Speaker
Description
H2O molecules from Europa's water plumes may be detected by the 2031 flyby of the JUICE mission spacecraft. Previous work on the feasibility of these detections has assumed a collisionless model of the plume particles (Huybrighs et al., 2017). More sophisticated models of the plumes including particle collisions have shown that a shock could develop in the plume interior as rising particles collide with particles falling back to the moon's surface, limiting the plume's altitude. We investigate to what extent the limited altitude of the shocked plumes reduces the ability of the JUICE spacecraft to detect plume H2O molecules, by comparing the density of H2O molecules at altitudes above the shock region with those indicated by a collisionless model. We compare the feasibility of detecting putative plume sources (e.g. Roth et al. 2014, Jia et al. 2018, and Arnold 2019) given by the two models. By comparison with previous work we predict the effect of plume temperature and initial velocity on the size and reach of the plume and hence its likelihood of detection. We will also investigate whether a lower altitude flyby would significantly improve the area on Europa's surface over which the spacecraft could detect plumes.
