Pern is an independent planet, located in the Rukcat System. The planet has a hundred-year-cycle orbit around the system's star, Ruby-Gold, and on the 50th year it is in close contact with the Mobius V system.
Pern is an almost exact replica of Earth, in that it has similar climates, a variety of environments, and is mostly water. This is made it a popular planet to visit or live on.
In the Five Day War, the planet was found and inhabitants lived there peacefully. They had mastered engineering defense mechanisms to protect themselves. The Ants found the planet and tried to take Pern for themselves, but failed, thus leaving the factions to fight over who would own Pern. What the factions didn't know was that Pern was independent and didn't need to be governed or treated by the three factions. So when the Empire won and was able to take the planet, a group of the strongest warriors there set forth and said they would join the Empire.
Pern belongs to no one, but will always welcome the factions and aid them throughout their goals. The Systems Alliance currently have a small military station orbiting the planet which aids the defence of the planet.