Sasoom (referred to as Jupiter, by Earthmen, and as Eurobus by its natives) is the fifth planet in the solar system, located between Barsoom and Xasoom.
Though long speculated by Earthmen to be completely uninhabitable, the surface of the world is completely livable by humanoid life and has gravity slightly lower than Barsoom, despite the planets size; John Carter attributes this phenomenon to the speed of the planet's rotation. To its inhabitants, there is no day and night, the volcanoes that dot the world acting like torches lighting the atmosphere making the day perpetual and everything cast under a red light. The world is also covered in oceans and jungles, having a generally universal climate because of the volcanoes. Many animals on the planet are ungulates, having hooves because of the volcanic terrain. And almost all plant life has features of animal life. It has two native species, the dreaded Morgors and the Human Savators.