Ganymede (Sol V - iii)
Image from Steve Bowers
Type: EuEuropan Type
Primary, Position: Jupiter vii
Primary, Distance from: 1,070,000 km
Satellites: None
Diameter / Gravity: 5,268 km / 0.145 G
Length of day / year: 7.155 days / 7.155 days (tidally locked)
Atmosphere: minimal
Surface temperature:
Surface composition: Dirty Ice
Discovery: Jan 11, 1610 by Galileo Galilei
Terragen Landing: unmanned: 2018; manned : 2118 c.e.
Colonization status: depends on polity (very limited immigration quota, or no immigration)
Population (surface and subsurface):
heavily tweaked superiors (several clades)
320 million
20 million
5 million
45 million
Population (orbital):
60 million
50 million
35 million
30 million
15 million
3 million
other sophonts
20 million
Administration: Organisation of Ganymedan States (loose alliance)


Several independent tweak nations on and under the surface; the orbital habitats each have various affiliations and government types. All polities affiliated with the Solar Organisation


specialist bionano, ice-art, finance, firmware templates, cold adapted neogens (subsapient and sapient), persona templates, parafractal crafts, historical simmimersions


On or under the surface and in the orbitals - a total of about about 0.6 billion sophonts, mostly heavily tweaked superiors, specialised dormbots, ais, vecs, cyborgs, and a few bioborgs and Europans


The largest of the Galileean Moons, Ganymede is a world larger than the planet Mercury. The icy surface was originally divided into dark regions mingled with younger brighter areas scoured by grooves and furrows with kilometer-high sides. Much of this has since been urbanised.

History and comments:

Ganymede was the original capital of the Jovian League, and in the late Interplanetary age the most populous of the Galilean moons. Most of the settlements were and still are underground and heavily shielded from the Jovian radiation field. The moon is home to half a dozen fairly large tweak polities, and a number of smaller states. All the tweaks are highly modified, and they tend to take a rather dim view of off- worlders. There are also some three dozen specialised orbital-states eager for the tourist credit.

For more details about Ganymede in the Current Era, see here.
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Development Notes
Text by M. Alan Kazlev
Initially published on 01 November 2001.