are few things more frustrating than trying to determine the geography
of an interstellar political entity without maps.
Even with clearly marked maps, it can be difficult; maps generally display two dimensions, while the actual stars are in three.
A few maps, usually poorly drawn, give us most of our geographic area; more rarely, dialogue or thoughts give us explicit dimensions, or held territories. Figures given are generally as non-specific as possible - two weeks' travel, eight thousand light years, a million worlds - which means our precision is essentially limited to one significant figure.
Fortunately, we have enough vague references to be absolutely sure of what that single significant figure means.