magine there were intelligent beings on Mercury, and they were at the state of development that Europe was in, in the early 1600s. Let's say they want to try and decide between the heliocentric (Sun-centered) model, and a model in which everything revolves around Mercury. Someone suggests looking at Earth, to see how lit-up it can look, like Galileo did with Venus. Let's assume you have a telescope that can magnify Earth well enough to see any phases it might have. Would this work well, for trying to tell the difference between the heliocentric and Mercury-centric models