Night after night, pixel Galileo Galilei has watched four tiny dots dance around Jupiter, never in the same place twice. Tonight he decides to stop sketching them and chase one instead, and he names the chase Jupiter Moon Trail.
The great planet sits in the middle of the sky like a striped boulder, and nothing can pass through it. Its moon keeps sliding round on its ring, so he has to guess where it will be rather than where it is. Every catch makes his trail of starlight longer and the sky a little more crowded.










