Introducing Geant4-IcyMoons!

Predicting and interpreting how energetic particles interact with ices is fundamental across various astrophysical settings, including interstellar clouds, comets, and the surfaces of icy planetary bodies. Within the Solar System, the subglacial oceans of icy satellites such as Europa and Enceladus represent some of the most compelling astrobiological environments. Clues of their composition can be gathered from their irradiated icy surfaces, to which they are coupled through various replenishment mechanisms.

Material exposed on these surfaces undergoes extensive alteration through continuous interaction with Jovian magnetospheric particles, a process that must be understood to interpret their chemical and spectral signatures.

We present Geant4-IcyMoons, a simulation toolkit that extends Geant4-DNA to describe the physical and chemical interactions between radiation, water ice, and material embedded within it. In this first stage, we focus on the fundamental elastic and inelastic scattering processes that govern how energetic electrons interact with both amorphous and hexagonal ice, determining energy deposition patterns and secondary electron cascades. This work paves the way for future extensions to ion irradiation and chemical reaction networks, including the transformation and degradation of additional compounds, such as salts and organics in planetary and interstellar environments.

We welcome new partners, ideas, and collaborations from anyone interested in radiation-driven chemistry, ice physics, or the origins of complex molecules in space. Learn more and get involved (soon) at github.com/Geant4-IcyMoons.