PLANET
CLASS X: ANOMALOUS
TYPE
Artificial construct
CORE
Unknown
MANTLE
Unknown
ATMOSPHERE
Unknown
LIFE
Highly advanced civilizations construct and inhabit these worlds.
Class X planets are extremely rare artificial constructs, created by highly advanced civilizations. Some could be built around an existing planet and contain geologic and organic properties. Others might be entirely synthetic.
In order to be considered a Class X planet, the construct must be part of a star system and in orbit of a star. Otherwise, it is classified as a starship.
In addition to artificial constructs, a Class X planet may also be used to describe a planet that is so unusual that it does not meet the criteria for the other classifications.
Due to the curious and unpredictable nature of Class X planets, they are not divided into other categories.
SUBCLASS XM: MOON
Building an entire planet is hard. Building a moon is easier. There is also an XM Satellite Radio joke in here somewhere, but it's not coming to me at the moment.
SUBCLASS XX: IRRADIATED
A planet that is heavily irradiated by its parent star.