The Hollow Moon was a small, nearly spherical moon, that orbited 60,000 miles above Wunderland . It was approximatly four mile in diameter. The moon got its name because radar scans had shown it to have a hollow portion at its center roughly a mile across. Its metal content, though lower than other orbiting bodies due to its hollow core, was still high enough to warrant interest by Belters from the Serpent Swarm.
Initial investigation of the moon revealed what appeared to be doors leading into the center of the moon, but they were blocked. Before scientific attempts could be made to gain access to the Hollow Moon, the invasion of the Wunderland system began, effectively putting all scientific endeavors on hold. However, there remained some curiosity regarding this anomalous celestial body and several hypotheses for its existence were proffered at one time or another. These included the idea that it was an artifact of the Thrintun Empire (despite its orbit being too low to have been from that era), and a theory postulated by Nils Rykerman , that it was a massive spacecraft used by the Pak Protectors to bring Breeders of their species to Wunderland.
MORLOCK PROTECTOR INCIDENT
It was Rykerman's idea that in the end proved true. After a desperate attempt by ARM to seed Wunderland with human Protectors with which to fight the Kzin, a Morlock gained acces to a container of Tree-of-Life root. After transforming into a Morlock variant of the Protector (Morlocks being distant descendents of the Pak and therefore cousins to humans) the the Morlock Protector used the Tree-of-Life root to transform several other Morlocks. He also was able to capture and mind control a Kzin named Chorth-Captain and use them to begin a breeding program for new Protectors, as well as a factory to produce a faster-than-light drive, inside of the Hollow Moon. It was only due to the intervention of Dimity Carmody and Vaemar Riit that these plans were thwarted, although their actions resulted in the total destruction of the Hollow Moon as well as the Wunderland cave system referred to as the Hohe Kalkstein and a large part of the surrounding countryside.