AOPP Seminar - The plasma environment of comets - wiggly lines and cold particles

As a comet approaches the Sun, ices on its surface sublimate and escape into space. Eventually, these neutrals are ionised and form a cloud of heavy (water) ions around the comet, forming a beautiful blue plasma tail that can be visible from Earth. Close up, the ion cloud presents an obstacle to the solar wind flow and the interplanetary magnetic field. The interaction between the two plasmas presents a fascinating laboratory to investigate an understand processes such as mass-loading and their influence on the tail and neutral coma. With decreasing heliocentric distance, the density of cometary heavy ions increases and thus the interaction of the two plasmas heavily depends on the heliocentric distance and activity of the comet.
The Rosetta spacecraft followed comet 67P/Churyumov-Gerasimenko for an entire perihelion passage observing the evolution of the cometary plasma and provided us with an extensive dataset to study the magnetic field and plasma at this comet at different activity stages.
In this talk we will journey with Rosetta and the comet and dive into the processes that govern the interaction region, its shape, variability and content. We will focus on boundaries such as the bow shock, and diamagnetic cavity and link our understanding of the small scales to the big scales that are visible to telescopes. Looking forward to the future, Comet Interceptor will provide a new, unique dataset which we’ll look forward to in the context of unanswered questions post-Rosetta.