0:00:13 > 0:00:16Welcome to a special Sky at Night.
0:00:16 > 0:00:19This marks our 60th anniversary.
0:00:19 > 0:00:21The first episode of Sky at Night was broadcast live
0:00:21 > 0:00:24on the 24th of April, 1957.
0:00:24 > 0:00:26And we've come a long way since then.
0:00:26 > 0:00:29The programme started before the dawn of the space age,
0:00:29 > 0:00:32when the idea of sending probes to distant planets
0:00:32 > 0:00:34was nothing more than a dream.
0:00:34 > 0:00:38In fact, we knew so little that the idea of advanced life on Mars
0:00:38 > 0:00:40seemed a distinct possibility.
0:00:40 > 0:00:43So we've come here to the Royal Observatory, Greenwich,
0:00:43 > 0:00:45home of British astronomy,
0:00:45 > 0:00:48to look back and see how our understanding of the universe
0:00:48 > 0:00:50has changed over the past six decades.
0:00:50 > 0:00:52Welcome to The Sky at Night.
0:01:30 > 0:01:33The 60th is a diamond anniversary.
0:01:34 > 0:01:37And the Department of Earth Sciences at UCL have been kind enough
0:01:37 > 0:01:39to lend us this.
0:01:39 > 0:01:42It's called carbonado, and it's a black diamond.
0:01:42 > 0:01:43Now if you have a closer look
0:01:43 > 0:01:45it might seem a little disappointing
0:01:45 > 0:01:47because it's not bright and shiny, like your everyday diamond,
0:01:47 > 0:01:50but it has a much more interesting story.
0:01:50 > 0:01:52One that is very relevant to today's programme.
0:01:54 > 0:01:55More about that diamond later,
0:01:55 > 0:01:59but first, back to the progress we've made in the last 60 years.
0:01:59 > 0:02:01We'll be taking a range of subjects
0:02:01 > 0:02:03and with the help of The Sky at Night archive,
0:02:03 > 0:02:06finding out what we've learned during the time we've been on air.
0:02:08 > 0:02:11We'll be going back to 1957,
0:02:11 > 0:02:14to see how we observed the night sky back then.
0:02:16 > 0:02:20Dallas Campbell will be retracing on a bicycle the journeys that have
0:02:20 > 0:02:23taken us from the surface of the Earth to the furthest reaches
0:02:23 > 0:02:25of the solar system.
0:02:28 > 0:02:32And Jim Al-Khalili will be showing us how in just 60 years
0:02:32 > 0:02:35we've created an entirely new history of the universe.
0:02:36 > 0:02:38Using maths and physics,
0:02:38 > 0:02:42we can really understand how the universe was made,
0:02:42 > 0:02:46where it came from, how it works, and how it might possibly end.
0:02:49 > 0:02:53But to start we have to go back to the beginning, to 1957.
0:02:57 > 0:03:01April 1957 was a very different world.
0:03:02 > 0:03:06Our culinary tastes were apparently so unsophisticated
0:03:06 > 0:03:08that Panorama could broadcast an April Fool's report
0:03:08 > 0:03:12into the spaghetti harvest in Switzerland.
0:03:12 > 0:03:14Harold Macmillan had just become Prime Minister.
0:03:16 > 0:03:21And a new series, with a new presenter - Patrick Moore - began.
0:03:24 > 0:03:28Good evening. Tonight, I want to show you a rather unusual film.
0:03:29 > 0:03:32'But at that time our ideas about the solar system
0:03:32 > 0:03:35'were very different from what they are today.'
0:03:35 > 0:03:38The first programme was about the comet Arend-Roland,
0:03:38 > 0:03:39but we don't have a copy.
0:03:39 > 0:03:42It was broadcast live and never recorded,
0:03:42 > 0:03:47but I do have this book, which Patrick wrote about Mars in 1956.
0:03:47 > 0:03:51And after dismissing the idea of Earth-like animal life,
0:03:51 > 0:03:52he goes on to say this.
0:03:52 > 0:03:56"When we turn to plant life the situation is brighter,
0:03:56 > 0:03:59"and as we have seen it is almost certain
0:03:59 > 0:04:02"that extensive vegetation does exist on Mars."
0:04:02 > 0:04:04It seems ridiculous today,
0:04:04 > 0:04:07but 60 years ago it was a widely held belief
0:04:07 > 0:04:10that there were plants on the surface of the red planet.
0:04:10 > 0:04:13And, really, there's no better example
0:04:13 > 0:04:16of how fast our ideas have changed than Mars.
0:04:18 > 0:04:21To guide us through 60 years of astonishing discoveries
0:04:21 > 0:04:25about the Red Planet, Maggie has been talking to Monica Grady.
0:04:26 > 0:04:28Monica, it seems amazing to me
0:04:28 > 0:04:31that just 60 years ago people thought that Mars
0:04:31 > 0:04:33was covered in vegetation. Why was that?
0:04:33 > 0:04:35Well, it's because of pictures like this.
0:04:35 > 0:04:38This was taken in about 1956
0:04:38 > 0:04:40from one of the Earth's biggest telescopes,
0:04:40 > 0:04:43and you can see this big, dark shadow here
0:04:43 > 0:04:46right across the front of the planet,
0:04:46 > 0:04:51and this is interpreted as being a sort of rainforest.
0:04:51 > 0:04:54And at the time, this was the best that the telescope could do.
0:04:54 > 0:04:57Yeah, it's pretty fuzzy, you can't see much here at all.
0:04:57 > 0:04:58No, you can't.
0:04:58 > 0:05:00The problem with looking from Earth
0:05:00 > 0:05:02is that you're looking through the Earth's atmosphere,
0:05:02 > 0:05:04which immediately starts blurring things,
0:05:04 > 0:05:07so what you need to do is get above the Earth's atmosphere.
0:05:12 > 0:05:15In 1964, Nasa launched the probe Mariner 4.
0:05:17 > 0:05:21Eight months later it flew within 10,000km of Mars,
0:05:21 > 0:05:26and pixel by pixel returned 22 images of the planet's surface.
0:05:26 > 0:05:29It seems like a long way to go for 20 photographs.
0:05:29 > 0:05:32Well, I mean these pictures from Mariner 4
0:05:32 > 0:05:37completely changed part of our ideas of Mars.
0:05:37 > 0:05:38What do they show us?
0:05:38 > 0:05:41Well, for a start you've got this hazy bit here and this is...
0:05:41 > 0:05:43Hey, Mars has got an atmosphere,
0:05:43 > 0:05:45so that's something that we didn't know,
0:05:45 > 0:05:47and you can see more structure here.
0:05:47 > 0:05:51You can see that there are these sort of circular patches.
0:05:51 > 0:05:54Now, at the time they were called craters,
0:05:54 > 0:05:56but there are two sorts of craters.
0:05:56 > 0:05:58There's the crater at the top of a volcano
0:05:58 > 0:06:01and there's the crater made by impact from an asteroid,
0:06:01 > 0:06:05and there's lots of discussion as to what sort of craters they were.
0:06:05 > 0:06:08For those who long to find life on Mars,
0:06:08 > 0:06:11the Mariner 4 pictures were a disappointment,
0:06:11 > 0:06:13but they weren't definitive.
0:06:13 > 0:06:16So just four years later Nasa tried again.
0:06:16 > 0:06:19Good evening. We've just had some amazing photographs sent back by the
0:06:19 > 0:06:22American probe to Mars, Mariner 6.
0:06:24 > 0:06:26As Mariner 6 approached in 1969,
0:06:26 > 0:06:31there was much excitement that Mars would finally give up its secrets.
0:06:32 > 0:06:35Mariner 6 came down over this direction,
0:06:35 > 0:06:37over these so-called deserts.
0:06:37 > 0:06:40The question is of course, are these dark areas due to organic matter,
0:06:40 > 0:06:43vegetation, if you like, or are they not?
0:06:43 > 0:06:44But when the pictures came back,
0:06:44 > 0:06:48they revealed a dry and barren surface.
0:06:48 > 0:06:51Now, what about this all important question of life on Mars?
0:06:51 > 0:06:53Primitive life, there may be, I don't even think so.
0:06:53 > 0:06:55Intelligent life? Certainly not.
0:06:55 > 0:06:57So, in other words, you rather think that Mars is a dead planet?
0:06:57 > 0:06:59Absolutely, dead as a dodo.
0:06:59 > 0:07:02Once it was realised there was no complex life on Mars,
0:07:02 > 0:07:05attention turned to the planet's past.
0:07:05 > 0:07:08And here, the story became much more interesting.
0:07:09 > 0:07:12So, this is from one of the Viking orbiters,
0:07:12 > 0:07:13and it's not a single picture.
0:07:13 > 0:07:15It's lots and lots of pictures.
0:07:15 > 0:07:16It's a mosaic that has been put together.
0:07:16 > 0:07:19- But it's glorious. - It's absolutely fantastic.
0:07:19 > 0:07:21Just looking at these pictures
0:07:21 > 0:07:25started to really capture how close Mars was to Earth
0:07:25 > 0:07:26in many of its features.
0:07:26 > 0:07:29It's got these volcanoes, which are like the volcanoes on Hawaii.
0:07:29 > 0:07:32It's got this rift valley, which is like East Africa,
0:07:32 > 0:07:34and, of course, it's got its icecaps.
0:07:34 > 0:07:38But you've also got the features that on Earth we would interpret
0:07:38 > 0:07:39as being from rivers,
0:07:39 > 0:07:42so you've got something that looks as if
0:07:42 > 0:07:43it's going out into a huge delta.
0:07:43 > 0:07:46You've got other channels, meandering channels,
0:07:46 > 0:07:49and these were formed by flowing water.
0:07:49 > 0:07:50They were formed by rivers.
0:07:50 > 0:07:53So, with the orbiter, we suddenly get evidence
0:07:53 > 0:07:54- for past liquid water on Mars? - You do.
0:07:54 > 0:07:58So, you get a picture of a planet
0:07:58 > 0:08:01which has had all the ingredients,
0:08:01 > 0:08:05all the things that would allow life to get going.
0:08:05 > 0:08:09So the idea is that, yes, Mars could have harboured life,
0:08:09 > 0:08:11it might still harbour life,
0:08:11 > 0:08:13but if it is, it's not big life.
0:08:13 > 0:08:15We're looking at small life.
0:08:15 > 0:08:17So, if we are still looking for life, how do we find out the detail?
0:08:17 > 0:08:21Well, what you have to do is, you have to get down there,
0:08:21 > 0:08:24so you have to actually land.
0:08:24 > 0:08:26That takes us to these pictures?
0:08:26 > 0:08:28This brings us right up to date
0:08:28 > 0:08:31with the most recent spacecraft to land on Mars,
0:08:31 > 0:08:33which is Curiosity,
0:08:33 > 0:08:37which landed a few years ago and has been trundling across the surface
0:08:37 > 0:08:39near Mount Sharp in the Gale Crater.
0:08:39 > 0:08:42It has been taking the most amazing pictures.
0:08:42 > 0:08:45These are so brilliant. I feel as if I could step inside.
0:08:45 > 0:08:47We've come a long way in 60 years.
0:08:47 > 0:08:50We started off with that fuzzy image 60 years ago. We're now on this,
0:08:50 > 0:08:53where you can actually see the details of single pebbles.
0:08:53 > 0:08:54What are we looking for here?
0:08:54 > 0:08:56Well, we're still looking for life on the planet.
0:08:56 > 0:08:57We still haven't found it.
0:08:57 > 0:09:00So far, a lot of the missions have been following the water.
0:09:00 > 0:09:04Now what we haven't done yet is dug below the surface.
0:09:04 > 0:09:06Below the surface,
0:09:06 > 0:09:11there's a chance that you might find something still living.
0:09:11 > 0:09:15Very difficult to get into those places.
0:09:15 > 0:09:19We need to get more intelligent rovers and eventually,
0:09:19 > 0:09:23we need to get the most intelligent rover of all,
0:09:23 > 0:09:24and that's a person.
0:09:24 > 0:09:26Can it be me?
0:09:27 > 0:09:30I just can't wait to see what the next 60 years bring.
0:09:30 > 0:09:32- It's going to be brilliant.- Yes. Thank you so much for coming in.
0:09:32 > 0:09:33My pleasure. Thanks a lot.
0:09:38 > 0:09:43Hello, this is Buzz Aldrin, Apollo 11 astronaut,
0:09:43 > 0:09:48first landing on the moon, now working on humans to Mars.
0:09:48 > 0:09:54I do remember Patrick Moore with great respect, great reverence.
0:09:54 > 0:09:58I want to wish The Sky at Night happy birthday,
0:09:58 > 0:10:0360 years of all of that wonderful education
0:10:03 > 0:10:08as to what is going on up there at night. Thanks so much.
0:10:08 > 0:10:11It's been a joy having you with us.
0:10:14 > 0:10:17The Sky at Night isn't the only astronomical institution
0:10:17 > 0:10:20celebrating its 60th birthday this year.
0:10:20 > 0:10:24This is the Lovell Telescope, at Jodrell Bank, in Cheshire.
0:10:25 > 0:10:28It was first switched on in August 1957.
0:10:30 > 0:10:34It's still one of the most sensitive radio telescopes in the world.
0:10:34 > 0:10:37Over the years, we've filmed here on many occasions.
0:10:41 > 0:10:44To mark our shared anniversary, we asked Tim O'Brien,
0:10:44 > 0:10:46one of the astronomers at Jodrell Bank,
0:10:46 > 0:10:49to reveal some of its secrets,
0:10:49 > 0:10:53and to celebrate its most important contributions to astronomy.
0:10:55 > 0:11:02This is the incredible 76-metre wide 3,200 tonne Lovell Telescope,
0:11:02 > 0:11:04the brainchild of Bernard Lovell,
0:11:04 > 0:11:07an astronomer who had an ambitious vision.
0:11:09 > 0:11:11Back in the 1950s,
0:11:11 > 0:11:15Lovell was a pioneer in the relatively untested science
0:11:15 > 0:11:17of radio astronomy.
0:11:17 > 0:11:20They used huge dishes as aerials,
0:11:20 > 0:11:23gathering not light but radio waves from space
0:11:23 > 0:11:28in the hope that this would reveal new information about the universe.
0:11:29 > 0:11:33His revolutionary proposal was to build this telescope,
0:11:33 > 0:11:38ten times larger than any that had gone before.
0:11:38 > 0:11:39But in those early days,
0:11:39 > 0:11:42few believed in radio astronomy as much as Lovell.
0:11:44 > 0:11:46Even as construction began,
0:11:46 > 0:11:48he knew he was taking a high-stakes gamble...
0:11:49 > 0:11:53..as The Sky at Night discovered years later.
0:11:53 > 0:11:55During the building of the telescope,
0:11:55 > 0:11:59were there are any real crises, either with design or with cash?
0:11:59 > 0:12:00Endless crises.
0:12:00 > 0:12:04We started building the telescope in 1952, the foundations,
0:12:04 > 0:12:09and very soon discovered that the cost,
0:12:09 > 0:12:12whilst going to be far greater than the £30 million we got,
0:12:12 > 0:12:14but I didn't tell anybody.
0:12:14 > 0:12:18Then we had, I think, the most colossal stroke of luck,
0:12:18 > 0:12:20that certainly I've ever had in my life.
0:12:22 > 0:12:25The Russians launched the first of the Sputnik.
0:12:25 > 0:12:29After a few days, we got a most magnificent radar echo
0:12:29 > 0:12:32from the carrier rocket of the Sputnik.
0:12:32 > 0:12:34I've still got it, showing it going over the Lake District.
0:12:36 > 0:12:37200 miles above the Earth.
0:12:37 > 0:12:42And it turned out, to my astonishment,
0:12:42 > 0:12:44that this was the only instrument in the world
0:12:44 > 0:12:46capable of detecting this rocket.
0:12:46 > 0:12:50Suddenly, the telescope became world-famous
0:12:50 > 0:12:53and the establishment finally realised its true value.
0:12:55 > 0:12:57Now completely operational,
0:12:57 > 0:13:00the telescope was pulled in two completely different
0:13:00 > 0:13:04and often opposing directions - political and scientific.
0:13:05 > 0:13:10The politicians wanted to use it to monitor our Cold War enemies,
0:13:10 > 0:13:13tracking Russian missiles and space projects.
0:13:13 > 0:13:17But away from the high-profile space tracking work,
0:13:17 > 0:13:20the telescope was actually being used for real science,
0:13:20 > 0:13:22and those early results were breathtaking.
0:13:24 > 0:13:26This is a map of the whole of the sky,
0:13:26 > 0:13:30but seen in radio waves rather than visible light.
0:13:31 > 0:13:35It revealed that space was awash with radio.
0:13:35 > 0:13:38It was a powerful scientific vindication of Lovell's vision.
0:13:39 > 0:13:41And all the more amazing,
0:13:41 > 0:13:44given that some key components of the telescope
0:13:44 > 0:13:46were actually recycled.
0:13:47 > 0:13:50We're here at the top of the towers,
0:13:50 > 0:13:52right on the axis of the tipping of the ball,
0:13:52 > 0:13:56and that tipping of the giant ball is done on these gear racks.
0:13:56 > 0:14:01These are actually from the 15-inch guns of two World War I battleships.
0:14:03 > 0:14:06Once all the engineering challenges had been overcome,
0:14:06 > 0:14:09the new discoveries started to roll in.
0:14:12 > 0:14:15When these first radio astronomers started to scan the skies,
0:14:15 > 0:14:20they spotted intense points of radio light they called the radio stars.
0:14:20 > 0:14:23We used the Lovell Telescope and other radio antennas
0:14:23 > 0:14:27spread across the country to zoom in on these points of light.
0:14:27 > 0:14:28We found they weren't stars at all,
0:14:28 > 0:14:30they were actually distant galaxies
0:14:30 > 0:14:34and they were powered by supermassive black holes.
0:14:34 > 0:14:38These became known as Quasi Stellar Objects.
0:14:38 > 0:14:40The Quasars.
0:14:40 > 0:14:42Hardly noticeable to optical telescopes,
0:14:42 > 0:14:47these objects completely changed the way we thought about the universe.
0:14:48 > 0:14:51Turns out that this new radio sky
0:14:51 > 0:14:53is not full of stars held by nuclear fusion,
0:14:53 > 0:14:55like we see with our eyes,
0:14:55 > 0:14:59it's actually full of supermassive black holes powered by gravity.
0:14:59 > 0:15:04Gathering this kind of data from space is a huge technical challenge.
0:15:04 > 0:15:08So the Lovell is constantly being updated and improved,
0:15:08 > 0:15:12but that leaves it with its own share of quirky idiosyncrasies.
0:15:14 > 0:15:15This is the control room.
0:15:15 > 0:15:19At its heart is the control desk dating from 1957,
0:15:19 > 0:15:21although it is now packed with new electronics.
0:15:21 > 0:15:23Back in the day, the control system
0:15:23 > 0:15:27was an ingenious electromechanical analogue computer.
0:15:27 > 0:15:30There were ten boxes arrayed around the desk here,
0:15:30 > 0:15:32packed with dials and whirring gears,
0:15:32 > 0:15:35and they were used to drive the telescope
0:15:35 > 0:15:37to exactly the position that the astronomers wanted.
0:15:41 > 0:15:46Over its 60 years, the dish itself has undergone some major overhauls.
0:15:47 > 0:15:53In the 1970s, a new surface was built, several metres above the old.
0:15:53 > 0:15:56And this was then replaced again in 2002.
0:15:57 > 0:16:01We've also taken the opportunity to upgrade the electronics,
0:16:01 > 0:16:06networking it to telescopes right across Britain and around the world.
0:16:06 > 0:16:10It gives the Lovell a new and constantly evolving role.
0:16:12 > 0:16:14One of the things we're very interested in at the moment
0:16:14 > 0:16:18is a very weird phenomenon called fast radio bursts.
0:16:18 > 0:16:21These are very brief, fraction of a second,
0:16:21 > 0:16:23strong flashes of radio waves
0:16:23 > 0:16:25that appear to come randomly from across the sky.
0:16:25 > 0:16:27There's about 20 of them known at the moment,
0:16:27 > 0:16:31but we estimate that there's probably as many as 10,000 of them
0:16:31 > 0:16:35every single day and we've no idea what they are.
0:16:35 > 0:16:38Theories range from neutron stars falling into black holes,
0:16:38 > 0:16:41to perhaps rather bizarrely, beams of radio energy
0:16:41 > 0:16:44that are being used to accelerate alien spacecraft.
0:16:44 > 0:16:46Whatever their true origin,
0:16:46 > 0:16:50the fast radio bursts and other similar mysteries will, I'm sure,
0:16:50 > 0:16:52mean that the next 60 years of radio astronomy
0:16:52 > 0:16:55will be just as exciting as the last.
0:16:59 > 0:17:01Happy 60th birthday!
0:17:01 > 0:17:03What a marvellous occasion.
0:17:03 > 0:17:07I think one of my favourite ones was Michael Bentine discussing
0:17:07 > 0:17:12if there were civilisations existing on other planets outside the Earth.
0:17:12 > 0:17:15They both agreed there wasn't any then behind them appeared,
0:17:15 > 0:17:19I think it was a spaceship from another world.
0:17:19 > 0:17:21I thought that was inspirational.
0:17:21 > 0:17:24What do you think of the planet Earth?
0:17:24 > 0:17:26To be frank, old man, not very much.
0:17:30 > 0:17:35Technology has transformed every aspect of life since 1957.
0:17:35 > 0:17:36Take television for instance.
0:17:36 > 0:17:39This is the kind of camera that would have been used
0:17:39 > 0:17:41when The Sky at Night was first broadcast.
0:17:41 > 0:17:45Its four prime lenses on the front here allowed you to select
0:17:45 > 0:17:49between different shot sizes so there's no need for a zoom.
0:17:49 > 0:17:53Compare this magnificent machine to what we use today.
0:17:53 > 0:17:56This camera is not only smaller but it's much more sensitive
0:17:56 > 0:17:59and so we can use it to shoot the night sky.
0:17:59 > 0:18:02If technology has changed television,
0:18:02 > 0:18:06that's doubly true for space exploration.
0:18:06 > 0:18:09To explain how advances in technology have allowed us
0:18:09 > 0:18:11to explore the planet around us,
0:18:11 > 0:18:14we asked Dallas Campbell to take us on a cycling tour
0:18:14 > 0:18:15of the solar system.
0:18:19 > 0:18:21The solar system is a pretty big place.
0:18:21 > 0:18:26This scale model just outside York, that's the sun behind me,
0:18:26 > 0:18:29gives us an idea of some of the challenges faced
0:18:29 > 0:18:31in crossing the huge distances in space
0:18:31 > 0:18:34and how actually reaching the planets
0:18:34 > 0:18:37has stretched our science and our engineering to the limit.
0:18:39 > 0:18:43So I'm setting off to cycle between the planets.
0:18:43 > 0:18:47Retracing the steps of my six favourite spacecraft.
0:18:48 > 0:18:51The pioneering missions that have taken us
0:18:51 > 0:18:55from the surface of the Earth to Pluto and beyond.
0:18:56 > 0:18:59When The Sky at Night first transmitted,
0:18:59 > 0:19:01the space age hadn't even begun.
0:19:01 > 0:19:03The first object that made it into orbit
0:19:03 > 0:19:07was the Soviet satellite Sputnik, and that wasn't launched
0:19:07 > 0:19:10until six months after that first broadcast.
0:19:11 > 0:19:14Sputnik was as simple as a spacecraft can be.
0:19:14 > 0:19:17Really nothing more than a radio transmitter
0:19:17 > 0:19:20that had been strapped to the top of a rocket.
0:19:20 > 0:19:23MAN SPEAKS RUSSIAN
0:19:25 > 0:19:26But it makes my list
0:19:26 > 0:19:29because it showed that space travel was possible.
0:19:31 > 0:19:32Within a matter of months,
0:19:32 > 0:19:35the sights of the world's rocket scientists
0:19:35 > 0:19:37were set on the other worlds of the solar system.
0:19:40 > 0:19:44The first target was obviously the nearest - our own moon -
0:19:44 > 0:19:47and actually from here, it looks really, really close to the Earth,
0:19:47 > 0:19:50but this whole model, and that includes the size of the planets
0:19:50 > 0:19:52and the distance between them,
0:19:52 > 0:19:56is built at the scale of around about 575 million to one,
0:19:56 > 0:20:01so in the real world, that distance is around about 250,000 miles.
0:20:01 > 0:20:07In the 1950s, getting from A to B was a huge technological challenge.
0:20:09 > 0:20:11But within just a couple of years,
0:20:11 > 0:20:15The Sky at Night was able to report on Soviet success.
0:20:16 > 0:20:18In September 1959,
0:20:18 > 0:20:21the Russians landed their Lunik 2 on the moon's surface,
0:20:21 > 0:20:27and then in October 1959, came that great triumph with Lunik 3,
0:20:27 > 0:20:29which actually went round the moon
0:20:29 > 0:20:31and photographed that part of the moon's surface
0:20:31 > 0:20:33which we can never see from the Earth
0:20:33 > 0:20:35because it's always turned away from us.
0:20:35 > 0:20:37Well, I for one certainly won't forget those pictures.
0:20:40 > 0:20:44But the real triumph came ten years later
0:20:44 > 0:20:48with the second mission on our list, Apollo 11.
0:20:48 > 0:20:51That's one small step for man,
0:20:51 > 0:20:54one giant leap for mankind.
0:20:54 > 0:20:59This was one of the defining achievements of the 20th century,
0:20:59 > 0:21:01but in retrospect, what is startling
0:21:01 > 0:21:03is just how simple the technology was.
0:21:06 > 0:21:08The guidance computer on the lunar lander
0:21:08 > 0:21:12had less processing power than a modern toaster.
0:21:12 > 0:21:14When Neil Armstrong returned to Earth,
0:21:14 > 0:21:16he came to The Sky at Night studio.
0:21:16 > 0:21:19When you were actually walking about on the moon's surface
0:21:19 > 0:21:21and kicking about a certain amount of dust,
0:21:21 > 0:21:23did you notice any local colour?
0:21:23 > 0:21:27The colour is a puzzling phenomenon on the moon.
0:21:27 > 0:21:31Aside from the characteristics that I've already mentioned,
0:21:31 > 0:21:36you generally have the impression of being on a desert-like surface
0:21:36 > 0:21:39with rather light coloured hues,
0:21:39 > 0:21:45yet when you look at the material at close range, as if in your hand,
0:21:45 > 0:21:47you find it's a charcoal grey, in fact.
0:21:47 > 0:21:49And we were never able to find any things
0:21:49 > 0:21:52that were very different from that colour.
0:21:54 > 0:21:59Having conquered the moon, it was time to start exploring the planets.
0:21:59 > 0:22:00Mars was the main target.
0:22:00 > 0:22:05A mere 34 million miles from the Earth at its closest approach,
0:22:05 > 0:22:06it's still a long way to go.
0:22:08 > 0:22:09Reaching it is hard enough,
0:22:09 > 0:22:12but putting landers on the surface
0:22:12 > 0:22:14is a feat that has proved consistently difficult.
0:22:18 > 0:22:22All in all, we've tried to land 17 spacecraft on Mars,
0:22:22 > 0:22:24half of which have failed,
0:22:24 > 0:22:26which is understandable when you consider
0:22:26 > 0:22:28you're actually trying to send packages
0:22:28 > 0:22:32of extremely delicate electronic equipment
0:22:32 > 0:22:35across tens of millions of miles of hostile empty space
0:22:35 > 0:22:39and then land very carefully on the surface.
0:22:39 > 0:22:42One of the main difficulties of landing on Mars
0:22:42 > 0:22:46is that the atmosphere is so thin that parachutes are of limited use,
0:22:46 > 0:22:50so more ingenious ways of landing have to be devised.
0:22:53 > 0:22:56Viking, the first craft to successfully land on Mars,
0:22:56 > 0:22:58used a system of retrorockets.
0:23:00 > 0:23:04The Opportunity and Spirit rovers touched down in a bouncing air bag.
0:23:05 > 0:23:10But the next generation of rovers was too heavy for air bags,
0:23:10 > 0:23:12so in 2012 Nasa did this.
0:23:15 > 0:23:18Just for sheer ambition and panache,
0:23:18 > 0:23:22the third of my favourite spacecraft is the Curiosity Sky Crane,
0:23:22 > 0:23:26a triumph of engineering and technological sophistication
0:23:26 > 0:23:30designed to lower the Curiosity rover onto the Martian surface.
0:23:33 > 0:23:34If getting to Mars is hard,
0:23:34 > 0:23:37it's still a lot easier than getting to the outer planets,
0:23:37 > 0:23:39the gas and the ice giants.
0:23:39 > 0:23:42So the next planet out in the solar system, Jupiter,
0:23:42 > 0:23:46is just under a kilometre that way - or, in the real world,
0:23:46 > 0:23:48just over half a billion kilometres.
0:23:48 > 0:23:51And actually getting to it presents a whole new set of challenges.
0:23:54 > 0:23:56And that brings us to the next mission,
0:23:56 > 0:23:58and, really, it's my favourite of them all.
0:23:58 > 0:24:02Though it's actually two spacecraft, Voyager 1 and 2,
0:24:02 > 0:24:05which were both launched in the summer of 1977.
0:24:07 > 0:24:09These plutonium powered emissaries
0:24:09 > 0:24:13were designed to keep functioning for decades in the depths of space.
0:24:14 > 0:24:18They would take advantage of a rare alignment of the planets
0:24:18 > 0:24:21that would see them visit Jupiter, Saturn, Uranus
0:24:21 > 0:24:25and eventually Neptune over the course of 12 years.
0:24:27 > 0:24:31In early 1978, Voyager 1 approached Jupiter.
0:24:32 > 0:24:35The world watched in awe as it returned stunning views
0:24:35 > 0:24:40of the planet's clouds, storm systems and moons.
0:24:40 > 0:24:43It was the first sign of how these two spacecraft
0:24:43 > 0:24:46would go on to transform our concept of the outer solar system.
0:24:51 > 0:24:56Moving on from Jupiter, the Voyagers visited Saturn in 1980 and '81,
0:24:56 > 0:25:00giving us a tantalising glimpse of the magnificent ring systems.
0:25:03 > 0:25:06But to really appreciate the Saturn system,
0:25:06 > 0:25:09we needed a spacecraft and a camera that could study the rings
0:25:09 > 0:25:11in much greater detail.
0:25:13 > 0:25:16For that, we had to wait for another 25 years
0:25:16 > 0:25:20and the fifth spacecraft on our list, Cassini,
0:25:20 > 0:25:23which entered orbit around Saturn in 2004.
0:25:26 > 0:25:31The remarkable thing about Cassini is that it was launched 20 years ago
0:25:31 > 0:25:33with the technology that was around at the time.
0:25:33 > 0:25:37So its cameras, for example, a resolution of about one megapixel,
0:25:37 > 0:25:38a fraction of what's on your smartphone,
0:25:38 > 0:25:42and yet that technology is incredibly reliable.
0:25:42 > 0:25:46It's still sending back the most extraordinary images of Saturn,
0:25:46 > 0:25:47its rings and its moons.
0:25:49 > 0:25:52The Cassini mission is scheduled to end in September this year.
0:25:52 > 0:25:55After a series of closer and closer flybys to the rings,
0:25:55 > 0:25:58it is then going to be crashed into the planet.
0:25:58 > 0:26:00A glorious, a poignant end
0:26:00 > 0:26:03to one of the most transformative missions ever.
0:26:09 > 0:26:14After Saturn, missions get pretty thin on the ground, as do planets.
0:26:14 > 0:26:16So our next planet is Uranus,
0:26:16 > 0:26:19which is twice the distance from the sun as Saturn is.
0:26:19 > 0:26:22Now, for me cycling along here it is about 2.5km,
0:26:22 > 0:26:26in the real world up there it is about 1.5 billion kilometres.
0:26:26 > 0:26:28There's only ever been one spacecraft that's visited it.
0:26:29 > 0:26:35In 1986, Voyager 2 flew within 80,000 miles of Uranus.
0:26:35 > 0:26:37Well, just about two minutes ago...
0:26:38 > 0:26:42..Voyager 2 passed through its closest approach to Uranus.
0:26:45 > 0:26:49And three years later it sailed past Neptune.
0:26:49 > 0:26:52After Neptune, Voyager 2 just kept on going,
0:26:52 > 0:26:55and now both of the Voyager spacecraft are exploring
0:26:55 > 0:26:57the very edges of the outer solar system.
0:27:01 > 0:27:03And since those first two Voyager missions,
0:27:03 > 0:27:06only one other spacecraft has ventured
0:27:06 > 0:27:08into the outer solar system.
0:27:08 > 0:27:13The sixth and final spacecraft on our list is New Horizons,
0:27:13 > 0:27:16the most technologically sophisticated mission
0:27:16 > 0:27:18to visit the outer solar system.
0:27:18 > 0:27:19Half the size of Voyager,
0:27:19 > 0:27:23it made it all the way to Pluto in just nine years.
0:27:26 > 0:27:28In July 2015,
0:27:28 > 0:27:30Chris and Maggie were in mission control
0:27:30 > 0:27:33as New Horizons aimed to pass between Pluto
0:27:33 > 0:27:35and the orbit of its moon, Charon.
0:27:37 > 0:27:38OK, copy that.
0:27:38 > 0:27:40We're in lock with telemetry with...
0:27:40 > 0:27:41Yes!
0:27:41 > 0:27:43We've got data!
0:27:43 > 0:27:44CHEERING AND APPLAUSE
0:27:47 > 0:27:49I told you it would be fine!
0:27:49 > 0:27:50I wasn't worried!
0:27:50 > 0:27:53The jubilation was justified.
0:27:53 > 0:27:56Pluto had been thought to be a frozen and dead world,
0:27:56 > 0:27:59but the data that New Horizons returned showed that,
0:27:59 > 0:28:01against all expectations,
0:28:01 > 0:28:04this tiny world at the edge of the solar system
0:28:04 > 0:28:07was alive with active geology.
0:28:08 > 0:28:09Blimey!
0:28:11 > 0:28:14Here we are. Finally, we make it to Pluto.
0:28:14 > 0:28:18Look how tiny Pluto is. And that's one of its moons, Charon.
0:28:18 > 0:28:22Now, on my scale, Pluto to the Earth, about 10km.
0:28:22 > 0:28:26And in reality it would be round about 6 billion kilometres.
0:28:26 > 0:28:28It's amazing to think in the last 60 years
0:28:28 > 0:28:32we've developed this technology that's allowed us to explore
0:28:32 > 0:28:34pretty much the whole of the solar system,
0:28:34 > 0:28:37from the moment that Sputnik first left the Earth
0:28:37 > 0:28:41all the way to the New Horizons' mission to Pluto and beyond.
0:28:42 > 0:28:45And the extraordinary thing is that every step of the way
0:28:45 > 0:28:46along that history timeline,
0:28:46 > 0:28:49we have been surprised, we have learned something new.
0:28:49 > 0:28:52Nothing is as we thought it would be.
0:28:52 > 0:28:55And who knows what our technology will be like
0:28:55 > 0:28:58in the next 60 years and what we might find out?
0:29:02 > 0:29:06Of course, we've sent many more than six missions into the solar system.
0:29:08 > 0:29:11This graphic represents every single probe
0:29:11 > 0:29:13that we've sent to the planets,
0:29:13 > 0:29:16and between them they have revolutionised our understanding
0:29:16 > 0:29:18of the solar system.
0:29:18 > 0:29:2460 years ago, we thought there were nine planets orbited by 30 moons.
0:29:24 > 0:29:28Now we have just eight planets but over 180 moons.
0:29:29 > 0:29:32And it's the moons that have been the greatest surprise,
0:29:32 > 0:29:35particularly the icy moons of the outer planets.
0:29:38 > 0:29:39Well, I'm joined by Michele Dougherty,
0:29:39 > 0:29:41an explorer of the outer solar system -
0:29:41 > 0:29:44particularly with Cassini, the mission to Saturn.
0:29:44 > 0:29:47I think the thing that strikes me is wherever we've been,
0:29:47 > 0:29:50we've been surprised, and maybe nowhere more so than Saturn.
0:29:50 > 0:29:52Can you tell us about the exploration of Saturn?
0:29:52 > 0:29:55We were launched in 1997, we took a long time to get there,
0:29:55 > 0:29:58got there in July 2004,
0:29:58 > 0:30:02and we've essentially spent the last 13 years orbiting around Saturn.
0:30:02 > 0:30:07The biggest surprise was linked to one of its small moons, Enceladus.
0:30:07 > 0:30:08What are we looking at here?
0:30:08 > 0:30:11It's a very small world, its diameter is 500km.
0:30:11 > 0:30:14We would have long thought if from when it first formed
0:30:14 > 0:30:16there were to be some kind of heat in the interior,
0:30:16 > 0:30:19but over time that dies away, so we thought it was dead.
0:30:19 > 0:30:23But what we are looking at here is a very young surface.
0:30:23 > 0:30:25You can see there are some craters on the surface,
0:30:25 > 0:30:28but there aren't as many as you would expect.
0:30:28 > 0:30:32But I think the most exciting of all are these blue cracks
0:30:32 > 0:30:33at the South Pole.
0:30:33 > 0:30:36The imaging team on Cassini calls them tiger stripes,
0:30:36 > 0:30:38and it was from these cracks
0:30:38 > 0:30:41that we found there was this plume of water vapour
0:30:41 > 0:30:42coming off from the South Pole.
0:30:42 > 0:30:44In fact, we've got an image of the plume.
0:30:44 > 0:30:47You can see it better. This is the night side of Enceladus,
0:30:47 > 0:30:50what we were just looking at is this surface,
0:30:50 > 0:30:52and then there's this jet of material.
0:30:52 > 0:30:54Absolutely. If you look really closely,
0:30:54 > 0:30:56you can see there are individual plumes
0:30:56 > 0:30:58- coming out of the different... - Separate fountains.
0:30:58 > 0:30:59It's not just water vapour.
0:30:59 > 0:31:03There's organic material, there is dust.
0:31:03 > 0:31:07There's an instrument on board, the Ion Neutral Mass Spectrometer,
0:31:07 > 0:31:09that can actually taste what's in the plume,
0:31:09 > 0:31:11and it found that there was ammonia.
0:31:11 > 0:31:14And we found that out, actually, on one of the really close flybys.
0:31:14 > 0:31:16It was 25km above the surface.
0:31:16 > 0:31:18So you flew straight through the plume?
0:31:18 > 0:31:20We flew straight through the plume.
0:31:20 > 0:31:22We won't do that again,
0:31:22 > 0:31:24because the density of the plume is so strong
0:31:24 > 0:31:28that the spacecraft almost began to actually tumble, and so they said,
0:31:28 > 0:31:30"No, we aren't going to do that again."
0:31:30 > 0:31:33So this is a small moon in the cold outer solar system
0:31:33 > 0:31:34with liquid water?
0:31:34 > 0:31:35Yes. It's weird, isn't it?
0:31:35 > 0:31:39It's very strange. So why is there so much water there?
0:31:39 > 0:31:40How is it liquid?
0:31:40 > 0:31:43What we think is happening is tidal forces,
0:31:43 > 0:31:46as Enceladus is orbiting around Saturn,
0:31:46 > 0:31:49on some parts of the orbit, it's slightly closer to Saturn
0:31:49 > 0:31:52than on others, and so the gravitational force is stronger,
0:31:52 > 0:31:54and so that's where the tidal forces are coming from.
0:31:54 > 0:31:56So it's squeezed and then stretched by its orbit?
0:31:56 > 0:31:58Absolutely.
0:31:58 > 0:32:00I think from my perspective, the most exciting part
0:32:00 > 0:32:02is the fact that, you know, people are very interested
0:32:02 > 0:32:03about potential habitability.
0:32:03 > 0:32:07You know, you need four things for life to be able to form.
0:32:07 > 0:32:08You need liquid water...
0:32:08 > 0:32:10- Got that. - You need organic material...
0:32:10 > 0:32:13- You've seen that too. - You need a heat source...
0:32:13 > 0:32:14Something's got to be heating this up.
0:32:14 > 0:32:17And it needs to be stable over a period of time.
0:32:17 > 0:32:19That's what we're not sure about with Enceladus.
0:32:19 > 0:32:22So whether we might have got lucky, maybe we saw something that...
0:32:22 > 0:32:25- This is a recent phenomenon? - Absolutely.- And it's not just here,
0:32:25 > 0:32:28we've seen this sort of thing at Jupiter as well?
0:32:28 > 0:32:30There's the Galileo probe to Jupiter.
0:32:30 > 0:32:32Tell us about its explorations of the moons?
0:32:32 > 0:32:33What the Galileo spacecraft did
0:32:33 > 0:32:36is it orbited around Jupiter for four years.
0:32:36 > 0:32:39What they found is on some of the close flybys of the moons,
0:32:39 > 0:32:41in particular Europa...
0:32:41 > 0:32:43- So this is Europa, and it looks kind of similar.- It does.
0:32:43 > 0:32:48You've got cracks and ice and, I guess, no craters again.
0:32:48 > 0:32:50I think the difference with Europa
0:32:50 > 0:32:53is that they look as if they're icebergs.
0:32:53 > 0:32:58We think that there are some very thin surface regions,
0:32:58 > 0:33:01because if you have a close-up view of Europa, and I think...
0:33:01 > 0:33:02Yes, let's pull one up.
0:33:02 > 0:33:06To me, it looks like it's almost as if you're sitting in an aeroplane,
0:33:06 > 0:33:08flying over Greenland and you look out of the window
0:33:08 > 0:33:10and you see the ice shelf,
0:33:10 > 0:33:12and it's almost as if you can see an iceberg breaking off
0:33:12 > 0:33:16and moving on a slushy surface.
0:33:16 > 0:33:19So we think there might be regions on the Europa surface
0:33:19 > 0:33:22where it's really... The ice crust is very thin.
0:33:22 > 0:33:25And that's one of the reasons we want to go back,
0:33:25 > 0:33:28and so the Juice mission is going to go to Jupiter,
0:33:28 > 0:33:30and there's a Nasa mission called Europa Clipper,
0:33:30 > 0:33:33which is going to go to Europa.
0:33:33 > 0:33:36And thinking back over the 60 years that Sky at Night's been around,
0:33:36 > 0:33:38how big a change has there been?
0:33:38 > 0:33:39It's a huge change.
0:33:39 > 0:33:41No-one thought there would be liquid water oceans
0:33:41 > 0:33:43in the outer solar system. It's too cold.
0:33:43 > 0:33:45And so that's been a sea change
0:33:45 > 0:33:48as far as the search for potential habitability.
0:33:48 > 0:33:52We now know you can get most of the conditions that you need
0:33:52 > 0:33:54in our outer solar system,
0:33:54 > 0:33:56and potentially outside of our solar system.
0:33:56 > 0:33:59There are plenty of other places to look in our solar system as well.
0:33:59 > 0:34:00Absolutely, that's right.
0:34:08 > 0:34:11Hello, and congratulations to the BBC's Sky at Night
0:34:11 > 0:34:13on your 60th birthday.
0:34:13 > 0:34:15Thank you so much for bringing the wonders of the universe
0:34:15 > 0:34:17into our living rooms
0:34:17 > 0:34:20and for inspiring me and so many others to look up to the stars.
0:34:24 > 0:34:28Amateur observing has always been an integral part of the show,
0:34:28 > 0:34:30but even here things have changed.
0:34:30 > 0:34:34So we set Pete Lawrence and a group of amateur observers a challenge -
0:34:34 > 0:34:36to see if they could capture the night sky
0:34:36 > 0:34:39using the technology of the 1950s.
0:34:40 > 0:34:42Although the technology used to view the night sky
0:34:42 > 0:34:45may have changed over the last 60 years,
0:34:45 > 0:34:48amateur astronomers have always had to contend
0:34:48 > 0:34:49with a very British problem.
0:34:49 > 0:34:51..general direction of the moon, frankly,
0:34:51 > 0:34:53I can't see a single star at the moment.
0:34:53 > 0:34:55It's totally obscured.
0:34:55 > 0:34:59We were hoping to see Vega, the star straight above our heads,
0:34:59 > 0:35:01but even that's gone now.
0:35:01 > 0:35:03No, we've got to abandon it for a moment or two.
0:35:03 > 0:35:04We are blacked out.
0:35:06 > 0:35:09These days, we have computer-controlled telescopes
0:35:09 > 0:35:14and high sensitivity cameras to capture images of the sky.
0:35:14 > 0:35:18But have we lost some of the magic of stargazing as a result?
0:35:20 > 0:35:22Tonight I've gathered a group of astronomers
0:35:22 > 0:35:26under the impressive Lovell Telescope at Jodrell Bank,
0:35:26 > 0:35:30and we're going to see what amateur astronomy was like, 1950s style.
0:35:30 > 0:35:33One of the key things I've noticed
0:35:33 > 0:35:37is that there's quite a big difference in type of kit we use.
0:35:37 > 0:35:40So, Richard, I've been admiring this scope from across the field,
0:35:40 > 0:35:41it's beautiful. How old is it?
0:35:41 > 0:35:44This is nearly 50 years old. It's a 1971.
0:35:44 > 0:35:47With an open frame like this you can see everything inside, can't you?
0:35:47 > 0:35:49You can see the primary mirror at the bottom,
0:35:49 > 0:35:51which, actually, looks very clean.
0:35:51 > 0:35:52Light from the object in the sky
0:35:52 > 0:35:55bounces off the primary mirror at the bottom,
0:35:55 > 0:35:59focusing it via the secondary mirror into the eyepiece.
0:35:59 > 0:36:02This kind of telescope works just as well with an open frame.
0:36:04 > 0:36:07And what I've really noticed about it is how heavily engineered it is
0:36:07 > 0:36:09as well, this mount looks...
0:36:09 > 0:36:11It's almost overkill, very heavy and very solid,
0:36:11 > 0:36:14and it gives it perfect balance.
0:36:14 > 0:36:15It does move beautifully.
0:36:15 > 0:36:18That move's so smooth. Isn't that gorgeous?
0:36:18 > 0:36:20Thank you very much for showing me this.
0:36:20 > 0:36:23I wish it was clear, because I'd love to look through it.
0:36:23 > 0:36:25Wait a minute, there's some kind of a break over there.
0:36:25 > 0:36:28Can you see it? Look, over there.
0:36:28 > 0:36:31- Something... - I can't see anything in it, though.
0:36:31 > 0:36:32No.
0:36:32 > 0:36:36In the '50s, even when you could see something,
0:36:36 > 0:36:38photographing it was complex...
0:36:38 > 0:36:40and expensive.
0:36:40 > 0:36:44So a lot of amateur astronomers turned to sketching.
0:36:44 > 0:36:47Luckily the night before had been beautifully clear
0:36:47 > 0:36:50and some of our amateurs were out looking at the moon.
0:36:50 > 0:36:53So, Paul, you had a beautifully clear night
0:36:53 > 0:36:54and you did some sketching?
0:36:54 > 0:36:56- I did.- I can recognise that straight away.
0:36:56 > 0:37:00You've three very distinctive craters, that's Theophilus,
0:37:00 > 0:37:01Cyrillus and Catharina.
0:37:01 > 0:37:04- Yes.- What I love about your sketches
0:37:04 > 0:37:06is the way you've done them on the black paper.
0:37:06 > 0:37:07That's come out so well.
0:37:07 > 0:37:11It's much easier to see as well at night with a little light.
0:37:11 > 0:37:14It took quite a long time to do that, at least an hour.
0:37:14 > 0:37:17If I compare it with a photo I took last night, you can definitely see.
0:37:17 > 0:37:18You've got Theophilus up here
0:37:18 > 0:37:21with its central mountain peak very clearly,
0:37:21 > 0:37:23and you've got Cyrillus underneath
0:37:23 > 0:37:25with the two peaks in the centre, there.
0:37:25 > 0:37:27You've rendered that really well.
0:37:27 > 0:37:28Thank you very much.
0:37:28 > 0:37:29At their very best,
0:37:29 > 0:37:33amateur sketches are every bit as useful as photos.
0:37:33 > 0:37:36These ones from the '30s and '40s
0:37:36 > 0:37:39show a ring plane crossing of Saturn
0:37:39 > 0:37:43and the surface of Mars in incredible detail.
0:37:43 > 0:37:45Just a few minutes to try and get...
0:37:45 > 0:37:48The moon is just being awkward.
0:37:48 > 0:37:50The moon is just being awkward at the moment, I'm afraid.
0:37:50 > 0:37:54Donna, you have performed something of a miracle this evening,
0:37:54 > 0:37:56and you actually managed to get a sketch of the moon.
0:37:56 > 0:37:59Yes. It was very fleeting, but it was there.
0:37:59 > 0:38:02I can recognise that immediately as the Mare Crisium.
0:38:02 > 0:38:05It was very hazy, but I was using binoculars.
0:38:05 > 0:38:09I found myself actually observing as opposed to just looking.
0:38:09 > 0:38:14Do you know, that is really the essence of what you've done here,
0:38:14 > 0:38:17and that's... I think that's something which,
0:38:17 > 0:38:20to a certain degree, we've lost in amateur astronomy.
0:38:20 > 0:38:23Because looking through the eyepiece to sketch something,
0:38:23 > 0:38:26you really do have to look at it.
0:38:26 > 0:38:27It did make me concentrate, I have to say.
0:38:27 > 0:38:29I did actually concentrate.
0:38:29 > 0:38:30- It's a wonderful feeling, isn't it?- Oh, yes.
0:38:33 > 0:38:37Although tonight the sky might have been typically disappointing,
0:38:37 > 0:38:40I've been powerfully reminded of the romance of sketching
0:38:40 > 0:38:43and how it makes the act of observing
0:38:43 > 0:38:45a more intense and involving experience.
0:38:49 > 0:38:52So if you've got pen and paper at home, why not give it a go yourself?
0:38:52 > 0:38:56Now, to find out what's happening in the April and May night sky,
0:38:56 > 0:39:00why not pop along to our website and look at our latest star guide?
0:39:03 > 0:39:07Also on the website, you can find our viewers' gallery,
0:39:07 > 0:39:10showcasing some of the finest images of the night sky
0:39:10 > 0:39:14captured by Sky at Night viewers using today's technology.
0:39:21 > 0:39:23Happy birthday, Sky at Night!
0:39:23 > 0:39:26I watched you when I was a kid in England,
0:39:26 > 0:39:29all the nice stuff got me into space,
0:39:29 > 0:39:34and then I got involved in Voyager, Galileo, Cassini, and now Juno!
0:39:38 > 0:39:41Over the past 60 years there's been a transformation
0:39:41 > 0:39:45in our understanding of the history of the universe and how it works.
0:39:45 > 0:39:47What we call cosmology.
0:39:47 > 0:39:49We asked Jim Al-Khalili to explain more.
0:39:57 > 0:40:01For thousands of years astronomy was a descriptive science.
0:40:01 > 0:40:06Astronomers made ever more detailed maps of the night sky,
0:40:06 > 0:40:09but they seldom addressed fundamental questions.
0:40:10 > 0:40:15What was a star, a galaxy, a planet?
0:40:15 > 0:40:18How did the universe work?
0:40:18 > 0:40:22But then, unexpectedly, at the beginning of the last century,
0:40:22 > 0:40:24this all changed.
0:40:26 > 0:40:28In the early 20th century,
0:40:28 > 0:40:30the scientific establishment was rocked by the emergence
0:40:30 > 0:40:33of Einstein's theories of relativity
0:40:33 > 0:40:35and the bizarre theories of quantum mechanics.
0:40:35 > 0:40:38And they began to realise that with this new physics,
0:40:38 > 0:40:41not only could they explain phenomena here on Earth,
0:40:41 > 0:40:45but that these theories might apply on an epic scale
0:40:45 > 0:40:46across the universe as a whole.
0:40:49 > 0:40:53And one of the first projects was to try to use this new science
0:40:53 > 0:40:58to explain how the universe actually began.
0:40:58 > 0:41:02By the 1940s, two schools of thought had developed,
0:41:02 > 0:41:05the Big Bang and the Steady State.
0:41:05 > 0:41:07The Big Bang theory said that the entire universe
0:41:07 > 0:41:09was formed at a single moment.
0:41:09 > 0:41:14A cataclysmic explosion from an infinitesimally small point,
0:41:14 > 0:41:19marking the birth of space and time, and it's been expanding ever since.
0:41:19 > 0:41:22Whereas the Steady State theory said that while the universe
0:41:22 > 0:41:24has been constantly expanding,
0:41:24 > 0:41:28new matter is being created all the time, everywhere,
0:41:28 > 0:41:31always the same, nothing changing, no beginning or end.
0:41:33 > 0:41:36In 1957, when The Sky at Night was first broadcast,
0:41:36 > 0:41:40this argument over which theory was right was still raging.
0:41:41 > 0:41:46Patrick Moore returned many times to this theme over the next few years.
0:41:46 > 0:41:49And the one inescapable fact, at least I think it is,
0:41:49 > 0:41:52is that you and me and your television set
0:41:52 > 0:41:55and the kitchen sink and Aunt Emily, they actually exist.
0:41:55 > 0:41:59So the matter making up ourselves must have come from somewhere.
0:41:59 > 0:42:01There are some astronomers who believe
0:42:01 > 0:42:03in what's known as the Steady State theory,
0:42:03 > 0:42:08that the universe has always existed and will exist forever.
0:42:08 > 0:42:12But the problem was the Steady State and the Big Bang theories
0:42:12 > 0:42:15remained pure conjecture,
0:42:15 > 0:42:17because there was no measurable evidence
0:42:17 > 0:42:21that would tell which was right and which was wrong.
0:42:21 > 0:42:27Then in 1964, an accidental discovery changed all that.
0:42:28 > 0:42:32Two young astronomers, Arno Penzias and Robert Wilson,
0:42:32 > 0:42:37had just inherited a strange looking radio telescope, the horn antenna.
0:42:37 > 0:42:41But this unlikely telescope would surprise everyone
0:42:41 > 0:42:44and reveal how the universe actually started.
0:42:50 > 0:42:55The horn antenna was built to look for very specific radio signatures -
0:42:55 > 0:42:57microwaves.
0:42:57 > 0:43:01Penzias and Wilson tweaked it to make it super sensitive
0:43:01 > 0:43:03so they could study the Milky Way.
0:43:03 > 0:43:06But then wherever they looked in the sky,
0:43:06 > 0:43:08they could hear a very annoying hiss
0:43:08 > 0:43:11which they simply couldn't get rid of.
0:43:11 > 0:43:15HISSING
0:43:15 > 0:43:17Eventually, they realised that this hiss
0:43:17 > 0:43:22coming from everywhere in the universe could only be one thing.
0:43:22 > 0:43:27It was actually the faint remnant of the Big Bang itself.
0:43:33 > 0:43:36The discovery of this hiss, the cosmic microwave background,
0:43:36 > 0:43:39by Penzias and Wilson in 1964,
0:43:39 > 0:43:43proved, conclusively, that the Big Bang theory was correct.
0:43:43 > 0:43:45And it told us something else too,
0:43:45 > 0:43:49that astronomy is much more than just a descriptive science.
0:43:49 > 0:43:52What's more, using maths and physics,
0:43:52 > 0:43:56we can really understand how the universe was made -
0:43:56 > 0:44:00where it came from, how it works and how it might possibly end.
0:44:03 > 0:44:07The confirmation of the Big Bang by the cosmic microwave background
0:44:07 > 0:44:11gave astrophysics a massive confidence boost
0:44:11 > 0:44:16and it led to a burst of new and astonishing ideas and discoveries.
0:44:19 > 0:44:22One of the insights of this new science
0:44:22 > 0:44:24was the idea that gravity plays a key role
0:44:24 > 0:44:26in the story of the universe.
0:44:26 > 0:44:29As well as describing the orbits of planets around the sun
0:44:29 > 0:44:32and the motion of stars within galaxies,
0:44:32 > 0:44:36scientists also began to understand that it works within stars,
0:44:36 > 0:44:39crushing them together to create the conditions for nuclear reactions
0:44:39 > 0:44:42that make stars shine so fiercely.
0:44:42 > 0:44:46But their theories also predicted that, on a cosmic scale,
0:44:46 > 0:44:50gravity would produce unexpected and bizarre outcomes.
0:44:55 > 0:44:58For instance, as stars ended their lives,
0:44:58 > 0:45:00the theoreticians suggested they
0:45:00 > 0:45:02would continue to collapse under gravity,
0:45:02 > 0:45:07crushing their cores until they were just a few kilometres across at
0:45:07 > 0:45:08unbelievable densities.
0:45:11 > 0:45:13It seemed the stuff of science fiction.
0:45:17 > 0:45:22Then in November 1967, and using a rather underwhelming radio antenna,
0:45:22 > 0:45:25more like a clothesline than something like this,
0:45:25 > 0:45:28a young research scientist by the name of Jocelyn Bell
0:45:28 > 0:45:30saw something strange.
0:45:30 > 0:45:32In her data was a pulsing radio signal
0:45:32 > 0:45:36incredibly fast and incredibly regular.
0:45:36 > 0:45:40At first it was genuinely thought that this might be a signal from an
0:45:40 > 0:45:45alien world. In fact it was dubbed LGM for little green men.
0:45:45 > 0:45:49But it was soon realised that these so-called pulsars were in fact
0:45:49 > 0:45:51superdense stars or neutron stars
0:45:51 > 0:45:54that physicists had already predicted.
0:45:58 > 0:46:01There was another incredible prediction too,
0:46:01 > 0:46:04perhaps gravity could crush stars so powerfully
0:46:04 > 0:46:06that even light couldn't escape.
0:46:06 > 0:46:09These were called black holes.
0:46:14 > 0:46:16Over the next few years,
0:46:16 > 0:46:20pulsars and black holes shifted from pure speculation
0:46:20 > 0:46:22to astronomical orthodoxy.
0:46:23 > 0:46:27And it seemed as though the universe was finally beginning to
0:46:27 > 0:46:28make some sense.
0:46:30 > 0:46:33But then in the mid-1970s,
0:46:33 > 0:46:35a new series of observations threatened to turn
0:46:35 > 0:46:39everything we thought we knew upside down.
0:46:44 > 0:46:49In the USA, scientists led by astrophysicist Vera Rubin,
0:46:49 > 0:46:52were studying huge spiral galaxies deep in space.
0:46:54 > 0:46:56Rubin had initially thought that
0:46:56 > 0:46:59just like the outer planets of the solar system,
0:46:59 > 0:47:03the outer stars of the galaxy should be orbiting around
0:47:03 > 0:47:07more slowly than the inner stars, but they weren't.
0:47:07 > 0:47:10It was as though they weren't obeying the laws of gravity.
0:47:10 > 0:47:15Her crazy explanation was that the spiral arms of the galaxy contained
0:47:15 > 0:47:19a new kind of material called dark matter.
0:47:19 > 0:47:24This invisible material provided the extra gravity needed
0:47:24 > 0:47:26to control the motion of the stars.
0:47:28 > 0:47:30We just couldn't see it.
0:47:30 > 0:47:34Patrick Moore himself sometimes found dark matter hard to stomach.
0:47:34 > 0:47:37Well, we can see the effect of dark matter where they have a
0:47:37 > 0:47:39gravitational effect and these seem to be definite.
0:47:39 > 0:47:42But what is dark matter?
0:47:42 > 0:47:44Is it something we can't understand?
0:47:44 > 0:47:46More a fudge, isn't it?
0:47:46 > 0:47:50Well, you can call it a fudge but it turns out that it's incredibly
0:47:50 > 0:47:53- consistent with all our observations.- Really?
0:47:53 > 0:47:55And there was to be more, too.
0:47:55 > 0:47:59In the 1990s, as scientists peered deeper and deeper into space,
0:47:59 > 0:48:02they noticed another inconsistency.
0:48:03 > 0:48:08Sure the universe was expanding but it seemed to be expanding quicker
0:48:08 > 0:48:13and quicker. To explain this, theorists came up with the idea of
0:48:13 > 0:48:14dark energy,
0:48:14 > 0:48:19a mysterious something that pervaded the whole universe and that was
0:48:19 > 0:48:21pushing it apart ever more rapidly.
0:48:24 > 0:48:27As yet, there is no material evidence
0:48:27 > 0:48:31of dark matter or dark energy but if they do exist,
0:48:31 > 0:48:37scientists predict that they make up about 95% of the known universe,
0:48:37 > 0:48:41meaning almost everything out there in space is a mystery.
0:48:46 > 0:48:49As The Sky at Night celebrates its 60th,
0:48:49 > 0:48:54it seems as though the universe is more fascinating and more mysterious
0:48:54 > 0:48:56than ever before and everything we
0:48:56 > 0:48:58thought we knew is still up for grabs.
0:48:59 > 0:49:01And one thing is for sure -
0:49:01 > 0:49:05the next 60 years is likely to be just as interesting.
0:49:13 > 0:49:14Hello, Sky at Night,
0:49:14 > 0:49:15well done on the signals
0:49:15 > 0:49:17from your very first programme
0:49:17 > 0:49:18now having travelled
0:49:18 > 0:49:2060 light years into the universe.
0:49:20 > 0:49:22Congratulations and let's hope you
0:49:22 > 0:49:25haven't started an interplanetary war.
0:49:28 > 0:49:30All that cosmology, the Big Bang,
0:49:30 > 0:49:33the physics of black holes and pulsars.
0:49:33 > 0:49:36It all seems rather distant,
0:49:36 > 0:49:39but sometimes you can find a little bit of a distant universe right here
0:49:39 > 0:49:44on earth which brings us back to the black diamonds, the carbonados.
0:49:45 > 0:49:49To find out more about them, we've been joined by diamond expert,
0:49:49 > 0:49:51Adrian Jones.
0:49:51 > 0:49:54Adrian, let me give this back before I lose it.
0:49:54 > 0:49:56Can you tell me, how does a carbonado differ
0:49:56 > 0:49:58from a standard diamond?
0:49:58 > 0:49:59- They look different.- They do.
0:49:59 > 0:50:02Especially when you look down a microscope.
0:50:02 > 0:50:04Have a quick look and see what you can see.
0:50:04 > 0:50:08They look quite grey, there's some shiny bits but one of the strange
0:50:08 > 0:50:10things is if they've got lots of holes all over them,
0:50:10 > 0:50:13which is a bit unusual, isn't it? It looks porous.
0:50:13 > 0:50:15They are, exactly. They look a little bit like pumice.
0:50:15 > 0:50:17And the little holes inside them are baffling
0:50:17 > 0:50:20because diamonds are formed at very high
0:50:20 > 0:50:23pressure and high temperature and normally when you make a very high
0:50:23 > 0:50:24pressure, you squeeze things.
0:50:24 > 0:50:26It's very hard to imagine how the
0:50:26 > 0:50:28holes are formed or remain in the diamond.
0:50:28 > 0:50:32Yes. So how do we think they were formed?
0:50:32 > 0:50:35One explanation would be that they have been formed at extremely high
0:50:35 > 0:50:38temperatures, perhaps high enough to melt the diamond,
0:50:38 > 0:50:41so there's a possibility of liquid diamond and there's also the
0:50:41 > 0:50:46possibility of vapour diamond making some little holes.
0:50:46 > 0:50:50You said there liquid diamond. I didn't know that was possible.
0:50:50 > 0:50:53It's certainly extraordinary and not possible on the Earth today.
0:50:53 > 0:50:56- Yes.- This is one of the main lines of evidence these could be
0:50:56 > 0:50:58- extraterrestrial.- So, if they weren't formed on Earth,
0:50:58 > 0:51:00where did they originate from?
0:51:00 > 0:51:02So, you need something pretty extraordinary,
0:51:02 > 0:51:05something rich in carbon because diamonds are made from carbon.
0:51:05 > 0:51:08Pressures, perhaps, as great as twice the pressure at the centre of
0:51:08 > 0:51:11the earth, temperatures greater potentially than
0:51:11 > 0:51:13- the surface of the sun. - Oh, wow!
0:51:15 > 0:51:18One of the few places in the universe where you'd find those
0:51:18 > 0:51:21conditions is in heart of white dwarfs -
0:51:21 > 0:51:23the collapsed remnants of stars like our sun.
0:51:30 > 0:51:34As these stars undergo gravitational collapse at the end of their lives,
0:51:34 > 0:51:37they generate the sort of temperatures and pressures within
0:51:37 > 0:51:40their carbon-rich cores that would be required to
0:51:40 > 0:51:42create carbonado diamonds.
0:51:44 > 0:51:46If that white dwarf was then ruptured,
0:51:46 > 0:51:49it would be broken into diamond-rich asteroids.
0:51:50 > 0:51:54It's thought that all the carbonados on earth may have been delivered by
0:51:54 > 0:51:57just one of those asteroids.
0:51:57 > 0:51:59So, these carbonados from Brazil and
0:51:59 > 0:52:01we know they are found only in Brazil
0:52:01 > 0:52:06and Africa, so they probably arrived as a single asteroid made of
0:52:06 > 0:52:08carbonado which broke up and
0:52:08 > 0:52:11collided with the earth a long time ago.
0:52:11 > 0:52:12In fact before Africa and Brazil
0:52:12 > 0:52:15were separated by the Atlantic Ocean.
0:52:15 > 0:52:17So you find them in both places but they're probably from the same
0:52:17 > 0:52:19- asteroid.- Probably from the same
0:52:19 > 0:52:21asteroid which broke up and then distributed
0:52:21 > 0:52:22itself over those two continents.
0:52:22 > 0:52:25I see. So this is billions of years old?
0:52:25 > 0:52:28So billions of years old. Three, maybe four billion years old.
0:52:28 > 0:52:31- Or three quarters of the age of the earth.- Oh, wow!
0:52:31 > 0:52:34Gosh. So, our Sky at Night diamond,
0:52:34 > 0:52:37we think was probably formed in a white dwarf,
0:52:37 > 0:52:40landed on Earth billions of years ago and is now
0:52:40 > 0:52:42sitting in front of us...
0:52:42 > 0:52:45- Yes.- ..for our celebrations. - That's exactly right, yes.
0:52:45 > 0:52:46Well, that's pretty impressive if you ask me.
0:52:46 > 0:52:49- Thank you so much for bringing them in.- Thank you. A pleasure.
0:52:54 > 0:52:55Hi, Sky at Night.
0:52:55 > 0:52:57Happy 60th from everyone
0:52:57 > 0:52:59here at the European Space Agency
0:52:59 > 0:53:01and from Rosetta. Nice one, keep up
0:53:01 > 0:53:03the good work.
0:53:05 > 0:53:08One of the other questions that has haunted astronomy, the proverbial
0:53:08 > 0:53:12elephant in the universe is, are we alone?
0:53:12 > 0:53:15Not just within our solar system but throughout the cosmos.
0:53:15 > 0:53:16In 1957,
0:53:16 > 0:53:19nobody knew if there were worlds orbiting other stars.
0:53:20 > 0:53:22The first exoplanet wasn't detected
0:53:22 > 0:53:24until 1995.
0:53:24 > 0:53:29But now we know of over 3,000 planets orbiting distant stars.
0:53:30 > 0:53:32In February this year,
0:53:32 > 0:53:34the most exciting discovery yet was announced.
0:53:36 > 0:53:40A whole system of potentially habitable earth-like planets.
0:53:40 > 0:53:43Orbiting the cold dwarf star, TRAPPIST-1.
0:53:45 > 0:53:48Chris has been talking to one of the lead scientists on the project,
0:53:48 > 0:53:50Amaury Triaud, to find out more.
0:53:52 > 0:53:53I think, one of the most significant
0:53:53 > 0:53:56discoveries in the Sky at Night's 60 years is just last month
0:53:56 > 0:53:58the announcement of planets around
0:53:58 > 0:53:59a star called TRAPPIST-1.
0:53:59 > 0:54:02Can you tell us what you were looking for and what you found?
0:54:02 > 0:54:05What we found is around this small star,
0:54:05 > 0:54:08we have seven planets all turning very close to the star.
0:54:08 > 0:54:12The outermost planet is only 6% of the Earth's sun.
0:54:12 > 0:54:14So all of those will be well within the orbit of Mercury?
0:54:14 > 0:54:17- Completely.- So it's a very packed system.
0:54:17 > 0:54:18What do we know about those planets?
0:54:18 > 0:54:21All seven planets have sizes and
0:54:21 > 0:54:24they are masses measured to be comparable
0:54:24 > 0:54:26to the Earth. So they have compositions,
0:54:26 > 0:54:29densities comparable to the Earth.
0:54:29 > 0:54:32All seven are far enough from the star that we consider them to be
0:54:32 > 0:54:34temperate, meaning that under certain
0:54:34 > 0:54:36geological and atmospheric conditions,
0:54:36 > 0:54:38water could be liquid if there is water there.
0:54:38 > 0:54:40And that is why we are so excited
0:54:40 > 0:54:42because this is the first system where
0:54:42 > 0:54:46we can test whether liquid water can exist on the surface of a world
0:54:46 > 0:54:50outside the solar system and then hunt for evidence of life.
0:54:50 > 0:54:53A lot of the discussion after the discovery was immediately about the
0:54:53 > 0:54:56star. This is a very different star.
0:54:56 > 0:54:59Stars like TRAPPIST-1 form the majority of stars in our galaxy.
0:54:59 > 0:55:01Most stars are smaller than the sun.
0:55:01 > 0:55:04That's right. Just like TRAPPIST-1 and slightly bigger.
0:55:04 > 0:55:07Most planets similar in size and mass to the Earth
0:55:07 > 0:55:09mostly exist around such stars.
0:55:09 > 0:55:12So looking at TRAPPIST-1 is looking at
0:55:12 > 0:55:15the majority of earth-like planets in the universe.
0:55:15 > 0:55:17But how will new facilities affect this?
0:55:17 > 0:55:20I know people are excited about the James Webb Space Telescope,
0:55:20 > 0:55:21for example.
0:55:21 > 0:55:25The James Webb Space Telescope will be launched in late 2018.
0:55:25 > 0:55:28It has the time to study each of the passages of the planet
0:55:28 > 0:55:32in front of the star and so through those observations
0:55:32 > 0:55:36we will note what type of atmosphere, what climate,
0:55:36 > 0:55:38the level of greenhouse gases,
0:55:38 > 0:55:41so we will infer the conditions on the surface
0:55:41 > 0:55:43in terms of pressure and temperature.
0:55:43 > 0:55:44Well, good luck and come back
0:55:44 > 0:55:48- and tell us as the discovery goes on.- Thank you very much.
0:56:07 > 0:56:10Well, that's how far we've come in the last 60 years but what about the
0:56:10 > 0:56:14future? What will we be talking about in 60 years' time?
0:56:14 > 0:56:16We've got our experts here.
0:56:16 > 0:56:18Monica, what are you looking forward to?
0:56:18 > 0:56:19Well, I'm looking forward to
0:56:19 > 0:56:21understanding more about Mars because by six
0:56:21 > 0:56:26years' time, we will have found fossilised life on Mars.
0:56:26 > 0:56:31I really don't think I'm afraid that we'll find evidence of current life
0:56:31 > 0:56:33on Mars but we will have found
0:56:33 > 0:56:35evidence that there was life on Mars which
0:56:35 > 0:56:39will link to life on Earth and this is, you know,
0:56:39 > 0:56:41a really interesting question.
0:56:41 > 0:56:43Michelle, what about the outer solar system?
0:56:43 > 0:56:46I'm much more interested in the outer solar system, absolutely.
0:56:46 > 0:56:48But we've got missions going to Europa.
0:56:48 > 0:56:50Where else do you think we will have been?
0:56:50 > 0:56:52Well, there's talk about going to
0:56:52 > 0:56:54Uranus or Neptune because those are the gas giants
0:56:54 > 0:56:57we know the least about in our solar system.
0:56:57 > 0:57:00- We just had one flyby.- That's right, that's right.
0:57:00 > 0:57:01But from my perspective,
0:57:01 > 0:57:05our understanding of the icy moons of Jupiter and Saturn are making us
0:57:05 > 0:57:10wonder about whether we might find liquid water outside of our
0:57:10 > 0:57:13solar system around some of the exoplanets that have been found.
0:57:13 > 0:57:15So let's have a prediction.
0:57:15 > 0:57:18In 60 years' time, what's the hot topic in exoplanets?
0:57:18 > 0:57:21I think the biggest hot topic is finding out how frequently life can
0:57:21 > 0:57:24emerge. Not just is their life but how frequently can we find life in
0:57:24 > 0:57:27- the universe?- So you are convinced we will find life out there and
0:57:27 > 0:57:29then we'll just have many examples of it.
0:57:29 > 0:57:33I think there will be a lot of claims.
0:57:33 > 0:57:37The road is really hard but I do hope that before I pass away,
0:57:37 > 0:57:43- we will know.- But do you think maybe an extraterrestrial intelligence
0:57:43 > 0:57:46will have got in touch with us to put everything into perspective?
0:57:46 > 0:57:48I've got my list of questions.
0:57:50 > 0:57:52They might have the answers, you know?
0:57:52 > 0:57:54It's just like you can speculate.
0:57:54 > 0:57:58If they do, we'll definitely interview them on The Sky at Night.
0:57:58 > 0:58:01That's all we've got time for this month but it's clear there's a lot
0:58:01 > 0:58:04to look forward to and whatever happens and whatever is discovered,
0:58:04 > 0:58:06we'll be here to report it for you.
0:58:06 > 0:58:09We'll be back in June with a special from Rome.
0:58:09 > 0:58:11In the meanwhile, enjoy the spring skies,
0:58:11 > 0:58:13check out this month's Star Guide
0:58:13 > 0:58:17- online and, of course, get outside and get looking up.- Goodnight.