Hermes

Mercury is the first planet in the Sol system.

Physical characteristics
Mercury is the smallest terrestrial planet in the Sol system, smaller than the largest satellites of Jupiter and Saturn. However, Mercury is incredibly dense, rich with metals as well as a high iron content in its core. Mercury-type worlds are common candidates for ideal systems for colonization, not only for their rich minerals and resources, but the presence of a magnetosphere makes them good areas to discharge a drive a core. Building settlements on such worlds are relatively easy as a result.

Mercury is littered with craters due to its thin atmosphere. These craters range in many sizes, the largest having a diameter of 1,550 km.

Mercury has a slight axial tilt and has a long day/night cycle as a result of being close to its star.

Colonization
Mercury was settled by the Eteno Imperial Triumvirate. They built core pumping facilities on the surface, making it one of many iron worlds.