You're the Galileo for a developing society on a remote archipelago on the far side of a tide-locked moon orbiting a gas giant. How do you figure out your place in that solar system? How do you convince others, who believe your world to be the center of the universe, of the truth? Will a road trip be involved, or can this be shown otherwise? I figure watching other moons in your planetary system fall into the shadow of the gas giant will play a big part in it, but knowing how well it worked out for Galileo (and others) in our history, how can my hero(ine) convince the masses they orbit a planet they can't see?