Mbale: Recovered-Mass Density and Fragment Statistics of an Equatorial Shower

This paper computes a complete entry budget for the Mbale shower, working only from published values and stated assumptions. The nominal body has a diameter of 1 metres at a bulk density of 3.40e+03 kilograms per cubic metre, giving an incoming mass of 1.78 tonnes. At the published entry speed of 13 kilometres per second its kinetic energy is 0.036 kilotonnes of TNT equivalent. At the characteristic altitude of 18 kilometres the exponential atmosphere has a density of 0.101 kilograms per cubic metre, the ram pressure on the body is 17 megapascals, the stagnation heating flux is 1.10e+05 megawatts per square metre, and the aerodynamic deceleration is 764 times terrestrial gravity. The ram pressure first reaches representative material strengths at computed altitudes of 55, 38.4 and 26.8 kilometres for the weakest, intermediate and strongest cases examined. The recovered material, the collected stones of the Mbale shower, amounts to 863 kilograms, which is 48.5 percent of the computed incoming mass. The largest recovered piece, at 27 kilograms, has a characteristic diameter of 24.8 centimetres, a terminal velocity of 138 metres per second, a fall time of 65.1 seconds from the end of the luminous path at 9 kilometres, and a wind drift of 651 metres under a representative wind. Over the mapped strewn area of 16.5 square kilometres, the recovered mass corresponds to 52.3 kilograms per square kilometre. The fragment census gives a mean collected mass of 0.863 kilograms per fragment. The largest stone, at 27 kilograms, carries 3.13 percent of the recovered total. All values are computed by the deposited program from the stated inputs; scenario calculations accompany every headline figure so that the sensitivity of each conclusion to its inputs is visible in the same record.