Named in honor of Erik Asphaug (1961– ), currently in the Earth Sciences Department at the University of California at Santa Cruz. Asphaug has pioneered the application of fracture mechanics and hydrodynamics to numerous problems in planetary science. Using a radar-derived model of (4769) Castalia, he has explored how effects of a hypervelocity impact depend on the projectile’s energy, the equation of state of the target material and the target’s internal configuration of fractures and voids. His calculations have important implications for our understanding of the collisional evolution of minor planets and for the mitigation of hazards due to comets and minor planets. (M 32791) _ _.