Non-grav. modeling of 9P/Tempel 1 Davidsson, Gutiérrez, Rickman Best mass estimate: 5.8x1013 kg (A’Hearn et al.: 7x1013 kg, now about 5x1013 kg) Outgassing restricted to northern hemisphere (5% in north, 0.1% in south) Zero thermal inertia, solid material  problem in reproducing  Thermal inertia <100 (SI units); still problems, unless layer energy absorption in porous material accounted for.

ISSI Comet Modeling Project Univ. of Michigan (Gombosi, Combi, Hansen, Tenishev) Univ. of Kansas (Cravens) Univ. of Colorado (Horanyi) NASA/JPL (Alexander) TU Braunschweig (Bagdonat, Glassmeier, Motschmann) Univ. of Bern (Altwegg, Balsiger, Thomas) Univ. of Uppsala (Rickman, Davidsson) ISSI (Bonnet, Geiss, von Steiger) ESA/ESTEC (Schwehm, Ho) ARIAS (Burgi) MSSL (Coates)

Goal Improve our understanding of how the cometary nucleus, coma (dust, neutral gas, ions, electrons), and the magnetized solar wind interact as a coupled physical system. Provide a state-of-the-art numerical model of an “entire comet”.

Goal Comet environment modeling in support of the Rosetta mission (67P/Churyumov-Gerasimenko) Data analysis, as spacecraft data starts rolling in (e.g., from OSIRIS)

Method Connecting existing state-of-the-art 3D models of various sub-regions of the comet. Writing model interfaces and passing data between sub-models (iteration if needed)

The following figures were happily stolen from Kenneth Hansen’s (+ISSI team) DPS (2005) poster “Rosetta-ISSI Comet 67P/Churyumov-Gerasimenko Environment Model”

Current status Working with simple cases (i.e., spherical nucleus, axisymmetric models) to demonstrate connectivity.

Near future Implement (or improve) remaining feed-back mechanisms Consider truly non-symmetric 3D cases