379. [Apollo 15] SPECTACULAR LUNAR HORIZON ABOVE THE SEA OF RAINS: pioneering high-resolution metric camera view Alfred Worden, 26 July - 7 August 1971 Printed 1972. Vintage gelatin silver print on fibre-based paper [NASA image AS15-M-1550]. With NASA metric camera ID number "AS15-M-1550" written on the reverse (issued by NASA). 23 x 23 cm. (9 x 9 in.) Historical context Apollo 15 was the first mission to deploy the metric camera in lunar orbit, revolutionizing our ability to study the Moon's landscape with precision. This rare and unreleased photograph captures the breathtaking lunar horizon in exceptional detail, taken from an altitude of 102 km over the northern Sea of Rains (Mare Imbrium). The image was acquired during Apollo 15's 35th revolution around the Moon using the automatic Fairchild metric camera, mounted in the Scientific Instrument Module (SIM) bay of the Endeavour Service Module and operated by Command Module Pilot Alfred Worden. With its 3-inch focal length, the metric camera provided an unparalleled perspective on the rugged lunar surface, offering a level of clarity essential for geological mapping. The sun, positioned at a 13° elevation, casts long shadows that accentuate the Moon's vast topography. This high-resolution view (28° N, 16.5° W) showcases the immense scale of Mare Imbrium while revealing intricate surface textures and crater formations. On the right side of the frame, the silhouette of the gamma-ray spectrometer mounted on the SIM bay is visible. This instrument played a key role in mapping the Moon's elemental composition by detecting gamma radiation from the surface, helping scientists better understand its geological history.