At present, most knowledge of detailed geologic conditions on the moon is limited geographically to the photographic missions of the Lunar Orbiter program which has primarily covered the Apollo Zone. Complications caused by albedo, high sun elevations, and electronic imagery distortion hamper photo interpretation.
The lunar stratigraphy is divided into four systems: pre-Imbrian-highlands ringing the oldest mare; Imbrian—the oldest lowland mare; Eratosthenian—“eroded” crater material; and Copernicus-recent crater material.
Ubiquitous craters appear to be formed by both impact of meteors and volcanic activity. Faults, slump or creep, flowage—all appear to be present on the lunar surface.
Synoptic orbital photography of the earth is a logical outgrowth of the lunar program. Use of synoptic photography will improve exploration geologists’ understanding of their individual areas of interest as they relate to the regional geologic setting.
Geologic processes and theories developed on earth will aid the interpretation of morphological and structural conditions on the moon. Likewise, technologies developed from the lunar and planetary program will aid exploration on the earth.