The Commonwealth of Callisto


  •  Callisto (1,200,000 pop)
  •  Trojan Asteroids (3,500 pop)
  •  Greek Asteroids (1,600 pop)


  • Outside of Jupiter's radiation belt; most distant of the large Galilean moons from Jupiter.
  • First of Jupiter's moons to be colonized.
  • Second largest moon in Jupiter system. Size of Mercury but only a third of the mass.
  • Approximate population of 1,200,000
  • Not part of the orbital resonance of Io, Europa and Ganymede; no tidal heating.
  • Tidally locked to Jupiter.
  • Composition is a mix of rock and ice (so not at all like Europa or Triton)
  • Slushy subterranean ocean a little bit like Europa’s, but not practical to access since crust is not pure ice. About 125 km down.
  • No plate tectonics or volcanism.
  • Heavily cratered (lack of tectonics and volcanism means surface retains impacts)


  • Valhalla (crater-city, capital, central 600 km in diameter + 1,800 km rings)
  • Asgard (crater-city, 1,600 km rings)
  • Gomul Catena (line of impact craters, metal mines)

Primary Industries:

  • Major industry includes:
    • Carbonates
    • Silicates
    • Metals (uncommon)
  • Powerful, general economy hampered only by lack of good sources of fuel.
  • Extensive shipyards.


  • Callisto’s primary conflict is a state of open war with the Sovereign Republic of Ganymede The war is fairly balanced, with Callisto having the industrial and material advantage but Ganymede having superior military technology.
  • The Saturnian polities of the Republic of Titan and the Rhean Divisional Authority are together mutually hostile with Callisto due to Ganymede’s active support of their efforts at repelling Alliance.
  • Vesta’s research treaties with the Europan Consortium and military research arrangements with the Sovereign Republic of Ganymede has resulted in cold relations with Callisto.
  • Callisto also occasionally suffers from terrorism by certain extremist factions from Haumea.
  • Callisto is on very friendly terms with State, Union and the Oceanic League on Earth, mostly due to those polities support of Callisto in the face of Eastern Federation support of Ganymede.
  • Callisto provides significant aid and engages in extensive trade with Iapetus and Dione.

Politics and Culture:

  • Callisto’s government is reasonably democratic, but due to the relatively homogenous nature of Callistan society, the democratic nature of their institutions is more theoretical than actual.
  • Callisto actively - even aggressively - pursues a policy of national culture and acculturation for any immigrants. It tightly restricts citizenship, and as a result has a large proportion of its population who are residents - but not citizens.
  • Callistans are very proud of their strong anti-authoritarian polity. Callisto is quite insular and has a reputation for a certain amount of assumed arrogance in its dealings with the rest of the Outer Solar System in particular, which it sees itself as the obvious capital.