[meteorite-list] Traces Of The Vitim Meteoroid

From: Ron Baalke <baalke_at_meteoritecentral.com>
Date: Mon May 2 13:43:33 2005
Message-ID: <200505021743.j42Hh1g13717_at_zagami.jpl.nasa.gov>

http://www.innovations-report.com/html/reports/earth_sciences/report-43821.html

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).

More information: www.informnauka.ru
Received on Mon 02 May 2005 01:43:00 PM PDT