The first two episodes of the latest Star Wars series, Ahsoka (which launched this week), focus on the struggle to acquire, unlock and interpret a map to an unknown destination. Sound familiar? It should: The Force Awakens did something awfully similar. Gizmodo’s James Whitbrook explores Star Wars’ apparent map obsession, and concludes it’s about knowledge, and how easily it’s lost. “And that’s it, really: maps are important in Star Wars because knowledge is power in Star Wars as much as a Death Star or the Force is. And specifically in the case of a long, long time ago, archival knowledge and history is incredibly vital to understanding why Star Wars is the way it is.”

Previously: Mapping Star Wars.

From a certain point of view, The Force Awakens is the story of how a rare and valuable map was kept out of the hands of an unscrupulous and extremely motivated collector. While a map served as the MacGuffin of Episode 7, maps of the Star Wars universe have been a thing for a while, at least in terms of supporting material.

According to this 2015 article on the Star Wars website about the history of maps of the Galaxy Far, Far Away, the first official map was produced in 1998. Since then the Star Wars galaxy’s map has been surprisingly consistent despite the addition of a huge amount of material (movies, TV shows, ancillary books and comics) and the canon shift that took place when Disney bought Lucasfilm: older maps—such as fan websites like Modi’s or W. R. van Hage’s, or the 2009 Star Wars: The Essential Atlas (updated with online appendices)—may not include planets that appear in later movies and TV shows (e.g., Jakku, Scarif or Lothal), but what does appear stays in the same place from map to map (i.e., Tatooine and Coruscant are in the same place). Jason Fry’s System Database keeps track of things.

The most up-to-date map I’ve been able to find is Henry Bernberg’s interactive Star Wars Galaxy Map, which has several advantages. Built using ArcGIS—he’s a GIS professional—and hosted using Carto, it has toggleable layers and is searchable (many maps online are simple images, which is tricky when you’re looking for a specific planet). It is, in other words, a useable map, which is a rare thing in science fiction and fantasy, and almost essential when dealing with an imaginary universe of Star Wars’ size.