Destruction of basaltic bodies by high-velocity impact

As a simulation of collisional processes among solid bodies of various sizes in the solar system, polycarbonate projectiles of mass 0.37 g were impacted against cubic basaltic rocks of about 2 to 10 cm and larger with a velocity of 2.6 km/sec. The corresponding energy imparted per unit mass of target ranges from about 10⁶ to 10⁹ ergs/g. The phenomena are classified into four categories with increasing target size: (1) complete destruction, (2) remaining core, (3) transition region, and (4) crater formation. Empirical formulas for the cumulative mass of the fragments and the mass of the maximum fragment are given. The similarity of these formulas is briefly discussed. The experimental results are applied to the examination of the hypothesis that a single Martian satellite was once ruptured by impact, leaving the present two satellites. It is suggested that the radius of the parent satellite was larger than about 30 km.