The fractality of the TGD Universe motivates a model for planetary systems as miniature version of the model of spiral galaxy discussed in (see this). The first two key elements are many-sheeted space-time, the notion of magnetic flux tubes - both monopole flux tubes and gravitational flux tubes without monopole flux - and the identification of dark matter as phases of ordinary matter labelled by effective Planck constant heff=n× h0 (h=6h0 is a good guess (see this, this and this). Also the TGD generalization of Nottale's model for planetary system as analog of Bohr atom characterized by large gravitational Planck constant hgr identified as heff is in a key role (see this) and this).
A further key aspect is the prediction of twistor lift of TGD (see this) and this) that cosmological constant is length scale dependent and characterizes various systems in all scales. The phase transitions reducing the cosmological constant lead to expansion of space-time sheet and define a sequence of jerks replacing smooth cosmic expansion for astrophysical objects expected in standard cosmology but not observed.
TGD provides a model for "cold fusion" based on dark fusion (see this) and suggests the possibility of fusion outside stellar cores perhaps serving as "warm-up band" for hot fusion during pre-stellar evolution. Also a new view about nuclear fusion in stellar interiors is suggestive (see this).
I did not originally end up with the model to be discussed from general theoretical considerations.
See the chapter Could solar system be modelled as a miniature version of spiral galaxy? or the article with the same title.