Io

Once the most volcanic of Jupiter's Galilean moons, Io was also the last one to be colonized. Due to difficulties in altering the planet's mantle as well as problems with the functionality of terraformer satellites in orbit, Io was colonized over half a century later than its sister moons. Because Io's terraformation was completed after the end of the era of solar expansion, the moon never developed to the same degree as those around it and never received as many settlers. It has a much smaller population than the moons nearby, with few urban centers. Around a quarter of Io's surface is covered in sprawling suburbs, while the rest is rural farmland and oceans. Io is the largest food producer in the Jupiter planetary system, responsible for over 70% of all food consumed in Jupiter's orbit. In addition to animal pasturing and wide-scale automated agriculture, Io's seas are carefully monitored and adjusted so that the maximum amount of seafood can be harvested from them, and are essentially the largest aquaponics reservoirs ever constructed. Io is a calm and serene planet with a low crime rate and a consistently above average standard of living. Residency on Io is more expensive than on the planets nearby, but far less so than on Mars, the next closest rural world to Earth, and so Io is a popular destination for retirees.