Eayn is the Jackal homeworld and is a satellite orbiting the planet Chu'ot. The gravity is about 0.875 G's, making the inhabitants lighter on Eayn than on Earth. Eayn's atmosphere is composed of oxygen, nitrogen, and Carbon Dioxide (Rather similar to Earth). It contains a surface temperature ranging from -18°C to 45°C (-0.4F to 113F). It could be supposed that the "planet" is extremely similar to Earth.
The planet lies within the inner region of the system's massive asteroid belt. The world's surface was characterized by a single large ocean, sparse volcanic activity and an almost total lack of glacification. About one third of the Kig-yar population in the Y'Deio system called the satellite their home. The remaining Jackals chose to set up colonies within the asteroid belt even before their discovery by the Covenant.