Carancas: The Entry Budget of a Small Body That Reached the Ground Fast Enough to Excavate a Crater

This paper computes a complete entry budget for the Carancas impact, working only from published values and stated assumptions. The nominal body has a diameter of 1.5 metres at a bulk density of 3.00e+03 kilograms per cubic metre, giving an incoming mass of 5.3 tonnes. At the published entry speed of 15 kilometres per second its kinetic energy is 0.143 kilotonnes of TNT equivalent. At the characteristic altitude of 10 kilometres the exponential atmosphere has a density of 0.305 kilograms per cubic metre, the ram pressure on the body is 68.7 megapascals, the stagnation heating flux is 5.15e+05 megawatts per square metre, and the aerodynamic deceleration is 2.34e+03 times terrestrial gravity. The ram pressure first reaches representative material strengths at computed altitudes of 57, 40.5 and 28.9 kilometres for the weakest, intermediate and strongest cases examined. The recovered material, the meteoritic material recovered around the crater, amounts to 20 kilograms, which is 0.377 percent of the computed incoming mass. The crater diameter of 13.5 metres exceeds the body diameter by a factor of 9, and the incoming energy, spread over the crater area, corresponds to 4.17e+09 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.