Jupiter

Although the gas giant is itself uninhabited, a considerable number of its 79 natural satellites are, with the total population of the Jovian system reaching 45 million.  Both Earth and Mars had important colonies here.

Both the UNN and the MCRN had a fleet stationed in the key Jovian system, and tensions always ran high in this part of the Solar System.  The MCRN still has major shipyards on the Callisto moon.

The Jovian system was the focal point of the 2340-2341 war between Earth and Mars.

Geographical information :

Planet Diameter : 139,822 km
Population : 400 million (in the Jovian system)
Gravity : 2,528 g
Length of Day : 0.41 days
Length of Year : 12 years
Natural Satellites : 79
Surface temperature : -160°C to -110°C