These systems are named Crestus Alpha, Beta, Gamma, and Delta, in order of their distance from Ventix and Alexandria. The only settlements here are military Service Bases orbiting the major planet of each system. There are no underground colonies or installations, other than tracking and communications facilities.

Aliens Adventure Game (1991), Leading Edge Games

Resources

1. Aliens Adventure Game (1991), Leading Edge Games.
2. Andrew Hodgson, Senior Hard Surface Modeller at Industrial Light & Magic.