Atmosphere: Thin (95.97% carbon dioxide, 1.93% argon, 1.89% nitrogen)
Ares 4 lies just outside the official territory of the Union, placing it in a legal no-mans land.
As such, the Union Aerospace Corporation has established a base on the planet, to use it for research and development which would be illegal under the laws of the Union.
Despite this clear avoidance of the Unions’ laws, the UAC nevertheless enjoys support from many Union Governors. Business as usual, for the corrupt bureaucracy.