Geological Chronicle
Positioned on the lunar far side along the northeastern margin of Mare Ingenii, Van de Graaff is a 240.47-kilometer-wide crater formation distinguished by an unusual figure-eight outline. The structure consists of two merged impact depressions with no intervening rim dividing the two sections. Dating to the Nectarian epoch, the formation ranks among the largest surviving craters from that period, though its outer walls are heavily worn and eroded.
The floor reflects the dual nature of the depression, with a smoother northeastern floor and a southwestern section containing a central peak. Orbital infrared spectroscopy identified the signature of pure crystalline plagioclase on the central peak. Along the southeast rim, the crater Birkeland sits adjacent to the narrower midpoint of the formation.
Surrounding terrain exhibits an unusual grooved texture linked to the distant impact that created Mare Imbrium. Van de Graaff lies at the antipode of the Imbrium basin, where focused seismic energy converged and generated tremors, landslides, and ejecta deposits. Orbital measurements also revealed an elevated local magnetic field and higher concentrations of radioactive materials, pointing to buried volcanic deposits beneath the surface.