Mare Humboldtianum
What Mare Humboldtianum is
Mare Humboldtianum is a mare — a large dark plain — an ancient lava flood, not a sea — on The Moon, 231 km across, centred at 56.9° N, 81.5° E in the Belkovich quadrangle. It is the 82nd largest named feature on The Moon and the 20th largest of its class there.
Where the name comes from
Humboldt, Alexander von; German natural historian (1769-1859). The International Astronomical Union approved the name in 1935, under the theme it applies to every mare on The Moon. Of the 22 features of this class catalogued on The Moon, the naming categories run Latin (20), Great Britain (1), Germany (1).
What it would take to settle Mare Humboldtianum
The Moon scores 29.1 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 56.9° N, 81.5° E.
What this spot has going for it is ground — flat ground — the easiest thing to land on and build across. What works against it is water — outside the ice-bearing latitudes.
Computed from Mare Humboldtianum's catalogued latitude, longitude and feature class — 84% of the model's weight had a basis here, and one axis was dropped as not applicable to The Moon (radiation geometry). Gravity, pressure, delta-v and distance from the Sun are the same everywhere on The Moon 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 mare features on The Moon
All 22 maria on The Moon — mapped together, with the naming theme and the size distribution.