Before the location of the 7-Star Republic's Base was known, the Moon was thought to simply be a docking station for space shuttles on route to the Space Station. These docking trips of the supply shuttles made it possible for the 7-star republic to secretly construct a base deep in the interior of the moon without raising suspicion. Outside of the base and the docking station, there is little of note on the moon.
When Whitning and Blackout were attempting to locate the 7-Star Republic's base, Whitning made note of mass portal activity emanating from the moon, specifically the interior. It was then discovered that this was the location of the 7-star republic's headquarters. During the course of their missions, Blackout and Whitning have made multiple trips to the base.