These images, acquired by the Galileo spacecraft, show a comparison of the surfaces of the three icy moons Europa, Ganymede and Callisto, scaled to a resolution of 150 metres per pixel. The different distances from Jupiter and the associated balance of forces and heat inside the moons are the cause of these differences. Callisto is 'littered' with impact craters, but also covered by a dark layer of material of as yet unknown origin. The landscape of Ganymede is also characterised by many impacts, but unlike Callisto, many tectonic deformations are also visible. In contrast to Ganymede and Callisto, almost no craters are visible on Europa, which means that geological activity took place until more recent times.