Propagated formal uncertainties in Europa’s position (from 2030 to 1890) for the radio science, astrometry and combined solutions (obtained with Tudat and NOE). Panel a: radio science solution, panel b: astrometry-only and combined solutions. The errors are given in the RTN (radial, tangential, normal) directions and the scales are identical on both panels a and b. To keep both the computational and memory loads manageable, we used a propagation output of one point per year and performed data smoothing over five-year windows to avoid aliasing effects. While this does not allow for local uncertainty analyses, it is nonetheless sufficient to investigate the long-term behaviour of the position errors far from the missions period.