Open Access

Nonlinear MHD waves and discontinuities in the Martian magnetosheath. Observations and 2D bi-ion MHD simulations

Earth, Planets and Space201450:BF03352171

https://doi.org/10.1186/BF03352171

Received: 4 August 1997

Accepted: 19 May 1998

Published: 6 June 2014

Abstract

The characteristic scale of the Martian magnetosheath is less than the pick-up gyroradius of oxygen ions. This leads to admissible differential motion of protons and heavies and a strong coupling between both ion fluids. 2D biion MHD simulations reveal many new interesting features in such Large Larmour Radius systems. The formation of an ion-composition boundary, which separates both plasmas, and structuring of the transition from proton dominated plasma of the solar wind origin to massive planetary plasma are the main features of the interaction. A comprehensive multi-instrument study of Martian plasma environment and the comparison with theoretical modelling initiated in the framework of the Visiting Science Programme of the International Space Science Institute (ISSI) in Bern (Switzerland) gives confirmation that Mars interacts with the solar wind like a comet which has a outgassing rate near to that of Grigg-Skjellerup. The results may also be relevant for small bodies which are surrounded by a neutral gas atmosphere (icy moons, asteroids, Mercury).