Astrocartography is the science of pinpointing locations in the galaxy to ensure that navigational computers will have up-to-date charts. This is a fairly important component of galactic society as the entire galaxy is always in motion, and stars have a tendency to drift. Without up-to-date data, a ship would emerge from hyperspace off target, by anywhere from a few meters, to several light-years, depending on just how out of date the information is.