Peekskill Dark Flight: Terminal Velocity and Fall Time of the Fragment That Struck a Parked Car

This paper computes a complete entry budget for the Peekskill fireball, working only from published values and stated assumptions. The nominal body has a diameter of 0.45 metres at a bulk density of 3.50e+03 kilograms per cubic metre, giving an incoming mass of 0.167 tonnes. At the published entry speed of 14.7 kilometres per second its kinetic energy is 4.31e-03 kilotonnes of TNT equivalent. At the characteristic altitude of 38 kilometres the exponential atmosphere has a density of 6.25e-03 kilograms per cubic metre, the ram pressure on the body is 1.35 megapascals, the stagnation heating flux is 9.93e+03 megawatts per square metre, and the aerodynamic deceleration is 131 times terrestrial gravity. The ram pressure first reaches representative material strengths at computed altitudes of 56.7, 40.2 and 28.6 kilometres for the weakest, intermediate and strongest cases examined. The recovered material, the fragment that penetrated the rear of a parked car, amounts to 12.4 kilograms, which is 7.43 percent of the computed incoming mass. For scale, a single spherical fragment carrying that recovered mass would have a diameter of 19.1 centimetres, a terminal velocity of 121 metres per second, a fall time of 181 seconds from the end of the luminous path at 22 kilometres, and a wind drift of 1.81e+03 metres under a representative wind. 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.