Lunar Soil: Size Distribution and Mineralogical Constituents

Abstract

The lunar soil collected by Apollo 11 consists primarily of submillimeter material and is finer in grain size than soil previously recorded photographically by Surveyor experiments. The main constituents are fine-grained to glassy rocks of basaltic affinity and coherent breccia of undetermined origin. Dark glass, containing abundant nickel-iron spheres, coats many rocks, mineral, and breccia fragments. Several types of homogeneous glass occur as fragments and spheres. Colorless spheres, probably an exotic component, are abundant in the fraction finer than 20 microns.

The nature of the Moon's surface: evidence from shock metamorphism in Apollo 11 and 12 samples

“…(iii) The higher degrees of shock damage observed in the regolith (King et al;Quaide et al, 1970) and its extensive fine comminution (Duke et al, 1970) support the interpretation that the regolith has been continually subjected to multiple meteorite impacts which have increased the overall level of shock and reduced the average particle size. This in.…”

“…Judging from observable fracture densities, some smaller fragments, including single mineral grains, can be described as crushed although it is reasonable to expect that such fragments usually would granulate into individual pieces if they are so severely fractured. The general state of comminution of constituents (Duke et al , 1970), and the increase in fracture densities (qualitatively assessed) within the soil and microbreccias indicate a process that repeatedly shocked these rock materials so as to increase the average level of shock damage.…”

“…Melt Glass: Many investigators of Apollo 11 samples have reported on the character, types, composition, and distribution of dense to vesicular, homogeneous to heterogeneous glasses in the lunar soil and microbreccias (e.g., Agrell et al ;Chao et al ;Duke et al ;King et al McKay et al, 1970) . This phenomenon constitutes one of the most prevalent and diagnostic signs of shock damage in the lunar materials.…”

“…9a) which occupies most of the matrix between discernible particles and fragments. The bulk of the very fine (< 5,u m) material in the soil also appears to be glass (Quaide et al , 1970) but the general deficiency of particles smaller than 15 microns may indicate that comminution towards the finer sizes is reversed by some aggregation process that enlarges the particles (Duke et al, 1970).…”

Lunar dust transport and potential interactions with power system components

“…In establishing the mass of each size particle, m(D), the particles are assumed to be spherical for simplicity, and the material density is taken to be 3 g/cm3 after Duke et al (1970) The 666 kg of lunar soil that was removed and dispersed from the region directly under the engine bell alone corresponds to a large number of particles: . 666 kg) 1095µg / kg = 2.05 x 10 16 particles (12) 3.25 x 10 -µg / particle If these particles were distributed homogeneously over the region defined in equation (8) by a 148.5-m radius, the resulting deposition would be 9.6 g/m2, or 3x10 11 particles/m2.…”