Аннотация:Impact rate estimates for the upper atmosphere are significantly higher than for the Earth's surface due to the presence of the atmosphere. Thus to account for this properly, one needs to model drag and ablation processes along the atmospheric trajectory (e.g. Bland and Artemieva, 2003). The best way to validate the resulting model is to apply it to meteorite-producing fireballs with a complete observational record. We consider the recent meteorite
fall – Košice (2010). In this investigation, we propose a special model based on the analytical solution of the drag and mass-loss equations (Gritsevich, 2009; Gritsevich et al., 2012). Using the available trajectory data (Borovička et al., 2013), two key dimensionless parameters (the ballistic coefficient and mass loss parameter) are obtained which allow us to describe the mass and velocity changes of the main fragment of the meteoroid entering the
atmosphere, as well as to estimate the pre-atmospheric meteoroid mass. Good agreement between the calculated functions and real trajectory characteristics is shown. We also apply statistical methods to describe the fragmentation process and provide insights into the pre-atmospheric meteoroid shape (Vinnikov et al., 2014). Furthermore, the most probable scenario suggests that the Košice meteoroid, prior to further extensive fragmentation in the lower atmosphere, consisted of two independent pieces with cumulative residual masses of approximately 2 kg and 9 kg respectively (Gritsevich et al., 2014a). The conducted analysis leads to the conclusion that two to three larger Košice fragments of 500-1000 g each should exist in addition to the already reported meteorite finds.