On the Temperatures of Aerodynamic Heating of Spherical Microparticles Modeling Microbiological Objects Entering the Earth’s Atmosphere at Cosmic Velocities

A mathematical model has been developed describing the motion in near–Earth space (NES) and aerodynamic heating upon entry into the atmosphere of spherical microparticles of carbon (graphite) with radii from 0.5 to 3 μm, modeling spores of terrestrial bacteria, as well as spores of hypothetical bacteria of extraterrestrial origin. The model is based on a joint numerical solution of the equations of motion in the NES of the specified model microbiological object (MBO) and the heat balance equation describing the change in the internal energy of the MBO. The calculated data obtained show that the maximum temperatures of aerodynamic heating of spores of terrestrial bacteria separating from the surfaces of large low-orbit objects of artificial origin are significantly lower than the maximum temperature of survival of spores of terrestrial bacteria during pulsed heating. In addition, the results of numerical experiments give grounds for the assumption that the spores of hypothetical extraterrestrial bacteria with a size of no more than 1 μm are able to withstand aerodynamic heating when entering the Earth’s atmosphere at speeds greater than both the second and third cosmic speeds.