Umma Sulcus
What Umma Sulcus is
Umma Sulcus is a sulcus — a set of parallel grooves and ridges — on Ganymede, 1,270 km across, centred at 4.1° N, 110.5° E. It is the 34th largest named feature on Ganymede and the 26th largest of its class there.
Where the name comes from
Sumerian town. The International Astronomical Union approved the name in 2000, under the theme it applies to every sulcus on Ganymede. Of the 35 features of this class catalogued on Ganymede, the naming categories run Assyro-Babylonian (13), Greek (7), Sumerian (7), Babylon (3).
What it would take to settle Umma Sulcus
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 4.1° N, 110.5° E.
What this spot has going for it is radiation geometry — under closed field lines, the shielded part of the only magnetosphere on any moon. What works against it is temperature — about -156 °C mean at this latitude.
Computed from Umma Sulcus'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 sulcus features on Ganymede
All 35 sulci on Ganymede — mapped together, with the naming theme and the size distribution.