Model for the atmospheric fragmentation and scattering of a small celestial body

This paper considers the interaction of a small celestial body with a planetary atmosphere, which is treated as a two-stage process: the first stage is the fragmentation of the parental body (a model for this stage was developed by the authors) and the second stage involves breakup and scattering of the fragments. A model for the second stage is proposed in which the breakup is treated as a two-phase process of macrodisplacement of the fragments resulting from the fracture of the parental body. In the first phase there is accelerated rotation of the fragments around their centers of mass with preservation of contact between them. By the moment the contact ceases, they acquire a transverse velocity and there comes the second phase – the dispersion of the fragments, which ends with their scattering on the ground. A feature of this model is that the breakup occurs by an aerodynamic mechanism. In an analysis of the first phase of breakup, a system of differential equations for the kinetostatics of the fragments is formulated. Calculations are performed using as an example the atmospheric breakup of the Sikhote Alin meteoroid and the scattering of its fragments on the ground. It is shown that along with the numerical method for solving the system, an approximate analytical method is also possible. Calculation results for both methods are close and are in good agreement with observations of the indicated phenomenon.