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The Mbale meteorite shower
Author(s) -
Jenniskens Peter,
Betlem Hans,
Betlem Jan,
Barifaijo Erasmus,
Schlüter Thomas,
Hampton Craig,
Laubenstein Matthias,
Kunz Joachim,
Heusser Gerd
Publication year - 1994
Publication title -
meteoritics
Language(s) - English
Resource type - Journals
eISSN - 1945-5100
pISSN - 0026-1114
DOI - 10.1111/j.1945-5100.1994.tb00678.x
Subject(s) - meteorite , geology , chondrite , radionuclide , altitude (triangle) , crust , mineralogy , radiochemistry , astrobiology , geochemistry , physics , chemistry , nuclear physics , geometry , mathematics
— On 1992 August 14 at 12:40 UTC, an ordinary chondrite of type L5/6 entered the atmosphere over Mbale, Uganda, broke up, and caused a strewn field of size 3 × 7 km. Shortly after the fall, an expedition gathered eye witness accounts and located the position of 48 impacts of masses between 0.1 g and 27.4 kg. Short‐lived radionuclide data were measured for two specimens, one of which was only 12 days after the fall. Subsequent recoveries of fragements has resulted in a total of 863 mass estimates by 1993 October. The surfaces of all fragments contain fusion crust. The meteorite shower caused some minor inconveniences. Most remarkably, a young boy was hit on the head by a small specimen. The data are interpreted as to indicate that the meteorite had an initial mass between 400–1000 kg (most likely ∼1000 kg) and approached Mbale from Az = 185 ± 15, H = 55 ± 15, and V ∞ = 13.5 ± 1.5/s. Orbital elements are given. Fragmentation of the initial mass started probably above 25 km altitude, but the final catastrophic breakup occurred at an altitude of 10–14 km. An estimated 190 ± 40 kg reached the Earth's surface minutes after the final breakup of which 150 kg of material has been recovered.