The Tunguska phenomenon of 1908 in Siberia
An electric discharge between the earth surface and a hot plasma ?

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Norbert Brügge, Germany


The Tunguska event was a large explosion that occurred near the Podkamennaya Tunguska river in Yeniseysk Governorate (now Krasnoyarsk Krai) in Siberia, on the morning of June 30, 1908. The explosion over the sparsely populated Eastern Siberian Taiga flattened an estimated 60 million trees over an area of 2,000 km2 of forest.

Around 7:00 a.m., a glowing object appeared in the clear summer sky, the shape of which was similar to a cylinder or a beam and whose brightness was compared with the sun. According to eyewitnesses, the object appeared at the level of the low sun in the east. The brilliantly bright object poisy across the sky and disappeared on the western horizon. At the point where the object had disappeared, the sky lit up and there a high cloud of smoke appeared. After that, strange detonations could be heard and the earth shook far from the explosion site. A bright glow of fire, a strong shock, a pressure wave and thunder noises were perceived even at a great distance.

Locals saw this "second sun" relatively close to the explosion site. After violent explosions, earthquakes and hot squalls were registered. Further observations suggest that at least two other objects coming from the south and west led to explosions, which lasted about an hour with breaks.
The seismographs registered the tremors in all meteorological stations in Europe and North America. During the strangely bright nights that followed, silver shining clouds of an extraordinary sheen appeared over Eastern and Western Europe.

Since Leonid Kulik's expedition in 1930, which was the first to document the enormous damage in the taiga, there have been several other expeditions to investigate the cause of the explosions. To date, however, there is no useful scientific information. Neither craters nor remains of meteoric material were found. All previous attempts to design a scenario of the event are for the trash, or at least questionable. Based on the dramatic reports of eyewitnesses, we only know that glistening bright "objects" passing the atmosphere dissolved completely in strange explosions near the earth's surface and that there was a bright night in the wider area before the event.

Only the proposed theory to the origin of the Tunguska event by Dr.-Phys. Andrei Ol'khovskaya is worth to discussing.
"Tunguska event of 1908 was to be of geophysical origin !"

Comment: Even though I am skeptical of his theory as a geologist, he has thankfully collected a lot of facts that are worth studying and from which I have ultimately benefited.


An electric discharge between the earth surface and a hot plasma

From the sum of the observations I derive my theory that the Tunguska event was the explosions of "hot" plasma. It probably originates from the boundary layer between the ionosphere and the plasmasphere of the earth and was transported along lines of the magnetic field to a strongly positively charged hotspot on the earth's surface (Tunguska region), where explosive discharges took place.

The plasmasphere is the inner, to a torus closed part in the terrestrial magnetosphere and is filled with a relatively dense and cold plasma. It consists of ionized atomic nuclei (ions) with a critical mass of released electrons and is fed from the ionosphere. It is electrically conductive, but is in energetic equilibrium.
Recent satellite observations have shown that irregularities in density in the form of clouds or imperfections can form in the plasmasphere. New observations have also shown that the plasma could be in principle arranged like a tube along the field lines of the magnetic field.

The "cold" plasma can become the "hot" plasma if significantly more energy is supplied. The energetic equilibrium is considerably disturbed by more electrons released from the already ionized atomic nuclei (ions). The ionization increases. This plasma lights up when free electrons are captured again by the ions, releasing the previoisly absorbed energy in the form of light.

The scenario of the Tunguska event could be described as follows:

In the bright nights (perceived above the taiga before the event), a plume of cold plasma in the lower plasma sphere at the border to the ionosphere rapidly became negatively charged. The observed light phenomena document energetic interactions within the plasma. A plume of strongly negatively charged plasma along magnetic field lines reached an equally strongly positively charged (
magnetic*) hotspot in Siberia on June 30, 1908. Due to the objects arriving from four (?) points of the compass (turned by 90°) combined with violent explosions, it can be assumed that the plasma was split up ("tubes") and reached this strongly positively charged part in the Tunguska region at various times. The apparently "flat" trajectories of the objects can be explained by the fact that there has been a diversion towards the positive hotspot.
* Note: The Tunguska explosion is located on the southern edge of the Siberian Trapp with an exceptional accumulation of magnetite-diatrems (Fig. 4).

The explosions can be described as electric discharges, comparable to the mechanism the "Townsend Avalanche", in which there is an avalanche-like reaction between "hot" plasma and a positively charged hotspot. A multitude of repetitive noises such as popping, knocking and rattling could indicate the decaying electrical discharges.

An object that came with a roar from the east was perceived as a beam or tube. The statement that a "devil with two eyes" came from the south (?) could be a sighting of two tubes. Statements about a divided sky also suggest tubes.
The bright night sky, which was still be seen over Europe for days, is an indication of the spread of other charged plasma, which however, as in the case of Tunguska, did not reach the earth's surface. The insignificant column of smoke above the Tunguska cannot be the cause of the glow.
Remarkable, in Irkutsk (almost 950 km away from the Tunguska epicenter) a geomagnetic disturbance was registered which lasted for several hours.

In order to give weight to this theory, however, the cause of the energy supply in the case of plasma in the plasmasphere should be clarified, as well as the fact that the plasma leaves the plasmasphere and passed the ionosphere und finally reaches the earth's surface along magnetic field lines.

Townsend Avalanche
The avalanche occurs in a gaseous medium that can be ionised (Plasma). The electric field and the mean free path of the electron must allow free electrons to acquire an energy level (velocity) that can cause impact ionisation.
The electric field is applied across a gaseous medium; initial ions are created with ionising radiation (for example, cosmic rays). An original ionisation event produces an ion pair; the positive ion accelerates towards the cathode while the free electron accelerates towards the anode. If the electric field is strong enough, the free electron can gain sufficient velocity (energy) to liberate another electron when it next collides with a molecule. The two free electrons then travel towards the anode and gain sufficient energy from the electric field to cause further impact ionisations, and so on. This process is effectively a chain reaction that generates free electrons. Initially, the number of collisions grows exponentially.

In order to approach the problem of the "Tunguska phenomenon", the numerous reports by eyewitnesses are invaluable. Many sources and quotations have been collected on Andrei Ol'khovatov's website:

Eyewitnesses accounts

Fig.1 Applied Townsend Avalanche

Fig.2  Map with sightings and the obviously arranged object trajectories

Fig. 3 Detailed map of the epicenter

 Fig. 4 Magnetite diatrems

Eastern Object (azimuth 104 °) and/or the others
A certain Semonov was at the Vanavara trading post (about 40 kilometers south of the explosion) and suddenly saw that directly to the north, the sky was split in two and fire appeared high and far above the forest. The split in the sky widened and the entire northern horizon was covered with fire. Heat came from the north. Then the sky closed and a strong thump sounded and he was thrown a few meters. Then came a sound like stones falling or cannons shooting, the earth shook. As the sky opened, a hot wind raced between the houses.

The Evenk brothers Chekaren and Chunchanka reported: We slept in our tent. We suddenly woke up. Somebody pushed us. We heard whistling and felt a strong wind. We couldn't see what was going on outside in the tent. Suddenly I was pushed again, this time so hard that I fell into the fire. There was noise behind the tent, we could hear trees falling. We wanted out, but then the thunder struck. This was the first thunder. The earth began to move and rock, the wind overturned our tent. Then I saw trees fall and branches burn, it grew mighty light, as if there was a second sun. And immediately there was a loud clap of thunder. This was the second thunder. Our sun was shining brightly as always and suddenly another one came. Then we saw that in another place there was another lightning and loud thunder came. This was the third clap of thunder. The wind came again, knocked us off our feet. Suddenly we saw another lightning bolt, followed by another thunder. But the noise was less than before. This was the fourth thunder. I can still remember there was another clap of thunder, but it was quieter and somewhere far to the west.

Newspaper "Sibir", July 2, 1908: On the morning of June 30, around 7:00 a.m., residents of the settlement Karelinski (213 km north of Kirensk) in the northwest, quite high above the horizon, observed some strangely bright (impossible to look on.) bluish-white objects moving down for 10 minutes. One object appeared as a "tube" (cylinder). As the object approached the ground (forest), the light-colored body seemed to smear and then turned into a huge cloud of black smoke, and a loud knock was heard, as if large stones were falling or artillery was being fired. At the same time, the cloud began to emit flames with irregular shapes. An observer was in the forest about 4 kilometers north of Kirensk and heard this type of artillery fire in the northwest, repeating at least 10 times every 15 minutes.

Newspaper "Krasnoyarets", July 13, 1908: Kezhemskoe settlement (northwest of Illimsk). At 7:43 a.m. the sound of a strong wind was heard. Immediately thereafter, there was a terrible thud, followed by an earthquake that literally shook the buildings. The first blow was followed by a second and then a third. The pause between the first and third beat was accompanied by an unusual underground rattle, similar to a railroad where dozens of trains run at the same time. After that, a similarity of artillery fire could be heard for 5 to 6 minutes: 50 to 60 shots at short, equal intervals, which became progressively weaker. After 1.5 to 2 minutes after one of the "barrages", six more blows could be heard, like cannon fire, but individual, loud and accompanied by tremors. In the north, where most of the beating could be heard, a kind of ashen cloud could be seen near the horizon, which became smaller and more transparent and disappeared completely after hours.

Nizshne-Karelinskoye (465 km, 133°). Extremely bright (it was impossible to look at it) luminous body was seen rather high in the north-western sky soon after 8 a.m. It looked like a tube (cylinder) and for 10 minutes moved down to the ground. The sky was clear, but only in the side, where the body was seen, a small dark cloud was present low above the horizon. While coming to the ground, the body dispersed (flattened) and at this place a large puff of black smoke appeared. Then a flame emanated from this cloud.

Nizshne-Ilimskoye (419 km, 168°). The fireball was seen which while going to the ground at first flattened into"flying saucer". Then coming nearer to the ground it transformed into 2 fire columns.
Os'kino (330 km, 89°). Innokentii Farkov said a gradually rising boom coming from afar was heard since morning hours. The old men, thinking their dying hours had come, were changing into clean shirts, and one of them even washed in the bath house to meet the death clean. The ground trembled as a black body flew past, trailing a fiery tail.

Kezhma (214 km, 193°). In Kezhma was to see a flying luminous cloud, multicolored luminous bands, a fireball, a flame over the northern horizon. For example, A. K. Kokorin, the observer of the Kezhma meteorological station marked in the observational register that at 7 a.m. two giant fiery circles appeared on the north. They persisted for 4 minutes and then disappeared. Soon after, noise, like a wind was heard. It came from the north to the south and its duration was 5 minutes. Then other sounds, resembling large cannon shots and crackling appeared. These shots continued for 2 minutes, then a crackling like a gun shot appeared and persisted for 2 minutes. The sky was clear.

Tetere (92 km, 165). Fire columns were seen in the north.

Western Object (Azimut 284°)
The Russian ethnographer Vainshtein had been collected a remarkable account during his 1948 expedition to the settlement of Sulomay (61.6°N, 91.2°E) which is situated about 577 km west of the Tunguska epicentre. The native Tyganov reported that for one or even two nights before the Tunguska event (he did not remember precisely) the night sky was extraordinarily bright. The next morning, he saw with horror "the second Sun," as he described it, flying from the left bank of the Podkamennaya Tunguska River—brighter than the one we all know (it was painful for eyes to look at). At the same time, there was a strong rumble.. "The second Sun" quickly moved across the sky. Soon after that, a bright fire without smoke rose to the sky and a deafening explosion sounded, from Vanavara's side. The earth began to tremble, and a strong wind swept in. The wind uprooted tall trees nesr Sulomay. Then everything abated, the sky was still bright for one or two nights.

There is a further account from the settlement of Podkamennaya Tunguska (western distance of 632 km from the Tunguska epicentre). The account stated seeing (early in the morning in 1908) a lengthy fiery strip flashing across the sky, and hearing accompanying thunder that sounded as if it came from a cannon.

Much closer to the Tunguska epicentre, there is a account stating that a fireball moved from the west, then descended to Chuvar (a large ridge), and then went down. Also, the fireball scorched and unrooted trees, but did not fall from the sky. Instead, it went further away. The position of the Chuvar ridge is at a western distance of 23 km from the Tunguska epicentre. A strip-like forest fall was noted on this ridge in 1959.

Southern Object (Azimut 194°)
Probably the strangest report comes from the hunter Aksenov, who found himself on June 30 near the mouth of a tributary of the Chamba, about 40 km south of the epicenter of the disaster. It is the description of a "flying devil with two eyes" who flew over him along the Chamba and made a sound "troo-troo". It is unclear whether the trajectory of the object ran from south to north or vice versa. The "down the Chamba" is ambiguous. It can mean the course of the river or also the down-fall over the northern part the Chamba.

Northern Object (Azimut 14°)
There are no sightings for the theoretical northern object.