Destruction Models for Bodies Entering a Planetary Atmosphere

L. A. Egorova, V. V. Lokhin

Protecting the Earth against Collisions with Asteroids and Comet Nuclei, In: A. M. Finkelstein, W. F. Huebner, V. A. Shor (Eds) Proceedings of the International Conference “Asteroid-Comet Hazard-2009”, StP: Nauka, 222–227 (2010)

Ключевые слова: Very Long Baseline Interferometry (VLBI), Near Earth Objects (NEOs), a body moving in a planet atmosphere, aerodynamic loads, the forces of inertia, heat flux, ablation, the Lam? equations, the nature of the destruction of the body, the altitude of destruction for well-known meteoroids, composition and space velocities, flight of small fragments, thermoelastic forces, the process of destruction, the fragment's size, the state of stress in the hot object of decreasing radius, "thermal explosion" due to the rapid evaporation of small fragments, a typical size range of fragments, the length of run, time of evaporation of small particles, explosive outbreak and disappearance of asteroids, final stages of asteroids' demise

Аннотация

A body moving in a planet atmosphere is under the influence of aerodynamic loads, the forces of inertia, and heat flux. As a result, the body undergoes ablation and even could be completely destroyed. First of all, the stressed state within the body at any time is determined through an accurate solution of the Lam equations. Based on the solution, one can investigate the nature of the destruction of the body and evaluate the altitude of destruction for well-known meteoroids if their composition and space velocities are known. During the flight of small fragments thermoelastic forces become significant. Unlike large fragments smaller fragments heat up in a short time resulting in accelerating the process of destruction, which also contributes to the ablation, i. e., reduces the fragment's size. The state of stress in the hot object of decreasing radius is under consideration in this paper. Finally, "thermal explosion" due to the rapid evaporation of small fragments in a typical size range of the fragments was considered. Assessment of the length of run and time of evaporation of small particles allows one to speak about the explosive outbreak and disappearance of the asteroid in the final stages of its demise