3D hybrid simulations of the interaction of the solar wind with a weak comet

The interaction of the solar wind with weak comets, leading to the formation of the cometary magnetosphere with different types of structures in the solar wind and heavy ion plasmas, is simulated using a three-dimensional hybrid code. The simulations were performed for a wide range of gas production rates (6.2 x 10(26) mol/s less than or equal to Q less than or equal to 10(28) mol/s) and for an interplanetary magnetic field which is perpendicular to the incoming solar wind. When Q < 8.2 x 10(26) mol/s the cometary atmosphere forms a strong cycloid-type tail, whereas for Q greater than or equal to 10(27) Mol/S the cometary atmosphere forms a cone-type tail and structuring of the coma occurs. The results of these simulations may be applied to other weak massloading sources, e.g., dusty plasmas and cometary ion dynamics in the inner coma, AMPTE releases, and nonmagnetic bodies like Phobos, Deimos or even Pluto. Furthermore, the results presented here may be important for studying the dynamics of the ionized environment near the 'Solar Probe' spacecraft in the future. (C) 2002 Elsevier Science Ltd. All rights reserved.