Tunguska Event Research Articles

Educational Activities of the First Special Meteor Expedition of the Russian Academy of Sciences in 1921–1922

Investigating the activities of the First Soviet Meteorite Expedition of 1921–1922, the paper aims to analyze the objectives of the expedition and fill in some gaps in the Quest for the Tunguska Meteorite. Aiming to recover either the fragments of the Tunguska meteorite or any other meteorite, the expedition was launched by the Russian Academy of Sciences and led by Leonid A. Kulik. The Yenissei province in Siberia was among several territories where the Expedition worked. The paper hypothesizes that the First Soviet Meteorite Expedition (1921– 1922) was a factor that contributed not only to the development of the new Soviet space science but became a unique driving force behind the vigorous attempt of the Soviet state to shift the backward mental paradigm full of prejudices and cognitive misconceptions and introduce the new one that prioritized scientific knowledge. The paper identifies the legal basis for the Expedition, its overall educational impact on ordinary people. The paper argues that the First Soviet Meteorite Expedition of 1921–1922 became a factor in transforming the sociocultural space and an incentive for further scientific research. The paper presents a historiographical review within the framework of the topic and introduces some new data obtained from the documents stored in the local archives (the towns of Yeniseisk and Minusinsk, Krasnoyarsk Territory).

Registration of the atmospheric effect of the Hunga Tonga volcano eruption

The paper presents the results of recording of acoustic waves, caused by the Hunga Tonga volcano eruption in the South Pacific Ocean on January 15, 2022, in Eastern Siberia at a distance of about 11230 km from the eruption. The received acoustic signal is interpreted as a set of atmospheric waves in a wide range of oscillations. The structure of the signal is similar to signals from the previously known powerful sources: the thermonuclear explosion on Novaya Zemlya in 1961 and the explosion of the Tunguska meteorite in 1908. The acoustic signal was preceded by three trains of low-frequency damped oscillations. We assume that these three trains of oscillations are associated with three important stages in the Hunga Tonga volcano eruption: 1) destruction of Tonga island and formation of an underwater caldera; 2) release of hot magma from the caldera to the ocean surface and release of a large volume of superheated steam into the atmosphere 3) formation of a layered structure from a mixture of superheated steam, ash, and tephra on the ocean surface and formation of an eruptive convective column. Successive phases of the eruption might have contributed to the excitation of acoustic vibrations in a wide range of periods including Lamb waves, internal gravity waves (IGW), and infrasound. We compare the structure of the acoustic signal received in Siberia at a distance of more than 11000 km from the volcano and that of the acoustic signal recorded in Alaska at a distance of more than 9300 km. Using the solution of the linearized Korteweg — de Vries equation, we estimate the energy released during the volcanic eruption.

О регистрации атмосферного эффекта извержения вулкана Хунга-Тонга

The paper presents the results of recording of acoustic waves, caused by the Hunga Tonga volcano eruption in the South Pacific Ocean on January 15, 2022, in Eastern Siberia at a distance of about 11230 km from the eruption. The received acoustic signal is interpreted as a set of atmospheric waves in a wide range of oscillations. The structure of the signal is similar to signals from the previously known powerful sources: the thermonuclear explosion on Novaya Zemlya in 1961 and the explosion of the Tunguska meteorite in 1908. The acoustic signal was preceded by three trains of low-frequency damped oscillations. We assume that these three trains of oscillations are associated with three important stages in the Hunga Tonga volcano eruption: 1) destruction of Tonga island and formation of an underwater caldera; 2) release of hot magma from the caldera to the ocean surface and release of a large volume of superheated steam into the atmosphere 3) formation of a layered structure from a mixture of superheated steam, ash, and tephra on the ocean surface and formation of an eruptive convective column. Successive phases of the eruption might have contributed to the excitation of acoustic vibrations in a wide range of periods including Lamb waves, internal gravity waves (IGW), and infrasound. We compare the structure of the acoustic signal received in Siberia at a distance of more than 11000 km from the volcano and that of the acoustic signal recorded in Alaska at a distance of more than 9300 km. Using the solution of the linearized Korteweg — de Vries equation, we estimate the energy released during the volcanic eruption.

Sediments and morphology of deep lakes of Central Tunguska Plateau (Krasnoyarsk krai, Evenkia): on the problem of the Tunguska Event at 1908

The shape of the bottom and the thickness of sediments of small lakes Zapovednoye and Peyungda, located 50-60 km from the supposed epicenter of the “Tunguska Event” of 1908, were studied using echo-sounding and seisimo-acoustic profiling, and their age was estimated using 137Cs, 210Pb, 14C. It was revealed that both lakes have funnel shape with a depth of 60 and 34 m, respectively, and are similar in shape and size to Lake Cheko, which, according to some researchers, is an impact crater formed by a celestial body as a result of the “Tunguska Event 1908”. The examples of lakes Zapovednoye and Peyungda show that the shape of Lake Cheko is not unique to this area. The age of the bottom sediments of lakes Zapovednoye and Peyungda exceeds several thousand years. In the sediments of lakes Zapovednoe and Peyungda, a layer with a high content of terrigenous elements was identified, presumably formed due to the input of disturbed soil layer as a result of the massive fall of trees after the “Tunguska 1908”. Thus, the presence of two deep funnel-shaped lakes near the epicenter of the “Tunguska 1908” much older than 1908, casts doubt on the uniqueness of Lake Cheko, and therefore its impact origin. In addition, according to our estimate, the age of Lake Cheko is no less than 300 years, which contradicts the hypothesis of its origin as a result of the “Tunguska 1908”.

Dark Galaxies, Sun-Earth-Moon Interaction, Tunguska Event—Explained by WUM

Dark Galaxies, Sun-Earth-Moon Interaction, Tunguska Event—Explained by WUM

Bottom sediments of Lake Peyungda as a natural archive of climatic and catastrophic events in the past

Using scanning micro-XRF using synchrotron radiation, profiles of changes in the section depth of the elemental composition of the banded clays of Lake Peyungda (Krasnoyarsk region), located 33 km southwest of the epicenter of the Tunguska disaster of 1908, were obtained. The age model is confirmed by the presence of a dated layer of anomalous thickness associated with the fall and explosion of the Tunguska cosmic body (TCB). Changes in element contents in dated core layers are compared with instrumental meteorological observation data over the last century, and a relationship is found between the average annual temperature of the region and the elemental composition of coeval layers of bottom sediments (transfer function). According to scanning electron microscope and Raman spectroscopy, the 1908 layer is characterized by increased concentrations of Ti-containing minerals (anatase). The appearance of anatase is probably associated with the explosion of the TCB and the subsequent intense erosion of dolerite bodies, which are widely represented in the catchment area.

Computation of a possible Tunguska’s strewn field

On June 30, 1908, at about 0h 14.5 m UTC, the Tunguska Event occurred, most likely caused by the fall of a small stony asteroid of about 50–80 m in diameter over the basin of the Tunguska River (Central Siberia). The first expedition was made by the geologist Leonid Kulik 19 years after the event, and macroscopic meteorites have never been found around epicenter. In this paper, we want to establish whether stony macroscopic fragments could have survived the TCB’s airburst (Tunguska Cosmic Body) and where they might have fallen. For this purpose, we have implemented a fall model to describe the mass ablation, pancake expansion, airburst and fragments’s dark flight. In our scenario, the fragments have a higher mean strength than the main body due to Weibull’s law. The results, for a TCB with a kinetic energy of 15 Mt, atmospheric entry speed in the range of 11–20 km/s, trajectory inclination of 35° and average strength in the range of 3–70 MPa, tell us that for a macroscopic fragment with a mean strength between 14–85 MPa would be possible to survive the high pressure and temperature airburst to reach the ground. The falling speed of the fragments is in the range of 0.8–0.5 km/s, which favored their burial in the permafrost. The range of mean strength values for the TCB’s macroscopic fragment appears physically plausible if we consider the fall of Carancas in 2007, with an estimated strength of 20–40 MPa. So our possible strewn field, computed for a typical fragment’s speed of 10±3 km/s, is located about 11 km North-West from the epicenter, with an area of about 140km2. Finally, Cheko Lake, which by some authors is considered an impact crater, falls about 3.5 km outside the strewn fields at 3 sigma level and it is unlikely that it could be a real impact crater: only if the TCB’s trajectory had an azimuth in the range 150∘–180∘ would be in the strewn field area, but this is not consistent with the most likely trajectory azimuth.

Comment on Rogozin et al., (2023), Morphology of Lakes of the Central Tunguska Plateau (Krasnoyarsk krai, Evenkiya): New Data on the Problem of the Tunguska Event of 1908

In a recent paper, Rogozin and coauthors present a morphologic/seismostratigraphic study of two small lakes, Lake Zapovednoye (LZ) and Lake Peyungda (LP), located 50‒60 km east from the alleged epicenter of the 1908 Tunguska Event (TE), a large explosion believed to have been caused by an extraterrestrial impact. Data presented in that paper suggest a similar (although not specified) origin of these two lakes and Lake Cheko, located close to the TE epicenter. This led Rogozin et al., to question the impact crater origin of Lake Cheko, whose depression was interpreted by Gasperini et al., as caused by the freefall of an extraterrestrial fragment, which survived an atmospheric explosion. We analyze Rogozin et al., data, focusing on similarities and differences between Lake Cheko, LZ and LP, to determine whether their findings are relevant to the TE problem.

Comments on Paper by A.A. Kirsh “Electric Explosion of Aerosols. To the 115th Anniversary of the Tunguska Meteorite”

Comments on Paper by A.A. Kirsh “Electric Explosion of Aerosols. To the 115th Anniversary of the Tunguska Meteorite”

Electric Explosion of Aerosols. To the 115th Anniversary of the Tunguska Meteorite

Electric Explosion of Aerosols. To the 115th Anniversary of the Tunguska Meteorite

Comments on Paper by A.A. Kirsh “Electric Explosion of Aerosols. To the 115th Anniversary of the Tunguska Meteorite”

Comments on Paper by A.A. Kirsh “Electric Explosion of Aerosols. To the 115th Anniversary of the Tunguska Meteorite”

Morphology of Lakes of the Central Tunguska Plateau (Krasnoyarsk Krai, Evenkiya): New Data on the Problem of the Tunguska Event of 1908

Morphology of Lakes of the Central Tunguska Plateau (Krasnoyarsk Krai, Evenkiya): New Data on the Problem of the Tunguska Event of 1908

MORPHOLOGY OF LAKES OF THE CENTRAL TUNGUSKA PLATEAU (SIBERIA, EVENKIA): NEW INFORMATION ON THE PROBLEM OF THE “TUNGUSKA EVENT 1908”

The bottom morphology and thickness of bottom sediments of lakes Zapovednoye and Peyungda were studied by echo-sounding and seismic reflection profiling. The lakes are located in 60 km and 50 km from inferred explosion epicenter of “Tunguska event 1908”, respectively. We showed that both lakes have circular shape and funnel-like morphology with 60 and 34 m maximum water-depth, respectively, close to their geometrical centers. The shape of the lake is similar to famous Lake Cheko which is believed to be a secondary impact crater for Tunguska event of 1908. The shape of Lake Cheko was suggested to be highly unusual that was one of arguments to support the hypothesis of impact origin of Lake Cheko. We have shown that lakes Zapovednoye and Peyungda are examples of funnel-like deep lakes, and the age of both lakes exceeds are two thousand years. Therefore, we assume that all three lakes are most likely of karst origin. The similarity of the shape of the three reservoirs and their location in the riverbeds indicate the similar origin and testify against the hypothesis of the impact origin of Lake Cheko in 1908.

TRIC EXPLOSION OF AEROSOLS. TO THE 115TH ANNIVERSARY OF THE TUNGUSKA METEORITE

A hypothesis has been proposed according to which the preserved traces of the impact on the nature caused by the explosion of the Tunguska meteorite are the result of electrical discharges in a cloud of solid particles, which, when moving at the space velocity in the upper atmosphere, were heated up to a high temperature and, due to thermionic emission, acquired large positive charges. The released thermo-electrons attached to air molecules and lagged behind the charged particles. The separation of the charges in the cloud caused powerful discharges similar to horizontal lightnings in clouds. The consequences of the discharges in the cloud of highly charged solid particles, which gave rise to the generation of hard ionizing radiation, are discussed.

Macroparticle Charcoal in Lake Sediments of the Central Tunguska Plateau (Siberia, Evenkia) as an Indicator of Forest Fires and a Possible Trace of the Tunguska Event of 1908

Macroparticle Charcoal in Lake Sediments of the Central Tunguska Plateau (Siberia, Evenkia) as an Indicator of Forest Fires and a Possible Trace of the Tunguska Event of 1908

Detection of an Extremely Large Impact Flash on Jupiter by High-cadence Multiwavelength Observations

We report the detection of an optical impact flash on Jupiter on 2021 October 15 by a dedicated telescope, Planetary ObservatioN Camera for Optical Transient Surveys, for the first time. Our temporally resolved three-band observations of the flash allowed investigations of its optical energy without the need for approximations on the impact brightness temperature. The kinetic energy of the impactor was equivalent to approximately two megatons of TNT, an order of magnitude greater than that of previously detected flashes on Jupiter and comparable with the Tunguska impact on Earth in 1908. This detection indicates that Tunguska-like impact events on Jupiter occur approximately once per year, two to three orders of magnitude more frequently than terrestrial impacts. The observed flash displayed a single-temperature blackbody spectrum with an effective temperature of approximately 8300 K without clear temporal variation, possibly representing common radiative features of terrestrial Tunguska-class superbolides.

Suzdalevo Lake (Central Siberia, Russia)—A Tunguska Event-Related Impact Crater?

In 1908, a massive explosion known as the Tunguska Event (TE) occurred in Central Siberia. However, its origin remains widely discussed and environmental impacts are not known in detail. We investigated evidence of the TE in sediments of Suzdalevo Lake, which is located near the explosion epicenter. According to local nomads (Evenkis), Suzdalevo Lake did not exist before the TE and was considered as a possible impact-origin water body. However, apart from oral testimony, there is no evidence of the lake formation process. Two short sediment cores (SUZ1 and SUZ3) were retrieved from the lake and dated using 210Pb and 137Cs. The sedimentary record was characterized using magnetic susceptibility, X-ray fluorescence, and the screening for melted magnetic microspherules. To study possible effects of the TE on the lake ecosystem, we performed diatom and freshwater fauna remains analyses. Results indicate that the lake contains sediments that originated before the TE and thus its formation was not related to the impact. Also, the depth to diameter ratio of the lake basin is too low (<1/100) for a young impact crater. In one of the two cores (SUZ1), we documented distinct changes in the lake-catchment ecosystem that occurred within a 5-cm-thick depth interval calculated for the best fit depths for the year 1908 using three alternative age-depth models (CRS, CIC, CFCS), namely, increases in terrestrial matter input (abundant fine plant macroremains, peaks in magnetic susceptibility and the Sr to Rb ratio) and taxonomic diversity and relative abundance of benthic taxa. The shifts in aquatic biota assemblages were likely caused by nutrient supply and improved water column mixing following a catchment disturbance. Nevertheless, precise timing of the observed abrupt changes in relation to the TE is not clear due to uncertainty of the 210Pb dating method and absence of melted magnetic microspherules or an event layer. The disturbance signals in the proxy data may postdate the TE. Our results demonstrate potential usefulness of the paleolimnological approach to understand the possible environmental consequences of the TE and similar events elsewhere.

Substantiation of the Western Trajectory of the Tunguska Cosmic Body

Although more than 100 years have passed since the Tunguska event, no hypothesis has yet been proposed that would be consistent with the entire set of available facts and observations. A hypothesis has been put forward that the Tunguska Cosmic Body was an ice comet and its fall was accompanied by the fall of smaller fragments, whereas the TCB and fragments fell from intermediate Earth orbits. This explains all the observed phenomena without exception, including those that occurred long before the catastrophe. In this paper, we present eyewitnesses’ reports and objective materials obtained in the event area and confirming the TCB passage in the direction from West to East. The western trajectory has been traced for 3500 km from the Volga to the Lower Tunguska. We have carried out a detailed analysis of the eyewitnesses’ reports revealing the circumstances of passage of a huge fireball. We provide criticism of trajectories constructed without taking new information into account. We have estimated the energy released during this event and determined the mechanical properties of the comet matter. Science may obtain with new objects to study the direct impact of the comet matter on the Earth’s surface. This may be useful for evaluating the comet-related hazard.

Gupeiite Body in the Siberian Taiga (the Zone of Passage of the Tunguska Meteorite and the Vitim Bollid)

Many years have passed since the two cosmic bodies of the Tunguska meteorite and the Vitim bollid fell to Earth, but so far the substance of these bodies has not been found on Earth. Therefore, each metal body found on the territory of their passage is of particular interest. The body of iron silicide weighing 12 kg was studied, which was accidentally discovered by a hunter of the village of Kyker in the Siberian taiga on the right bank of the Nercha River, Tungokochensky district, Trans-Baikal Territory. Coordinates of the place of discovery are: 53º19'N lat, 116º19'E long. The territory is located in the zone of the passage of the Tunguska meteorite and the Vitim bollid, 25 km from the hunting village of Green Lake. The body is named “Ilekta” after the nearest stream flowing into the Nercha River. The composition and magnetic properties of the exotic find have been determined. It is established that its main mass is composed of iron silicide, gupesiite Fe3Si (zussite?) and contains inclusions of needle-like rhabdite. On the surface, the body is covered with a melting crust, with signs of boiling, a bubbly structure and a film of clay minerals of terrestrial origin. In the molten porous crust, eutectic-schreibersite-gupeiite is observed, and rare titanium carbide crystals are also noted. The magnetic susceptibility of the samples is not uniform (286.6 - 461.8 10-6E-06 m3/kg). It is assumed that a drop of melt separated from the flying space body, and experienced overheating and boiling of the surface layer in the dense layers of the atmosphere.

Atomic Visitors from Outer Space: The Tunguska Nuclear Hypothesis in Soviet Technological Imagination

In the mid‐1940s an idea arose that a crash of an atomically‐powered alien spaceship had caused the mysterious Tunguska explosion of 1908 in Siberia. Initially expressed as fiction, this speculation evolved into an active hypothesis that inspired decades’ worth of amateur investigations. This article examines the history of the Tunguska nuclear hypothesis and what it reveals about nuclear and technological culture in the USSR. It argues that Soviet technological imagination had a tendency to place the country's developments into a cosmic perspective that drew parallels between contemporary circumstances on Earth and the possible existence of technologies among civilizations elsewhere in the universe. Seeing the country's communist project as part of a cosmic drama involved a form of universalism that aligned with Marxist ideology, but also possessed distinctive influences and afterlives. By concentrating on cosmic analogies at play in Soviet technological imagination about Tunguska, this article also underscores how the suspected link between otherworldly civilizations and earthly actions informed ways of conceptualizing race and ethnicity, the boundaries of scientific knowledge, and the natural environment.