About:

Charlotte Goetz is a lecturer at Northumbria University, where she studies the interaction of the solar wind with comets. Her current work seeks to understand the formation of the diamagnetic cavity, a magnetic field free region in the inner coma that is so far poorly understood. She is the chair of the Far Environment Working Group for ESA’s upcoming mission Comet Interceptor and Co-I of the magnetometers on two of its three spacecraft. Her work includes analysing data from ESA’s Rosetta mission and numerical simulations of the plasma environment. 

Charlotte completed her PhD in Physics at Technische Universität Braunschweig in 2019 and spend three years as a Research Fellow at ESA in The Netherlands before joining Northumbria University.

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, which presents an obstacle to the solar wind flow and its magnetic field. 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 in particular focus on the formation of the diamagnetic cavity, a completely magnetic field free region unique to cometary environments and discuss latest results.