Geological Chronicle
Dryden is a lunar impact crater spanning 54.45 kilometers in diameter across the southern hemisphere on the far side of the Moon. The feature sits entirely within the vast Apollo walled plain, where several craters commemorate contributors to the Apollo space program. Positioned along the west-northwest segment of Apollo's inner mountainous ring, Dryden borders the inner mountain ridge at its southeastern exterior, while the crater Chaffee lies further south along the same range.
Formed during the Upper Imbrian period, the crater exhibits a crude circle broken by minor outward bulges. Along its eastern flank, the rim has slumped inward to produce an irregular outline, yet the perimeter retains a sharp edge without heavy signs of impact degradation. A less distinct northeastern extension of Apollo's inner ring structure appears to begin near this eastern rim.
Inside Dryden, gently sloping walls descend to a base lined with fallen debris, enclosing an interior floor populated only by sparse micro-craters. A central peak rises slightly northeast of the crater midpoint, displaying spectroscopic signatures of olivine-bearing gabbroic norite excavated from depths between 5.1 and 7.7 kilometers.