Describing the fragment mass distribution in meteorite showers

Abstract

The mass distribution of fragments is an important characteristic that often needs to be defined for forward modelling the interaction of disrupted meteoroids and asteroids with the atmosphere, and which can be inferred to some extent by the distribution of meteorites that fell to the ground. In previous studies, we derived a formula for the mass distribution of fragments of a disrupted body assuming a power law for the distribution in a differential form, and applied this formula to describe the results of many impact experiments modelling fragmentation of asteroids in outer space. The formula represents the cumulative number of fragments as a function of the fragment mass normalized to the total mass, the mass fraction of the largest fragment and the power index, which is the only free parameter adjusted to best fit the analytical distribution to the empirical one. Here, we use the proposed formula to describe the mass distributions of recovered meteorites that fell to the ground after the passage and disruption of thirteen extraterrestrial objects in the atmosphere, as well as the mass distributions of fragments of meteorite samples disrupted in impact experiments. A comparison is made between the distributions of unevaporated fragments of bodies disrupted in the atmosphere and the distributions obtained after the disruption of bodies in experiments. Some regularities in meteorite distributions and the influence of the incompleteness of the available collection of meteorites on their mass distribution are discussed.