Galilean satellite obliquities

The obliquities, or angular separations between spin pole and orbit pole, for the Galilean satellites of Jupiter are all small but nonzero. We present calculations of the expected obliquity values based on the well known orbital parameters and recent estimates of the moments of inertia of the satellites, under the assumption that all are in Cassini states. The nonzero obliquities of these bodies are dynamically significant because they imply the existence of components of tidal and librational stress and dissipation which have been previously ignored. In addition, accurate observational determination of the obliquities will provide more direct estimates of the moments of inertia of these bodies than are currently available.