One of the four galilean moons of Jupiter, and one of the most important worlds of the Iron Pact. It has been successfully terraformed - although it is widely believed to be one of the most unpleasant worlds known to Mankind. Regardless of that, the Iron Pact has successfully transformed it into the center of its heavy industry, taking full advantage of the fact that it's already hellish enough - no ammount of pollution can make it worse.
Majority of Io's surface are large plains with an altitude variations of up to 2km. The only major exceptions to that are numerous volcanoes (some as tall as 8km) as well as occasional depressions. It also has an ocean, albeit one that (due to the tidal movements caused by Jupiter's presence) has waves ranging up to one kilometer, making the coastal areas rather inhospitable. The volcanoes erupt regularly, covering their neighborhood with ash. That, however, is the smaller of the problems they cause - the biggest one is the fact that they damage fragile atmosphere, causing heat to rapidly evaporate from their area (together with bits of atmosphere) after eruption. Eventually the still-present terraforming nanites repair the damages, although typically not before the volcanoes' surroundings are covered in snow. There are also very common earthquakes, and an occasional firestorm caused by the volcanic eruptions setting a large, near-surface sulphur deposit aflame (while also spawning a lot of sulphur dioxide to choke everything in the vicinity). Needless to say, Io isn't a pleasant place to live.
The parts of the planet where life can thrive, tend to be akin to terran wetlands (high atmosphere moisture and year-long ~15C temperature does that to places). As a result, one can expect an ecosystem that's doing fairly okay, at least for as long as there are no active volcanoes nearby.
Io has rivers of sulphur, high volcanic activity, a very limited hydrosphere and the atmosphere that (due to volcanic eruptions damaging its outer shell regularly) is periodically getting replaced. As a result, it's practically speaking a dream Industrial World - a lot of resources present at the site, no need to worry about the ecosystem or pollution, almost limitless geothermal energy and some chemical components that are easy to gather.
Distance from Sun: 778.57 mil. km
Distance to Jupiter: 0.422 mil. km
Diameter: 3643 km
Solar Constant: 0.073
Mass: 0.015 Earths
Mean Density: 3.528 kg/l
Day Length: 1.769 Earth days
Year Length: 11.862 Earth years
Rotation Axial Tilt: <10 degrees
Avg. Temperature per Latitude
poles: 13 C
75 deg: 14 C
60 deg: 15 C
45 deg: 15 C
30 deg: 16 C
15 deg: 16 C
equator: 16 C
Type: Moon [Terraformed]
Location: Jupiter Subsystem