Mars has assumed a special position within the Sol system, as the only major planetary settlement other than Earth. Its residents live mainly in Twelvetowns, a megalopolis in Valles Marineris, which, being home to an estimated 120 million inhabitants, is the largest continuous settlement in the Sol system. High above this settlement, a breathable atmosphere was established using a particle layer, which also protects the surface from the Sun's radiation and keeps its temperature steady.
The space around Mars is also of vital importance to the Terran military. Previously home to the USC, the military industry in this sector is responsible for some of the most respected ship designs in the Terran fleet. These days it is still the base of operations for the Terran Protectorate's war efforts, and since it is the outermost sector with access restrictions, it also serves as a barrier between those regions of Sol that are accessible to the majority, and the more well-guarded, gated sectors surrounding Earth.
Mars is the first of the systems to require an entry license and remains under constant guard by a Syn and its escorts which will become hostile to any unauthorised entry. upon gaining access to Mars and the rest of the outer core significant profit can be made from importing raw materials from the outer planets and from other systems for the Terran's intensive factories.