"BBC Four Collections." "Specially chosen programmes from the BBC archive." "Good evening." "We've just had some amazing photographs sent back by the American probe to Mars - Mariner 6." "Mariner 7, by the way, has been brought back under control and we await news from that." "But meanwhile, we have this superb series of close-ups from Mariner 6 and I'd like to show you those pictures now, beginning with Mars, as 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." "And even so, you can see there some of the dark areas, which may be vegetation." "And at the bottom, you can see the white polar cap, which has always been thought to be some kind of icy or frosty deposit." "So let's go in now to 572,000 miles." "And this time, you can see there on the left of the centre of the picture that V-shaped marking, which is known to astronomers as the Syrtis Major." "It used to be called the Hourglass Sea." "And just in passing, all these pictures are shown with north at the top and south at the bottom, which is the way the Americans do it." "And again, there, you can see the polar cap." "Let's go in now to 463,000 miles." "And now the details are starting to be even more distinct." "And at the top, we can see the polar snows of the northern hemisphere." "At the moment, it's winter in the southern hemisphere of Mars and summer in the northern hemisphere." "And this, of course, explains why the southern ice cap is so much the larger of the two." "Now into just over 200,000 miles." "So that when this picture was taken, Mariner was closer to Mars than we are to the Moon." "And again, you can see the southern cap beautifully." "And you can note that the edge of the cap is not hard and sharp." "It appears to be rather jagged and this was something of a surprise." "But let's go in still closer to 156,000 miles." "And now the dark areas are showing up in all their firmness." "And in now to 126,000 miles." "And now you can see that the dark areas also haven't got such hard and sharp boundaries as might be thought." "But when Mariner went past Mars at only about 2,000 miles, we got the really spectacular pictures." "And just look at that!" "Craters on Mars, very similar to those of the Moon." "And the largest crater on that picture is about 160 miles across." "And remember, when Mariner took that picture, it was only about as far from the surface of Mars as we are from Moscow." "And I wonder how those craters got there." "What are they?" "Are they due to things hitting Mars?" "Or are they volcanic?" "I believe, myself, that most of them are likely to be volcanic, but I remain to be proved wrong." "And let me show you now the most spectacular of all these pictures sent back so far by Mariner 6." "And just look at that!" "It's a crater 24 miles in diameter, seen from 2,000 miles." "And just to give you an idea of scale, the area covered in that picture is about 63 miles by 48 miles." "And I think you'll agree that that crater on Mars is very similar to a crater on the Moon." "Well, of course, we did know that Mars had craters on it." "This had been shown by the previous American probe Mariner 4 some years ago now." "But nobody from Earth has actually seen them direct, because Mars is too far away." "But all the same, you can see Mars with the naked eye, if you want." "You can see Mars itself." "And if there are no clouds where you happen to be, you can go outside and see it now, because it's there, visible rather low down in the south west." "And if you know the right star Vega and the square of Pegasus in the east and Altair in the eagle, you can find Mars quite easily in the scorpion, not very far away from the bright red star Antares." "But, in fact, you can't confuse Mars with a star because it is very much brighter and, of course, it has got this strong red colour." "If you look at Mars through a moderate telescope, you can see these markings." "And, in briefly, I'd just like to show you three of the drawings that I made myself with my own 12-and-a-half-inch telescope earlier on this year." "And over there, on the right-hand picture, you can see again that V-shaped marking, which we call the Syrtis Major." "Again here, north is at the top." "Well, that marking is also shown on the Mariner pictures and here again is one of those Mariner shots taken from a long way out, showing the two polar caps and the Syrtis Major." "In fact, the markings of Mars, the dark ones, have always been something of an enigma." "We know quite definitely that they are permanent and you can draw maps of them." "And, in fact, I have got a Mercator map of Mars here, which I drew from my own observations." "There again is the Syrtis Major and Mariner 6 came down over this direction, over these so-called deserts." "Well, the question is, of course, are these dark areas due to organic matter, vegetation if you like, or are they not?" "And what about those polar ice caps?" "Well, these also have been photographed by Mariner very nicely." "And there again is the southern polar cap at the bottom." "And you can see indications of the northern one at the top of the picture." "And we've got some close-ups also of the southern cap." "And there the jagged edge is quite clear." "And the question is, are they due to some kind of icy or frosty deposit, or are they solid carbon dioxide?" "This is one of the things we hope that Mariner 6 and 7 are going to tell us." "Well, those are the pictures." "And I think you'll agree they are incredibly good." "But to get the latest news about Mars and Mariner," "I've just been in contact with the Jet Propulsion Laboratory in California and there I talked to Dr Pickering, who is, in fact, in charge of the investigation." "And I asked him about the latest news from Mariner and, in particular, what was the news about those strange, icy polar caps." "It appears as though the south polar cap, which photographs very well in the pictures, does have a sharp edge on its northern boundary." "And, in fact, when we look at this in detail, we see that the sharp edge appears to be following the outlines of some craters." "So that it must be on the ground and must be following the local topography." "And, on the other hand, the southern edge of this polar cap does not seem to go all the way to the pole." "And this is very curious." "I think it must be due to some sort of haze, which is covering the actual pole." "We hope that on Mariner 7 that we will get some close-up pictures of this area of the planet." "So that we will know much more about it after the flyby on Monday evening." "What do you think is the cause of the polar caps?" "Water ice or frost or solid carbon dioxide?" "Let's wait until we get a temperature reading!" "Which I hope we will do on Monday." "You know, we got some very good temperature readings from the infrared radiometer on the flyby last Wednesday night." "But that was more or less along the equatorial part of the planet." "This time, we will be conducting a flyby which will reach right down to the polar regions." "What other things have you got a particular interest in at the moment?" "Well, the other things I think that are of interest are the ultraviolet data." "This gives us some indications about the nature of the upper atmosphere." "And the fact that we found no nitrogen I think is very interesting." "Very interesting indeed." "And I think this question of the Martian atmosphere is all-important." "And, of course, these pictures have come in and already the experts are starting to discuss them." "And I'm glad to say we've got two of these experts here in the studio with us for this evening's Sky At Night." "We've got Dr Gilbert Fielder and we're also delighted to welcome back Professor Samuel Tolansky." "And I'm going to ask Professor Tolansky first what he thinks about these pictures and, in particular, what he thinks about the famous canals of Mars." "Well, I'm very particularly struck and intrigued of the fact that these pictures show great similarities to the Moon pictures." "We see an enormous number of craters." "And I think this ties up with the theory, which is a sound theory in my opinion, about how the Moon and Mars both originated at the same time." "This theory is this." "The Earth is supposed to have spun round very fast, like that." "And, in spinning, bulged at the equator." "Then, when bulging, the bulging increased and gradually instability set in and a little neck developed, something like an hourglass." "And, finally, a huge piece, about a tenth of the weight of the Earth, was thrown up." "This is Mars." "A smaller piece, about 1% of the weight of the Earth, was thrown off in between." "This is the Moon." "But at the same time, an awful lot of debris thrown around." "Now, according to this theory, the Moon and Mars should have the same structure, the same density as Earth rock." "And so they have." "They are very similar." "And it's probable that all the craters on the Moon were due to this debris pitting the Moon." "At least a lot of the craters was due to this debris pitting the Moon." "And it's very likely that this debris, the similar debris pitted Mars." "So you think, in fact, that these craters on the Moon and Mars were produced by a kind of bombardment?" "A lot of them." "A lot of them were, I think." "There may have been some of them which were volcanic, but a lot of them were." "And because of that, this is why I predicted that, on the Moon, there would be little marbles." "And I think there will be the same thing on Mars." "Only, they won't be circular." "They'll be peardropped, because of the atmosphere." "I don't think Dr Fielder quite agrees with you." "What do you think about it?" "Well, of course, there must be impact craters on Mars." "I think the point that I wish to make is that there may be more volcanic craters than people have been thinking." "Mars is close to the asteroid belt, where it will get bombarded more than the Moon, of course." "And there will, therefore, be more impact craters, one would expect, on Mars than there are on the Moon." "They may have been eroded out more quickly on Mars, however, because it has an atmosphere and water and so on and dust." "Well, if we look at some of the close-up pictures of Mars..." "This one here, for instance, shows a crater 24 miles in diameter and it is not quite circular, you notice." "It is slightly polygonal and there are many of these linear features on Mars, ridges and troughs." "The next picture will show a similar crater." "And these linear features are characteristic of things produced internally by tectonic forces and possibly volcanism." "We know this from a study of the Moon." "And, therefore, I think the evidence, based on these polygonal craters and these linear features, these linear troughs and graben and ridges is that there is at least some volcanism on Mars." "And I would be inclined to say there's probably quite a lot." "What about this question of the canals being strings of craters?" "Well, I don't believe there are canals." "I never did believe there are canals." "And it's my view that, in the past, people with insufficient resolving power have seen chains of craters due, probably, to meteors coming in along trajectories which are fairly common." "And the chain of craters, a line of craters, which you did not separate, would look like a line." "And as to why this changed in colour," "I think that's merely sandstorms." "There is an atmosphere." "There is probably a sandy surface." "And at different times of the year, sandstorms will change the colour of the surface." "Now, what about this all-important question of life on Mars?" "Do you think these dark areas are due to anything organic, Dr Fielder?" "I think the question is still to be resolved by use, principally, of spectrometers, which are carried, particularly infrared spectrometer and the ultraviolet spectrometer, on-board Mariner 6, which will look for bands in the infrared part of the spectrum," "which are known to be characteristic of organic molecules or plant life, if you like." "If these bands are found to be sharp and in the right places, then, by comparison with vegetation on Earth, we will know that there is vegetation on the surface of Mars." "What do you think about that?" "Primitive life, there may be." "I don't even think so." "Intelligent life, certainly not." "So you rather think that Mars is a dead planet." "Absolutely dead as a dodo." "And I suppose that is one of the things we'll find out fairly soon." "Well, another person who we asked about this was Professor Sir Bernard Lovell." "And we went up to his home in Cheshire and we asked him what he thought were the most striking features of these pictures of Mars sent back by Mariner 6." "Well, the most obvious feature of these Mariner photographs is, of course, the craters which we see." "And the surprising thing to me is not that there are so many of them, well, there aren't a lot more." "You see, Mars is much closer to the asteroid belt than the Earth and the Moon and calculations indicate that the rate of impact of asteroids on Mars has been about 20 or 25 times greater than that on the Earth and the Moon." "Well now, on Earth, why aren't we full of craters like this?" "The answer is a very simple one." "That, over a few thousand million years of our evolution, they've largely been weathered out and are now lakes or such things." "On the Moon, we still see them." "Now, on Mars, the situation is intermediate." "Mars has an atmosphere." "At the surface of Mars, the pressure is only a tenth of that on Earth." "But at a height of about 20 miles, the atmospheric density is about the same." "And, on the whole, one would have expected, I think, to see rather more craters than one sees on the Moon." "Therefore, I suspect that these features of Mars, which we're now seeing, are rather young." "By that I mean perhaps less than a thousand million years." "If this turns out to be the case, then the situation is extremely interesting, because it will give us important clues as to the changes which have occurred since Mars was formed from the primeval material." "Biologically, I don't think the situation has been changed very much by these photographs." "There must still be intense interest and importance attached to the future biological investigations." "You see, it's extremely likely that the planets Earth, Mars and Venus began their development in roughly the same form." "And in the beginning, at least, had the same type of atmosphere, because of the differences in mass and temperatures." "Because of their different distances from the Sun, there have been these vastly different atmospheres developed, where we have large amounts of carbon dioxide both on Mars and Venus and which are now not very favourable to life." "Nevertheless, it would be extremely important to investigate the existence of any primeval life forms." "Of course, we haven't yet got the full story." "And, in particular, we await the results of Mariner 7, which is going to pass over the Martian pole." "But already, we've learned much more about Mars than we have ever known before." "And I think now, in a few weeks at least, we ought to have an answer to that age-old question..." "Is Mars a dead world or is it a world where there are things which live and grow?" "Goodnight."