Ghanaz had once been a hospitable planet which was inhabited by experimental subjects under Nirrti's rule and was used as a breeding ground for these subjects. Once it entered an ice age around 1000, with its sun beginning a helium-burning phase which meant that it was reduced in size and less energy reached the planet, Nirrti gave up on the planet and it became abandoned. (RPG: "Friends and Foes: Stargate Season Two")