Global Evolution of Solids in the Circumplanetary Subnebula

Grant #: NNX12AI81G
Senior Scientist: Paul Estrada


In this proposal, we seek to improve our understanding of the coagulation, growth, and evolution of solids in nebulae by specifically attacking a problem that has here-to-fore never been broached: the evolution of solids in the subnebulae of giant planets from which the observed giant planet satellite systems presumably formed. This unique set of observables offer great insight into the problem of solid body formation as a whole because the subnebulae of the giant planets differ greatly from their nebular analogs in terms of densities, pressures, temperatures, and dynamical times. The bulk of the mass of the satellites are found very close to their parent planets where dynamical times are comparable to solar nebula distances of ~0.05 - 0.5 AU, distances at which it is widely believed growth is problematic simply due to catastrophic particle-to-particle impact velocities. We will accomplish our goal by employing a global solids evolution code that we have developed for the nebula which can be tailored with few modifications to the study of the subnebular environment. The perceived significance of this project should be clear - the formation of planetesimals from dust remains the major seriously unexplained step in planetary formation, and our work here will improve our understanding of these important processes.