Samhain Catenae
What Samhain Catenae is
Samhain Catenae is a catena — a chain of craters — on Ceres, 715 km across, centred at 2.7° S, 107.1° W. It is the 2nd largest named feature on Ceres and the 1st largest of its class there.
Where the name comes from
Gaelic festival at the end of the harvest season. It was observed in Ireland and Scotland during 7 days in October and November, nearly halfway between the autumn equinox and the winter solstice. The International Astronomical Union approved the name in 2015, under the theme it applies to every catena on Ceres. Of the 6 features of this class catalogued on Ceres, the naming categories run Gaelic (1), Nigeria (1), Brazil (1), Udmurtian (1).
What it would take to settle Samhain Catenae
Ceres scores 43.8 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 2.7° S, 107.1° W.
What this spot has going for it is sunlight — 100% of the sunlight the sunniest latitude on Ceres gets. What works against it is ground — mixed ground — a rim, a floor and slopes between them.
Computed from Samhain Catenae's catalogued latitude, longitude and feature class — 68% of the model's weight had a basis here, and 3 axes were dropped as not applicable to Ceres (radiation geometry, earth link, known ground). Gravity, pressure, delta-v and distance from the Sun are the same everywhere on Ceres 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.