I am having the hardest time figuring out the angular distance between Jupiter and Io, Europa, Ganymede and Callisto! I asked my teacher for help: "How would one find the angular distances between Jupiter and its moons?" and he said: "Do you know the field of view of your telescope? Once you know that, you can just compare the apparent Jupiter-moon distance to the full width of the field of view.: I'm must be just missing something. Can someone help me by either explaining what he meant, or by giving me a somewhat easy (it's late) way of finding it out for myself?