Vallis Snellius
What Vallis Snellius is
Vallis Snellius is a vallis — a valley — on The Moon, 640 km across, centred at 30.9° S, 57.8° E in the Petavius quadrangle. It is the 11th largest named feature on The Moon and the 1st largest of its class there.
Where the name comes from
Named from nearby crater. The International Astronomical Union approved the name in 1964, under the theme it applies to every vallis on The Moon. Of the 14 features of this class catalogued on The Moon, the naming categories run Germany (5), The Netherlands (Dutch) (1), Czechoslovakia (1), Austria (1).
What it would take to settle Vallis Snellius
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 30.9° S, 57.8° E.
What this spot has going for it is earth link — near side — Earth stands 27° above the horizon and never moves. What works against it is water — outside the ice-bearing latitudes.
Computed from Vallis Snellius'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 vallis features on The Moon
All 14 valles on The Moon — mapped together, with the naming theme and the size distribution.