Estimating mechanical properties of ice on Europa: Impact simulation and sensitivity analysis

The primary objective of NASA’s Europa Multiple Flyby Mission to Jupiter’s moon Europa is to determine the thickness of the ice covering the global subsurface ocean. If the ice proves too thick for the ice penetrating radar, however, an indirect method must be used to estimate the depth of the ice-water boundary. Unfortunately, the properties of Europan ice are not known precisely, with Young’s modulus having two orders of magnitude of uncertainty. It has been suggested that seismic response produced by an artificial impact could help estimating the mechanical properties of this ice. By optically measuring the induced surface motion with enough resolution, the dispersion curves can be determined. The associated elastic wave speeds are then used to estimate the moduli and density of the ice. The seismic response of the ice is modeled using a Finite Element Method solver. This presentation describes the sensitivity of the estimated mechanical properties to both temporal and spatial resolutions of the optica...