Haydn is a crater — a circular depression, almost always an impact scar — on Mercury, 251 km across, centred at 27.2° S, 71.6° W in the Discovery quadrangle. It is the 82nd largest named feature on Mercury and the 18th largest of its class there.
J.; Austrian composer (1732-1809). The International Astronomical Union approved the name in 1976, under the theme it applies to every crater on Mercury. Of the 449 features of this class catalogued on Mercury, the naming categories run France (36), United States (35), Japan (33), Italy (31).
Mercury scores 46 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 27.2° S, 71.6° W.
What this spot has going for it is sunlight — 89% of the sunlight the sunniest latitude on Mercury gets. What works against it is water — outside the ice-bearing latitudes.
Computed from Haydn'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 Mercury (radiation geometry, earth link, known ground). Gravity, pressure, delta-v and distance from the Sun are the same everywhere on Mercury 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.
All 449 craters on Mercury — mapped together, with the naming theme and the size distribution.