HR: 0800h
AN: P51A-0910    [Abstracts]
TI: Numerical Simulations of Impacts Into Icy Targets Using the Pactech/SAIC Equation of State for Water
AU: * Ong, L
EM: long@ucsc.edu
AF: UCSC, Earth Sciences Dept. University of California, Santa Cruz, CA 95064
AU: * Ong, L
EM: long@ucsc.edu
AF: LANL, Los Alamos National Laboratory, Los Alamos, NM 87545
AU: Gisler, G
EM: grg@lanl.gov
AF: LANL, Los Alamos National Laboratory, Los Alamos, NM 87545
AU: Asphaug, E
EM: asphaug@es.ucsc.edu
AF: UCSC, Earth Sciences Dept. University of California, Santa Cruz, CA 95064
AU: Gittings, M
EM: gittings@lanl.gov
AF: LANL, Los Alamos National Laboratory, Los Alamos, NM 87545
AU: Gittings, M
EM: gittings@lanl.gov
AF: SAIC, Science Applications International Corporation, San Diego, CA 92121
AU: Weaver, R
EM: rpw@lanl.gov
AF: LANL, Los Alamos National Laboratory, Los Alamos, NM 87545
AB: Recent missions to comet 9P/Tempel 1 and other icy bodies in the outer solar system, in addition to ongoing debates over the significance of water in crater formation on Mars, have focused attention on impact processes on icy and ice-silicate bodies. Despite the varying effects of porosity, strength, composition, and target structure on impact processes on these diverse planetary bodies, ice-rich objects are often grouped together because of our limited understanding of cratering processes in ice. We have validated the new Pactech/SAIC water equation of state by calling the EOS directly, as well as by using a tabular version, in the continuous adaptive mesh Eulerian hydrocode RAGE (jointly developed by SAIC and LANL; Clover and Gittings 2002). The Pactech/SAIC water EOS incorporates six ice phases in the tested pressure range (0 to 1000 GPa), the liquid phase, and the gas phase. Pactech/SAIC water EOS phase boundaries correspond very well to empirical phase boundary data, including all triple points and a Maxwell construction for the vapor dome. We have used the validated Pactech/SAIC water EOS in two-dimensional RAGE simulations of vertical impacts of ice, nylon, and metal projectiles into ice targets. We also have varied target properties such as strength and porosity to explore the effects of material properties on crater morphologies. We have compared simulations with results from low-velocity (Kato et al. 1995) and hypervelocity (Burchell and Johnson 2005) impact experiments into water ice, as part of this broad-scale validation and verification of RAGE for diverse planetary applications including impacts on Mars and Europa.
DE: 5420 Impact phenomena, cratering (6022, 8136)
DE: 5422 Ices
DE: 6020 Ices
SC: Planetary Sciences [P]
MN: Fall Meeting 2005