Publications

The processes by which craters disappear from the lunar surface have been of principal concern since the first high-resolution pictures of the lunar maria were returned by Ranger VII. Those pictures revealed that craters smaller than a few hundred meters on the lunar maria vary morphologically from sharp and pristine features to shallow, highly subdued depressions. The constancy of the population

The materials of most light or terra plains predate the lunar maria and postdate the Imbrian event. In the vicinity of the Imbrium Basin, these materials have been called the Cayley Formation (ref. 29-3) but because of the subtle diversity of the terra plains over the near side, Whilhelms and McCauley (ref. 29-4) simply called these materials Imbrian plains (Ip). The age relationships between the

Approximately 35 reasonably good candidates for specialized photometric studies were found during a thorough examination of the frames exposed by the Apollo 15 metric camera. Of these, the majority was of value in heiligenschein studies (refs. 25-36 to 25-38). A few were of value for limited-interval delineation of the photometric functions of crater walls, wherein it is now known from past Apollo

Preliminary examination of Apollo 15 orbital photographs indicates a large number of volcanic features. One area of exceptionally interesting volcanic activity is depicted in figure 25-74. Located approximately at latitude 25° S and longitude 123° E on the lunar far side, this region also is covered by panoramic camera photographs AS15-9954, 9956, 9958, and 9960 and by stereoscopically overlapping

A panoramic camera frame (fig. 25-69) was used as the base for a geologic sketch map (fig. 25-70) of an area near Proclus Crater. The map was prepared to investigate the usefulness of the Apollo 15 panoramic camera photography in large-scale geologic mapping and to assess the geologic value of this area as a potential Apollo landing site. The area is being considered as a landing site because of t

The Proclus Crater region was mapped to test the value, for photogeologic mapping purposes, of Apollo 15 metric photographs and to estimate the scientific value of the area as a potential landing site. A metric photographic frame (fig. 25-67) serves as a base for a map of the region around the Proclus Crater (fig. 25-68), and adjacent frames were overlapped with the base frame to provide stereogra

The photograph in figure 25-59 and the corresponding map (fig. 25-60) show the geology of part of the lunar surface just east of the Littrow rilles at the eastern edge of Mare Serenitatis. The most striking feature of the region is the extremely low albedo of the area mapped as Eld in the western half of the map. The low albedo is believed to be caused by a thin layer of pyroclastic volcanic mater

Study of the sinuous Hadley Rille (fig. 25-45) was a primary goal of the Apollo 15 mission. Local geology of the rille near the landing site is described in section 5 of this report. Preliminary study of orbital photography from Hasselblad, metric, and panoramic cameras makes possible a description of some regional relationships of the rille. Considerable use is also made of a preliminary topograp

Mapping of large areas of the Moon by photogrammetric methods was not seriously considered until the Apollo 15 mission. In this mission, a mapping camera system and a 61-cm optical-bar high-resolution panoramic camera, as well as a laser altimeter, were used. The mapping camera system comprises a 7.6-cm metric terrain camera and a 7.6-cm stellar camera mounted in a fixed angular relationship (an a

The three cameras—stellar, mapping, and panoramic—together with the laser altimeter, all included in the scientific instrument module (SIM) bay, represent an integrated photogrammatric system with extraordinary potential for extending knowledge of the lunar figure, surface configuration, and geological structure.

Many Apollo 15 orbital photographs, particularly those taken at low Sun-elevation angles, reveal grid patterns of lineaments. In some circumstances, the grid pattern is present in areas where structural control seems unlikely. For example, in an oblique view (fig. 25-52), the ejecta blankets of two fresh impact craters seem to have two intersecting sets of lineaments. Because previous studies of i

The Apollo 15 lunar module (LM) landed at longitude 03°39'20'' E, latitude 26°26'00'' N on the mare surface of Palus Putredinis on the eastern edge of the Imbrium Basin. The site is between the Apennine Mountain front and Hadley Rille. The objectives of the mission, in order of decreasing priority, were description and sampling of three major geologic features—the Apennine Front, Hadley Rille, and