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The Vitim Bolide.

Russian Impact Event

25th September 2002

Page Created: 30th October 2002

Updated: 3rd May 2005
Updated: 26th March 2006

I have taken great interest in the event that occured in Russia on the night of 24th/25th September 2002. I have recently been in contact with the the Institute of Solar-Terrestrial Physics (ISTP) at the Siberian Branch of the Russian Academy of Sciences and the Deputy Director, Victor Grigoryev was kind enough to send me this release of preliminary results which is in full below. Very interesting reading. Especially compared with everything that has already been said about this event in the last month. I will keep this page regularly updated as more news comes.


THE VITIM BOLIDE. PRELIMINARY RESULTS. (29th October 2002)

As has already been reported, a bright bolide was observed in the Irkutsk region in the night from September 24 to 25, 2002, which was accompanied by dramatic luminous and acoustic effects. 

The first reconnaissance expedition was sent to the Mamsko-Chuisky district of the Irkutsk region and carried out a relevant exploration of the phenomenon from October 22 to 27. The expedition was organized by the Institute of Solar-Terrestrial Physics (ISTP) at the Siberian Branch of the Russian Academy of Sciences, and by Irkutsk State University. The expedition was fitted out by the Institute of Geochemistry and the Institute of the Earth’s Crust SB RAS. The scientific program was worked out by Corresponding Member of RAS, Deputy Director of the ISTP SB RAS Victor Grigoryev, in close collaboration with  Vice-Chairman of the Meteorites Committee of RAS Mikhail Nazarov.

The expedition included its leader, senior researcher of the ISTP SB RAS, Director of the Astronomical Observatory at Irkutsk State University, Cand.Sc. (Phys.&Math.) Sergei Yazev, and the staff-member of the Observatory, Editor-in-Chief of the “Commersant - Vostochnaya Sibir” newspaper (supplement to the “Commersant” newspaper) Dmitri Semenov. In co-ordination with the ISTP SB RAS administration, the expedition was joined by journalists: Head of the Science and Education Division of the “Komsomolskaya pravda” newspaper Andrei Moiseyenko, the correspondents of the “Itogi” magazine Denis Ryabtsev and Dmitri Plenkin, and the correspondent of the Irkutsk “Pyatnitsa” weekly Sergei Solonenko. It was hoped that Alexander Perepelov from the Institute of Geochemistry SB RAS would join the expedition to collect a number of snow samples in the area of the fall, for a subsequent chemical analysis, but, for some reasons, his participation had to be canceled.

About 25 eye-witnesses from 6 populated localities in the Mamsko-Chuisky district were polled directly and by phone. The expedition members arrived in the settlement of Mama by plane; after polling the eye-witnesses, they departed by automobile to the settlement of Muskovit on the left bank of the Vitim river, upstream from Mama. Under way they polled the eye-witnesses in the settlement of Lugovsky (Lugovka). On October 24, the expedition members sailed across the Vitim by a motor boat (sludge ice had already been flowing in the river) and put up in the abandoned settlement of Bolshoi Severny. On the map, it is at about 10 km from the end point of the bolide’s path (explosion) as determined by the USAF satellite. In the evening of October 24, the passage was set up across the Bolshaya Severnaya river.

On October 25, the expedition got to the left bank of the Bolshaya Severnaya river and arrived the point indicated by the satellite. The geographical coordinates were monitored using the portable GPS receivers provided by the Institute of Geochemistry and the Institute of the Earth’s Crust SB RAS. Photographing pictures and selective video shooting, and also a radiation (from gamma-radiation) monitoring of terrain were carried out.

The information obtained is being processed and studied. Preliminary results of the expedition may be summarized as follows.

1. An exceptionally bright bolide was sighted over the territory of the Irkutsk region in the night from September 24 to 25, at about 1 hour 50 minutes of local time. In the settlement of Mama, through low clouds (cloud amount 10) with rain (the lower edge of clouds 1100-1200 m), the illumination brightness was very high (it hurt one to look at). because of the clouds, there were virtually no sightings of the bolide itself along the path of its flight. There were only a few observations of a “sphere with a tail”, perhaps, through rarely occurring openings in the clouds and from a large distance when looking sideways at the path. The flight of the fire-ball was sighted from distances of 70 kilometers at least. In the area over which there were continuous  clouds, the phenomenon look like a gradual appearance of a uniform white bright luminescence in the south-west that flooded the entire skies and then left north-eastwards. In the area of the settlements of Mama and Lugovka, the color of luminescence was observed to change from white to blue and reddish-claret-colored.

2. The Vitim bolide may be categorized as so-called electrophonic bolides. At the time of luminescence in the area of the settlement of Mama, eye-witnesses report sounds (rustling, buzzing). The employee of the Mama airport Georgy Konstantinovich Kaurtsev witnesses that the filament lamps of the chandelier glowed to half their intensity at the time of the bolide’s flight, although the entire settlement was devoid of electrical power supply that night. The airport guards Vera Ivanovna Semenova and Lidiya Nikolayevna Berezan pointed to a scaring phenomenon : a bright luminescence at the upper ends of thin little wood poles of the fence surrounding the airport’s meteorological ground. All that may be treated as resulting from a strong alternate electric current that was produced when the bolide was flying. It should be noted that the distance from the flight path in upper atmospheric layers to the settlement of Mama was several tens of kilometers.  

3. The explosion yield of the meteoroid flying at a high altitude in the atmosphere was significant. Local residents, who have a wealth of experience on mining operations using large (from hundreds to thousands of kilograms) charges of ammonite, claim that the explosion was extremely powerful. That was concluded from their sensations from the explosion and the shock wave. A strong shock, shakings, vibration of window-panes, etc. were observed within a radius of no less than 30-50 km from the epicenter.

4. It does not seem that, originally, the location of the explosion’s epicenter was accurately estimated. At the point indicated by the American satellite, the expedition detected only separate pine-trees, with their tops cut away (chopped off) at the height of 5-7 meters. The upper parts of the trees, 3-5 meters long, that had fallen in the northern direction, lay nearby one another. Obviously, that was not the result of the shock wave, because the adjacent trees remained intact. A sample of one of the spalled piece was brought to Irkutsk. It may be suggested that the forest was hit by fragments of the meteorite that exploded in the atmosphere. as witnessed by two hunters Dmitri Sasun and Pyotr Fedorchuk (the other hunters  now are in the taiga and are unable to be communicated with), to the south-east of the concerned point there are more conspicuous effects (topless tress occur more frequently than areas of recent cutting (especially on hill tops). Animals (sable) had left the area, so no hunting is possible there). Many hunter’s paths are obstructed by fallen trees. It was surmised that the epicenter of the exposure zone lies father to the east (or, perhaps, south-east) of the point previously indicated by the satellite, in the area between the Bolshaya Severnaya and Takhtynga rivers.

5. It was agreed upon with the District Mayor Nikolai Chekashin, once the rivers are frozen, in the anticipated area it is planned to use the snow-tractor in order to estimate the situation in the vicinities of the expected epicenter. Currently that place is virtually inaccessible because the rivers are not frozen yet. After the end of the hunting period (and the hunters have left the taiga), the exposure area will be determined more exactly. It has been ascertained already now that a minimum diameter of such an area is at least 25 kilometers.

6. As would be expected, the level of radiation (in gamma-radiation) was in the limits of natural background.

7. It seems appropriate to think of the organization of a large-scale (perhaps, international) summertime expedition in which professionals would participate. The members of the expedition think that there is good chance of spotting the traces of the fall of large fragments and, possibly, fragments themselves, on the slopes of tall mountains (without vegetation) facing the bolide’s flight direction.

8. The members of the expedition put special emphasis on a huge number of inaccuracies and  corruptions of facts which have recently been announced by the mass media, both regional and Russia-wide and in foreign countries, in connection with the sightings of the Vitim bolide. It should be especially stressed  that  there were no brightenings for the several days which would be associated with the meteorite (some of the eye-witnesses sighted a polar aurora a few days thereafter, but it had nothing to do with the meteorite). Contrary to reports, neither helicopter, nor all-terrain vehicle nor cutter were at the expedition members’ disposal. The expedition has not brought to Irkutsk any fragments of burnt trees, because no signs of inflammation have been able to be found to date. No impact craters were discovered. The expedition period was such as pointed out in this press release.

9. The objectives that were pursued by the expedition (polling of eye-witnesses, as well as a more exact determination of  the area in which possible fragments could have fallen, and of the character of damage) have been achieved. The success of the expedition is in many respects due to the very good organizational support from the administration of the Mamsko-Chuisky District (headed by Nikolai Chekashin), and of the settlement of Vitimsky (headed by Alexander Sergiy).

10. It should be noted that all what has been said here is of strictly preliminary character. Details will be available as the information from eye-witnesses and records made by the expedition members are processed. The IGTRK company is planning to prepare a special television item using video material acquired by the expedition.

 


Traces Of The Vitim Meteoroid
Informnauka (Informscience) Agency
May 2, 2005

"In 2002-2003, three expeditions involving specialists of the Institutes of Geochemistry, of Solar-Terrestrial Geophysics, and of the Earth’s Crust, Siberian Branch, Russian Academy of Sciences (Irkutsk) looked for traces of meteoroid that had fallen down in the north-east of the Irkutsk Province, in the Mamsko-Chuisk region. None of the expeditions found either craters or meteoroid fragments. Only fallen trees and minor particles of meteorite substance mark the direction of celestial body falling.

At night of September 25, 2002, inhabitants of the Mamsko-Chuisk and Bodaibinsk regions (Irkutsk Province) watched the flight of a bright bolide. Although the weather was bad, a lot of people distinctly saw the surgeless white bright fluorescence flaming up in the south-west. It filled up all the sky and then moved from the valley of the Vitim River to the north-eastern direction. The fluorescence turned from white to blue and then to redly vinous. The flight of meteoroid was accompanied by hollow rumble and completed with a blow and shaking of the earth.

The rumble and rustling heard by multiple natives may be connected with occurrence of electric wave in the atmosphere. The variable electric field was so strong that in the apartment houses of Mama settlement, which were cut off power supply at that time, incandescent lamps began to shine dimly. Seismic stations of the Irkutsk Province recorded only feeble local shaking. Bright fluorescence at the altitude of 62 kilometers was recorded by a US satellite which tracked the fluorescence down to the 30 kilometer altitude. The satellite identified the altitude and position data of two points, based on which the Russian scientists managed to reconstruct the meteorite’s trajectory and sent several expeditions in search of it.

Nearby the lane, the researchers found a lot of broken and uprooted trees. No hurricanes took place there at that time, so the forest could be brought down only by the blast wave of meteoroid flying in the lower atmosphere. However, amplitude of the wave coming down from the altitude of 20 to 30 kilometers was unable to cause such damage. This contradiction has not been resolved by specialists yet.

The second Vitim expedition looked for cosmogeneous substance particles, which could be preserved in the snow covering tops of the hills in the area where the meteorite had fallen down. However, the researchers found only hollow spherules, their size normally not exceeding 100 to 200 mcm. Fragments of these fragile spherical components colored brown and deep-brown contain oxide and silicate minerals typical of meteorites, namely of chondrites. The researchers also found grains of nickel-containing pyrite and particles of ferriferous compounds. The spherules’ shape and peculiarities of their structure do not contradict the version that they could drop out of the dust ablative trace of meteoroid. Substances contained in the spherules can hardly be related to the rock substance in the Mamsko-Chuisk region. Since no fragments of the Vitim meteoroid have been found so far, these spherulesare are now the single probable evidence of its material composition.

Nevertheless, the researchers have not given up hopes for finding fragments of the Vitim meteoroid. Probably, the bulk of its fragments dropped out either farther along the trajectory (if the US satellite erroneously determined altitudes of two points in the falling route) or aside from the calculated path (if the two points’ position data was identified mistakenly).
"

This information has been sourced from www.innovations-report.com and all credit goes to them and the writers of the above article.

 


Detection of Infrasound from the Vitim Bolide on September 24, 2002
O. I. Shumilov, E. A. Kasatkina, E. D. Tereshchenko,
S. N. Kulichkov, and A. N. Vasil’ev

Excerpt: "An infrasonic signal from an atmospheric bolide explosion was detected on September 24, 2002 near the Vitim river, Irkutsk region (57.9 N, 112.9 E). The signal was detected by three spatially separated microbarographs of the Polar Geophysical Institute (PGI), Kola Science Center, Russian Academy of Sciences, Apatity (67.6 N, 33 E) at a distance of 4000 km from the source. The acoustic-gravity signal from a falling meteorite at highlatitudes was detected at such a distance for the first time in Russia. ©2003 MAIK “Nauka/Interperiodica”."


The full abstract is available to download here in PDF format. (78 KB)

 

INFRASOUND FROM THE SEPTEMBER 24 2002 VITIM (SIBERIAN) FIREBALL
O.I. Shumilov, E.A. Kasatkina, E.D. Tereshchenko, S.N. Kulichkov,
O.M. Raspopov, A.N. Vasiljev and A.G. Struev


The full brief is available to download here in PDF format. (11 KB)

 


 

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