Jack J Lissauer, NASA Ames Research Center, Moffett Field, CA, United States, Peter Bodenheimer, University of California Santa Cruz, Santa Cruz, CA, United States, David J Stevenson, California Institute of Technology, Pasadena, CA, United States, Gennaro D'Angelo, Los Alamos National Laboratory, T-3 Fluid Dynamics and Solid Mechanics Group, Los Alamos, NM, United States and Stuart J Weidenschilling, Planetary Science Institute, Tucson, AZ, United States