Solar wind proton precipitation onto the surface of Mercury

Mercury exhibits unique interactions with the plasma environment of space due to its intrinsic magnetic dipole and lack of atmosphere.

Although its magnetosphere exhibits similar phenomena to Earth, Mercury’s magnetosphere, being 7-8 times smaller relative to the planet, is more compact and dynamic. In addition, the absence of an atmosphere allows space plasma to interact with the planet’s surface directly.

These plasma-surface interactions both alter the plasma itself, as a majority of these particles are absorbed, and sputter the surface material to form an exosphere.

Plasma-surface interactions are common on other planetary bodies, but at Mercury these processes are strongly coupled to magnetospheric dynamics.

In this project, we will investigate the precipitation of solar wind protons onto Mercury’s surface using BepiColombo spacecraft data and a particle tracing model.

We will use energetic neutral atom and precipitating plasma data obtained by the Energetic Neutrals Analyzer (ENA) and the Miniature Ion Precipitation Analyser (MIPA), developed by IRF Kiruna, to address the following three scientific questions: When and where do the solar wind protons precipitate onto Mercury’s surface?

How do solar wind protons travel in the magnetosphere to precipitate to the surface? What physical mechanisms govern the temporal and spatial variations of plasma precipitation? Upon completing this project, we will have thoroughly characterized proton precipitation on Mercury’s surface.