New Data concerning the Fall of the Great [Tungus] Meteorite on June 30, 1908, in Central Siberia*

Abstract

203This article contains a brief review of previous research; chiefly, however, new d&ta concerning the fall of the Tungus, central Siberia, meteorite on June 30, 1908: New testimony of eyewitnesses was collected by the author and others in 1928-32. A map of the region of the fall has been plotted. The meteorological QOIlditions on the morning of June 30, 1908, have been studied on the basis of data from meteor~ogical stations in central Siberia. The atmospheric phenomena accompanying the flight were studied with the aid ofbarograms from Siberian and European stations as well as seismograms recorded at Irkutsk. On the basis of sound phenomena and data supplied by barograms and seismograms, the moment of the explosion of the meteorite was determined <as ()h16'aG.M.T.). On the basis of investigations of acoustic and light phenomena, an estimate of the number of Wind-fallen ,trees, the amplitude of oscillation of the atmospheric pressure at Slutsk: and in England, and, finally, a comparison with other phenomena, the order of the work done 'by the explosion was calculated and found to be [between] 10"" and 10-ergs. From the testimony of eyewitnesses, the brightness, color, and form of the bead and the envelope of the meteorite, the character of the explosion, and the geocentric velocity were determined. Bounds for the [positions of the] trajectory and the radiant of the meteorite were found. [In §10 of this translation a simplification and an extension of Astapowitsch's discussion of the position of the t~ory and the radiant are given.]IfIIrDtluction.-Among the known great meteoritic phenomena of the last several thousand years, the fall of the meteorite of Oh 16'aG.M.T., June 30, 1908, must be placed in probably the front rank as far as the grandeur of the phenomena accompanying its movement within the limits of the 'Earth's atmosphere is conlished originally in theAstr. Jour. of the Soviet Union, 10,465-86, 1933. A brief English abstract and extensive bibliography were published by Astapowitsch in P. A., 48, 310-17, 1938. Unfortunately, errors appearing in the original remain uncorrected in that abstract and the carefully collated map published in Astapowitsch's paper is omitted.. tTranslated from the Russian of 1. S. Astapowitsch by Gerhard Wiens, at the suggestion and with the cooperation of Lincoln LaPaz. Words, symbols, and critical commentaries inclosed in square brackets [] have been inserted by the senior translator, who wishes to express his appreciation of a grant generouslỹ ovided by the Graduate Council of the Ohio State University to cover expenses incidental to the preparation of this translation.

New data on accounts of the 1908 Tunguska event

“…Astapovich was also a little bit more cautious than Kulik, and while excluding "an ordinary windstorm", he recognized clouds in the north [Astapowitsch, 1940]:…”

“…Remarkably that Astapovich marked the map as of indefinitely "on the day of the event", while even data from the meteorological station in Kezhma (which Astapovich presented in [Astapowitsch, 1940]) shows complete cloud cover at 1 p.m. Moreover at 1 p.m. cloudiness strongly increased at several more meteorological stations to the south from the epicenter.…”

“…The Bronsten's attempts to "improve" the account will be not commented, just adding that a barograph in Kirensk recorded arrival of the air-pressure disturbance at 7 h. 48 min. [Astapowitsch, 1940], and the barograph detected air-pressure disturbances of very low frequency.…”

“…In the course of the astronomical and geophysical expeditions of 1930 -1932, on the rivers Angara and Lena, he gathered data regarding the event. A. Ovchinnikov (Geophysical Institute, Irkutsk), who visited the epicenter in August, 1932 shared some info with him [Astapowitsch, 1940]. Anyway, in 1951 Astapovich published a relatively large review of the event, and wrote in there the following info (the author is unaware why the Ovchinnikov's name changed from 'A.'…”

Thermal Radiation and Fires After Impacts of Cosmic Objects

“…The observational data obtained by the early expeditions of the 1920s and 1930s indicate that a complete burn uniformly covered the trunks of leveled and standing trees for many kilometers, and soils also bore evidence of thermal damage (Astapovich 1933). Although the boundary of an ignition area was not determined, the distance of burn from the epicenter was estimated to be 15-20 km (Kulik 1939(Kulik , 1976, and >25 km in the southeastern direction (Krinov 1949).…”