Rotation of fragments in catastrophic impact

The rotation of fragments produced by catastrophic impacts into basalt targets was investigated using framing camera records taken by Fujiwara and Tsukamoto (1980, Icarus44, 142–153). Most of the cores have low rotation rates, of the order 1 rev · sec^?1 or less. Many spall fragments have high rotation rates in the strong shear field produced in the target material by impact.