Arcta is an ice planet that appears to have been uninhabited prior to the arrival of Dr. Ravashol. A brilliant scientist, Dr. Ravashol bred clones to assist him in his work, known as Theta class lifeforms. The Thetans have created large underground excavations for their small city, since the surface is unlivable, due to di-ethene storms on places like Deathpoint Plateau.
The Cylons later established a garrison on Arcta using Dr. Ravashol's technology to construct the Ravashol pulsar. The pulsar was later destroyed by a team from Galactica (TOS: "The Gun on Ice Planet Zero, Part II").