Lumenite and Eludium. Cities built on these moons have some special restrictions:
- They have a permanent -1 Morale penalty: "-1 Harsh Environment Penalty"
- Citizens only immigrate and emigrate at half the normal rate: "Harsh Environment reduces immigration"
- Every building requires some extra building materials. From the manual: "Harsh environments add 1 electronic part, 3 metal, and 2 plastic to the construction of every building level."
- Of course, moonbases require air to be imported or made from water, which must also be imported when ice is unavailable. One unit of air is required per citizen per minute, or 13 units per citizen per city report cycle.
Besides these restrictions, a moonbase is equal to a normal city in every known way.
The name can also refer to cities built on planets with harsh enviroments where the same effects apply.