Heliocentrism, Geocentrism, etc... 

The whole section on the various models of the Solar System proposed throughout history seems to me a bit tangential and too detailed for this article.  After all, the Heliocentrism and Geocentrism articles exist for this very reason.  Going into the details of who came up with what is a little much, and no effort is made to connect the various models to the observation of Mars itself.    It might thus be a good idea to prune the section down to essentials, and relate to Mars specifically.