In a way, the last 2 episode was a epilogue of sorts. Due to the nature of the story, the writing has to tie back to reality and the reality is human curiosity is bound to discover heliocentrism even if it's just an inspiration or a mention of someone else's work. Of course due to the heavy weight writing and time put into the other characters, the final 2 in no way live up to what they have delivered. Quite fitting end but not the best i'd say.