18:22. > :18:29.Celtic is one week -- one of many objects of a large size in the
:18:29. > :18:35.Kuiper belt. We are on our way to Pluto at the moment. This is a
:18:35. > :18:39.picture of a spacecraft on its way. It left in January 2006. When it
:18:39. > :18:45.left Pluto was a planet. When it got to about there, Pluto was
:18:45. > :18:46.demoted, but by that time it was too late to stop. It makes no
:18:46. > :18:51.too late to stop. It makes no difference to the mission. These
:18:51. > :18:56.are the best images we have of Pluto now. They are from the Hubble
:18:56. > :19:03.Space Telescope. It is extremely cold. We don't know a lot about
:19:03. > :19:10.Pluto other than these images. is ice. For is an ice, about -200
:19:10. > :19:15.Celsius. Finally you step into this region, the far reaches of the
:19:15. > :19:22.solar system, the Kuiper belt. This is a picture of the Oort cloud, a
:19:22. > :19:27.spherical cloud. This is a disc of the solar system? Yes. This is more
:19:27. > :19:33.spherical. It is a vast collection of large and small lumps of ice and
:19:33. > :19:37.rock. It stretches out about a light year, we think. A quarter of
:19:37. > :19:43.the way to the nearest star. Nearly all of the Committee's wheezy come
:19:43. > :19:47.from either the Kuiper belt or the Oort cloud. -- comets we see.
:19:47. > :19:51.wanted to work out what things were in danger of hitting. We need to
:19:51. > :19:53.know where the Earth is at any time. How do we were kicked out? The
:19:53. > :20:02.How do we were kicked out? The answer lies in the southern
:20:02. > :20:07.hemisphere's guy. -- southern- hemisphere sky. This is an iconic
:20:07. > :20:11.constellation. It even features on the Australian national flag. It
:20:11. > :20:18.was by interpreting patterns have stars in the sky that we began to
:20:18. > :20:22.make sense of our cosmic surroundings. On Earth, it is easy
:20:22. > :20:26.for me to work out my position relative to the object I can say. I
:20:26. > :20:30.can understand my place in this world. If you're an astronomer, you
:20:30. > :20:35.have a problem because all you can see on little points of light in
:20:35. > :20:39.the sky and for the early astronomers, they knew nothing more
:20:39. > :20:46.than that. To make progress, people began to make maps of the night sky
:20:46. > :20:53.end as much detail as possible. He this is an early start shot of the
:20:53. > :20:58.southern sky from 1801. It is a two dimensional representation of the
:20:58. > :21:05.position of the stars. This is the Southern Cross. When you follow
:21:05. > :21:12.what you get to the bright southern star. 200 years ago, the way these
:21:12. > :21:16.maps were made meant their accuracy was limited. When he made this map,
:21:16. > :21:21.he did it by hand. He looked at this guy and transcribed the
:21:21. > :21:27.positions of the stars on to this piece of paper. A huge opportunity
:21:27. > :21:33.for human error in that process. But in the late 19th century, a new
:21:33. > :21:37.technique allowed astronomers to achieve real precision. Photography.
:21:37. > :21:42.If you have a photograph, a plate and a telescope, the marks on a
:21:42. > :21:47.plate are not made by the human hand, they are made by photons of
:21:47. > :21:54.light that have travelled from the stars themselves, hundreds or even
:21:54. > :21:59.thousands of light-years to register their position on the map.
:21:59. > :22:03.By fitting a camera to a telescope, the accurate positions of thousands
:22:03. > :22:10.of stars could be recorded in a single exposure. Something
:22:10. > :22:15.astronomers hoped would help them determine our place in the universe.
:22:15. > :22:20.In 1887, a decision was taken to map the position of every star that
:22:20. > :22:30.can be seen in this guide with high precision. That was a project that
:22:30. > :22:32.
:22:33. > :22:38.An incredible commitment, like building a cathedral. Much of the
:22:38. > :22:42.southern sky was mapped here, at Sydney Observatory, and this is one
:22:42. > :22:46.of the photographic plate that was used Clinton's -- to construct the
:22:46. > :22:52.used Clinton's -- to construct the Astra graphic catalogue. An
:22:52. > :22:59.exposure, just over six hours, and you can see very faint black dots
:22:59. > :23:03.on the plate. Each one of these black dots is a star and the
:23:03. > :23:13.positions were measured and transcribed into here. The Astra
:23:13. > :23:13.
:23:13. > :23:21.graphic catalogue. This is 1893, John Reid 20th. Documenting the
:23:21. > :23:24.positions of the stars in this photograph. What we have here is a
:23:24. > :23:34.perfect representation of the positions of the stars in the sky
:23:34. > :23:35.
:23:35. > :23:39.from Sydney on January 20th, 1893. 750,000 stars were recorded at
:23:39. > :23:43.Sydney Observatory and the results were combined with surveys made at
:23:43. > :23:49.19 other observatories around the world, creating a single, huge
:23:49. > :23:54.catalogue of the stars across both hemispheres. For the very first
:23:54. > :23:59.time, astronomers had an accurate record of our position relative to
:23:59. > :24:05.4.5 million stars. That has helped us to make another intriguing
:24:05. > :24:10.characteristic of the stars with great precision. In the 1990s,
:24:10. > :24:16.these measurements were repeated, this time by a satellite the
:24:16. > :24:22.European Space Agency Bill. What was found was that for at least
:24:22. > :24:29.some of the stars, their positions had changed an appreciable amount.
:24:29. > :24:33.For his slow drift is unique to each star and because it takes
:24:33. > :24:37.years to become apparent, comparing recent satellite data with this
:24:37. > :24:45.catalogue has given us the most accurate ever record of this
:24:45. > :24:49.phenomenon. He the reason for this movement is that all of the stars
:24:49. > :24:58.in the Milky Way are a orbiting around the centre of the galaxy,
:24:58. > :25:04.but each at its own particular speed. Today, even deeper in the
:25:04. > :25:11.universe, it is not just stars fat have their own unique motion. -- of
:25:11. > :25:15.that have. By looking out beyond the stars in the Milky Way, we
:25:15. > :25:21.found that all the galaxies in the universe on moving relative to each
:25:21. > :25:24.other as well. We are part of a group loan -- known as a local
:25:25. > :25:30.group. 43 galaxies bound together in the same way the stars are bound
:25:30. > :25:37.together in the Milky Way. That group itself is moving roughly in
:25:37. > :25:42.that direction to something called the Super cluster, a group of 5,000
:25:42. > :25:48.galaxies or more, about half a billion light years in that
:25:48. > :25:54.direction. And we are travelling towards this enormous cluster of
:25:54. > :25:58.galaxies that is over 500 -- at over 500 kilometres per second.
:25:58. > :26:02.What we discovered over hundreds of years of astronomy, making
:26:02. > :26:08.precision measurements of the sky, is that everything in the universe
:26:08. > :26:13.is moving relative to everything else. We've learned that the stars
:26:13. > :26:23.and galaxies are all taking part in a vast cosmic doused which we --
:26:23. > :26:26.
:26:26. > :26:31.dance which we can now plot with We have all of these objects in an
:26:31. > :26:36.Orbit around the sun. Why are some of them suddenly lurching out on
:26:36. > :26:41.these crazy journeys? The answer, as with every answer, lies with
:26:41. > :26:47.mathematics. We've got Tim O'Brien to explain. The mathematics of
:26:47. > :26:52.this? You remember that all these objects orbiting around the Sun a
:26:52. > :26:57.doing it under Newton's law of gravity. It turns out that there's
:26:57. > :27:01.only four possible shapes of orbits they can have. They are really --
:27:01. > :27:08.the really neat bit of mascot those shapes are defined by slices
:27:08. > :27:12.through a core. Depending on what angle you slice through, you get a
:27:12. > :27:18.circular Orbit, and elliptical Orbit, a Parabolica or Orbit or a
:27:18. > :27:23.hyperbolical bit. Fees are in her elliptical orbits, some of them a
:27:23. > :27:30.more secular. But in general, everything... They go round and
:27:30. > :27:35.back. A most common or bits of the elliptical and hyperbolic her.
:27:35. > :27:38.Hyperbolic Orbit is open. If something gets bumped into a
:27:38. > :27:43.hyperbolic Orbit, that will go around the same place as before,
:27:43. > :27:49.but it will shoot off. Yes, and it never comes back. It goes out into
:27:49. > :27:53.interstellar space. The difference is essentially to do with energy
:27:53. > :27:59.and angular momentum. Let's say we are in the Kuiper belt and
:27:59. > :28:06.something has a gravitational interaction. It interacts with lets
:28:06. > :28:09.a Pluto. It will change the energy of that object. It will change the
:28:09. > :28:14.Orbit because these shapes are defined partly by the energy. One
:28:14. > :28:21.of these things can be perturbed spirit begins a journey into the
:28:21. > :28:26.inner solar system. Halley's Comet, which came from the Oort cloud,
:28:27. > :28:31.that comes in. It is still an ellipse. It is. A period of 76
:28:31. > :28:37.years, it comes back every 76 years. It could have jumped from a
:28:37. > :28:45.circular Orbit into an elliptical Orbit. Because of an interaction.
:28:45. > :28:50.The Oort cloud is interesting because it is so far out. Many of
:28:50. > :28:58.the perturbations come from passing stars. They are very weakly bound.
:28:58. > :29:02.The false drops away. -- force. bombed sit by passing and Zenit
:29:02. > :29:06.heads off on a new journey. These hyperbolical orbits are interesting.
:29:06. > :29:11.You don't see them coming because they come in and they have such an
:29:11. > :29:20.Orbit that they go round once and disappear. Something perturb them
:29:20. > :29:26.and dumps them. It is gone and we Bonevacia him again! Maybe some
:29:26. > :29:36.time he will pass you. Let's find out if there are clear skies where
:29:36. > :29:37.
:29:37. > :29:41.you are tonight. Let's go to Susan We are up against it this evening
:29:41. > :29:45.thanks to a lot of cloud piling into the UK. To the east of the UK,
:29:45. > :29:49.we have had a weather front that has hung around for much of the day
:29:49. > :29:52.today. So that will obscure the skies here. Further west, another
:29:52. > :29:57.front that's fizzling out. We will lose the rain but the cloud is
:29:57. > :30:01.going to stick around. Between the two, a few clearer spells across
:30:01. > :30:11.the North West and for Northern Scotland. My top picks for the
:30:11. > :30:12.
:30:12. > :30:16.clearest skies - it will be in the west. And give it a couple of hours
:30:16. > :30:23.and Northern Ireland will be looking almost crystal clear.
:30:23. > :30:27.More information as ever on the BBC More information as ever on the BBC
:30:27. > :30:32.Weather website. Thanks. Mark Thompson has been
:30:32. > :30:42.building a modern interpretation of William Herschel's 20-foot
:30:42. > :30:47.
:30:47. > :30:52.telescope. Anyway, in a tribute to his work,
:30:52. > :30:56.Mark has been trying to re-create that telescope.
:30:56. > :31:00.Over the past three weeks, I have been working with the local
:31:00. > :31:06.community in Derby and a crack team of experts. We have had to make
:31:06. > :31:11.changes to Herschel's plans to keep everyone safe, but we have remained
:31:11. > :31:16.true to his principles. So far, we have built the supporting structure.
:31:16. > :31:25.Big, isn't it? Now we have the small matter of making the
:31:25. > :31:29.telescope. In Herschel's Telescope, right at the bottom of the tube was
:31:29. > :31:33.a piece of polished metal to reflect the light from the stars.
:31:33. > :31:37.It was shaped and positioned to focus the light towards the top of
:31:37. > :31:41.the tube and here, Herschel would have stood on this viewing platform
:31:41. > :31:45.and looked down the barrel through an eye-piece. This is our telescope
:31:45. > :31:50.tube. We will put a mirror up this far end. So light comes down the
:31:50. > :31:54.tube, hits the mirror, bounces back up the tube and then all the way up
:31:54. > :31:57.to the top into this special adjustment we have made. We have
:31:57. > :32:00.had to cut some of the tube out where the eye-piece is going to go
:32:00. > :32:05.and hopefully, we will see some stunning views of the sky through
:32:05. > :32:15.it? Want me to push? Not too much! Now we need to get it up into the
:32:15. > :32:16.
:32:16. > :32:23.cradle. Chris Hill is on hand to supervise. That will do. That's it.
:32:23. > :32:28.It is finally starting to look like a telescope. Inside the university
:32:28. > :32:34.workshop, Chris is putting the final touches to the mount for the
:32:34. > :32:40.mirror. An instrumentation expert is here with the missing piece.
:32:40. > :32:44.It's arrived! We are using a modern glass mirror in our telescope.
:32:44. > :32:49.Herschel would have used a piece of metal and that would have easily
:32:49. > :32:56.tarnished. Even though he polished it for hours, it still wouldn't
:32:57. > :33:00.have been very reflective. Herschel would have been blown away by this.
:33:00. > :33:06.Yes, this would have been his Christmases! The mount has a set of
:33:06. > :33:10.screws on the back, so that the angle can be adjusted. Now, we can
:33:10. > :33:16.align the mirror. So the light from the stars is reflected through the
:33:16. > :33:24.eye-piece. Shall we put it in then? Let's try it. The time has come.
:33:24. > :33:28.Yeah. You got the screws? Back a bit. There! The first step is to
:33:28. > :33:32.cover the opening with a large sheet of paper. For the next bit,
:33:32. > :33:38.Herschel would have probably used a candle but we are going to use a
:33:38. > :33:42.laser pointer. The light travels through a small hole in the paper,
:33:42. > :33:47.down the tube and hits the mirror at the bottom. It is reflected back
:33:47. > :33:52.at an angle to hit the paper again. I need to guide Chris to adjust the
:33:52. > :33:56.mirror. Until the reflected laser light moves into position where the
:33:56. > :34:03.eye-piece will be. Chris, if you can tilt the bottom towards me so
:34:03. > :34:09.bring that away from you? Got you! Can you see it moving? Yes, keep
:34:09. > :34:13.going. Woah! Spot on! How is that looking? Perfect. Excellent. That
:34:13. > :34:17.is perfect, mate. Well done. This laser beam is simulating star light
:34:17. > :34:23.and it is bouncing back out of the tube which is where I need to look.
:34:23. > :34:30.If I spray this, you can see where the beam is coming out the tube. It
:34:30. > :34:35.shows that we are ready for some clear skies!
:34:35. > :34:40.After all that work, the time has come to reveal the telescope. Let's
:34:40. > :34:50.cross live to Mark at the University of Derby.
:34:50. > :34:55.There is a fantastic atmosphere. We have our own Herschel quintet. We
:34:55. > :35:03.have the children from the school here. CHEERING We have also got the
:35:03. > :35:09.members of the Derby Astronomical Society. Hello, guys. Now it's
:35:09. > :35:15.taken us five weeks and hundreds of man hour. It weighs in at just
:35:15. > :35:20.under half a tonne. It is Stargazing Live's Herschel
:35:20. > :35:24.Telescope. CHEERING Now, it is the most amazing piece of kit. It has a
:35:24. > :35:28.crank to turn the whole telescope. The whole structure moves around so
:35:28. > :35:32.that you can access any part of the sky that you want to. It is the
:35:32. > :35:37.most amazing piece of kit. Hopefully, we might get a chance to
:35:38. > :35:42.look through the telescope. With me is Professor Alan Chapman. Alan,
:35:42. > :35:46.what do you make of it? It is absolutely remarkable. It is a
:35:46. > :35:50.tremendous realisation of Herschel's Telescope, using
:35:50. > :35:54.scaffolding and modern equipment. I have never seen anything like it
:35:54. > :35:59.before. Me neither! Even to the chaps pushing it around. Herschel
:35:59. > :36:04.probably used sailors! We have used the same tube dimensions, the same
:36:04. > :36:13.mirror diameter. We only had a drawing to work from. It took him a
:36:13. > :36:16.year. We did it in five weeks. That is incredible? To him it was
:36:16. > :36:25.entirely experimental and a brilliant piece of inspired
:36:25. > :36:32.engineering. Herschel was a skilled worker with his hands. He employed
:36:32. > :36:37.carpenters to do the heavy work for him. Yet, Herschel was a skilled
:36:37. > :36:41.musician. A string player, a keyboard player and I think all of
:36:41. > :36:47.those skills were necessary to the manipulation and adjustment of that
:36:47. > :36:51.instrument. I will have to stop you there. Thanks to the guys from the
:36:51. > :36:54.Derby Rugby Team. I'm really looking forward to looking through
:36:54. > :36:58.the telescope. It is still cloudy here. It is foggy in Derby. With a
:36:58. > :37:03.bit of luck, it may clear up. Do come back to us later on tonight
:37:03. > :37:08.and we will see if we can re-create the images that Herschel saw.
:37:08. > :37:12.Hopefully we will. We have been talking about asteroids and comets.
:37:12. > :37:15.Of course, we will be struck by large objects from space. It's
:37:15. > :37:19.happened all through history. It isn't necessarily a bad thing.
:37:19. > :37:23.Without these impacts, our world might not be the place that we know
:37:23. > :37:28.today. If you want to see one of the best
:37:28. > :37:32.preserved meteor impact sites on Earth, you need to travel to the
:37:32. > :37:37.Barringer crater in Arizona. Craters can be found all over the
:37:37. > :37:42.Solar System like this. The battle scars of a long history of impacts.
:37:42. > :37:47.Most are the result of one period, around 3.6 billion years ago, when
:37:47. > :37:52.the whole Solar System was turned upside-down. It was all to do with
:37:52. > :38:00.the combined gravitational force of our two biggest planets, Jupiter
:38:00. > :38:09.and Saturn. We now believe that the giant planets formed much closer to
:38:09. > :38:14.the Sun than they are today. Their orbits drifted hundreds of millions
:38:14. > :38:19.of years until Jupiter and Saturn fell into a regular pattern. Once
:38:19. > :38:29.every cycle the two planets aligned creating a gravitational surge that
:38:29. > :38:29.
:38:29. > :38:35.played havoc with the orbits of all the planets. Neptune was catapulted
:38:35. > :38:41.outwards and smashed into the ring of comets surrounding the Solar
:38:41. > :38:48.of comets surrounding the Solar System with dramatic consequences.
:38:48. > :38:55.For 100 million years, the Solar System turned into a shooting
:38:55. > :39:00.gallery as the comets ploughed through it. Millions of comets were
:39:00. > :39:09.scattered in all directions peppering the planets. It was
:39:09. > :39:15.called the Late Heavy Bombardment. It created many of the craters we
:39:15. > :39:25.see throughout the Solar System today. It left scars all over our
:39:25. > :39:25.
:39:25. > :39:29.Moon. And it had a lasting impact on the Earth as well. The only
:39:29. > :39:34.impact craters we see on Earth today, like this one in Arizona,
:39:34. > :39:44.were made much more recently, but they reveal the scale of these
:39:44. > :39:47.
:39:47. > :39:57.impacts. Today, impacts like this are relatively rare. They will
:39:57. > :39:58.
:39:58. > :40:03.happen again. But during the late Late Heavy Bombardment, the
:40:03. > :40:07.environment was changed radically and dramatically. Those changes
:40:07. > :40:13.weren't necessarily catastrophic. It's now thought that a significant
:40:13. > :40:17.amount of the water in the Earth's oceans was delivered by the impacts
:40:17. > :40:21.of water-rich comets and other objects during the Late Heavy
:40:21. > :40:31.Bombardment. That means that impacts could have played a key
:40:31. > :40:33.
:40:33. > :40:42.role in the development of life on Earth. Before the Late Heavy
:40:42. > :40:47.Bombardment, the Earth was a barren rock. Afterwards, it supported the
:40:47. > :40:52.oceans that would become the Crucible for life. Without the
:40:53. > :40:57.water delivered in the Late Heavy Bombardment life on Earth may never
:40:57. > :41:07.have evolved. All this may have been caused by the violent
:41:07. > :41:10.
:41:10. > :41:14.gravitational pull generated by two Joining us now is Dr Richard
:41:14. > :41:19.Greenwood. We have seen one of your fantastic samples already.
:41:19. > :41:25.talked about Vesta. It is from Australia. It has a special
:41:25. > :41:33.composition that we know matches Vesta. One billion years ago, a
:41:33. > :41:38.meteorite smashed into the southern hemisphere of Vesta. They drifted
:41:38. > :41:42.into the three to one resonance with Jupiter and it is a real
:41:42. > :41:47.conveyer belt. We have ten times as many meteorites coming from Vesta
:41:47. > :41:52.as we have from the Moon, or Mars. That is remarkable. It is to do
:41:52. > :41:58.with this gravitational interaction with Jupiter throwing these things
:41:58. > :42:01.our way. Absolutely. This is iron? That is. If we pick it up, you will
:42:01. > :42:06.see it is three times denser than a rock that you find in your garden.
:42:06. > :42:11.It is pure metal. It is the core of an asteroid that melted. When it
:42:11. > :42:16.melted, the metal sank and formed a core. We used to think these were
:42:16. > :42:23.quite young. That is one of the oldest objects in the Solar System.
:42:23. > :42:27.The reason for that is - at that time, they had a short
:42:27. > :42:34.concentration of Aluminium 26. That would have been formed in a
:42:34. > :42:42.supernova. Yes. It's probably the shockwave from the supernova that
:42:42. > :42:48.triggered the collapse which formed Within two million years, which is
:42:48. > :42:53.a small length of time, it would have gone. These are relatively
:42:53. > :43:01.unstable and made in a supernova explosion? Exactly. Heated the
:43:01. > :43:11.asteroids up. That is why you get the iron sinking? That's right.
:43:11. > :43:11.
:43:11. > :43:18.is not the oldest thing? This fell in Tanzania, it is called Ivuna.
:43:18. > :43:26.That is some of them there. In there, there are diamonds, graphite
:43:26. > :43:33.and they came from some of the stars that pre-dated... This is
:43:33. > :43:37.older than the Solar System? Yes. 4,567 million years. That is older.
:43:37. > :43:41.That is older. The story of the origin of the Solar System is a
:43:41. > :43:45.supernova went off, a shockwave came through this gas and dust,
:43:45. > :43:50.that caused it to collapse and pieces of that shockwave - this is
:43:50. > :43:57.from outside the Solar System? Exactly. And got trapped? Yes.
:43:57. > :44:01.Startling. Technology now allows us to get up close and personal with
:44:01. > :44:05.asteroids and comets whilst they are still in orbit. Let's go back
:44:05. > :44:08.to Liz in the Goldstone Observatory to hear more. Thank you very much.
:44:08. > :44:12.Goldstone and the rest of the Deep Space Network have communicated
:44:12. > :44:16.with some truly remarkable missions getting us very close to asteroids
:44:16. > :44:26.and comets that are speeding through space. Amy, if we can talk
:44:26. > :44:28.
:44:28. > :44:32.about a few of them? Stardust? Stardust Mission flew through the
:44:32. > :44:36.comet and it collected tiny pieces of the comet and it brought them
:44:36. > :44:45.back to Earth. It has given us a new window into the Solar System.
:44:45. > :44:50.None of that material has changed for 4.5 billion years? Exactly.
:44:50. > :44:56.Deep Impact Mission does what it says on the tin? Exactly. It was
:44:56. > :45:01.two spacecraft in one. An impacter spacecraft and an observer. They
:45:02. > :45:07.separated when they got close to a comet. The observer watched and
:45:07. > :45:10.allowed us to see the inside of the comet. What have we learned from
:45:10. > :45:16.that material? It was a really surprising result. It turns out
:45:16. > :45:26.that this particular comet was more dust than water-ice. Also, the
:45:26. > :45:33.
:45:33. > :45:38.They have a lot more in common than we thought. And then for Dawn
:45:38. > :45:42.Mission which sent an order to do my to it -- mighty fester. It has
:45:42. > :45:46.been orbiting Vesta and it has returned spectacular images that
:45:46. > :45:53.have allowed us to see the turbulent history that has happened
:45:53. > :45:58.to this asteroid. Two giant impact craters on the South poll of the
:45:58. > :46:04.asteroid and joy and scrapes that I even larger than the Grand Canyon.
:46:04. > :46:09.Thank you for joining us. Dawn is on its way to Ceres, the biggest
:46:09. > :46:15.rock in the asteroid belt, 950 kilometres in diameter and it has
:46:15. > :46:21.been declassified as a dwarf planet. It will reach it in 2015 and will
:46:21. > :46:24.begin its exploration then. That space around our planet is not
:46:24. > :46:32.just filled with natural objects, it is also filled with staff and we
:46:32. > :46:36.put up there. So much stuff that there's a pilot waiting to happen.
:46:36. > :46:41.He in a quiet corner of Hertfordshire is a radar tracking
:46:41. > :46:45.station that is used to monitor the movement of objects 2000 kilometres
:46:45. > :46:52.above the earth. There are lots of things we got up
:46:52. > :46:56.there. 1,000 satellites, nearly 20 telescopes and one space station.
:46:56. > :47:02.But there's also a lot of junk, affectionately known as space
:47:02. > :47:07.debris. So space debris is effectively all of the stuff in
:47:07. > :47:12.space we know longer use or need. It could be dead satellites, did
:47:12. > :47:14.rockets, fragments, pieces of electronic circuits, pieces of
:47:14. > :47:22.paint from the outside of the spacecraft. They are floating
:47:22. > :47:27.around. The Final Frontier is packed with rubbish, litter.
:47:27. > :47:33.There's everything from an astronauts glove, that one stage in
:47:33. > :47:39.Orbit for a month, to particles of you're in, flushed from early space
:47:39. > :47:46.craft. There are bits of rock left by the Apollo missions. Even 32
:47:46. > :47:50.nuclear reactors that used to power satellites. This shows you a
:47:50. > :47:57.simulation of what we can see in Orbit. It ranges from debris close
:47:57. > :48:01.to the Earth to places where TV satellites up operating. Fees range
:48:01. > :48:05.in size from some things are size of a mobile phone up to a space
:48:05. > :48:10.station. Her these objects mean we are getting tight for space in
:48:10. > :48:15.space. We've realised over many years that although the universe is
:48:15. > :48:18.potentially infinite, the space around the Earth is very finite.
:48:18. > :48:25.But the problem isn't just that it is crowded up there, it is also
:48:25. > :48:32.dangerous. All these objects are hurtling about at over 25,000
:48:32. > :48:37.kilometres per hour. It is like a cloud of flying pockets. It has a
:48:37. > :48:41.high energy moving at that speed. A pound coin in Orbit around the
:48:41. > :48:46.earth has the same energy as a minibus travelling at 1,000
:48:46. > :48:52.kilometres an hour. If that hit a spacecraft, it would destroy it.
:48:52. > :48:59.1983, a chip of paint collided with the Space Shuttle. The impact was
:48:59. > :49:04.enough to crack its 1.5 centimetre thick windscreen. In 2009 a US and
:49:04. > :49:11.Russian satellite hit each other. Both were completely destroyed and
:49:11. > :49:15.created up to 1,500 new bits of junk. It can only get worse. In 60
:49:15. > :49:22.years we've gone from no man-made objects in Orbit to an estimated 35
:49:22. > :49:25.million. And the worry is that areas of space we rely on to send
:49:25. > :49:33.satellites for navigation, weather forecasting and TV will soon become
:49:33. > :49:38.no-go areas. Currently there's no working answer, but all sorts of
:49:38. > :49:44.plans are being hatched. From sales that would slow an object down so
:49:44. > :49:51.they fell back to earth to giant balloons that would inflate to help
:49:51. > :50:00.put the brakes on. But the UK's largest space company has come up
:50:00. > :50:07.Astrium in Stevenage is better known for building satellites that
:50:07. > :50:13.get sent to space. But engineer Jamie's job is to use his harpoon
:50:13. > :50:18.to drag them back to work. We've got a harpoon we are going to fire.
:50:18. > :50:23.It goes into the barrel inside a protective chamber. I will put some
:50:23. > :50:29.goggles on. For harpoon uses compressed air rather than
:50:30. > :50:39.explosives to fire. It is safer for space. We are ready to fire now.
:50:40. > :50:43.
:50:43. > :50:48.Turn the firing switched on. Sadly At the moment, Jamie is test firing
:50:48. > :50:52.his harpoon into pieces of actual satellite. It's early days, but
:50:52. > :50:59.when complete the harpoons will have a spring loaded barrel and her
:50:59. > :51:05.capers. If the system works, the harpoon will be mounted on a
:51:05. > :51:10.satellite that will Chasetown space junk, harpoon it and tow it back
:51:10. > :51:15.towards earth where we it will burn up socially in the atmosphere. --
:51:15. > :51:21.safely. This only works with large objects. In Orbit, pig objects are
:51:21. > :51:25.just thousands of small objects waiting to happen. -- big object.
:51:25. > :51:31.Something has to be done and this could be the big thing -- best
:51:31. > :51:35.thing. But until somebody can enforce an intergalactic litter
:51:35. > :51:40.campaign, the research has to continue.
:51:40. > :51:48.This is a vivid demonstration of the problem. This is lent was by
:51:48. > :51:52.the National Space Centre a, a panel from a satellite. That is a
:51:52. > :52:00.great picture with us shuttle underneath. The office was in Orbit
:52:00. > :52:06.for six years. They saw this Goring. These are impact of micro meteors.
:52:07. > :52:09.Invisible to the human eye. They are travelling between 8 and 9
:52:09. > :52:18.kilometres per second and up to 30 kilometres per second. A tremendous
:52:18. > :52:25.amount of energy. The plasma Burns. If you lift it up, you can see...
:52:25. > :52:33.This is the spacecraft... That is a whole and that is a whole. You can
:52:33. > :52:38.see the Dent. Minuscule pieces of dust. Back over to mark in Dobbie.
:52:38. > :52:44.Last time we saw him he had unveiled our version of Herschel's
:52:44. > :52:47.telescope. Have they observed anything with it?
:52:47. > :52:51.Unfortunately not. It is amazing standing on this platform like
:52:51. > :52:55.Herschel did all those years ago. Herschel did it in the damp English
:52:55. > :53:01.weather. I'm safer than he is because I have harnessed to make
:53:01. > :53:04.sure I don't fall off. There have been times observers have fallen
:53:04. > :53:08.off those platforms. We can't show you any pictures, but it is
:53:08. > :53:13.incredible to think that Herschel spent many years observing the
:53:13. > :53:18.British night sky with the weather to contend with. We did get some
:53:18. > :53:19.clear skies a few nights ago. We managed to record some images of
:53:19. > :53:23.managed to record some images of things in the sky. The first
:53:23. > :53:28.things in the sky. The first picture we got was Jupiter. Moving
:53:28. > :53:30.very gracefully across the screen, caused by the rotation of the Earth.
:53:30. > :53:35.The telescope doesn't have the The telescope doesn't have the
:53:35. > :53:45.drive system so you can't see the object being tracked. A picture of
:53:45. > :53:52.a beautiful Binary Star system in Cygnus. We have the picture of a
:53:52. > :53:56.star cluster inside the Orion nebula. We have a final image of
:53:56. > :54:00.Uranus which Herschel discovered with a slightly smaller telescope.
:54:01. > :54:05.There's a very slight distortion which is caused by the orientation
:54:05. > :54:09.of the optics in a telescope. He will have had to have contended
:54:09. > :54:13.with these poor images. We can't show you anything live tonight, but
:54:13. > :54:16.it is great to follow in Herschel's footsteps. Without greater
:54:17. > :54:21.astronomers like him, we would not have learned as much about the
:54:21. > :54:24.universe as we can see now. It is great that we can leave his
:54:24. > :54:28.telescope to the residents of Derby so hopefully in the years to come
:54:28. > :54:33.they can enjoy the night sky like Herschel did all those years ago.
:54:33. > :54:37.Back to the studio. They are beautiful images and that
:54:37. > :54:42.talent the scope will be in Derby for the next three years. --
:54:42. > :54:47.telescope. This week you have been doing your own pioneering
:54:47. > :54:51.scientific work thanks to our online experiment. We asked you to
:54:51. > :54:58.study Mars's surface looking for unusual features. I spend a lot of
:54:58. > :55:01.time looking at this guy thinking it is amazing. In this case, the
:55:01. > :55:08.hyperbolic and third -- adjectives are appropriate. This is wonderful
:55:08. > :55:12.and amazing. Real science in two days. More than 100,000 people have
:55:13. > :55:18.helped us explore an area about the size of Holland. It was
:55:18. > :55:21.Switzerland! We are working our way up. We found some great stuff. We
:55:21. > :55:25.were looking at the Antarctic region of Mars and these strange
:55:25. > :55:27.France which we think on from material suddenly erupting
:55:27. > :55:31.material suddenly erupting underneath the surface of Mars. We
:55:31. > :55:38.had this idea that it has to do with ice under the surface that was
:55:38. > :55:44.being heated up. It is the time lapse. Yes. It was a year on Mars
:55:44. > :55:48.has put together by users. At some point in the year, in the Martian
:55:48. > :55:53.spring, these things erupt as the planet heats up? That is what we
:55:53. > :55:59.now know. I can tell you for sure because we only find these around
:55:59. > :56:02.March in the Marshin calendar. They happen close to the equator and
:56:03. > :56:06.then they head closer to the polls and we thought they were rare, but
:56:06. > :56:14.look at this. This whole region of ground would have erupted
:56:14. > :56:18.underneath your feet. Don't go there in the spring! What about
:56:18. > :56:22.this are titters -- artistic impression. We discovered that. Our
:56:22. > :56:25.viewers discovered that is what is happening. We know when and where
:56:25. > :56:32.it happens and we now know it is much more common than we thought.
:56:32. > :56:35.That is because people used pattern recognition skills. More than that.
:56:35. > :56:39.A good scientific experiment always leaves you with more questions.
:56:39. > :56:45.We've no idea what this is. This is a type of terrain I'd never seen
:56:45. > :56:49.before. It has angular features. These moved from year to year. No
:56:50. > :56:53.idea what this is. It is something to do with ice escaping from
:56:53. > :56:57.underneath and going into the Martian atmosphere. People will be
:56:57. > :57:06.working on this the years. Wonderful. We have more time in the
:57:06. > :57:11.show afterwards. I pledged applied to somebody. -- a pint. Tell us
:57:11. > :57:16.what to think that is. The best week, I will buy you another pint.
:57:16. > :57:21.I'm very excited. What is that? other guy is still waiting for his
:57:21. > :57:30.plight. Before we go, just time to say goodbye to Liz and NASA. How
:57:30. > :57:34.has it been? 30 seconds. Thanks. It's been such a privilege to meet
:57:34. > :57:37.all of the people behind so many or inspiring endeavours. What struck
:57:37. > :57:41.inspiring endeavours. What struck me most is how every single mission
:57:41. > :57:46.seems impossible on paper. I'm not sure what impresses any more, for
:57:46. > :57:51.fact they are able to dream up crazy schemes like lowering a road
:57:51. > :57:54.on to Mars using as Guy Cramer and sampling, it as they hurtle through
:57:54. > :58:00.space or the fact they are able to make those ideas a reality. They
:58:00. > :58:04.are always thinking ahead. By the mid- 2020s, there's talk of putting
:58:04. > :58:08.a man on an asteroid, and a few decades after that a man on another
:58:08. > :58:15.planet. It is an exciting time. Sadly, it is time for us to say
:58:15. > :58:22.goodbye to everybody at NASA and you at home. At night from NASA.
:58:22. > :58:25.Thank you for wearing your telescope hat especially! Don't
:58:25. > :58:29.forget there are hundreds of stargazing events happening up and
:58:29. > :58:36.down the country. Details are on the website, bbc.co.uk/stargazing.
:58:37. > :58:42.Don't forget about our Star Guide. We're going to be back in a second,
:58:42. > :58:45.but do you want to wrap up? discoveries on Mars are real
:58:45. > :58:50.scientific discoveries. Chris was telling me there's going to be a
:58:50. > :58:53.paper written. There's a scientific paper written and everybody