Atmosphere and Weather
The atmosphere on Ysau is almost completely Carbon Dioxide. The atmosphere is the reason for the pink color of the planet. Because the planet is tidally locked, a large hurricane is constantly on the hot side.
The surface of Ysau has a few very large craters. The cold side is mostly frozen carbon dioxide ice. The middle is home to some liquid carbon dioxide, causing some very small lakes
Ysau has 5 dwarf moons, all small cool asteroids. 4 of the moons orbit in a tight area, while one orbits in a polar alignment, suggesting a recently captured asteroid.