Ionospheric Plasma Transported into the Martian Magnetosheath

<p>How the heavy ionospheric ions escape the Martian atmosphere is still not solved. Missions such as the Mars Express (MEX) satellite have observed significant heavy ions (O<sub>2<sup>+</sup></sub> and Co<sub>2<sup>+</sup></sub>) on the night side of the terminator. The hot oxygen corona when ionized gives rise to the pickup ions but they are of lighter mass.  With the more comprehensive instrumentation on the MAVEN mission, it is clear that cold heavy ions are transported down the tail of the planet. However, there has not yet been a good explanation of how heavy ions can reach into the Martian sheath in high density concentrations. In December 2020 the MAVEN satellite was observing on the dusk side tailward of the terminator with an orbital configuration allowing the density changes and the ion compositions to be followed. In this presentation the focus is on three subsequent orbits where a channel of heavy ions with high densities reaches out into the sheath. In this presentation we will argue for different possible processes that could explain the observations.</p>