The Mars Magnetosphere in the Tail of Comet C/2013 A1(Siding Spring)

Thursday, 18 December 2014
Yingjuan Ma1, Ying-Dong Jia2, Christopher T Russell3, Andrew F Nagy4, Gabor Toth5, Michael R Combi5, Roger V Yelle6, Chuanfei Dong7 and Stephen W Bougher7, (1)University of California Los Angeles, Los Angeles, CA, United States, (2)UCLA-IGPP, Los Angeles, CA, United States, (3)Univ California, Los Angeles, CA, United States, (4)University of Michigan Ann Arbor, Ann Arbor, MI, United States, (5)Univ Michigan, Ann Arbor, MI, United States, (6)University of Arizona, Tucson, AZ, United States, (7)AOSS, Ann Arbor,, MI, United States
Comet C/2013 A1 (Siding Spring) is an Oort cloud comet with an open path. In October 2014, comet Siding Spring passes about 12 Mars radii from the center of the planet. Carrying multiple active spacecraft, Mars is expected to enter the plasma tail of the comet, providing a unique opportunity to study the response of the Mars magnetosphere to the supersonic cometary tail.

We use our multi-fluid MHD model, which has been successfully applied to various comets, to simulate the composition of plasma trailing the comet. We include the effects of the decomposition, ionization, and charge exchange of major ion species around the comet in the model. The model result is then extracted along Mars orbit into a time dependent plasma distribution. Second, we simulate the real-time response of the Mars magnetosphere in the comet tail using a multi-fluid model of Mars. The comet tail plasma distribution is used as the upstream boundary conditions for the Mars model. The simulation results will be used to quantify the perturbations of the plasma environment around Mars and provide a baseline for interpreting plasma observations along the MAVEN orbit during the comet passage.