Survival of the impactor during hypervelocity collisions II: An analogue   for high porosity targets
  We investigated how a target's porosity affects the outcome of a collision, with respect to the impactor's fate. Laboratory impact experiments using peridot projectiles were performed at a speed range between 0.3 and 3.0 km/s, onto high porosity water-ice (40%) and fine-grained calcium carbonate (70%) targets. We report that the amount of implanted material in the target body increases with increasing target's porosity, while the size frequency distribution of the projectile's ejecta fragments becomes steeper. A supplementary Raman study showed no sign of change of the Raman spectra of the recovered olivine projectile fragments indicate minimal physical change. 
Chrysa Avdellidou, Mark C. Price, Marco Delbo, Mike J. Cole
astro-ph.EP