Presentation #308.11 in the session “Active Satellites”.
Events which emplace fresh material onto Europa’s surface may be irregular and catastrophic, (e.g., large-scale impacts) or localized, potentially extant, processes in which faults, fractures, or brine transport bring subsurface liquid to the surface. This liquid may originate from shallow reservoirs within the ice shell or directly from the ocean . Emplacement may be a slow, extrusive process, or quicker, potentially accompanied by cryovolcanic plumes (e.g. [2,3,4]). Material emitted in these processes could allow Europa’s subsurface ocean to be characterized via either: 1) Detection and analysis of ejecta particles lofted by micrometeoritic impacts; 2) Direct sampling of plume particles in space (if plumes are present). The SUrface Dust Analyzer (SUDA) time-of-flight mass spectrometer, onboard the Europa Clipper spacecraft, is designed to measure the compositions and trajectories of such impact ejecta particles and/or plume material . The trajectories of impact ejecta, and potentially even those of directly emitted plume grains, are likely to be considerably affected by local surface properties, over a range of scales. Here we present our initial progress in producing new, and collating existing, digital terrain models (DTMs) of the Europan surface, together with the development of Monte Carlo impact ejecta trajectory simulations. DTMs have been produced using both stereophotogrammetry and photoclinometry techniques . The DTMs of features of interest, with their associated roughness and slope information, will provide important inputs for ejecta trajectory simulations. Previous models [7,8] have assumed particles originate from perfect planar surfaces, whereas actual micrometeoroids impact surfaces with varying characteristics, such as roughness and slope, over a range of incidence angles. Utilizing DTM-derived surface information, and realistic assumptions of surface properties at smaller scales, an impact ejecta simulation code is under development. The initial output of this code is shown in Fig. 1, which shows the trajectories of multiple ejecta originating from a location within Powys Regio.
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