Publications

On July 20, 1969, America's Eagle touched down in southwestern Mare Tranquillitatis beginning man's firsthand exploration of the moon. This document is an edited record of the conversations between astronauts Neil Armstrong and Edwin "Buzz" Aldrin, Jr., at Tranquility Base, and Bruce McCandless at Mission Control in Houston during the approximately 22 hours spent on the lunar surface. It includes

Regional relations and characteristics of the dark material as observed on photographs of the Taurus-Littrow region of the moon are reviewed to provide a background for interpretations of its nature and origin. The dark material seems to be a surficial deposit that covers mare and highland areas near the southeastern edge of the Serenitatis Basin. The age of the dark material, as deduced from phot

Stereoscopic photographs of the Moon taken by the metric and panoramic cameras on board the service module of Apollo spacecraft provide a source for quantitative data on lunar topography. The accuracy of the topographic data depends, in part, on the repeatability of elevation measurements. The repeatability depends on contrast in the stereoscopic image and is affected by many factors, such as phot

Lunar slope-frequency distributions obtained by photogrammetric techniques are compared with results from the bistatic-radar investigations of the Apollo 14, 15, and 16 missions (refs. 33-16, 33-17, and 33-32) and of Explorer 35 (ref. 33-27). Algebraic standard deviations of slope-frequency distributions from photogrammetric data are equivalent to rms slopes of slope-frequency distributions from b

Stereoscopic photographs taken by the metric and panoramic cameras can be used to obtain information on the roughness and slope-frequency distributions of lunar surfaces (see appendix to this part). Bistatic radar on board Apollo 14, 15, and 16 spacecraft may also be used to obtain information on lunar surface roughness at two wavelengths—13 cm (S-band) and 116 cm (VHF).

A large quantity of data on backscattered polarized and depolarized radar echoes from the Moon has been collected from Earth at 3.8-cm wavelength (ref. 33-23). Depolarized echoes are particularly interesting because theory indicates that relatively strong depolarized echoes can be caused by the following factors.

Mare Serenitatis is a circular mare approximately 600 km in diameter in the northeast quadrant of the lunar near side. It occupies an old multi-ringed basin (refs. 33-1 and 33-2) and is the site of a prominent mascon (ref. 33-3). A conspicuous dark annulus in this mare prompted subdivision of the mare materials into different stratigraphic units (refs. 33-2 and 33-4). A revised stratigraphic sequ

Morphometry, the quantitative study of shape, complements the visual observation and photointerpretation in analyzing the most outstanding landforms of the Moon, its craters (refs. 32-1 and 32-2). All three of these interpretative tools, which were developed throughout the long history of telescopic lunar study preceding the Apollo Program, will continue to be applicable to crater analysis until d

Apollo 17 permission geologic studies of the Taurus-Littrow region of the Moon revealed numerous small structures, in both mare and terra, having somewhat similar morphologies and variously resembling fault scarps, flow fronts, and mare ridges. Many of these features are too small to be identified on Lunar Orbiter IV photographs, which provided the most comprehensive, high-resolution coverage of t

"Wrinkle ridges" in the Taurus-Littrow region along the eastern margin of the Mare Serenitatis appear very fresh and are probably among the youngest on the Moon. They include both mare ridges and similar-looking one-sided scarps. Evidence will be presented here to suggest that these ridges and scarps may be anticlines and thrust faults that resulted from sliding on a décollement surface. Alternati

Orbital photographs taken at low-Sun illumination during both the Apollo 15 (ref. 30-14) and Apollo 17 missions have provided excellent data on the lava flows in the southwestern Mare Imbrium. These photographs have been used recently to present a detailed photogeologic evaluation of these flows and their role in mare volcanism of Eratosthenian age in the basin (ref. 30-15). Eruption of these floo

Small volcanic cones with summit craters or breached walls occur in several areas on the Moon. Most of these features have basal diameters of approximately 1 to 2 km and probably are not more than a few hundred meters in height. None have been so clearly photographed, however, as those shown in Apollo 17 metric and panoramic camera coverage of the southeastern margin of the Serenitatis basin. Two