Osis

Osis is a medium-sized terrestrial world, and the planet on which the continent of Aarn is located. It is home to a variety of intelligent races with diverse civilisations and cultures, making it unique among the three inhabited worlds orbiting the Sun.

Whilst Osis has no moons, the planet is girdled by a series of huge planetary rings, unlike anything else in the solar system. Believed to be the remains of an ancient moon called Aiuna, the bright silver rings stretch out into space for over five thousand kilometres.