Meteor Crater as an Energy Scaling Problem: Impactor Size, Entry Speed and Excavation Ratio

This paper computes a complete entry budget for the Barringer crater impact, working only from published values and stated assumptions. The nominal body has a diameter of 50 metres at a bulk density of 7.80e+03 kilograms per cubic metre, giving an incoming mass of 5.11e+05 tonnes. At the published entry speed of 12.8 kilometres per second its kinetic energy is 10 megatonnes of TNT equivalent. At the characteristic altitude of 5 kilometres the exponential atmosphere has a density of 0.612 kilograms per cubic metre, the ram pressure on the body is 100 megapascals, the stagnation heating flux is 6.41e+05 megawatts per square metre, and the aerodynamic deceleration is 39.3 times terrestrial gravity. The ram pressure first reaches representative material strengths at computed altitudes of 54.8, 38.2 and 26.6 kilometres for the weakest, intermediate and strongest cases examined. The recovered material, the iron mass dispersed as fragments around the crater, amounts to 3.00e+07 kilograms, which is 5.88 percent of the computed incoming mass. The crater diameter of 1.20e+03 metres exceeds the body diameter by a factor of 24, and the incoming energy, spread over the crater area, corresponds to 3.70e+10 joules per square metre. 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.