Sotirsis was the arid, rocky homeworld of the Sotirsian race. It was covered in mountainous regions, deserts and canyons, and the air was poisonous to most species if inhaled for a long period of time. About 0.05% of the surface was covered in industrialized cities, built upward. Thin wires of rivers and rapids cover about 3% of the surface, making up the planet's entire water supply. Because of this, the Sotirsians cannot acquire much water, which is the third most important form of nourishment for Sotirsians.