none of the surface features on jupiter's moons would appear as prominent as the lunar maria do when the moon is viewed from earth. dark and light patches would be visible on io's surface due to the coloration of sulfur that covers io, and the largest volcanoes would be designated by dark points, but the lack of large, contrasting features results in a poor view of it. europa, however, would appear as a completely featureless white disc. even when viewed from nearby, most spacecraft images use contrast enhancements to clearly show the cracks in the europan ice. vague dark and light patches would be visible on ganymede, whereas callisto is much too distant for any features to be made out.