Publications

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.

No abstract available.

Apollo 17 metric photographs (fig. 29-26) provide the best available coverage for geologic interpretation of northern Mare Crisium and the northern Crisium basin. The area was covered previously by low-resolution telescopic and Lunar Orbiter IV photographs and by oblique, high-illumination, or low-resolution photographs from earlier Apollo missions. One region in particular, between...

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...

The lunar surface orientations of some of the Apollo 17 rock samples at the time of their collection (table 6-V) are shown in this appendix (figs. 6-65 to 6-87). These orientations were determined by correlating lunar photographs of samples before collection with shapes and shadow characteristics of the same samples in the LRL under oblique illumination with nearly collimated light. The...

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...

The Apollo 17 lunar module (LM) landed on the flat floor of a deep valley that embays the mountainous highlands at the eastern rim of the Serenitatis basin. Serenitatis, the site of a pronounced mascon, is one of the major multi-ringed basins on the near side of the Moon. The Taurus-Littrow valley, which is radial to the Serenitatis basis, is interpreted as a deep graben formed by...

The surface electrical properties (SEP) experiment was used to explore the subsurface material of the Apollo 17 landing site by means of electromagnetic radiation. The experiment was designed to detect electrical layering, discrete scattering bodies, and the possible presence of water. From the analysis of the data, it was expected that values of the electrical properties (dielectric...

"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

Mare Serenitatis has long been noted for its conspicuous dark border (fig. 29-1). The Apollo 17 metric photographs traverse this border in southern Mare Serenitatis and show clearly superposition relationships among the mare and mare-related stratigraphic units. These photographs, together with full-Moon photographs, albedo measurements, and color information (table 29-I), provide the...

The Apollo 16 crew photographed an unusual variety of impact craters, including the two craters produced by the impacts of Ranger 7 and 9 spacecraft, small craters produced by boulders as they bounced downslope, craters with marked bilateral symmetry, and primary craters with a wide range of morphologies and sizes. Ranger impact craters and examples of other craters are discussed briefly...

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...