Round particles on the lunar surface

Thorium abundances on the lunar surface

Measurements of absolute thorium abundances on the lunar surface are presented using both the highand low-altitude data taken with the Lunar Prospector Gamma-Ray Spectrometer. An analysis of the uncertainties shows that the measured uncertainties are < 0.5 μg/g and are close to the theoretical limit of Poisson statistics. Currently, the overall systematic uncertainties are likely dominated by v...

The Composition of the Lunar Surface Relative to Lunar Samples

Introduction: The non-mare pristine samples are divided into two major suites, the ferroan anorthosites (FAN) and the Mg-suite [1]. FAN is typically characterized by high values of plagiophile interelement ratios, for example, the calcium content of plagioclase, and very high plagioclase content (though more mafic members exist). FAN is well separated from the Mgsuite on a plot of Mg-number vs....

The Lunar Surface Gravimeter as a Lunar Seismograph

Lunar Surface Mechanical Properties

The surface material at the Surveyor 5 site is granular and slightly cohesive. Spacecraft footpads plowed trenches in this material as the spacecraft slid during landing. For a compressible soil model, a static bearing capacity of 2.7 newtons/cm •' gave best agreement with the observations. Static firing of the vernier engines against the surface moved surface particles; a crater 20 cm in diame...

A Note on the Radio Reflectivity of the Lunar Surface

T. Hagfors: Doesn't the theory presented here grossly overestimate the effects of shadowing, since the shadowed regions would not be inclined favorably for reflection anyway? R . M. Goldstein: It seems as though the returned power does not go to zero at the limb, in your ex· press ion. Answer: It goes to zero , cf. (14) for ()~ n/2. Answer: No; cf. sec III and IV of Beckmann [1965b]. (Paper 69D...