There are many star systems and planets in the Tech Infantry universe. Somewhat confusingly, most systems are named for their principal inhabited planets, not the stars they orbit. Thus, it is the Earth System, not the Sol System, even though Earth itself is now an uninhabited wasteland, its moon is gone, and Mars is the most populous world in the system. Two in-universe exceptions are Wilke's Star and Jennifer's Star, both of which have principal inhabited planets confusingly given the same name as the system primary star.
Early seasons of the game had no official map until one was finally created for Season 4.3 when many new players writing stories set all over the galaxy (instead of one core group of player characters sticking together as one military squad) made geography a more pressing concern.