Same thing with moons Callisto, Ganymede, Europa, and Io. They all have different sizes meaning to accomplish that they have different rotation speeds - yet still all keep the same face towards planet as they orbit, meaning that each moon turns once on its axis for every orbit around Jupiter or Saturn But, the view of the moons (from anywhere except the planet) is that you are always seeing their backside and frontside. The view from planet is that they face the same way. Other moons such as Hyperion and Phoebe do not do this. You constantly see both sides from Jupiter surface.