Meteorite Ablation Evaluated from the Data on the Density of Cosmic-Ray Tracks

We determined the form of the functional dependence of the rate of formation of tracks of galactic cosmic rays in meteorites (/t) on the shielding degree for ordinary chondrites with preatmospheric radius R > 5 cm based on published semiempirical data on /t. The resulting dependence was used to construct a nomogram which allowed us to estimate the ablation of a meteorite according to the average rate of track formation in it and its recovered mass. The calculated ablation of meteorites agrees with the estimates obtained by other methods. The average ablation for 83 ordinary chondrites was found to be equal to 78.4^+3.1 _–3.4%. The analysis of the data obtained demonstrated that the average preatmospheric mass of chondrites is M 90 kg, and for 95% of the meteorites, the preatmospheric masses fall in the interval 2–3500 kg, which corresponds to radii from 5 to 60 cm. It was found that meteorites with a small preatmospheric mass tend to higher ablation.