Fragments of the Chelyabinsk meteorite shower: Distribution of masses and sizes and constraints on the mass of the largest fragment

This paper reports data on the masses of fragments of the Chelyabinsk meteorite shower (fall of 15.02.2013). Assuming a lognormal distribution for the masses of fragments, the logarithm of the mean mass and standard deviation were estimated for the available data, describing the distribution density of masses and calculated diameters of fragments. Based on the dependence of the cumulative number of fragments with masses equal or greater than a given value, the mass of the largest fragment of the Chelyabinsk meteorite shower was estimated. It was shown that the most probable mass of such a fragment is hundreds of kilograms for a total mass of infalling material of 100 metric tons (t) and 1–2 t for a total mass of 1000 t, and the lower constraint for the maximum mass of the fragment is a few tens of kilograms.