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The Unknown Tunguska - What we know and what we do not know about the great explosion of 1908

Vladimir V. Rubtsov, Ph.D., FATE Magazine, May 2001

original source |  fair use notice

Summary: The summer of 2001 marks the 93rd anniversary of the enigmatic occurrence known as the Tunguska Event. In past decades, the most obvious features of this event were widely publicized in the popular and scientific press. Neither the general public nor the world scientific community has in fact paid serious attention to the real nature of this event.

First a note from Russian Ufologist, Paul Stonehill:

The following article was published in the May 2001 issue of FATE Magazine. It is titled "The Unknown Tunguska: What We Know And What We Do Not Know About The Great Explosion Of 1908".

Once again, Dr. Rubtsov has demonstrated his analytical abilities, and his wealth of knowledge of Soviet and the post-Soviet paranormal scene. I am glad that FATE decided to publish his work, and hope that he is not the last Ukrainian/Russian researcher of such standing to be published in that magazine.

I wish that English-speaking researchers would read some of his other wonderful publications heretofore available only in Russian. Such articles as the one in FATE promote cooperation across borders and oceans.

Years ago Dr. Haines and Dr. Rubtsov created a Federation (The joint American-Soviet Aerial Anomaly Federation) to promote joint Soviet-American UFO research. I still keep some of their publications, and cherish them. Dr. Rubtsov's books are among publications in the library of the Russian Ufology Research Center. My book "The Soviet UFO Files" (Philip Mantle has my gratitude, for without him the book would not have been possible) was a brief introduction to the history of Soviet ufology; but I am glad I was able to mention the two scientists and UFO researchers. He may be reached at:


The summer of 2001 marks the 93rd anniversary of the enigmatic occurrence known as the Tunguska Event. In past decades, the most obvious features of this event were widely publicized in the popular and scientific press. Neither the general public nor the world scientific community has in fact paid serious attention to the real nature of this event.

The language barrier is also difficult to surmount-the key publications on the subject matter are in Russian-and consequently the Tunguska problem is usually thought of either as solved long ago by specialists in meteoritics or as a complete blank in science. Neither of these approaches is close to the truth. We now know something very essential about the Tunguska phenomenon- the great extent to which it is anomalous.

A Surprise From the Blue

Beginning on June 23,1908, strange atmospheric optical phenomena were observed in many places in western Europe, European Russia, and western Siberia. They included unprecedentedly active formation ofmesospheric (silvery) clouds, bright "volcanic" twilights, extremely intense and long solar halos, and so on. These anomalies gradually increased in intensity for 10 days.

Then on the sunny morning of June 30,1908, a luminous space body of unknown origin flew over central Siberia, moving in a generally northwesterly direction. The body was seen in many settlements of the region, its flight being accompanied by thunder-like sounds. Although this region is only sparsely populated, and systematic gathering of the eyewitness testimonies started rather late, in the 1920s, we have by now some 500 written accounts that contain more or less detailed descriptions of the flying body. Its shape was mostly described as roundish, spherical, or cylindrical; its color as red, yellow, or white. There was no smoky trail typical of large, iron meteorites, but many witnesses saw vivid iridescent bands resembling a rainbow behind the body.

At 7:14 A.M. local time (12:14 A.M. Greenwich mean time), while passing over an area not far from the Podkamennaya Tunguska River, at 60¦ 53' N, 101¦ 54' E, the body exploded. The blast was equivalent to 30 to 50 megatons ofTNT and was accompanied by a bright flash.

S. B. Semenov lived in the little trading station of Vanavara some 70 kilometers southeast of the epicenter of the explosion, which was in a lonely marshy region known as the Southern Swamp. In 1927, he recalled:

"I sat on the steps of my house, facing the north... .Suddenly the sky in the north split apart and there appeared.. .a fire that spread over the whole northern part of the firmament. At this moment I felt intense heat, as if my shirt took fire. I wished to tear up my shirt and throw it off, but at this moment the sky shut and a pow-erful blow threw me down from the steps.... At this moment I fainted, but my wife ran out of the house and helped me to get up.... After the stroke, there started a very loud knocking-as if stones were bfalling from the sky..."

The sound of the explosion was heard as far as 1,200 kilometers from the epicenter, and northern-facing windows were broken within 200 kilometers. Its seismic wave was recorded in Irkutsk, Tashkent, Tbilisi, and Jena. The shock wave of the Tunguska explosion leveled more than 2,100 square kilometers of the forest. Over an area of some 200 square kilometers, vegetation was burned by the flash. After that, a major forest fire started.

Some six minutes after the explosion, a local magnetic storm began, very similar to geomagnetic disturbances that follow nuclear explosions in the atmosphere. It was detected by the Magnetographic and Meteorological Observatory in Irkutsk. The storm lasted four hours.

By the early morning of July 1, the strange light effects in the skies that had begun 10 days before the event jumped to their peak. After that date, these effects exponentially decreased. Still, some aftereffects took place.

Labyrinths of Hypotheses

The lack of any serious scientific reaction at the time is puzzling. Although some journals discussed the atmospheric anomalies, no attention was paid to the extraordinary event that had taken place in Siberia. Yet some local Siberian newspapers did publish eyewitness accounts, and the journalists supposed that a huge meteorite had fallen.

However, A. V. Voznesensky, director of Irkutsk Magnetographic and Meteorological Observatory, realized immediately after the event that the curious earthquake recorded by the instruments of the observatory had something to do with the fiery body described in the newspaper reports. After processing the seismograms, Voznesensky established the approximate time and coordinates of the event. But then the Tunguska "meteorite" was forgotten for more than a decade.

My description of the Tunguska Event has been simplified. Even now, 90 years after the event, many important details of the phenomenon remain obscure. We do not know for sure how many bodies were involved nor how many explosions there were. It is even not clear whether we can use the word "explosion" in its proper sense, or whether it would be better to use the expression "an explosion-like energy release." The real level of intricacy and anomaly of the Tunguska phenomenon was perceived only after many decades of active investigations in this region.

At first, however, the situation seemed more or less clear. In 1921, information about the Tunguska Event came to light anew, when an expedition of the Russian Academy of Sciences visited Central Siberia. Led by Leonid Kulik, it aimed at gathering data about various meteorites. At that time, there was no question that it had been a huge meteorite. Several well-equipped special expeditions were subsequently sent to the site. Kulik continued to actively explore the area up until World War II. In these expeditions, he obtained much valuable data.

Even when, immediately after discovering the area of the leveled forest, it was established that trees were still standing upright at the epicenter of the explosion and that there were no signs of a meteorite crater, no real significance was attached to this fact. It was merely supposed that, rather than a single meteorite body, there had been a meteorite shower arising from the destruction of the initial body due to air resistance at some altitude above the Earth's surface.

The forest was supposed to be leveled by the ballistic wave of the collapsed body. Kulik mistook thermokarst holes for meteorite craters. Being an eminent specialist in meteoritics, he looked for a meteorite, not for something else. Nevertheless, as time passed, some scientists began to feel, rather intuitively, that the meteorite hypothesis had serious weak points. In spite of intensive searches for remnants of the meteorite, not even a milligram of its substance was ever found. In the early 1930s, F. L. Whipple supposed that the Tunguska Space Body (TSB) had in fact been the core of a small comet. V. I. Ver-nadsky put forward a hypothesis about a cloud of cosmic dust, and I. S. Astapovich assumed that the TSB had ricocheted off the lower layer of the atmosphere.

But it was the Soviet engineer and science-fiction writer Alexander Kazantsev who understood in 1945 the real importance of the "first Tunguska anomaly"- the above-ground character of the explosion. He advanced the hypothesis of an extraterrestrial spaceship that had met with disaster due to a malfunction at the final stage of its space voyage. Kazantsev subsequently recalled that he had been much impressed by a description of the nuclear explosion over Hiroshima and its similarity to the Tunguska explosion.

Specialists in meteoritics at once raised objections to such a fantastic idea. A team of the most distinguished Soviet astronomers wrote in 1951 in the popular-science journal Science and Life: "There is no question that immediately after the meteorite fall.. .a crater-like depression formed where now the Southern Swamp exists.. .It was relatively small and soon became inundated with water. In subsequent years it was covered by silt and moss, filled with peat hummocks, and partly overgrown with bushes. The dead trees standing upright can be seen not at the center of the catastrophe, but on the hillsides which surround the hollow..."

However, the work by the first postwar Tunguska expedition, organized in 1958 by the Committee on Meteorites of the USSR Academy of Sciences (KMET), compelled everyone involved in the discussion to agree: the Tunguska space body had in fact exploded in the air and therefore could hardly have been an ordinary meteorite.

Thereafter, the number of anomalies discovered on the site of the Tunguska explosion began to grow steadily. The hypothesis of a thermal explosion, according to which the Tunguska space body was a meteorite or the core of a small comet that exploded as a result of the rapid deceleration in the lower atmosphere, met with difficulties. As early as 1962, the Committee on Meteorites got rid of the affair, turning it over to the Commission on Meteorites and Cosmic Dust of the Siberian Branch of the USSR Academy of Sciences. The problem of the Tunguska phenomenon was, so to speak, exiled to the place of its birth.

The Interdisciplinary Independent Tunguska Expedition (KSE) became the center of the Tunguska studies. It was not the only research body in this field, but its role can hardly be overestimated.

The KSE is a kind of informal scientific research institute aimed at thorough studies of the Tunguska problem. It was formed in 1958 in the Siberian city of Tomsk, initially under the leadership of G. F. Plekhanov, and consisted at first of a dozen specialists in various scientific disciplines, mainly physicists and mathematicians. A few years later the core of this informal institute involved about 50 scientists. Some 100 specialists per year took part in the field work on the site, and no less than 1,000 researchers in various "formal" institutes all over the country analyzed the collected materials. At present the head of the expedition is Dr. N. V. Vasilyev, Member of the Russian Academy of Medical Sciences and the Russian Academy of Natural Sciences. Although traces of the Tunguska explosion begin to disappear with time, some of them are still clearly visible. Examining these traces, KSE performed a really huge amount of work, and its results have been published in a series of collections of scientific papers. Nonetheless, these results remain virtually unknown in the West.

The "meteoritic establishment" exemplified by KMET was ready to consider every hypothesis ofTSB origin, even the technogeneous one. However, KSE combines its unconventional research strategy with strictly normal, rigorous scientific research methods.

I would also like to emphasize the importance of the not-so-peaceful coexistence of the "technogeneous" (or "artificial"-A) and "natural" (N) conceptions of the TSB for the development of Tunguska studies. In fact, the entire history since 1946 is one ofA-N competition. The alternative nuclear-thermal (explosion) and artificial-natural (body) theories have remained the keynote in the whole Tunguska affair. The research team led by A. V. Zolotov succeeded in establishing the most important point of the affair: that the forest destruction was made by the blast and not by the ballistic wave.

Empirical facts gathered by KSE and other Tunguska investigators during the last decades, although sometimes strange, are well-established, and no model of the phenomenon may ignore them. What's more, any conception that does ignore these facts cannot be considered serious and scientific. Unfortunately, many theorists (especially-although not only- Western ones) try to solve this enigma in a flash, being aware only of two facts: that something flew over Western Siberia in 1908 and that it exploded.

Stranger and Stranger...

What do we know about the Tunguska explosion and the TSB? And-no less important-what do we still not know?

The basic facts of the Tunguska phenomenon can be set forth as follows:

(1) The explosion was just the most striking event in a set of large-scale atmospheric anomalies that occurred in the summer of 1908 and were probably interrelated.

(2) The main explosion occurred in the atmosphere at an altitude of five to seven kilometers. The area of the leveled forest has peculiar contours, something like a gigantic butterfly, and a complex structure. In general, the forest fell strictly radially, but near the epicenter there are local deviations from the radial pattern, which allows one to assume that there were at least two or three sub-epicenters.

(3) There is no meteorite crater in the region of the explosion, nor any substance that could be identified with that of the TSB. The meteoritic dust that was found on the site does not differ from the usual background fall of extraterrestrial matter.

(4) The axis of symmetry of the fallen forest field is 81- W of the true meridian. It is interpreted as the imprint of the ballistic shock wave of the TSB at the final stage of its flight; that is, immediately before the explosion. It is essential to note that this wave was rather weak, leveling j none of the trees and introducing only minor deviations in the radial pattern. The leveling was in itself fully due to the effect of the blast wave. This points to the fact that the speed of the Tunguska body ; at the final stage of its flight was relatively · low. Zolotov has estimated this speed at 1.2 kilometers per second. Therefore, the explosion was due to the internal energy of the body, not to the energy of its motion.

(5) The concentration of this energy approached that of nuclear explosions, and no less than 10 percent of it was released as the flash. This suggests some kind of nu-| clear reaction, but what kind remains unknown. No firm evidence of such a reaction has been found in soil and vegetation in the region of the explosion.

However, directly under the path of the TSB, thermoluminescence of minerals has substantially increased. This could have been due to hard radiation emitted in the course of the flight and possibly at the instant of the explosion.

A complex set of serious ecological consequences has been revealed in the region of the explosion. A very rapid restoration of the forest occurred after the catastrophe, and there was an accelerated growth of trees, both new and those which survived the incident. There was also a sharply increased frequency of mutations in the local pines-by a factor of 12. Both of these effects tend to concentrate towards the corridor of the TSB flight path. The genetic impact of the phenomenon is of a patchy character.

A rare mutation among the human natives of the region also arose in the 1910s in one of the settlements near the epicenter.

According to Dr. N. V. Vasilyev, medico-ecological examination of the state of health of the native inhabitants reveals population genetic effects similar to those observed in the regions affected by nuclear weapon tests. These facts (as well as the local magnetic storm that started after the explosion) count in favor of the nuclear character of the Tunguska explosion. Maybe we are even dealing in this instance with a novel type of nuclear reaction.

(6) Apart from the main explosion at a relatively high altitude, there were three or four additional low-altitude, and probably low-power, explosions. This is borne out both by the fine structure of the fallen forest field and by the testimony of some eyewitnesses who found themselves in the immediate vicinity of the epicenter.

Chuchancha and Chekaren, two brothers belonging to the kin of Shaniaguir in Evenk, were sleeping at the moment of the explosion in their chum (a tent of skin or bark) situated on the bank of the Avarkitta River, very close to the epicenter. Suddenly they were awakened by tremors, whistling, and a loud sound of the wind.

"Both of us were very much frightened," Chuchancha told I. M. Suslov in 1926. "We began to call our father, mother, and third brother, but nobody replied. A loud noise was heard from the outside of the chum; we understood that trees were falling. Chekaren and me, we got out from our sleeping bags and were going to go out of the chum, but suddenly there was a very great clap of thunder. This was a first blow. Earth trembled, a strong wind hit our chum and threw it down. The elliun [the skins covering a chum] rode up and I saw something terrible: trees were falling down, their pine-needles burning. Dead branches and ; moss on the ground were burning as well.

"Suddenly there appeared above a mountain, where the trees had already fallen down, bright light like a second sun.... At the same moment, a strong agdyllian, a thunder, crashed. This was a second blow. The morning was sunny, no clouds, the sun shone as always, and now a second sun!

"With an effort Chekaren and I crawled out from under the chum poles and elliun. After that we saw a flash again appear and a thunder crash heard again overhead, although in another place. This was a third blow. Then there was a new gust of wind that knocked us down and we knocked ourselves against a levelled tree.

" [A short time later] Chekaren cried out: 'Look up!' and stretched his hand upward. I looked in this direction and saw a new lightning, with an agdyllian. But its sound was not so loud as before. This fourth blow was like a usual thunder.

"Now I can remember there was a fifth blow, but rather weak and far away from us." This last explosion took place somewhere far in the north.

(7) The zone of the radiant burn of trees is also "butterfly-like" in shape; its axis of symmetry approximately coincides with the ballistic one. It is also somewhat extended along the path of the Tunguska body; it appears that the latter was moving and exploding (or at least emitting powerful electromagnetic radiation) over the last 20 or so kilometers. This is not in good accordance with the strict radial pattern of fallen forest, and therefore we should probably assume that the source of the flash was not identical with that of the blast wave. The radiantly burned vegetation is arranged patchily; that is, areas seriously damaged and areas free from any thermal influence are intermittent. A workable model explaining this peculiarity would be a host of powerful "thermal rays," not just an isotropic fireball.

The fact that Chuchancha and Chekaren (as well as some other Evenk natives) survived near the epicenter of a 30 to 50 megaton explosion seems also to favor its highly anisotropic character.

(8) Some local geochemical anomalies have been discovered at the epicenter of ; the Tunguska explosion. Substantial shifts in isotopic compositions of carbon, hydrogen, and lead were found. The soil is also enriched with rare earths (samarium, europium, terbium, ytterbium, etc), as well as with barium, cobalt, copper, titanium, and some other elements. As was supposed by the late Dr. Sergey Dozmorov of Omsk, these results may indicate that the TSB contained appreciable quantities of superconducting high-temperature ceramic made on the basis of the following combination of elements: barium, a lanthanide, and copper. Such ceramic keeps superconductivity up to the temperature of liquid nitrogen (-196¦C) and can be used for constructing very effective energy and information storage devices. Obviously, such a substance cannot be natural.

(9) The combination of the butterfly shape of the area with the general radial pattern of fallen forest suggests that the Tunguska body consisted of two different parts-an explosive, and a non-uniform shell that gave rise to peculiarities in the blast-wave shape. Thereby it resembled an artificial construction. As A. N. Dmitriev and V. K. Zhuravlev note, the shape and structure of the fallen forest field can be easily explained if we assume that the shell had symmetric zones of increased and reduced strength of material. Another workable model would be a cone-shaped mass of explosive having cumulating hollows and a detonator in its forward part.

(10) The path followed by the Tunguska body through the atmosphere remains largely unclear. Immediately before the explosion, it was moving almost exactly east to west. The witness testimony that was collected in the 1960s bears out this variant. Yet testimony gathered in the 1920s suggests with equal likelihood that the body might have arrived from the south or possibly southeast. This evidence cannot be easily rejected, since it was obtained shortly after the event. Attempting to find a way out of this deadlock, Felix Y. Zigel, father of Soviet ufology, suggested in 1966 a possible maneuver of the Tunguska body at the final stage of its flight. However, the eastern variant of the path has been traced as far as the Lena River. This casts doubt on the possibility of a maneuver, at least for this body. Shouldn't we assume that there were several bodies moving from different directions toward more or less the same final point?

(11) Last but not least: What happened to the Tunguska body (or bodies) after the explosion? The hypothesis of a "ricochet," put forward in the early 1930s, was rejected, mainly because the TSB had no chance of surviving such a powerful explosion. It may be so, but nonetheless, as was noted by G. F. Plekhanov, the imprint of the ballistic wave on the fallen forest is observed even beyond the epicenter, approximately in the same direction as before it. Therefore, some part of the body (or one of several bodies) might have continued its flight after having taken this fiery bath.

Among other interviewed eyewitnesses of the Tunguska explosion, there was an elderly Evenk man named Ivan Ivanovich Aksenov, a shaman, who had been hiding in the taiga for many years from the Soviet authorities after the revolution of 1917. At the moment of the catastrophe, Aksenov, then 24, was hunting near the mouth of a tributary of the Chamba River some 40 kilometers south of the epicenter of the catastrophe. After the explosion, he saw an object flying down the Chamba; i.e., generally north to south. He called the object a "devil." "As I came to myself," recalled Aksenov in 1967, "I saw it was all falling around me, burning. No, that was not God flying there, it was really devil flying. I lift up my head- and see-devil's flying. The devil itself was like a billet, light color, two eyes in front, fire behind. I was frightened, covered myself with some duds, prayed (not to the heathen god, I prayed to Jesus Christ and Virgin Mary). After some time of prayer I recovered: everything was clear. I went back to the mouth of the Yakukta where the nomad camp was. It was in the afternoon that I came there..." The devil was going faster than airplanes now do. While flying, it was saying "troo-troo," but not loudly.

On the Way to the Truth

It is thus apparent that the intricacy and complexity of the Tunguska phenomenon far exceeds the limits of the simpler models still existing in popular science and even scientific literature. The results obtained during the years of Tunguska investigations tend to favor the artificial nature of the TSB and the unconventional character of its explosion. The techno-geneous hypothesis is thus coming to the fore. But of course, the hypothesis of an accidental crash of an extraterrestrial spaceship may be limited. It might well not have been accidental.

My working hypothesis, which I developed in the 1970s, is the so-called battle model. According to this scenario, in 1908 there was an aerospace battle between two or more alien spaceships, after which one of them survived and flew back to space.

Certainly, we still have much to learn about the flight and explosion of the TSB. Perhaps one day in the future it will be possible to deduce a convincing model of the phenomenon directly from the facts accumulated. To bring this day closer, Russian and Ukrainian scientists are trying to develop their studies in this area. Anomalists in other countries could help them.

Anyone wishing to participate in this search is welcome to contact the author of this paper by mail (Research Institute on Anomalous Phenomena, P. 0. Box 4684, 61022 Kharkov-22, Ukraine).

There seems to have been much more in the Tunguska sky than we can at present imagine.

Vladimir V. Rubtsov, Ph.D., is director of the Research Institute on Anomalous Phenomena in Kharkov, Ukraine.


The 1999 Bologna Expedition

In July 1999, the Department of Physics of the University of Bologna, Italy, which generously supplied the Tunguska photographs for this issue, organized an expedition to the area. Also taking part were the Turin Astronomical Observatory and the Institute of Marine Geology of the National Research Council of Bologna. It was necessary to construct a camp in the taiga (subarctic evergreen forest) hundreds of miles from towns connected by roads. Local support was provided by personnel of Tomsk University (Russia) led by N. V. Vasilyev and G. V. Andreev.

The object of the expedition was to carry out a systematic exploration of the site where the Tunguska Event took place to establish the nature of the body involved. Specific tasks included the study of lake sediments, magnetometric measurements, searching for cosmic body fragments and tree samples, and cosmic ray measurements.

The expedition left Bologna on July 14, 1999. Sir Arthur C. Clarke sent his best wishes. In Moscow, three walkie-talkies were confiscated by Russian customs. The team arrived at Ceko Lake in the Tunguska area on July 17 and began their investigations on the 18th. The lake turned out to be runnel shaped with large accumulations of trees at the bottom. They extracted 28 cores from the lake bed. These were confiscated by Moscow customs and not released until December. It was finally determined that the lake is older than the Tunguska Event and is probably of volcanic origin. Other final results have not been announced, but the expedition maintains a website at www-th.bo.infn.it/tunguska/

-David F. Godwin

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