Crustal Stratigraphy and Light Terrain Formation on Ganymede: Implications of Ray and Halo Impact Craters

Abstract

Ganymede, Jupiter's largest moon, offers diverse impact crater morphologies and their ejecta blankets, which often appear as rays or halos on its icy surface. These ejecta blankets consist of bright or dark ice and non-ice materials [1, 2]. They provide insights into the subsurface composition of the terrains in which these craters are found. The light and dark terrains are formed through tectonic resurfacing and various surface processes [3]. Thus, studying these impact craters and their ejecta blankets helps us understand the vertical stratigraphy of Ganymede's crust and the tectonic processes responsible for the formation of light terrains. This study contributes to the scientific goals of the current JUICE mission to the Galilean moons. The study is based on ballistic ejecta emplacement models [4, 5, 6] and applies these principles of excavation dynamics to gain insights into Ganymede's crustal structure.