1 00:00:30,000 --> 00:00:37,360 This Russian was in his youth one of the first men to gaze on the scene of perhaps the most 2 00:00:37,360 --> 00:00:42,080 awesome destruction ever wrought on the face of the earth, and he's lived with the riddles 3 00:00:42,080 --> 00:00:45,360 he found there ever since. 4 00:00:45,360 --> 00:00:53,280 Fifty years ago he set out by horse and sledge across the frozen wastes of Siberia to investigate 5 00:00:53,280 --> 00:00:57,880 the great catechism of Tunguska. 6 00:00:57,880 --> 00:01:04,200 Before on the morning of June 30th 1908 something came hurtling out of the sky, an enormous 7 00:01:04,200 --> 00:01:09,800 ball of fire which exploded above the Siberian forest with a sound that was heard a thousand 8 00:01:09,800 --> 00:01:15,480 miles away and a blast that laid waste the trees over an area the size of London and 9 00:01:15,480 --> 00:01:23,400 New York put together. 10 00:01:23,400 --> 00:01:30,880 For weeks afterwards the nights in Europe were almost as bright as day. 11 00:01:30,880 --> 00:01:34,480 These pictures were taken after midnight. 12 00:01:34,480 --> 00:01:39,640 A lifetime later the theories still abound about what it was that came out of the sky 13 00:01:39,640 --> 00:01:41,360 that June day. 14 00:01:41,360 --> 00:01:47,400 Was it a colossal meteorite, a black hole from interstellar space, an atomic bomb long 15 00:01:47,400 --> 00:01:50,040 before such bombs were invented? 16 00:01:50,040 --> 00:01:54,440 Could it even have been a spaceship? 17 00:01:54,440 --> 00:02:00,600 A mystery from the files of Arthur C. Clarke, author of 2001 and inventor of the communication 18 00:02:00,600 --> 00:02:03,520 satellite. 19 00:02:03,520 --> 00:02:09,720 Now living in Sri Lanka he has studied the enigma of the great Siberian explosion. 20 00:02:09,720 --> 00:02:19,400 So imagine that as I'm standing here that thing detonates five miles above us. 21 00:02:19,400 --> 00:02:24,400 Well, there would have been a flash in the sky so brilliant that by comparison the sun 22 00:02:24,400 --> 00:02:27,080 is a feeble electric light bulb. 23 00:02:27,080 --> 00:02:34,120 The flash of light and heat would have boiled the sea around us and set the city on fire 24 00:02:34,120 --> 00:02:36,040 instantly. 25 00:02:36,040 --> 00:02:42,960 In the blast wave the concussion, you can't use the word sound, just a devastating pulverizing 26 00:02:42,960 --> 00:02:48,160 concussion would have flattened all the buildings except possibly the one immediately beneath 27 00:02:48,160 --> 00:02:54,000 the explosion which might have stayed upright as indeed in Hiroshima buildings directly 28 00:02:54,000 --> 00:02:57,400 under the center of detonation remain standing. 29 00:02:57,400 --> 00:03:03,320 But what we're talking about now is something one thousand times more devastating than the 30 00:03:03,320 --> 00:03:05,320 first atom bomb in Hiroshima. 31 00:03:34,320 --> 00:03:39,760 More than 70 years after the great Siberian explosion the scientists still come together 32 00:03:39,760 --> 00:03:42,960 to puzzle over that catastrophic event in 1908. 33 00:03:42,960 --> 00:03:50,040 Dr. Nikolay Vasiliyev and Professor Alexander Dolgov have flown in from Tomsk and Novosibirsk 34 00:03:50,040 --> 00:03:53,520 to meet at the Soviet Academy of Sciences. 35 00:03:53,520 --> 00:03:59,680 Professor Yavnol comes from the meteorite committee of the USSR and Dr. Leonid Khrinov, 36 00:03:59,680 --> 00:04:11,120 one of the first scientists to reach the site is still active. 37 00:04:11,120 --> 00:04:16,960 The discussions go on because to this day they are still not sure what happened in the depths 38 00:04:16,960 --> 00:04:23,040 of the Siberian wilderness on that June morning. 39 00:04:23,040 --> 00:04:28,720 The investigation into the mystery of the Siberian explosion began in 1921 just after 40 00:04:28,760 --> 00:04:30,320 the Russian Revolution. 41 00:04:30,320 --> 00:04:34,720 The Academy of Sciences was one of the first institutions to be set up by the Bolsheviks 42 00:04:34,720 --> 00:04:37,200 in Petrograd, now Leningrad. 43 00:04:37,200 --> 00:04:42,040 And it was decided that the new scientific socialism should also be in the vanguard of 44 00:04:42,040 --> 00:04:49,560 the natural sciences. 45 00:04:49,560 --> 00:04:54,320 The Academy gave a commission to a young scientist called Leonid Kulik to investigate 46 00:04:54,320 --> 00:04:58,680 the falls of meteorites on the territory of the USSR. 47 00:04:58,680 --> 00:05:04,360 A friend showed Kulik an eyewitness story on the back of an old calendar, his first hint 48 00:05:04,360 --> 00:05:08,960 of the extraordinary happening 13 years before in 1908. 49 00:05:08,960 --> 00:05:10,760 It was a strange time. 50 00:05:10,760 --> 00:05:15,840 Far away in England, the Daily Express of July 3rd, 1908 reported the weird happenings 51 00:05:15,840 --> 00:05:18,440 of an already unusually hot summer. 52 00:05:18,440 --> 00:05:23,240 It said, the extraordinary occurrence of night trains running over the Grampian Hills without 53 00:05:23,280 --> 00:05:28,520 lights took place for the first time on record. 54 00:05:28,520 --> 00:05:33,040 A golfer wrote to The Times saying it was light enough for play on the links at Brankester 55 00:05:33,040 --> 00:05:35,160 in Norfolk at 11 p.m. 56 00:05:35,160 --> 00:05:38,000 And he himself was aroused at 1.15 a.m. 57 00:05:38,000 --> 00:05:42,320 and could read a book in his chamber quite comfortably. 58 00:05:42,320 --> 00:05:46,840 This photograph of Whitkirk Church in Leeds was taken long after what should have been 59 00:05:46,840 --> 00:05:49,080 dusk. 60 00:05:49,080 --> 00:05:56,080 And this houseboat at Gloucester was snapped towards midnight. 61 00:05:57,720 --> 00:06:04,720 What people took to be the northern lights lit up the whole east coast. 62 00:06:06,080 --> 00:06:11,000 The Royal Meteorological Society reported an extreme shock in southern England, followed 63 00:06:11,000 --> 00:06:18,000 by the vibrations of an air blast which travelled twice around the world. 64 00:06:20,120 --> 00:06:25,120 Culek found similar evidence in the local press of Siberia. 65 00:06:25,120 --> 00:06:32,120 The Tomsk paper thought a meteor had struck. 66 00:06:35,120 --> 00:06:40,600 Armed with these few details, Culek set off on the Trans-Siberian Railway from Petrograd 67 00:06:40,600 --> 00:06:46,520 across European Russia and half of Siberia to the small station of Tyshet. 68 00:06:46,520 --> 00:06:53,520 There he and his helpers left the train and set off towards the Angara River. 69 00:07:01,560 --> 00:07:06,080 From there on they had only horse and boat to take them through the ice and snow of the 70 00:07:06,080 --> 00:07:11,160 Siberian Forest, the Tiger. 71 00:07:11,160 --> 00:07:16,320 There were endless river crossings made more hazardous by the spring thaw. 72 00:07:16,320 --> 00:07:21,080 Eventually accompanied by the great Soviet cameraman Strukov, they reached the tiny trading 73 00:07:21,080 --> 00:07:28,080 post of Vanavara. 74 00:07:28,480 --> 00:07:33,520 The local people were fur traders, Mongols of the Ivanky tribe, with hunting territory 75 00:07:33,520 --> 00:07:36,640 running up the Timbuska River. 76 00:07:36,640 --> 00:07:42,400 It was now 20 years since they had experienced the extraordinary event of 1908, but as Dr. 77 00:07:42,400 --> 00:07:49,400 Khrinov recalls they still had the most vivid memories. 78 00:07:51,280 --> 00:07:54,960 Well there was Luchat Kansmyanov. 79 00:07:54,960 --> 00:08:00,680 I questioned him and he told me in detail how he was held from his porch by the wave 80 00:08:00,680 --> 00:08:02,240 of air. 81 00:08:02,240 --> 00:08:07,720 He was literally thrown from his porch and he lost consciousness. 82 00:08:07,720 --> 00:08:13,520 His daughter, a young girl, was at the time with her friend down by the stream and when 83 00:08:13,520 --> 00:08:20,520 they heard the thunder and all the explosions they ran back home and saw him lying on the 84 00:08:20,520 --> 00:08:24,720 ground. 85 00:08:24,720 --> 00:08:30,440 Another eyewitness was on the far side of his hut, hammering something or other there. 86 00:08:30,440 --> 00:08:37,440 So he was shielded by the hut from the place where the radiation came from. 87 00:08:40,400 --> 00:08:45,520 But he felt that his ears had been scorched just as if he had walked into a hot, fiercely 88 00:08:45,520 --> 00:08:47,480 heated steam bath. 89 00:08:47,480 --> 00:08:52,000 His ears were scorched and he grabbed himself by the ears and ran inside. 90 00:08:52,000 --> 00:08:59,000 Well by that time everything had already finished. 91 00:09:00,880 --> 00:09:07,880 At Vanavara, Kulik's expedition set about building small boats which could take them 92 00:09:12,960 --> 00:09:18,320 upriver towards the area where the locals said the explosion had happened. 93 00:09:18,320 --> 00:09:23,040 There were many privations. Negotiating the rivers needed all the skills the local porters 94 00:09:23,040 --> 00:09:28,520 could muster. At one point Kulik himself, with Stukov still filming, lost control of 95 00:09:28,520 --> 00:09:33,040 his boat and was almost swept away. 96 00:09:33,040 --> 00:09:37,720 It was the end of May before they made any significant progress. At one stage the porters 97 00:09:37,720 --> 00:09:44,720 refused to go on towards a place they still viewed with some terror. 98 00:09:58,520 --> 00:10:05,520 At last they reached the quieter waters of the Upper Tunguska and finally the junction 99 00:10:12,240 --> 00:10:19,240 with the river Chombi. 100 00:10:19,240 --> 00:10:26,240 From its southern bank they could see that the tops of all the trees had been sheared 101 00:10:30,040 --> 00:10:35,400 off. They crossed the river and climbed through the battered forest to be confronted at the 102 00:10:35,400 --> 00:10:42,400 top of a ridge by a chilling site. 103 00:10:43,400 --> 00:10:49,400 As far as the eye could see the trees lay like an annihilated regiment in serried rows, 104 00:10:50,160 --> 00:10:57,160 victims of some unimaginable slaughter. 105 00:10:59,160 --> 00:11:06,160 The Taiga, the mighty Siberian Taiga, had everywhere been thick and without any clearing 106 00:11:06,160 --> 00:11:13,160 or glades. But here we suddenly saw this place where the forest had been flattened 107 00:11:14,400 --> 00:11:21,400 for many kilometers. The young trees that had grown after the event were still not very 108 00:11:24,160 --> 00:11:31,160 tall and therefore they were covered by the snow. It was this that made the first and 109 00:11:31,400 --> 00:11:38,400 strongest impression. We clearly saw the dimensions of the destruction. Of course this made a shattering 110 00:11:45,760 --> 00:11:54,760 impression of Kulik, Krenov, Strukov and their helpers pressed on day after day through 111 00:11:54,840 --> 00:12:00,040 the debris of bare and fallen trees. They had no idea how far they would have to go 112 00:12:00,040 --> 00:12:07,040 to find the center of the devastation. They made camp, living as best they could with limited 113 00:12:15,080 --> 00:12:22,080 supplies, off the land and the water. Though even fishing had its hazards. 114 00:12:30,600 --> 00:12:37,600 Eventually, after fighting their way for more than 60 miles through the tangled mess of fallen 115 00:12:39,040 --> 00:12:45,480 trees and new growth, they reached 20 years after the event the heart of the explosion. 116 00:12:45,480 --> 00:12:51,240 Kulik was to call the place the Tunguska South Swamp, the center of 1000 square miles of 117 00:12:51,240 --> 00:12:58,240 devastation. Convinced a meteorite must be the cause of the 118 00:13:00,040 --> 00:13:06,520 cause, Kulik immediately began surveying the mosquito-ridden swamp. He thought that pieces 119 00:13:06,520 --> 00:13:11,480 of the object which had caused such immense damage might be found in peculiar pits in 120 00:13:11,480 --> 00:13:18,480 the swamp. His men drained the pits and excavated them without result. 121 00:13:19,080 --> 00:13:26,080 This tree stump at the bottom of one hole was proof that this at least couldn't be a crater 122 00:13:27,080 --> 00:13:33,080 caused by a meteor. Kulik persisted, but not a trace of a meteor was ever to be found. 123 00:13:33,080 --> 00:13:38,080 Then the weather deteriorated. 124 00:13:38,080 --> 00:13:45,080 So few provisions were left that I set off with one man to find the center of the devastation. 125 00:13:49,080 --> 00:13:56,080 For the Vanavara trading post with squirrel skins to trade for money to buy food. 126 00:14:02,440 --> 00:14:08,560 Kulik stayed behind with two men and he was forced to kill a dog to eat, though men with 127 00:14:08,560 --> 00:14:15,560 supplies did eventually arrive. 128 00:14:16,160 --> 00:14:23,160 I myself got frostbitten and the men who traveled with me also got frostbite in his feet and 129 00:14:24,280 --> 00:14:31,280 we were forced to go to the hospital at Kezhner where we spent two months. 130 00:14:31,440 --> 00:14:38,440 Well what was the thing that detonated above the Siberian swamp in 1908? 131 00:14:38,840 --> 00:14:44,000 We know end of theories. One is that it was a rather small lump of antimatter, perhaps 132 00:14:44,000 --> 00:14:50,520 only a few pounds. Antimatter is material which has its atoms oppositely charged from 133 00:14:50,520 --> 00:14:54,440 those of our ordinary terrestrial matter. So if a pound of antimatter meets a pound of 134 00:14:54,440 --> 00:15:00,240 ordinary matter, the two annihilate each other giving a colossal explosion. The other is 135 00:15:00,240 --> 00:15:05,040 that it was a very small black hole if such things exist. And that's a very small, perhaps 136 00:15:05,040 --> 00:15:10,320 too small to be seen, but yet still weighing millions and millions of tons. Again if a 137 00:15:10,320 --> 00:15:14,920 thing like that plowed into the earth it would go right through our planet and cause a colossal 138 00:15:14,920 --> 00:15:21,120 explosion at the point where it entered and the point where it went out. The remarkable 139 00:15:21,120 --> 00:15:28,120 similarity between the Tungastka event and the after effects of the Hiroshima bomb has 140 00:15:28,800 --> 00:15:33,960 prompted many people to suggest that it was some kind of nuclear explosion. The heat flash 141 00:15:34,000 --> 00:15:39,480 was very similar. Trees at Tungastka were charred on the side towards the explosion, 142 00:15:39,480 --> 00:15:43,600 but on the shadow side they were comparatively unaffected. Exactly the sort of thing that 143 00:15:43,600 --> 00:15:50,600 happened at Hiroshima and Nagasaki. Well how could one have a nuclear explosion 40 years 144 00:15:51,040 --> 00:15:57,720 before we had invented the atom bomb? Well perhaps a visitor from space had engine trouble 145 00:15:57,720 --> 00:16:02,920 and tried to make a forced landing on our earth and didn't make it, but blew up five 146 00:16:02,960 --> 00:16:08,040 miles above the surface. There's been at least one book written on this subject and a lot 147 00:16:08,040 --> 00:16:15,040 of science fiction stories and it is a plausible theory and certainly a very romantic one. 148 00:16:16,760 --> 00:16:21,600 But this romantic theory is still considered seriously by respectable scientists, particularly 149 00:16:21,600 --> 00:16:28,600 in the Soviet Union. This is Soviet academician Alexei Zolotov. The Tungastka explosion took 150 00:16:29,600 --> 00:16:36,600 place in the air. There exist only two possibilities for such an explosion. Either it came from an 151 00:16:36,600 --> 00:16:42,600 internal energy source in the body or from the natural energy caused by its movement. 152 00:16:42,600 --> 00:16:49,600 I believe it was a nuclear explosion from an artificially made object. 153 00:16:50,600 --> 00:16:57,600 The spaceship theory was born after the atomic bomb explosions of the 40s and 50s. The devastation 154 00:17:01,680 --> 00:17:07,040 caused by the bombs dropped on Japan was remarkably like that at Tungastka. The concrete 155 00:17:07,040 --> 00:17:12,560 buildings at the center of the Nagasaki blast still stood upright, as did the trees at the 156 00:17:12,560 --> 00:17:19,000 center of Tungastka. The charring of the trees, even signs of radiation at Tungastka, resembled 157 00:17:19,000 --> 00:17:26,000 atomic bomb after effects. Kulik was killed by the Nazis during the Battle of Moscow. 158 00:17:32,760 --> 00:17:37,520 And it was 1958 before the first post-war expedition was mounted. It was now possible 159 00:17:37,520 --> 00:17:44,520 to get by air to Vanavara. But the team still had to use precarious and inadequate boats 160 00:17:45,120 --> 00:17:52,120 and needed the help of the local reindeer herdsmen to carry their supplies. They also needed 161 00:17:52,520 --> 00:17:59,520 plenty of determination before they were able to get back to Kulik's original site. 162 00:18:07,120 --> 00:18:14,120 Although the new growth theory was not yet clear, the Tungastka explosion was not yet 163 00:18:14,520 --> 00:18:21,520 clear. The mass in the tiger was now 50 years old. The devastation was still very plain. 164 00:18:31,960 --> 00:18:36,960 Again there was the vile work of surveying and testing in the most impossible terrain, 165 00:18:36,960 --> 00:18:43,960 assorted still by summer insects. Slowly the evidence built up, but there was still 166 00:18:48,760 --> 00:18:55,760 no sign of any debris from the Tungastka blast, except for tiny globules of silica and metal. 167 00:18:56,800 --> 00:19:02,840 Carefully packed to be sent back for analysis, they were to provide an important clue. There 168 00:19:02,840 --> 00:19:08,460 were continuing echoes of a nuclear explosion. In the first place it was clear that the Tungastka 169 00:19:08,460 --> 00:19:15,080 blast, like that at Hiroshima, had been an air burst. No one had thought of that in 1928. 170 00:19:15,080 --> 00:19:21,980 But the Russians decided to check with a precise experiment. It was true. Whatever devastated 171 00:19:21,980 --> 00:19:28,980 the tiger in 1908 had exploded about 8 kilometers, 5 miles, up in the air. Out in the forest 172 00:19:29,980 --> 00:19:35,980 the researchers returning every year now by plane and helicopter and armed with sophisticated 173 00:19:35,980 --> 00:19:42,980 equipment, found extraordinary genetic effects. There seemed to be several mutated species 174 00:19:42,980 --> 00:19:49,980 of insects. And among the devastated skeletons of the trees, there were some which had survived. 175 00:19:50,980 --> 00:19:57,980 When these were felled, the tree rings showed a dramatic increase in growth after 1908. 176 00:19:57,980 --> 00:20:04,980 This effect had also appeared in Hiroshima. Whether or not this was due to nuclear radiation, 177 00:20:04,980 --> 00:20:08,980 the man who today leads the yearly expeditions to the tiger, Nikolai Vasilyev, is certain 178 00:20:08,980 --> 00:20:15,980 there is what he calls electromagnetic chaos. Right up to the present time we have been 179 00:20:16,980 --> 00:20:23,980 investigating certain geophysical and biological effects which are not observed when normal 180 00:20:24,980 --> 00:20:31,980 meteorites fall. In particular, the genetic pattern has been violated. This violation is 181 00:20:31,980 --> 00:20:38,980 to be seen in certain species of plants and in particular in the pine trees. There is 182 00:20:39,980 --> 00:20:44,980 certainly some new type of radiation here. The explosion of a cosmic body seems to have 183 00:20:44,980 --> 00:20:51,980 produced this new type of radiation field on the ground at the center of the blast. 184 00:21:01,980 --> 00:21:06,980 The discussion continues among the experts and volunteers at the annual summer camps. 185 00:21:07,980 --> 00:21:11,980 It has become apparent that the little globules they have collected contain elements that 186 00:21:11,980 --> 00:21:18,980 could only have come from outer space. Slowly many scientists have come around to a theory 187 00:21:18,980 --> 00:21:24,980 first proposed in the 30s by an Englishman, Frank Whipple, and dismissed then as far too 188 00:21:24,980 --> 00:21:29,980 fanciful. His theory was that for the only time in all our knowledge the earth had been 189 00:21:29,980 --> 00:21:39,980 struck by a comet. Comets are among the most romantic objects in the universe. Great shining 190 00:21:40,980 --> 00:21:45,980 bodies with tails thousands of miles long, sweeping through the solar system and turning 191 00:21:45,980 --> 00:21:51,980 around the sun, either to disappear forever or to return to our view only after many years. 192 00:21:53,980 --> 00:21:57,980 But the comet theory doesn't convince academician Zolotov. 193 00:21:59,980 --> 00:22:05,980 The main argument against it being a comet is the fact that the cosmic body was apparently 194 00:22:05,980 --> 00:22:11,980 moving at such a slow speed. For it to be an explosion involving natural energy the body 195 00:22:11,980 --> 00:22:17,980 would have to be moving extremely fast, in theory no less than 30 kilometers a second. 196 00:22:18,980 --> 00:22:24,980 If the body had been a natural object moving at this great speed with a mass of a million 197 00:22:24,980 --> 00:22:29,980 or more tons and a hundred meters across, then it would have uprooted the forest in a huge 198 00:22:29,980 --> 00:22:35,980 strip more than a hundred kilometers across for a great distance before the actual explosion. 199 00:22:36,980 --> 00:22:40,980 But Dr. Vassiliyev and his colleague Professor Alexander Dolgov, who did the chemical analysis 200 00:22:40,980 --> 00:22:45,980 of the globules, feel the evidence now points most clearly to a comet. 201 00:22:51,980 --> 00:22:56,980 We've got a large content of hydrogen which is a typical cosmic element. 202 00:23:00,980 --> 00:23:06,980 Then we got quite large amounts of carbon dioxide which in its frozen state seems to make up the 203 00:23:06,980 --> 00:23:12,980 heads of comets. We also got a certain quantity of hydrocarbons, probably methane. 204 00:23:13,980 --> 00:23:18,980 This too is very characteristic of the structure of the front part of comets. 205 00:23:18,980 --> 00:23:25,980 Now comets are associated with meteor streams, the sort of rivers of meteorites which flow 206 00:23:25,980 --> 00:23:30,980 around the sun and intersect the Earth's orbit at regular intervals. 207 00:23:30,980 --> 00:23:35,980 Another day I was going through a book on comets and meteors and I came across what I think is a 208 00:23:35,980 --> 00:23:42,980 solution to this particular mystery. The stream of meteors known as the beta torrid, 209 00:23:43,980 --> 00:23:49,980 the stream of meteors known as the beta torrid. They hit the Earth, the stream of meteors, 210 00:23:50,980 --> 00:23:56,980 every 30th of June, the same day as the Tungusta event. 211 00:23:57,980 --> 00:24:04,980 And I am pretty sure that the Tungusta explosion was something to do with the stream of meteorites, 212 00:24:05,980 --> 00:24:11,980 the beta torrid, every 30th of June. Inevitably something like Tunguska, 213 00:24:12,980 --> 00:24:17,980 will happen somewhere on the Earth. It could happen tomorrow, it could happen in the next five minutes. 214 00:24:18,980 --> 00:24:22,980 I would say it will certainly happen within the next thousand years. 215 00:24:23,980 --> 00:24:28,980 If it does happen fairly soon, and it isn't too large a comet, it might trigger a thermonuclear war 216 00:24:28,980 --> 00:24:35,980 because an explosion like that in any country could easily be mistaken for an attack by ICBMs. 217 00:24:36,980 --> 00:24:41,980 However, a very large comet, well I'm afraid it wouldn't leave anyone to worry about. 218 00:24:42,980 --> 00:24:49,980 At the end of every summer now, Dr. Vasiliev and his team with almost religious fervour 219 00:24:50,980 --> 00:24:57,980 watch the dawn in that still remote region of the Tunguska explosion in Siberia. 220 00:25:13,980 --> 00:25:22,980 Every year the Russians vow that they will return to seek a little more knowledge about the most awesome event 221 00:25:23,980 --> 00:25:27,980 which has ever struck this Earth in all the recorded history of man. 222 00:25:42,980 --> 00:25:47,980 Next week, the Riddle of the Stones.