All 196 named places on Ganymede, scored one coordinate at a time on sunlight, water, radiation, temperature, ground and access — then ranked. Marius Regio comes out first.
Ganymede as a whole rates 55/100 to settle, and that single number is the same for every square metre of it. It is also the wrong number for a mission, because sunlight, water, radiation dose and the ground itself all change with where you stand. The ranking below re-asks the question at each of 196 catalogued coordinates and reports the difference from the median site — so a score of 55 here means “typical for Ganymede”, not “good”.
Water on Ganymede: Water ice crust over a subsurface ocean.
Elevation. Every score above comes from a latitude, a longitude and a feature class — never from a terrain model — so slope, local shadowing and the polar peaks of eternal light are invisible to it. That last one matters: on a world tilted barely a degree, a ridge top near the pole can catch sunlight almost continuously while a crater floor a few kilometres away has not seen the Sun in two billion years. This model scores the average surface at a latitude, so it reads poles as dark and ranks them accordingly. Where a real mission targets a pole, that is usually the reason — and the reason to read this as one input, not a verdict.
