Io Penal Colony

History: Volcanic Io is the most geologically active world in the solar system. It is second only to Venus in being the most inhospitable. The surface is awash with hard radiation from the huge presence of Jupiter in her sky. There are no permanent structures on Io, for the surface is too unstable. All those who work on the surface live in huge mobile stripminers. These vehicles are nearly half a kilometer across, with huge treads. There are four major ones which prowl across the surface, ripping up the top layers of sulfur-permeated rock and extracting minerals. The stripminers are like huge mobile domes that shield out the worst of the environemnt; the actual work is done by convicts. Io is the prison colony of the Solar Colonies. Those whose crimes are heinous enough are sent to work in these huge refineries. The domes prowl about the surface of Io, while the convicts labor underneath, searching the rubble for precious gems and metals, so badly needed by the technology of the 23rd century. It was on Io that a large number of red diamonds has been found, the type of carborundum vital to the fast fusion drives developed in the 2190's. Io is also the second highest source of lithium. (The highest was Triton, nuked inthe Titan Wars).