* Astronomy

Title: On the pre-atmospheric size and maximum space erosion rate of the Patwar stony-iron meteorite
Authors: P. B. Price, R. S. Rajan, A. S. Tamhane

Within a given crystal grain inside a meteorite being eroded by collisions in interplanetary space, the production rate of tracks of heavy cosmic-ray nuclei increases with time. The results of calculations of track production rates and track densities as a function of depth, meteorite radius, and erosion rate are presented. Heavy cosmic-ray track densities in samples from the present surface of the Patwar stony-iron meteorite have been measured and are used, together with the calculations, to set an upper limit of ~10^-7 cm/yr on the space erosion rate of this meteorite and to deduce that its pre-atmospheric radius was between 14 and 16.5 cm, compared with the post-atmospheric radius of 13 cm. Over a large portion of the meteorite the maximum thickness of material ablated during atmospheric entry was ~1.4 cm.

Read more