Echus Palus
What Echus Palus is
Echus Palus is a palus — a small dark plain — on Mars, 715 km across, centred at 12.3° N, 77.3° W in the Lunae Palus quadrangle. It is the 131st largest named feature on Mars and the 2nd largest of its class there.
Where the name comes from
Classical albedo feature name, Echus Lacus. The International Astronomical Union approved the name in 2016, under the theme it applies to every palus on Mars. Of the 6 features of this class catalogued on Mars, the naming categories run Greek (3), Latin (2), India (1).
What it would take to settle Echus Palus
Mars scores 26.6 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 12.3° N, 77.3° W.
What this spot has going for it is sunlight — 98% of the sunlight the sunniest latitude on Mars gets. What works against it is water — outside the ice-bearing latitudes.
Computed from Echus Palus's catalogued latitude, longitude and feature class — 74% of the model's weight had a basis here, and 2 axes were dropped as not applicable to Mars (radiation geometry, earth link). Gravity, pressure, delta-v and distance from the Sun are the same everywhere on Mars 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.