The most prominent mass concentration on the near side. Dense mantle plug uplifted following giant impact, subsequently superloaded with 3–5 km of dense iron-rich flood basalt.

Strong positive gravitational anomaly causing significant orbital perturbations for low-altitude spacecraft (discovered during Apollo 8 navigation).

Isolated circular multi-ring basin surrounded by an intense negative gravity annular moat, indicative of unrelaxed flexural crustal stress.

Direct solar irradiance (~1361 W/m²) absorbed by low-albedo regolith; lack of atmosphere prevents convective cooling.

Rapid radiative equilibrium drop as solar incident flux vector approaches tangent to surface.

Unimpeded blackbody radiation to deep space (3K background); upper centimeters of porous dust insulate heat from depth.