Exploring the diversity of solar wind-cometary interaction

Comets are compelling natural labs for plasma physics, hosting a large range of collisional regimes with heliocentric and cometocentric distances, which cannot be replicated in labs on Earth. When comets approach the Sun, their outgassing increases and a coma is produced. This very extended envelope of gas gets partially ionised and interacts with the magnetised solar wind.

The Rosetta two-year escort phase of comet 67P and the Giotto flyby of comet 1P/Halley revealed a large range of solar wind-comet interaction, extending from the solar wind reaching the cometary nucleus at low activity, to the formation of a bow shock and of a large diamagnetic cavity at high activity. The recently selected, multi-spacecraft Comet Interceptor mission aims at visiting a dynamically-new comet near 1 AU where active outgassing is anticipated, though currently unknown.

The aim of the proposed modelling project is to assess how the solar wind interacts with a highly outgassing comet and how this interaction evolves under different interplanetary and cometary conditions. Such a tool will not only shed lights on the physics at play, but will also be critical in preparation of operations for Comet Interceptor as well as to ultimately help building a 3D picture of the solar wind-comet interaction from the multi-point observations.