Nonlinear Processes in Geophysics www.nonlin-processes-geophys.net 1023-5809 1607-7946 7 3/4 2000 10.5194/npg-7-201-2000 http://www.nonlin-processes-geophys.net/7/201/2000/ http://www.nonlin-processes-geophys.net/7/201/2000/npg-7-201-2000.html http://www.nonlin-processes-geophys.net/7/201/2000/npg-7-201-2000.pdf 201 210 0000-00-00 MHD effects of the solar wind flow around planets H. K. Biernat N. V. Erkaev C. J. Farrugia D. F. Vogl W. Schaffenberger Space Research Institute, Austrian Academy of Sciences, Graz, Austria also at: Institute for Geophysics, Astrophysics and Meteorology, University of Graz, Austria Institute for Computational Modelling, Russian Academy of Sciences, Krasnoyarsk, Russia Institute for the Study of Earth, Oceans and Space, University of New Hampshire, Durham, USA The study of the interaction of the solar wind with magnetized and unmagnetized planets forms a central topic of space research. Focussing on planetary magnetosheaths, we review some major developments in this field. Magnetosheath structures depend crucially on the orientation of the interplanetary magnetic field, the solar wind Alfvén Mach number, the shape of the obstacle (axisymmetric/non-axisymmetric, etc.), the boundary conditions at the magnetopause (low/high magnetic shear), and the degree of thermal anisotropy of the plasma. We illustrate the cases of Earth, Jupiter and Venus. The terrestrial magnetosphere is axisymmetric and has been probed in-situ by many spacecraft. Jupiter's magnetosphere is highly non-axisymmetric. Furthermore, we study magnetohydrodynamic effects in the Venus magnetosheath.