0:00:29 > 0:00:31Good evening. For this programme,
0:00:31 > 0:00:34we're going to talk about the strange little planet Mercury.
0:00:34 > 0:00:38So first of all, over to Chris Lintott for a quick little run-down.
0:00:39 > 0:00:43If you've ever seen Mercury, it's the most elusive of the bright planets,
0:00:43 > 0:00:45because it stays so close the sun.
0:00:45 > 0:00:47It does sometimes pop up in the evening sky,
0:00:47 > 0:00:51but this month, it's a morning object.
0:00:51 > 0:00:53'Mercury is the planet nearest the sun
0:00:53 > 0:00:56'and it's a world of extreme temperatures.
0:00:56 > 0:00:58'It's the smallest of the major planets
0:00:58 > 0:01:01'and it has the oldest surface.
0:01:01 > 0:01:02It has a large iron core,
0:01:02 > 0:01:05which accounts for about two thirds of the planet's mass.
0:01:05 > 0:01:10At a glance, it looks a lot like the moon, with craters and lava seas
0:01:10 > 0:01:14but it's got a weak magnetic field and an extremely thin atmosphere
0:01:14 > 0:01:19and these false colour images reveal a complex surface chemistry.
0:01:19 > 0:01:24Although Mercury orbits the sun very quickly, it's turning very slowly,
0:01:24 > 0:01:26so that one Mercurian day
0:01:26 > 0:01:29lasts the equivalent of 176 Earth days.
0:01:29 > 0:01:35The side facing the sun gets very hot, over 400 degrees Celsius,
0:01:35 > 0:01:39while the side facing away from the sun gets icily cold,
0:01:39 > 0:01:41minus 180 degrees.
0:01:41 > 0:01:43It's a world of mysteries.
0:01:43 > 0:01:47How did it form and why does it have this large iron core?
0:01:47 > 0:01:51Mariner 10 was the first spacecraft to fly past Mercury
0:01:51 > 0:01:55back in the '70s, but with the arrival of Messenger in 2011,
0:01:55 > 0:01:58we finally had our first spacecraft in orbit.
0:01:58 > 0:02:01Messenger has sent back stunning images,
0:02:01 > 0:02:04like this one of the Coloris Basin,
0:02:04 > 0:02:07the largest impact crater anywhere in the solar system.
0:02:08 > 0:02:13It's also discovered volcanic vents and these strange hollows, or pits,
0:02:13 > 0:02:15which give a Swiss cheese appearance
0:02:15 > 0:02:18where materials vanished into space.
0:02:18 > 0:02:21The poles of Mercury are also a mystery.
0:02:21 > 0:02:23We've seen the signature of water
0:02:23 > 0:02:26in the freezing, permanently-shadowed craters
0:02:26 > 0:02:28at both the north and south poles.
0:02:28 > 0:02:30For a planet so near the sun,
0:02:30 > 0:02:34this certainly challenges our ideas about the solar system.
0:02:35 > 0:02:39Katie Joy and Dave Rothery have come down to Selsey to talk to us
0:02:39 > 0:02:43about some of these strange features that we see on Mercury.
0:02:43 > 0:02:45Messenger has mapped the whole planet by now,
0:02:45 > 0:02:48but it has still thrown up more questions than it has answers.
0:02:51 > 0:02:53First of all, may I come to you, Katie?
0:02:53 > 0:02:57What's the very latest news from Messenger?
0:02:57 > 0:03:00Messenger has been in orbit about a year and a half now
0:03:00 > 0:03:03around Mercury and we're finding out huge amounts of information
0:03:03 > 0:03:07from all the experiments that are running on the spacecraft.
0:03:07 > 0:03:11So lots of new things about Mercury and understanding the planet that is closest to the sun.
0:03:11 > 0:03:14What about the Mercurian atmosphere?
0:03:14 > 0:03:17Well, we've observations from Earth to suggest
0:03:17 > 0:03:21that there are atoms around Mercury that form an exosphere,
0:03:21 > 0:03:24so not necessarily an atmosphere, but an exosphere.
0:03:24 > 0:03:28Some of the instruments on board the spacecraft are helping us
0:03:28 > 0:03:30to understand the coupling of the exosphere
0:03:30 > 0:03:33and the planetary surface in a bit more detail.
0:03:33 > 0:03:37- The atmosphere of Mercury is very, very tenuous.- Extremely tenuous.
0:03:37 > 0:03:41It's great for remote sensing the planetary surface.
0:03:41 > 0:03:43There's no air in the way, effectively.
0:03:43 > 0:03:46These atoms are extremely diffuse, but they are there.
0:03:46 > 0:03:50And what is recharging them is of considerable interest.
0:03:50 > 0:03:54There are places on the surface which are quite remarkable which we didn't expect.
0:03:54 > 0:03:57When we flew past Mercury, we saw craters
0:03:57 > 0:03:59with bright patches on the floor.
0:03:59 > 0:04:01I remember discussing them with you, Patrick.
0:04:01 > 0:04:05We were scratching our heads - what are these craters or bright patches?
0:04:05 > 0:04:08Now we are in orbit around Mercury, we see hollows on the surface,
0:04:08 > 0:04:11we see something is removing the surface, we don't know how.
0:04:11 > 0:04:15The only thing we can think of is that the surface material is somehow disappearing into space.
0:04:15 > 0:04:18Maybe it's subliming, turning from solid to vapour.
0:04:18 > 0:04:20It's a really strange landform
0:04:20 > 0:04:23and this is one way we can get these atoms into the exosphere.
0:04:23 > 0:04:28One point here, people compare Mercury with the moon.
0:04:28 > 0:04:33In some stages, it's like the moon, in others, it's totally unlike.
0:04:33 > 0:04:37It is, it's very different. We have the heavily-cratered areas
0:04:37 > 0:04:42which suggest Mercury has been bombarded by very large asteroids and comets throughout its history.
0:04:42 > 0:04:45We think most of those basins, which are over 300 kilometres
0:04:45 > 0:04:49in diameter, were probably formed very early on in Mercury's history.
0:04:49 > 0:04:51So prior to about 3.8 billion years ago.
0:04:51 > 0:04:55And then subsequently we've had vulcanism which has
0:04:55 > 0:04:59erupted in different areas on the surface of Mercury
0:04:59 > 0:05:02and flooded very thick lavas into those ancient basins.
0:05:02 > 0:05:07And Messenger is taking images of the surface in new detail
0:05:07 > 0:05:10so that we can study some of these volcanic sites.
0:05:10 > 0:05:13We hear about water holes on Mercury. I'm a total sceptic.
0:05:13 > 0:05:17- What about you, Chris?- No, I think some of the evidence is convincing.
0:05:17 > 0:05:21The first signs of what might be water were seen with radar.
0:05:21 > 0:05:26Yes, you can image parts of Mercury with radar from the Earth,
0:05:26 > 0:05:29and resolve individual craters
0:05:29 > 0:05:32and within some of the polar craters, at both poles,
0:05:32 > 0:05:36there was something which was sending back a strong radar return.
0:05:36 > 0:05:38So you've got a strong bounce.
0:05:38 > 0:05:41Something's scattered back strongly by something
0:05:41 > 0:05:44which has properties which could be water ice, could be sulphur.
0:05:44 > 0:05:47Mixed up with the soil as well.
0:05:47 > 0:05:50We're not talking about an ice rink that you can skate on.
0:05:50 > 0:05:53No, I think in terms of small crystals within the soil.
0:05:53 > 0:05:57Water or sulphur are the obvious ones to give this kind of radar return.
0:05:57 > 0:06:00We now know that these are areas on Mercury
0:06:00 > 0:06:03where parts of crater floors are in permanent shadow.
0:06:03 > 0:06:07They're so close to the poles, the sun never appears on the crater floor,
0:06:07 > 0:06:08so it's very cold all the time.
0:06:08 > 0:06:12Never gets above about minus 170 centigrade, something like that.
0:06:12 > 0:06:14A similar effect on the moon.
0:06:14 > 0:06:17So again, we have evidence from radar scattering
0:06:17 > 0:06:20of some of these permanently-shadowed craters at the south pole of the moon
0:06:20 > 0:06:23that they could have some of this water-ice properties.
0:06:23 > 0:06:27I'm a total sceptic. When someone gives me a cup full of lunar water,
0:06:27 > 0:06:29then I'll admit I was wrong.
0:06:29 > 0:06:33- That'll be a very expensive drink, Patrick.- Very.
0:06:33 > 0:06:37- Well, Dave, Katie, thank you very much.- Thank you.
0:06:37 > 0:06:40As we've heard, Patrick, Mercury has many mysteries
0:06:40 > 0:06:45and the next spacecraft to try and unravel them is a European one called BepiColombo.
0:06:45 > 0:06:49And that spacecraft is currently in Stevenage, being assembled,
0:06:49 > 0:06:51and Chris North went to take a look.
0:06:52 > 0:06:57Astrium have been building satellites in Stevenage for over 40 years.
0:06:57 > 0:07:01Walking the long corridors with Jessica Marshall,
0:07:01 > 0:07:05a spacecraft and satellite engineer, I'm reminded how far we've come
0:07:05 > 0:07:09since 1957 when Sputnik was launched into space.
0:07:09 > 0:07:13In the Andromeda lab, there are three satellites under construction.
0:07:13 > 0:07:17This communication satellite will eventually circle the Earth
0:07:17 > 0:07:20tens of thousands of miles up, beaming down digital television signals.
0:07:20 > 0:07:23It has the latest satellite technology
0:07:23 > 0:07:27and we've been asked not to film any details which competitors might see.
0:07:27 > 0:07:30It's a small world, with closely-guarded secrets.
0:07:30 > 0:07:34But we're here to see this satellite, called BepiColombo,
0:07:34 > 0:07:39which will eventually circle the least understood of the planets in the solar system, Mercury.
0:07:39 > 0:07:43It's named after the scientist who worked out the best way
0:07:43 > 0:07:45of getting a spacecraft to this tiny world.
0:07:45 > 0:07:49The scientific instruments which will tell us about Mercury's atmosphere,
0:07:49 > 0:07:53what the planet is made of and how it was formed will be fitted onto
0:07:53 > 0:07:57this structure, the middle section of a three-part satellite.
0:07:57 > 0:08:00Behind us we've got BepiColombo or part of BepiColombo.
0:08:00 > 0:08:03Tell us what we've got here.
0:08:03 > 0:08:07This is the very middle part of BepiColombo, the planetary orbiter.
0:08:07 > 0:08:10It's going to be the European scientific module,
0:08:10 > 0:08:13so all the science instruments will be mounted onto this
0:08:13 > 0:08:16and this will be in orbit looking down at the planet.
0:08:16 > 0:08:19But what you see here is only a third of that,
0:08:19 > 0:08:22so the whole thing will be about the size of a bus.
0:08:22 > 0:08:27On one side will be the transfer module to get the whole stack to Mercury.
0:08:27 > 0:08:30And on the other side will be another spacecraft
0:08:30 > 0:08:34which will be looking at the magnetic field around the planet.
0:08:34 > 0:08:37Jessica is part of a team spread across Europe and Japan,
0:08:37 > 0:08:40which is getting BepiColombo ready for its long journey
0:08:40 > 0:08:43under harsh conditions around the first rock from the sun,
0:08:43 > 0:08:47where temperatures will reach 350 degrees Celsius.
0:08:47 > 0:08:49Because we're so close to the sun
0:08:49 > 0:08:53and because we're going to heat up so much, we have to be very accurate
0:08:53 > 0:08:56to make sure the long bits don't point at the sun,
0:08:56 > 0:08:59so the scientific instruments, we can't point them at the sun.
0:08:59 > 0:09:02We have to make sure we are controlling the spacecraft properly.
0:09:02 > 0:09:05But also, there's a six-year journey to get there,
0:09:05 > 0:09:07in itself a big engineering challenge.
0:09:07 > 0:09:10So all these modules are stacked together
0:09:10 > 0:09:13and then spend six years going towards the planet.
0:09:13 > 0:09:15Then, after six years, we have to separate them.
0:09:15 > 0:09:18That's a big challenge because if it doesn't work
0:09:18 > 0:09:21then that's going to have huge implications on the mission.
0:09:21 > 0:09:25Today, the engineers are welding together the fuel pipes
0:09:25 > 0:09:29and putting in valves for the thrusters that will control BepiColombo
0:09:29 > 0:09:30when it gets to Mercury.
0:09:30 > 0:09:33Unlike its conventional neighbours with their big fuel tanks,
0:09:33 > 0:09:38BepiColombo will be travelling most of the way by ion propulsion.
0:09:38 > 0:09:41This is one of the tanks that will contain xenon gas.
0:09:41 > 0:09:44Not your conventional rocket fuel, but for BepiColombo,
0:09:44 > 0:09:47it's crucial to its novel ion propulsion engine.
0:09:47 > 0:09:51But when it gets to Mercury, it's key to slowing the spacecraft down
0:09:51 > 0:09:54and letting it get into orbit around the tiny planet.
0:09:54 > 0:09:57Ion propulsion might sound and look like science fiction,
0:09:57 > 0:10:00but while it is a relatively new technology,
0:10:00 > 0:10:03it has been well tested on previous space missions.
0:10:03 > 0:10:07Once in space, BepiColombo's engines will use a steady stream
0:10:07 > 0:10:12of tiny charged particles of ionised gas to push the spacecraft along.
0:10:12 > 0:10:16The ion thrusters are being developed in the UK too.
0:10:16 > 0:10:19This footage from QinetiQ in Farnborough
0:10:19 > 0:10:22shows the distinctive blue plasma produced by ion engines.
0:10:22 > 0:10:25And while the frost produced is relatively tiny,
0:10:25 > 0:10:28ion engines are incredibly efficient
0:10:28 > 0:10:31and can continue to fire for very long periods of time.
0:10:31 > 0:10:34They are ideal for a journey that will take more than six years
0:10:34 > 0:10:37and cover several billion miles.
0:10:37 > 0:10:39And there's one more key difference.
0:10:39 > 0:10:42For most of the journey, BepiColombo's engines will be acting
0:10:42 > 0:10:47like a brake, counteracting the sun's incredible gravitational pull.
0:10:49 > 0:10:52In order to get to Mercury, you have to slow down.
0:10:52 > 0:10:54So you've got to spiral in towards the sun.
0:10:54 > 0:10:57And that takes quite a lot of energy to do.
0:10:57 > 0:11:02It takes more energy to do that than to get us out to Jupiter or Saturn.
0:11:02 > 0:11:06And that orbit uses the moon, the Earth and Venus
0:11:06 > 0:11:09to do gravity-assist manoeuvres and to slow us down.
0:11:09 > 0:11:12So it's like the slingshots that we think of
0:11:12 > 0:11:15to get out to the distant reaches of the solar system,
0:11:15 > 0:11:18- but actually slowing you down rather than speeding you up.- Exactly.
0:11:18 > 0:11:23And it means that we are able to get to Mercury in the most fuel efficient way.
0:11:23 > 0:11:25We've got to make it as light as possible
0:11:25 > 0:11:29because if we make it too heavy, we won't be able to launch it,
0:11:29 > 0:11:32but also we won't be able to get it to Mercury.
0:11:32 > 0:11:36And we want to get to Mercury and do as much science there,
0:11:36 > 0:11:40and the more mass we save on the structure and propulsion means,
0:11:40 > 0:11:42the more mass we can give to the scientists
0:11:42 > 0:11:45and they can have bigger and better instruments on board.
0:11:45 > 0:11:50Bepi is currently being spun around to allow closer inspection.
0:11:50 > 0:11:53The Astrium engineers are very careful and rigorous.
0:11:53 > 0:11:56Bolts are tightened and everything is checked and rechecked.
0:11:56 > 0:11:58But it's still a tense time.
0:11:58 > 0:12:02A few years ago, an American company wasn't as careful and dropped
0:12:02 > 0:12:05a NASA satellite during a similar procedure.
0:12:05 > 0:12:07Oops!
0:12:07 > 0:12:10Finally, Bepi is turned over to reveal its huge radiator panel,
0:12:10 > 0:12:13which will help cool its science instruments
0:12:13 > 0:12:16and allow the engineers to start work on the next section.
0:12:16 > 0:12:18Of course, when it gets to launch,
0:12:18 > 0:12:21it's going to get a far less gentle treatment.
0:12:22 > 0:12:26And lift-off of Messenger on NASA's mission to Mercury.
0:12:26 > 0:12:29With the launch, it's the worst-case environment for a spacecraft.
0:12:29 > 0:12:34So you think about it being at the top of that rocket and the rocket's lit
0:12:34 > 0:12:39and it begins to accelerate out of the Earth's environment.
0:12:39 > 0:12:42It's shaking around, but there is also a big acoustic noise,
0:12:42 > 0:12:45big shock waves, which will go through that whole spacecraft.
0:12:45 > 0:12:48So on Ariane 5, when you release the side boosters,
0:12:48 > 0:12:50big shock waves going through the spacecraft.
0:12:50 > 0:12:53We have to make sure we survive that.
0:12:54 > 0:12:58Launch is on schedule for 2015. Not long to get Bepi ready.
0:12:58 > 0:13:03It's a long time in the planning and will take a long time to get there.
0:13:03 > 0:13:06But once at Mercury, BepiColombo should solve
0:13:06 > 0:13:08many of the mysteries that Messenger has uncovered.
0:13:08 > 0:13:11In the meantime, images of Mercury, never before seen,
0:13:11 > 0:13:13are being sent back all the time.
0:13:13 > 0:13:16But you don't need a multi-million pound spacecraft
0:13:16 > 0:13:20or ion propulsion to get you out of bed in order to appreciate Mercury.
0:13:20 > 0:13:23This month, it'll be on view from Earth in the early morning,
0:13:23 > 0:13:25just before sunrise.
0:13:25 > 0:13:28Back to Patrick's garden, where Pete and Paul can tell us more.
0:13:29 > 0:13:33Pete, here we are and we have a nice little planet in the morning sky,
0:13:33 > 0:13:37- the planet Mercury which I've only ever seen once.- Have you really?- Yes.
0:13:37 > 0:13:39Well, this is a good opportunity to see Mercury
0:13:39 > 0:13:41because it's in the morning sky,
0:13:41 > 0:13:43visible just before the sun comes up.
0:13:43 > 0:13:47It's actually joined by two other planets - Venus and Saturn.
0:13:47 > 0:13:50And it's Venus that's really the key to finding Mercury.
0:13:50 > 0:13:53Venus is moving between Saturn and Mercury
0:13:53 > 0:13:56over the first couple of weeks of December.
0:13:56 > 0:13:58But the morning I'd really recommend
0:13:58 > 0:14:00is 11th December
0:14:00 > 0:14:03because there's a fantastic little crescent moon there as well
0:14:03 > 0:14:06which joins the party. That really sets things off.
0:14:06 > 0:14:08Mercury is the lowest of the dots
0:14:08 > 0:14:11and it's fainter than Venus,
0:14:11 > 0:14:13- but it's still quite bright. - It's also one of those things
0:14:13 > 0:14:16that it's nice to say you've seen it. Also, we have in December
0:14:16 > 0:14:20the Geminid meteor shower. This will be a good one this year, won't it?
0:14:20 > 0:14:22I'm really looking forward to this because...
0:14:22 > 0:14:26- The moon is out of the way.- It's new, the moon, on 13th December.
0:14:26 > 0:14:28That's when the peak of the Geminids is.
0:14:28 > 0:14:32So what you have to do on 13th December, you must do this,
0:14:32 > 0:14:34is get yourself a sunbed or a sun lounger,
0:14:34 > 0:14:38- star lounger, shall we call it? - Star lounger!
0:14:38 > 0:14:42And lie outside just before midnight through to dawn,
0:14:42 > 0:14:43that's the best time,
0:14:43 > 0:14:47and you should get a fantastic view of the Geminid meteor shower.
0:14:47 > 0:14:50The peak rate is about 100 plus meteors per hour.
0:14:50 > 0:14:54I'll find somewhere dark away from the city, because I want to see some bright ones myself.
0:14:54 > 0:14:57To be honest, we've had a very poor period of weather,
0:14:57 > 0:15:01so I'm going to look for some clear skies in the country.
0:15:01 > 0:15:04- I'm just going to drive to them. - You can pick me up on the way!
0:15:04 > 0:15:08- I'll come with you. Well, all these things present lovely photo opportunities.- They do.
0:15:08 > 0:15:09People should go to our Flickr site.
0:15:15 > 0:15:17There also, we will find the observing guides,
0:15:17 > 0:15:20- written by your good self, for the Moore Winter Marathon.- Absolutely.
0:15:20 > 0:15:23That brings us on to our next bit, which is binocular objects.
0:15:23 > 0:15:25We have a nice collection of binoculars here.
0:15:25 > 0:15:28We should start off by talking a bit about binoculars.
0:15:28 > 0:15:31They're really just two telescopes coupled together.
0:15:31 > 0:15:35Yes, and some of the objects we picked for the Moore Winter Marathons
0:15:35 > 0:15:38are designed to be viewed with just binoculars.
0:15:38 > 0:15:43We have 8x30, and the ones I started with 10x50, all the way to 11x80.
0:15:43 > 0:15:47Yes, but you don't have to spend a fortune to get a decent pair.
0:15:47 > 0:15:50The size which you would normally recommend for astronomy
0:15:50 > 0:15:53would be either 7x50s or 10x50s.
0:15:53 > 0:15:55Those numbers, let me explain what they mean.
0:15:55 > 0:15:59With a 10x50 pair of binoculars, that's 10 times magnification
0:15:59 > 0:16:02and 50 millimetres diameter front lens, basically.
0:16:02 > 0:16:05So these 11x80s will magnify 11 times
0:16:05 > 0:16:07and they have 80 millimetre lens.
0:16:07 > 0:16:09Which is quite big, it's over three inches.
0:16:09 > 0:16:12It is, but that's a problem with bigger binoculars
0:16:12 > 0:16:16because to hold them steady, you really have to have arms like Popeye to keep them still.
0:16:16 > 0:16:18There's that problem, which is an issue.
0:16:18 > 0:16:21These are actually 15x70,
0:16:21 > 0:16:24so that's quite a high magnification, 15,
0:16:24 > 0:16:27so I've got them on a tripod here and that steadies the binoculars.
0:16:27 > 0:16:31It's a good solution. You do have a cheaper method, though, don't you?
0:16:31 > 0:16:33You can use a broom.
0:16:33 > 0:16:36I would not recommend that to anybody, because I tried it once
0:16:36 > 0:16:40and all of God's creatures, the spiders and slugs, all dropped out.
0:16:40 > 0:16:44Basically, you take the broom and invert it, so you put the binoculars
0:16:44 > 0:16:48- on the bristles and that helps you steady them as you look.- Absolutely.
0:16:48 > 0:16:51Let's talk about some of the objects in the Moore Winter Marathon
0:16:51 > 0:16:53which we can see with binoculars.
0:16:53 > 0:16:56Let's start with M33, the Triangulum galaxy.
0:16:56 > 0:17:00This is a spiral galaxy, one of the members of the local group
0:17:00 > 0:17:04which comprises our galaxy, the Andromeda spiral, a couple of others.
0:17:04 > 0:17:08It is an interesting object, but has a very low surface brightness,
0:17:08 > 0:17:09so quite a hard object.
0:17:09 > 0:17:13You can see it with the naked eye if you've got really good skies,
0:17:13 > 0:17:17but the way to guarantee a view is not to use a telescope
0:17:17 > 0:17:19because that's got too much magnification,
0:17:19 > 0:17:22it's to use a wide-field instrument, like binoculars,
0:17:22 > 0:17:25because it gives you a nice wide part of the sky to look at,
0:17:25 > 0:17:27collecting all that delicate light you've got.
0:17:27 > 0:17:31That's come from nearly 3,000,000 light years away.
0:17:31 > 0:17:33Interestingly, the way to find it,
0:17:33 > 0:17:37you normally use the Great Square of Pegasus to find the Andromeda galaxy.
0:17:37 > 0:17:40So if you start in the bottom right of the Great Square of Pegasus,
0:17:40 > 0:17:41so the one in the upper left,
0:17:41 > 0:17:43keep that line going
0:17:43 > 0:17:44until you come to a star
0:17:44 > 0:17:45of similar brightness.
0:17:45 > 0:17:47Then, if you turn at right angles
0:17:47 > 0:17:49to that, going up the sky,
0:17:49 > 0:17:50you get to a fainter star,
0:17:50 > 0:17:52then a fainter star still
0:17:52 > 0:17:53next to that.
0:17:53 > 0:17:55The Andromeda galaxy is the faint,
0:17:55 > 0:17:57elongated smudge next to that star.
0:17:57 > 0:17:59- Right.- Which, with clear, dark skies,
0:17:59 > 0:18:01isn't too difficult to see.
0:18:01 > 0:18:04If you then draw a line from the Andromeda galaxy to Mirach
0:18:04 > 0:18:07- and keep going for the same distance again...- Goodness me.
0:18:07 > 0:18:10It's just as well this is in your observing guide, honestly.
0:18:10 > 0:18:13If you draw a line from the Andromeda galaxy
0:18:13 > 0:18:15through the main star...
0:18:15 > 0:18:16I'm completely lost.
0:18:16 > 0:18:18Does this ever have an end?
0:18:18 > 0:18:23And go other way for the same distance, that point exactly at M33.
0:18:23 > 0:18:24Let's go from something
0:18:24 > 0:18:26which is outside of our own galaxy
0:18:26 > 0:18:28to something which is inside our own galaxy
0:18:28 > 0:18:31- and that's the Beehive Cluster. M44. - This is a lovely thing.
0:18:31 > 0:18:35It's one of those objects, I'm glad you put it in the binoculars,
0:18:35 > 0:18:37- because a telescope just does not do it justice.- Too much power.
0:18:37 > 0:18:40Too much power. You really want a low-field small pair of binoculars
0:18:40 > 0:18:43and you get all these beautiful stars in this cluster.
0:18:43 > 0:18:45I'm not a big fan of open clusters,
0:18:45 > 0:18:48but the Praesepe is a really good one.
0:18:48 > 0:18:51Quite interestingly, recently, we know some of the stars
0:18:51 > 0:18:54within that cluster now hold extra solar planets
0:18:54 > 0:18:56so it's a cluster of interest at the moment.
0:18:56 > 0:18:58There's another really nice cluster -
0:18:58 > 0:19:01- I'm annoying you here, aren't I, with clusters?- No, it's fine.
0:19:01 > 0:19:03I know you only put them in to annoy me.
0:19:03 > 0:19:05If you find Orion the Hunter, which is very easy,
0:19:05 > 0:19:07you can't miss it,
0:19:07 > 0:19:10you find the three stars which make the belt of Orion,
0:19:10 > 0:19:12and you follow them down to the left, they point to Sirius,
0:19:12 > 0:19:14the brightest star in the night sky.
0:19:14 > 0:19:17Well, just below Sirius, if you look at that region
0:19:17 > 0:19:21with a pile of binoculars, there's a lovely cluster known as Messier 41.
0:19:21 > 0:19:23Moving away from clusters now,
0:19:23 > 0:19:26there is a lovely thing that you put on the list,
0:19:26 > 0:19:27and I think this is probably
0:19:27 > 0:19:30one of the most beautiful things out of the whole thing,
0:19:30 > 0:19:33- and that's Kemble's Cascade. - Ah, yes.
0:19:33 > 0:19:35I've seen a few pictures on our Flickr site,
0:19:35 > 0:19:37so quite a few people have commented.
0:19:37 > 0:19:40This really is one of those undiscovered objects,
0:19:40 > 0:19:43so easy to find, and yet it's so rewarding when you do find it.
0:19:43 > 0:19:45You just don't think to look for it.
0:19:45 > 0:19:47It's in the constellation of Camelopardalis,
0:19:47 > 0:19:51which is very obscure and it's quite difficult to navigate around it.
0:19:51 > 0:19:53- But I can give you a trick to find it.- Go on, then.
0:19:53 > 0:19:56If you have the W of Cassiopeia
0:19:56 > 0:20:00and you join one end of the W to the other towards the left,
0:20:00 > 0:20:02if you extend that link the same distance again,
0:20:02 > 0:20:04that points exactly at Kemble's Cascade.
0:20:04 > 0:20:07- Yeah.- And that makes it very easy to locate.
0:20:07 > 0:20:09People can go and find them
0:20:09 > 0:20:12by using the Moore Winter Marathon guide and observing forms
0:20:12 > 0:20:15which are available via the BBC's Sky At Night website.
0:20:17 > 0:20:19Well, some lovely things to look for in the winter marathon,
0:20:19 > 0:20:23all we need is the skies to clear. Did you know that this is actually
0:20:23 > 0:20:26the 40th anniversary of the Apollo 17 mission?
0:20:26 > 0:20:29So here's Chris Lintott to look at some of the highlights
0:20:29 > 0:20:33of our last manned expedition to the moon.
0:20:33 > 0:20:3810, 9, 8, 7. Ignition sequence.
0:20:38 > 0:20:41Started, all engines are started.
0:20:41 > 0:20:43We have ignition. 2, 1, 0.
0:20:43 > 0:20:45We have a lift-off.
0:20:45 > 0:20:48We have a lift-off and it's lighting up the area.
0:20:48 > 0:20:51It's just like daylight here at the Kennedy Space Center.
0:20:51 > 0:20:54The Saturn V is moving off the pad.
0:20:54 > 0:20:59In December 1972, Apollo 17 left for the moon.
0:20:59 > 0:21:02It was the only night-time launch of a Saturn V rocket
0:21:02 > 0:21:05and a spectacular and dramatic sight.
0:21:05 > 0:21:08Its crew, Ron Evans, geologist Harrison Schmitt,
0:21:08 > 0:21:13and the last man to stand on the moon, Commander Eugene Cernan.
0:21:13 > 0:21:16RADIO: We've got a beautiful picture, you guys down there.
0:21:16 > 0:21:19Apollo 17 landed in the Littrow Valley,
0:21:19 > 0:21:24amongst a range of mountains formed by a huge and ancient impact.
0:21:24 > 0:21:27It made an ideal site for geological investigation,
0:21:27 > 0:21:32with layers of ancient bedrock and new volcanic deposits.
0:21:32 > 0:21:35The astronauts spent three days in all - collecting samples,
0:21:35 > 0:21:39setting up science experiments and just occasionally having fun.
0:21:39 > 0:21:43# I was strolling on the moon one day... #
0:21:43 > 0:21:46ALL SING
0:21:46 > 0:21:48May! May!
0:21:48 > 0:21:53Commander Eugene Cernan was an experienced Navy pilot.
0:21:53 > 0:21:57He first flew into space with Gemini 9, Apollo's predecessor,
0:21:57 > 0:21:59and then again with Apollo 10.
0:22:01 > 0:22:06In 1982, Patrick interviewed him for The Sky At Night.
0:22:06 > 0:22:09Recently, I went back to Texas to talk to the last man on the moon.
0:22:09 > 0:22:12What about navigational problems. Did you have any?
0:22:12 > 0:22:15We studied, due to a great deal of your work, of course,
0:22:15 > 0:22:18on the mapping of the moon, we studied the area
0:22:18 > 0:22:24we were going to land so well that I really believe I knew it,
0:22:24 > 0:22:28at least from the air, from above, as well as my own backyard.
0:22:28 > 0:22:30But it's hard for me to realise
0:22:30 > 0:22:32that I literally have been on another planet.
0:22:32 > 0:22:34The Littrow Valley did not disappoint.
0:22:34 > 0:22:38With its dramatic scenery and incredible boulders, the astronauts
0:22:38 > 0:22:42were kept very busy gathering bore samples and bits of rock.
0:22:42 > 0:22:45The discovery of orange soil at Shorty Crater
0:22:45 > 0:22:47was unexpected and exciting.
0:22:47 > 0:22:51Hey! There is orange soil!
0:22:51 > 0:22:53Well, don't move it till I see it.
0:22:53 > 0:22:57I've put my visor up. It's still orange!
0:22:57 > 0:23:00Fantastic, sports fans.
0:23:01 > 0:23:04The orange soil samples were returned to Earth.
0:23:04 > 0:23:07High in zinc, these glass beads
0:23:07 > 0:23:10are now thought to have formed in volcanic vents.
0:23:10 > 0:23:14Can you see this on your colour television? I'll bet you.
0:23:14 > 0:23:16How can there be orange soil on the moon?
0:23:16 > 0:23:20Eventually, the incredible adventure on the moon was over
0:23:20 > 0:23:22and the astronauts had to go home.
0:23:22 > 0:23:27It ended a remarkable chapter in the history of exploration.
0:23:28 > 0:23:30You were the last man on the moon.
0:23:30 > 0:23:32What were your overall impressions of the moon?
0:23:32 > 0:23:36My overall impressions of the moon are really...
0:23:36 > 0:23:39overshadowed by my impressions of looking back at the Earth.
0:23:39 > 0:23:45The moon itself, it's been called like a sandy beach,
0:23:45 > 0:23:50it's colourless, but it is beautiful. It's majestic.
0:23:50 > 0:23:52It's got towering mountains
0:23:52 > 0:23:55and it's got a tremendously overpowering landscape.
0:23:55 > 0:23:58What a nice day.
0:23:58 > 0:24:01There's not cloud a in the sky.
0:24:01 > 0:24:053, 2, 1. Ignition.
0:24:05 > 0:24:07We're on our way, Houston.
0:24:07 > 0:24:10The legacy of Apollo 17 still lives on.
0:24:10 > 0:24:14NASA's lunar reconnaissance orbiter is currently mapping the moon,
0:24:14 > 0:24:18and it recently imaged the Apollo 17 landing site.
0:24:18 > 0:24:21You can clearly see the lunar module, the buggy tracks
0:24:21 > 0:24:24and even those of the astronauts themselves,
0:24:24 > 0:24:28just as fresh as they were back in December 1972.
0:24:28 > 0:24:33With no weathering on the moon, time seemingly stands still.
0:24:33 > 0:24:36Back on Earth, the samples the astronauts returned
0:24:36 > 0:24:38are still telling us new things
0:24:38 > 0:24:41about the moon, our celestial neighbour.
0:24:41 > 0:24:43Katie Joy has been lucky enough
0:24:43 > 0:24:45to work with some of these precious relics.
0:24:45 > 0:24:49Apollo 17 went to a very special place on the moon,
0:24:49 > 0:24:52probably the most interesting of the Apollo sites.
0:24:52 > 0:24:54So why there? What was interesting?
0:24:54 > 0:24:57They went to the rim of the Serenitatis impact basin,
0:24:57 > 0:25:01one of these really large impact basins on the near side of the moon.
0:25:01 > 0:25:04And this is the boundary between the edge of that basin
0:25:04 > 0:25:08and the surrounding highland areas, where there is a steep valley,
0:25:08 > 0:25:12the Littrow Valley, which has been subsequently flooded with lavas,
0:25:12 > 0:25:15so this was a geologically diverse site.
0:25:15 > 0:25:16It had both highland rocks
0:25:16 > 0:25:18so we could look at the ancient materials on the moon
0:25:18 > 0:25:20and also the much younger lavas.
0:25:20 > 0:25:24So it was to provide as much diversity as possible
0:25:24 > 0:25:26to try and understand the geological history of the moon.
0:25:26 > 0:25:29The sea area there was absolutely magnificent.
0:25:29 > 0:25:32They brought back 110kg of moon rock,
0:25:32 > 0:25:36and this is far more than all the other Apollo missions.
0:25:36 > 0:25:39We had the deep drill core on Apollo 17 where they brought up material
0:25:39 > 0:25:41from three metres in depth below the lunar soil,
0:25:41 > 0:25:45so the lunar regolith, material that covers the surface of the moon,
0:25:45 > 0:25:47and so this deep drill core provided us
0:25:47 > 0:25:50with a snapshot back in time through what material was formed
0:25:50 > 0:25:52at different points in the past.
0:25:52 > 0:25:54So that's been really important.
0:25:54 > 0:25:58But having a scientist there, a geologist, to know where to go,
0:25:58 > 0:26:01I think helped a lot particularly for this latter mission.
0:26:01 > 0:26:0618, 19 and 20 would have been geologists. Sadly, they never went.
0:26:06 > 0:26:09No, the three latter missions that were planned but never went.
0:26:09 > 0:26:11But maybe in the future when we go back
0:26:11 > 0:26:14and explore the surfaces of other planets there will be
0:26:14 > 0:26:16more scientists that will have the opportunity to interact
0:26:16 > 0:26:18and sample the surface.
0:26:18 > 0:26:21Well, I volunteer, for starters. If you need an astronomer.
0:26:21 > 0:26:25I would love to have gone to a newer planet. No chance.
0:26:25 > 0:26:28What would you say are the real scientific legacies
0:26:28 > 0:26:31of the Apollo missions? Not just Apollo 17, but as a whole?
0:26:31 > 0:26:34Many of the samples are still being studied in laboratories
0:26:34 > 0:26:37around the Earth, so as technology has increased in the past 40 years
0:26:37 > 0:26:39we can study smaller and smaller amounts
0:26:39 > 0:26:41and find out new types of information.
0:26:41 > 0:26:45One of the really interesting things that's come out of the orange soils
0:26:45 > 0:26:47that Apollo 17 sampled
0:26:47 > 0:26:50was the identification that they were rich in water,
0:26:50 > 0:26:53suggesting the lunar material is actually relatively
0:26:53 > 0:26:55a lot wetter than we thought it was,
0:26:55 > 0:26:59which helps us to understand the internal structure of the moon
0:26:59 > 0:27:02and where these sorts of volatiles come from.
0:27:02 > 0:27:06And that's only been rediscovered within the last five years or so.
0:27:06 > 0:27:09But we also placed a series of experiments on the surface
0:27:09 > 0:27:11so the ALSEP packages which are in-situ experiments
0:27:11 > 0:27:15that were left on the surface of the moon to conduct science
0:27:15 > 0:27:17and that lasted after the astronauts left,
0:27:17 > 0:27:21so we have seismic information which provides us about the variation.
0:27:21 > 0:27:25- Looking for moonquakes.- Moonquakes, exactly. From this particular site.
0:27:25 > 0:27:27But also understanding the local heat flow,
0:27:27 > 0:27:31the thermal environment of the moon, and placing these retro reflectors
0:27:31 > 0:27:33where we shine lasers up from Earth
0:27:33 > 0:27:36to understand how the moon is moving away from us as well.
0:27:36 > 0:27:38So lots of good geology from rocks
0:27:38 > 0:27:41but lots of good surface science experiments as well.
0:27:41 > 0:27:44Well, Katie, thank you very much indeed.
0:27:46 > 0:27:50When we return this rock or some of the others like it to Houston,
0:27:50 > 0:27:52we'd like to share a piece of this rock with
0:27:52 > 0:27:54so many other countries throughout the world.
0:27:54 > 0:27:58We hope that this will be a symbol of what our feelings are,
0:27:58 > 0:28:01what the feelings of the Apollo programme are,
0:28:01 > 0:28:03and a symbol of mankind that we can live
0:28:03 > 0:28:06in peace and harmony in the future.
0:28:08 > 0:28:11Patrick, one more thing we have to talk about before we go.
0:28:11 > 0:28:15There was a total eclipse of the sun from Australia a few weeks ago.
0:28:15 > 0:28:18Beautifully clear over most of the eclipse, some great photos,
0:28:18 > 0:28:22including this video sequence I've been sent showing the sequences
0:28:22 > 0:28:25of the eclipse and totality itself,
0:28:25 > 0:28:28with the pearly-white corona, the sun's outer atmosphere
0:28:28 > 0:28:32shining out in what looks like a glorious eclipse.
0:28:32 > 0:28:35- Don't you wish we'd been there? - I wish we had.- Next time.
0:28:39 > 0:28:43Have you got a new telescope, or are you going to get one for Christmas?
0:28:43 > 0:28:47Next month I'll be giving you a few tips about how to set it up
0:28:47 > 0:28:51and how to use it. Until then, good night.
0:29:09 > 0:29:12Subtitles by Red Bee Media Ltd