The science of the heavenly bodies. Understanding of the objects in outer-space and their relationships, effects and reasons behind them. The knowledge of astronomy is based upon Tech-level and planet of origin as well as religious beliefs.
Linked with Planetary systems only to give specific understanding as to why certain things are what they are. Gives no bonus to navigating a system but may help with possible hindrance or short cuts etc. Primitive - Very Low Tech and Low Tech civilisations need astronomy or occult to give knowledge of their solar systems objects. In High Tech civilisations, it is generally known about the basic items in their system (i.e. Sun, Planets etc.), but Astronomy is necessary to know distances, effects, durations and other details pertinent to the whole universe.
Obligatory: