Argadnel Regio
What Argadnel Regio is
Argadnel Regio is a regio — a large area distinguished by its brightness or colour — on Europa, 1,900 km across, centred at 14.6° S, 151.5° E. It is the 15th largest named feature on Europa and the 5th largest of its class there.
Where the name comes from
In Celtic mythology, one of the islands of Earthly paradise seen during Bran's voyage. The International Astronomical Union approved the name in 2003, under the theme it applies to every regio on Europa. Of the 8 features of this class catalogued on Europa, the naming categories run Celtic (5), Wales (3).
What it would take to settle Argadnel Regio
Europa scores 60.9 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 14.6° S, 151.5° E.
What this spot has going for it is sunlight — 97% of the sunlight the sunniest latitude on Europa gets. What works against it is radiation geometry — on the boundary between the leading and trailing hemispheres.
Computed from Argadnel Regio'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 Europa (earth link, known ground). Gravity, pressure, delta-v and distance from the Sun are the same everywhere on Europa 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.