. . . It wasn't until the discovery of the Galilean moons of Jupiter that the philosophically desirable concept of a single center of celestial motion had to be abandoned in favor of systems with multiple systems . . . It wasn't really until Kepler with his simple elliptical orbits presented a new way of achieving the desired simplicity that heliocentrism became dominant, and it took Newton to make it unassailable.
Yes. Galileo's
The Starry Messenger is a beautiful, wonderful thing. It provided concrete evidence of celestial bodies (moons) orbiting something other than the Earth. That was important because it demonstrated that everything did not
have to orbit the Earth.
Kepler was a genius, and the amount of personal and religious turmoil going on around him (his mother being accused of witchcraft, estrangement from his wife, that he had to relocate because of the religious strife) meant that he had a lot of obstacles to overcome. That he was able to produce the 3 Laws of Planetary motion, the last being the Law of Harmony, destroyed the geocentric model, IMO.
Kepler's
The Somnium, which is a story, is one of my favorites.
Still, the fact that Aristarchus could figure out something like that way ahead of time is a feat of curiosity to me. There were simply too many assumptions that Aristarchus' findings ran counter to.
Also, from the little that I have read on this subject, I think geocentric theory had been around for longer and was better established, and since the Greeks lacked the tools to disprove geocentrism, this may have been a major factor in why heliocentrism failed to catch on (geocentrism was also important in certain variants of Greek religion, which could have been another reason).
That can never be underestimated. There was a belief, an erroneous one, that things by necessity orbited the Earth - and us, since we're in a favored position. Hence, the Copernican Principle: Check your assumptions!
