BBC The Sky at Night (1957) s24e00 Episode Script

Good evening.
We are going to go on a journey to Mars.
Now, Mars as a world, in some ways, is fairly similar to the Earth and always been of special interest, namely, I think, because of the chance of finding life there.
So, is there any life on Mars? We're still not sure, we're trying to find out.
Meanwhile, just for a moment, cast your mind back to the 1950s, science fiction enthusiasts had great fun with Mars, then.
Do you remember Quatermass? You know, when I was a boy, it was the great burning topic, were there really canals there and who made them? I remember my disappointment when somebody proved that Martians couldn't exist.
It's a funny word.
Worn out before anything turned up to claim it.
Martians.
Welcome now, Dr Chris Lintott.
Chris, I enjoyed Quartermass immensely.
I know you didn't see it in the original, but have seen it since, what do you think? It's fantastic - this vision of Mars as the place from which aliens come, which is right through 20th century sci-fi.
Even though we knew that there weren't aliens on Mars, we'd come a long way from the 19th century view.
Back then, observers with quite large telescopes were drawing elaborate canal structures on the planet, believing these were the products of advanced civilisations.
Pure affect of the eye.
Because there are dark patches on Mars, once thought to be seas and then thought to be tracts of low-type vegetation.
What you've got to remember, on Mars, the air is very thin, indeed, what we would call a vacuum.
It's also dry.
There's no water.
There's ice, but no water.
The question going into the space age was whether vegetation could survive on Mars.
I know the Sky At Night demonstrated pretty quickly what would happen if you tried to plant there.
We did.
We took two cacti.
One we kept under Earth conditions, the other we subjected to what we thought were Martian conditions.
This is what happened.
Well, it's rather unlikely, I think, that any of our higher terrestrial plants would survive under Martian conditions, although it's just possible that some very low leaf forms, which we've not yet tested, may.
To show you the fate of higher plants I've brought along tonight two cacti.
This cactus has been growing under Earth conditions.
And you see, it's quite a nice, firm-looking sort of cactus.
This one here has spent one night under Martian conditions.
I think you can see, without any doubt, that it's got a distinctly 'morning after' appearance.
Well, despite the lack of aliens, it's become very clear that Mars is a fascinating world.
But of course, it never comes much closer than 35 million miles, so we were bound to be limited.
The best way was to use space probes.
The first space probe went up in the early 1960s - both Russian and American.
The first real success came with America's Mariner 4, in 1965.
And like all the other early probes, this gave us a fleeting glimpse of Mars as it shot past.
It's much easier to do a flyby of the planet, than it is to slow down and go into orbit.
The early probes shot past and sent back what they could.
Mariner 4 saw some amazing things, nonetheless.
For example, it showed us the first real images of craters on the surface of Mars - something you couldn't see from Earth.
Then came those marvellous pictures from Mariner 6.
We've just had some amazing photographs, sent back by the American probe to Mars, Mariner 6.
Mariner 7 has been brought back under control, we await news of that.
Meanwhile, we have this superb series of close-ups from Mariner 6.
I'd like to show you those pictures now, beginning with Mars, a seen by Mariner, from a distance of more than 700,000 miles, which of course, is a great deal further than the moon is from the Earth.
Even so, you can see some of the dark areas, which may be vegetation, and at the bottom, you can see the white polar cap, which is thought to be due to some icy or frosty deposit.
And just look at that! The craters on Mars are very similar to those of the moon.
The largest crater on that picture is about 160 miles across.
Remember, when Mariner took that picture it was only about as far from the surface of Mars as we are from Moscow.
I wonder how those craters got there.
What are they? Are they due to things hitting Mars or are they volcanic? I believe myself most are likely to be volcanic, but I remain to be proved wrong.
Let me show you now the most spectacular of all these pictures sent back so far by Mariner 6.
Just look at that.
It's a crater 24 miles in diameter, seen from 2,000 miles.
Just to give you an idea of scale, the area covered in that picture is about 63 miles by 48 miles.
I think you will agree that that crater on Mars is very similar to a crater on the moon.
They may not look much compared to what we have now but those images are stunning.
It must have been wonderful to see such detail on a planet that's so frustrating through the telescope.
It teases you with detail.
You never see anything like this.
Suddenly you had Mars laid out for you.
Yes, don't forget, by sheer bad luck the first Mariners went over Mars in what we now know are the least interesting parts.
The first time I ever thought Mars might be a flat, dull kind of world.
It's not.
Mariner 9 showed that.
But it had problems on the way in of course.
Mariner 9 was supposed to go into orbit around Mars.
It did.
But it found a dust storm waiting for it.
Although the Martian atmosphere is so thin it evidently can produce dust.
We can seen dust storms before.
In fact, I, for one, was prepared for this because for some weeks now I've been watching it from my observatory way down in Sussex.
I've got three drawings here which will show, I think, more or less what I mean.
In September, before the dust storm started, with my telescope, I could see a great deal on Mars.
Here's one of the drawings I made then.
This shows the southern polar gap at the top.
It shows that rather V-shaped marking which we know as the Syrtis Major.
One of those markings we always thought to be due to vegetation, although they're not so sure now.
And above the Syrtis Major you can see a rather featureless area which we call Hellas.
And then, in October, the dust storms started.
There's a drawing that I made on October 4th.
This time, as you can see, the polar gap is very difficult to see and the other features are very much less clear.
Then the dust storm developed.
This last drawing was made this month, on November 1st, and there again, in the middle, you can see the V-shaped Syrtis Major but now you can only see a trace of it.
The entire southern part of the planet appears to be hidden by these swirling clouds of dust.
That is why, so far, we haven't had the spectacular pictures from Mariner 9 that we hoped we would.
Although, undoubtedly, they will come as soon as the dust clears.
Global dust storms like that encountered by Mariner are relatively common on Mars.
They certainly puzzled the Sky At Night back in 1971.
When you're talking about a planet like Mars, where the atmosphere is so extremely thin, approximately what we normally call a vaccum, just how can it hold particles in suspension? How could those particles be whipped up? Arthur, over to you, I know you have some ideas on this.
I've got a little demonstration here Patrick.
This is a magnetic stirrer.
In this little beaker on the top I'll put some fine silica dust.
If I then switch on the stirrer, which rotates the little bar magnet, I think you can see there's a considerable cloud of dust rising.
There certainly is.
Of course, this means that we've got here the thick atmosphere of the Earth.
This doesn't apply on Mars.
What puzzles me is how on Earth the Martian atmosphere manages to sustain a dust cloud.
So for this demonstration I've brought along a chunk of Martian atmosphere, which is inside this desicator, which has been evacuated to its 100th, Gilbert? Less than 100th .
.
atmospheric pressure.
If I can get this magnetic stirrer to rotate again in here There it goes.
There it goes.
We can see there isn't any dust coming up at all from there.
The atmosphere is not thick enough to sustain it.
Now to try and show we're not really cheating I will open this little cock on the top and let air in.
I have to do this very gently.
There we go.
Oh, yes, you see what happens.
That seems to be an experiment to prove there can't be dust clouds on Mars.
I don't understand it, Patrick.
It may simply mean that the dust particles on Mars are very much finer than anything we have.
Well, it was a good experiment, but we now know we got the atmosphere of Mars all wrong.
Yes, the composition is different from what you would have guessed then.
The dust is different, too.
It's smaller and finer grained that would otherwise have been expected.
That makes it easier to get up into the atmosphere.
These days we are used to dust storms, we see things like dust devils whipping across the Martian surface.
The winds are quite strong there, although not very much force because the air is so thin - barometric pressure below 10 millibars everywhere.
That's right.
Still, there's a quite evolved dynamic weather system.
In fact, the weather on Mars has become a research topic on its own.
Never mind the atmosphere.
What Mariner 9 really showed us were the glories of the planet.
For example, Olympus Mons.
Olympus Mons, a volcano taller than Mount Everest, much taller, and formally seen as the Olympic snow.
We didn't know what it was.
How could you not have realised it was a mountain? I mean this thing is taller than Everest.
How could you not have seen that from Earth? We simply could not see it clearly enough.
It merely appeared as a patch.
It might have been a lake or snow.
We really didn't know.
It took Mariner 9 to tell us.
Here it is.
Very interesting indeed.
You can see there the crater-like structure.
You can see it's got rather scalloped edges.
It is rather, obviously, a volcanic Caldera.
Here's another view of the Nix Olympica.
You can see there a very considerable amount of detail.
It looks very much like a volcano of the Hawaiian type, only the base is about 700 miles wide, which means it's even bigger than Hawaii.
Mars does seem to have been a world where volcanism has played a very, very important part.
Well, much as you'd liked to have visited Olympus Mons, that's a little difficult, even for the Sky At Night.
You did do the next best thing - visiting Mount Teide in the Canary Islands back in 1973.
I have to say, it looks pretty Martian to me.
Now, how do you think Teide matches up with a Martian caldera? I think very exactly.
One looks at the beautiful pictures taken by Mariner 9.
Looking straight down on the top of Nix Olympica, for example.
Here is a case of a caldera just like this one.
Active in the only recent past, I would imagine.
Would you say, Ron, looking as we are now, round the caldera of Teide that we are looking at a small version of the scenes that may be found when explorers finally go to Mars? I'm fairly sure, without the vegetation, without the blue sky, this is a typical solar system view.
Filming outside did pose a few problems for you, Patrick.
I'm sorry.
I had hat problems.
THEY LAUGH Hazards of filming, I think, Patrick.
You could see that.
Blast and hell! Well, Mariner 9 was a great step forward.
What you really want to do is to land and see what Mars is really like.
That brings us on to the Viking programme.
Yes, landing on Mars is a bit of a nightmare.
It's something that has challenged space agencies throughout the history of exploration.
The Russians had tries.
They had one success, Mars 3.
Not really a success.
It lasted for 15 seconds on the surface.
Yes.
So we'll give them some credit.
Yes.
But it's the challenge of getting through Mars' thin atmosphere.
It's not thick enough, like the Earth's, to allow you to brake on parachutes, the way the Apollo astronauts did, Nor is it thin enough to allow you to land with rockets, like they do on the moon.
It's a real problem.
The first to crack it, as you say, were the Vikings.
But selecting a landing site for the two Viking craft proved difficult.
They needed as flat an area as possible, clear of any possible hazard.
Let's begin by seeing what would happen if Viking came down in a permafrost area.
You can see what would happen.
It would put the spacecraft out of action.
In the end, both Viking craft landed safely in July 1976.
Touchdown.
We have touchdown.
CHEERING AND APPLAUSE We have, of course, landed on the surface of Mars and taken pictures both immediately after landing and again since then.
The first pictures to come back were startling.
This is Mars.
Incredible pictures sent back from Viking, showing a red, rock-strewn landscape under a pink sky.
The detail is absolutely amazing.
These pictures would have seemed science fiction not so very many years ago.
Let me show you the first picture ever received from the Martian surface itself.
There again, we see the rock-strewn landscape.
We realise how incredibly fortunate it was, as well as skilful, that Viking came down safely.
There we can see the landing pad.
We were discussing this in our last Sky At Night programme, before Viking became came down, when we were by no means sure whether the landing would be successful or not.
Well, it has been.
Viking is now standing in the Plain of Chryse.
It's working.
It's sending back information.
I was most impressed when looking at this superb panoramic view taken from the spacecraft, which I think is the most amazing picture sent back yet.
Just look at the detail.
But now, coming into view, as well as the spacecraft, we can see things which look remarkably like sand dunes.
They look so like sand dunes, I don't really think they can be anything else.
Wouldn't you agree, Geoffrey? Indeed.
Those are beautiful sand dunes, with the wind coming from the left across the picture, producing very nice streaking and sharp edges - quite characteristic of sand dunes.
Viking is now standing upon the Martian surface.
It will not come back.
It can never move again.
All it can do is to send us back information.
I think we have to wait a long time yet before we have a probe which can go to Mars and bring back samples.
That lies in the next decade or possibly the decade after that.
Well, that didn't happen.
No sample and thermoprobe quickly.
It hasn't happened even yet.
But don't forget the Viking orbiters.
They went on going round Mars and sending back priceless data, particularly about those polar caps.
Yes.
The orbiters are often overlooked, overshadowed by the landers which get all the glamorous attention.
They looked closely, in particular at the polar caps, these white areas that we'd seen wax and wane with the Martian seasons in the telescope.
The question was, what kind of ice is this? What are the polar caps made of? Was it thin layers of carbon dioxide ice? Was it a thick layer of carbon dioxide ice? Well, Viking told us.
It certainly strengthened my views because the most startling thing that's happened has been this northern polar cap, apparently the residual cap being composed of water vapour and not the carbon dioxide ice.
This is staggering.
When you look at the north polar cap, it gives the impression of being water ice.
We now believe that that is precisely what it is - an ice cap.
Certainly, the amount of water found above the ice cap is about 20 times we find in the Equator, and the surface temperature is about 20 or 30 degrees too high for CO2 ice to form, so we're sure we're looking at a layer of water ice.
The fact the polar caps really were water ice made the chances of life there decidedly brighter, and it was designed to find out.
That's right.
The Viking landers made an audacious attempt to try and directly detect the signs of life at their landing sites.
It was a long shot, and I'm not sure what people expected to find, but I'm sure they didn't expect the results they got.
They were looking for the types of chemical reaction that you expect if you have very simple life in the soil.
We're not taking aliens or plants, we're talking bacteria.
They found unusual chemical reactions.
But on the other hand, what was missing was any of the building blocks of life - none of the complicated molecules we'd expect, no organics.
So we have this mysterious picture left at the end of the Viking mission where something unusual is happening in the Martian soil, but who knows what it is? After Viking, there was a surprising hiatus.
Some probes were going elsewhere.
I think Mars was temporarily pushed rather into the background.
Then, in 1997, back to Mars with Pathfinder and Sojourner.
Pathfinder came down in July 1997, in the region of Ares Vallis, thought to be an old floodplain, which indeed it is.
It has rocks of various kinds.
Pathfinder sent back pictures, and the little Sojourner rover crawled round inspecting and analysing the various rocks.
They sent back amazing data.
The Sojourner rover went around analysing with its X-ray instrument the chemistry of the surrounding rocks, and you can see, in this vertical picture of the site, a composite picture, you can see a large boulder top right, with the little Sojourner jammed up against it, sticking its snout there, analysing that rock for its chemical components.
One of the first things that Sojourner showed us was that on Mars we not only have basaltic lavas, like many we have on the Earth, but also rocks called andesites, which are chemically different.
This was the first new piece of information that we got.
Pathfinder and Sojourner were the first of the new wave of Martian exploration.
They were followed by Mars Global Surveyor, which went into orbit in September 1997 and lasted for almost a decade.
We have ignition and liftoff of a Delta II rocket carrying NASA on an odyssey back to Mars.
It was quickly followed by Odyssey, which detected the signatures of large volumes of water ice under the soil, not just under the polar caps, but down towards the Equator, too.
Next, Mars Express.
Yes, this was the European mission, of course, most famous in the UK as Beagle's parent mission.
Beagle, sadly, didn't make it down to the surface intact, or at least never told us if it did.
But Mars Express has been a great success for all sorts of reasons.
It discovered water again - it looked directly at the polar caps and confirmed there was water there - but it also gives us the ability to see Mars in three dimensions.
It has a stereo camera, so you can produce three-dimensional maps of the surface.
We can go flying around the surface of some of the great valleys of Mars, and that's a stunning legacy for Mars Express, which is still working well.
To my mind, all these were eclipsed by those two splendid rovers, Spirit and Opportunity.
Spirit was the first.
It landed on Mars, in 2004, in the Crater Gusev, which is certainly an ancient lake.
Yes.
We know that because of the work that Spirit's done.
These rovers were supposed to last for 90 days, that was the warranty, and yet they both lasted more than five Earth years on the surface of the planet.
It's an incredible achievement.
The rovers were designed to look for clues that would tell us what the environment was like.
When we went into this, I never liked taking the attitude, "We're going there to find evidence of water.
" That's the wrong attitude to take.
That's not science.
Mars is what Mars is.
Our job is to go there and find out what Mars was like.
If it turned out that Mars had never had water at these two sites, so be it.
Spirit landed successfully, got off the lander just fine and everything worked, but we landed on lava.
I believe there are sentiments that were laid down in the lake in that crater, but a lot can happen in three or four billion years.
After the sentiments were laid down there were lavas deposited on top of them.
That was what Spirit landed on.
We came looking for evidence of water, all we were finding was volcanic rocks.
Opportunity, on the other hand, rolled to a stop inside a little tiny 20 metre-diametre impact crater.
We opened our eyes.
We looked.
The very first thing we saw, seven metres away in the wall of that crater was the spectacular outcrop of a layer of bedrock.
Within just weeks we drove over to it.
We found it was largely made of sulphate salts.
We found ripples.
Evidence for water.
All of that.
I mean, it just all happened in six weeks.
It was remarkable.
16, 17 months later we are sitting here and the rovers are working well.
They are working extraordinarily well.
Yeah.
The thing that we thought was going to kill them was dust on the solar arrays.
Mars is a very dusty place.
The dust is in the atmosphere.
It settles out of the atmosphere.
It coats everything.
The day that Spirit landed the solar rays were putting out about 900 watt hours of power.
That's enough power to run a 100 watt lightbulb for nine hours.
OK? As the dust built up it went down, and down, and down.
We got down to 350 watt hours.
We think that death is about 250.
It was getting close to the end.
It really was getting close to the end.
Then one glorious day, we got hit by this gust of wind.
It was just a blast of wind.
Nothing more.
Cleaned off the solar arrays.
As of like two days ago Spirit was producing more solar power than the day we landed.
Because the wind has cleaned it off.
The sun is in a more favourable part of the sky right now.
Coming back into the Martian summer.
Yes.
It's the middle of summer time.
We've got so much electrical power on Spirit right now we have to shut her down for about an hour and a half to two hours every afternoon to take a nap to keep them overheating.
Wow.
When I next caught up with Steve a year later, Opportunity had arrived at a breathtaking new site.
Victoria crater.
We spotted Victoria as a target the night that we landed.
There was this monstrous crater.
800 metres in diameter.
We had no idea how deep it was.
It turns out it was 75 metres deep.
I remember the night we landed.
Joking about, "Wouldn't it have been cool if we had landed there instead?" Never thinking we would have a chance to drive that far.
But after 21 months of struggling across the dunes and the drifts, we finally arrived at the rim of Victoria crater.
The place is just spectacular.
What sticks in my mind is this incredible image of Opportunity from above.
Oh, yes, that was very special.
This marvellous camera called High Rise on the Mars Reconnaissance Orbiter space aircraft was turned on and operated really for just about the first time at Mars.
The resolution of that camera is phenomenal, it's about 30 centimetres per pixel.
So you could see the rover.
You can see the rover tracks.
You can see the tracks, the rover itself.
You could see the high-gain antenna on the rover deck, it's phenomenal.
That imageit's hard to describe.
My reaction, when I saw it, it was so good to see the rover again.
If you thought that was impressive, Mars Reconnaissance Orbiter had another trick up its sleeve.
As it prepared for the arrival of NASA's next probe, Phoenix.
Phoenix was going to touch down in the Martian Arctic.
But MER-A managed to capture an image, not of Phoenix on the surface, we got that later, but of Phoenix on the way in.
This is the Phoenix probe hanging below its parachute as it's descending towards the surface of Mars captured by MRO in orbit looking down on the scene.
I think this photo is one of the most stunning technological achievements that the space race or the space age have ever produced.
It must be.
Phoenix was different.
It was not a rover.
It was a lander.
It came down.
It stayed where it was.
It had various tasks, in particular looking for underground ice.
Each succeeding mission had got us closer to Martian water.
What we really wanted to do was sample it directly.
This was Phoenix's mission.
Touch down signal detected.
By the time we got to Mission Control in Arizona it had already been successful.
We are doing really well.
We are meeting our goals and are on track.
One of the greatest thrills was looking back under the lander and seeing the thrusters had cleaned off the ice layer.
That what was we were looking for.
We were told there was ice from the orbiters.
The theory says it will be down five centimetres.
We look underneath and the thrusters had done our job for us.
Before you started digging, you knew there was ice there.
Even before we started digging, we didn't have to dig an inch.
We can't reach that ice because the struts and things under the lander prevent the arm going under there.
It's there, but we can't touch it.
Well, that's a steep back wall, isn't it? Yeah.
That really did dig inat the front there? When I returned to Mission Control a few months later, Phoenix was already feeling the chill of the harsh Arctic winter.
The temperature has been dropping during the summer.
The high temperature in the warmest part of day was maybe minus 20 degrees centigrade.
Now, it's down minus 30, minus 35.
The nights are getting very cold.
It could be minus 100, 110.
It's headed down to minus 130.
That will be the temperature throughout the entire day in the winter.
Minus 130.
Just a few short months after that visit to Mission Control, Phoenix's life was over as it was encased in the winter ice cap.
Like each of its predecessors, it had given us one small piece of the Martian puzzle.
We certainly know much more now than we did in the days when the first spacecraft flew past the Red Planet.
The really big question remains unanswered.
Is there life hiding somewhere on Mars? Phoenix is still there and also the other probe we sent to Mars.
They'll stay there quite passively.
In 50 years' time what would have happened? Will there be bases on Mars? Will there be cricket on Mars? Time will tell.
On Mars, bowlers have to contend not just with the lower gravity, but with lower atmospheric pressure as well.
It makes it really hard to get a swing on the ball.
Although it is travelling much faster when it reaches the batsman.
The down side is that if the batsman connects with it, it's really easy for him to hit a six.
CHEERING A fine shot for four runs.
No mistake.
Good night.