The Induced Magnetospheres of Mars, Venus, and Titan

Abstract

This article summarizes and aims at comparing the main features of the induced magnetospheres of Mars, Venus and Titan. All three objects form a well-defined induced magnetosphere (IM) and magnetotail as a consequence of the interaction of an external wind of plasma with the ionosphere and the exosphere of these objects. In all three, photoionization seems to be the most important ionization process. In all three, the IM displays a clear outer boundary characterized by an enhancement of magnetic field draping and massloading, along with a change in the plasma composition, a decrease in the plasma temperature, a deflection of the external flow, and, at least for Mars and Titan, an increase of the total density. Also, their magnetotail geometries follow the orientation of the upstream magnetic field and flow velocity under quasi-steady conditions. Exceptions to this are fossil fields observed at Titan and the near Mars regions where crustal fields dominate the magnetic topology. Magnetotails also concentrate the escaping plasma flux from these three objects and similar acceleration mechanisms are thought to be at work. In the case of Mars and Titan, global reconfiguration of the magnetic field topology (reconnection with the crustal sources and exits into Saturn's magnetosheath, respectively) may lead to important losses of C. Bertucci ( )

The Twisted Configuration of the Martian Magnetotail: MAVEN Observations

“…Early Mars missions that carried magnetometers revealed that this interaction results in a dual-lobe magnetotail with a central cross-tail current sheet, similar to a comet-or Venus-like interaction with the solar wind (Bertucci et al, 2011;Fedorov et al, 2006;Luhmann et al, 1991;Yeroshenko et al, 1990). To first order, this magnetosphere forms as the upstream interplanetary magnetic field (IMF) drapes around the planet while interacting with the obstacle presented by the upper atmosphere and ionosphere .…”

Imaging Plasma Density Structures in the Soft X-Rays Generated by Solar Wind Charge Exchange with Neutrals

“…Similar objectives govern the planetary discipline which seeks, amongst other tasks, to determine the nature of the solar wind's interaction with comets and the other planets within our solar system, and in particular to quantify the role that plasma processes play in the loss of their atmospheres. Once the conditions governing the occurrence patterns of the various fundamental processes (including reconnection, diffusion, instabilities, particle acceleration, and ion-neutral interactions) that control the mass, energy, and momentum flow are well understood, it will become possible to construct numerical simulations that provide accurate space weather predictions for the immediate environment of the Earth and other solar system objects (e.g., Bertucci et al 2011). Figure 1 presents results from state-of-the-art hybrid code simulations for the plasma interactions that occur in the vicinity of Venus, Mars, and the Earth.…”

Dependence of the location of the Martian magnetic lobes on the interplanetary magnetic field direction: Observations from Mars Global Surveyor

“…An extensive review on the different regions and boundaries of the induced magnetospheres of Mars, Venus, and Titan together with a comparison between them can be found in Bertucci et al [2011]. The induced magnetotail of Venus has been extensively studied by Pioneer Venus Orbiter (PVO) and Venus Express spacecrafts [McComas et al, 1986;Saunders and Russell, 1986;Zhang et al, 2010].…”