BepiColombo as upstream solar wind monitor for Mars’ ionosphere

Abstract

<p>BepiColombo is a joint mission of the European Space Agency (ESA) and the Japan Aerospace Exploration Agency (JAXA) to the planet Mercury. It was launched in October 2018 and it is due to arrive at Mercury in late 2025. It consists of two spacecraft, the Mercury Planetary Orbiter (MPO) built by ESA, and the Mercury Magnetospheric Orbiter (MMO) built by JAXA, as well as a Mercury Transfer Module (MTM) for propulsion built by ESA. The cruise phase to Mercury will last ~7 years and constitutes an exceptional opportunity for studying the evolution of the solar wind, solar transients, as well as for planetary science and planetary space weather. On this last topic, BepiColombo is proving to be an important upstream solar wind monitor for the terrestrial planets. This is especially important for case of Mars where we currently do not have many observations of the upstream interplanetary magnetic field or solar wind. As consequence, the analysis and interpretation of ionospheric observations is challenging, especially when coronal mass ejections and solar energetic particles hit Mars and we do not have Earth plasma observatories in good alignment with Mars to provide the space weather context. While Mars missions such as Mars Express or MAVEN are able to investigate the impact of the solar wind on the ionosphere, BepiColombo can be the solar wind sentinel for Mars, so we can see the cause and effect. Therefore, this work focuses on the response of the Martian ionosphere to solar transient events which have been previously detected by BepiColombo, and for which we can provide the right upstream solar wind context, such as during the last months of 2021. The objective is to evaluate the response of the Martian ionosphere and its dynamics with more accuracy knowing the exact energy inputs from the solar wind as detected in-situ in the solar wind by BepiColombo.</p>