Etana
What Etana is
Etana is a crater — a circular depression, almost always an impact scar — on Ganymede, 46 km across, centred at 74.7° N, 19.6° E. It is the 149th largest named feature on Ganymede and the 86th largest of its class there.
Where the name comes from
Assyro-Babylonian; asked the eagle for an herb to give him an heir. The International Astronomical Union approved the name in 1979, under the theme it applies to every crater on Ganymede. Of the 129 features of this class catalogued on Ganymede, the naming categories run Egypt (42), Assyro-Babylonian (30), Phoenician (18), Sumerian (16).
What it would take to settle Etana
Ganymede scores 55 as a world. That number is the same for every square metre of it — but sunlight, water, radiation and the ground under your feet are not. This is the same question asked at 74.7° N, 19.6° E.
What this spot has going for it is water — same as everywhere else on this world. What works against it is radiation geometry — inside the open-field polar cap, where the plasma gets down.
Computed from Etana's catalogued latitude, longitude and feature class — 84% of the model's weight had a basis here, and 2 axes were dropped as not applicable to Ganymede (earth link, known ground). Gravity, pressure, delta-v and distance from the Sun are the same everywhere on Ganymede and are already counted in the world's own index, not again here.
What this cannot see: elevation. Slope, local shadowing and the polar “peaks of eternal light” — ridge tops near the poles of a barely tilted world that catch sun almost continuously while a crater floor kilometres away never does — need a terrain model this does not have. Where a real mission targets a pole, that is usually why.
What is next to it
The largest crater features on Ganymede
All 129 craters on Ganymede — mapped together, with the naming theme and the size distribution.