Polarizing properties of pulverized materials with special reference to the lunar surface.

A review is presented of the application of polarimetry to the determination of the properties of the lunar surface layer by comparison with laboratory surfaces, from the time of Arago to the Apollo 11 sampling. The polarizing properties of pulverized volcanogenic products and chemicals, as they are determined by wavelength, particle size, phase angle, state of compaction, and composition, are studied. It is learned, through the study of the slope of the polarization/wavelength curve in the near uv, that the lunar surface must contain a large component of translucent rather than totally opaque particles. The lunar particles are basalt in composition, are less than 50 microm in size, and comprise a loosely arranged surface structure. Earth-based determinations are in good agreement with the Apollo 11 sampling results; thus these remote-sensing techniques are applicable to the studies of other planetary surfaces. Comparison between the surfaces of Mercury, some asteroids, and the moon is made.