5170 20210125135923.0 POSTER-2021-0009 Van Hoolst, Tim The rotation and interior of Ganymede 2020 2020-05-04 The rotation rate of Ganymede, the largest satellite of Jupiter, is on average equal to its orbital mean motion but cannot be constant on orbital time scale as a result of the gravitational torque exerted by Jupiter on the moon. Here we discuss small deviations from the average rotation rate, evaluate polar motion, and discuss Ganymede's obliquity. We examine different time scales, from diurnal to long-period, and assess the potential of using rotation as probes of the interior structure. The ESA JUICE (JUpiter ICy moons Explorer) mission will accurately measure the rotation of Ganymede during its orbital phase around the satellite starting in 2032. We report on different theoretical aspects of the rotation for realistic models of the interior of Ganymede, include tidal deformations and take into account the low-degree gravity field and topography of Ganymede. We assess the advantages of a joint use of rotation and tides to constrain the satellite's interior structure, in particular its ice shell and ocean. Prodex/ Prodex/ Prodex NO Baland, Rose-Marie Coyette, Alexis Yseboodt, Marie 22nd EGU General Assembly, held online rose-marie.baland@observatoire.be https://meetingorganizer.copernicus.org/EGU2020/EGU2020-13749.html 297173 http://publi2-as.oma.be/record/5170/files/EGU2020-13749-print.pdf 11378 http://publi2-as.oma.be/record/5170/files/EGU2020-13749-print.jpg?subformat=icon-180 icon-180 8278 http://publi2-as.oma.be/record/5170/files/EGU2020-13749-print.gif?subformat=icon icon CPOSTER