Yridia I is the most geologically active body within the Yridia System. Fault lines cover most of the surface, and subduction occurs along at least seventeen crustal plates at any time. Every 100,000 years the entire crust liquefies, producing new tectonics and reshaping the terrain every cycle. The entire surface is full of holes where volcanoes spew carbon dioxide and sulphur dioxide into the atmosphere. Massive sulfur flows dominate the equatorial regions. Vast plumes rise off of the planet, ejecting gases hundreds of kilometers into space. An array of colors paint the hot surface, indicating hot, cool, and solidified lava flows. The massive outflow of silicon dioxide and carbon dioxide from the volcanoes makes for a rather thick atmosphere with increased pressure, barely livable by most humanoids. Massive acid rain storms are known to pour on the surface during the winter and spring months when the lower atmosphere is coolest. The polar regions, while areas of decreased volcanic activity, are victim to constant earthquakes from eruptions elsewhere on the planet, pitting the more brittle polar surfaces with hundreds of fault lines. The planet is unlivable and is considered to be off limits to all Tarentum personnel.