During recent decades new satellite data and numerical and theoretical models of convection-driven dynamos have greatly improved our understanding of planetary magnetic fields. It is a good time to take stock of the current state of knowledge. This session invites presentations that deal with all aspects of the internal magnetic fields of the solar system planets, their satellites, differentiated asteroids and exoplanets, including the processes in the interior that are relevant for their generation. Topics can include, for instance, new observational constraints on magnetic field geometry and history, the dynamo process in the deep interior of planets, and processes in the overlying silicate shell or insulating envelope that are relevant for the magnetic field. We also welcome contributions that focus on the geodynamo or on the evolution of the Earth's core-mantle system if they can be extrapolated to other planets. Priority will be given to presentations that use or explain observational data or that provide a significant progress in the general understanding of planetary magnetism.