• Experimental study on the collisional disruption of porous gypsum spheres

      Okamoto, C.; Arakawa, M. (The Meteoritical Society, 2009-01-01)
      In order to study the catastrophic disruption of porous bodies such as asteroids and planetesimals, we conducted several impact experiments using porous gypsum spheres (porosity: 50%). We investigated the fragment mass and velocity of disrupted gypsum spheres over a wide range of specific energies from 3 x 10^3 J/kg to 5 x 10^4 J/kg. We compared the largest fragment mass (ml/Mt) and the antipodal velocity (Va) of gypsum with those of non-porous materials such as basalt and ice. The results showed that the impact strength of gypsum was notably higher than that of the non-porous bodies; however, the fragment velocity of gypsum was slower than that of the non-porous bodies. This was because the micro-pores dispersed in the gypsum spheres caused a rapid attenuation of shock pressure in them. From these results, we expect that the collisional disruption of porous bodies could be significantly different from that of non-porous bodies.