Structure of Callisto and Ice Holes on Its Surface

The discovery of the induced magnetic field of Callisto that is a satellite of Jupiter has been interpreted as evidence for a subsurface salty liquid-water ocean, so we consider a layered structure of Callisto, i.e., a rock-metal core, an outer layer of ice and a middle layer of ocean. For the rock-metal core we try to indicate how the temperature, pressure and mass density depend on the depth. Due to motion across the magnetic field of Jupiter in a plasma environment, the ice shell of Callisto must be broken down by electric current.