Luna 9 pictures: implications.

Evidence from Luna 9 does not preclude the possibility that the moon may have a surface made up largely of very fine rock particles. The degree to which they attach to each other and the resulting firmness of the ground cannot yet be closely estimated.

Radiation bleaching of thin lunar surface layer.

The thin, lighter-colored, upper layer of lunar soil shown in the television pictures from several Surveyor missions may be due to reversible bleaching by solar radiation. Of several possible bleaching reactions, the one considered most important is the photoreduction of Fe(+3) to Fe(+2).

The opposition effect of the moon: the contribution of coherent backscatter.

The opposition effect, the sharp surge in brightness of an astronomical object observed near zero phase angle, which has been known for more than a century, has generally been explained by shadow hiding. The reflectances of several Apollo lunar soil samples have been measured as a function of phase angle in linearly and circularly polarized light. All samples exhibited a decrease in the linear polarization ratio and an increase in the circular polarization ratio in the opposition peak. This provides unequivocal proof that most of the lunar opposition effect is caused by coherent backscatter, not shadow hiding. This result has major implications for the interpretation of photometric observations of bodies in the solar system, including the Earth.

Solar radiation effects in lunar samples.

Optical properties of the pulverized crystalline rocks from the Apollo 11 samples are different from the optical properties of lunar soil. Changes in these properties were induced in the samples by ultraviolet and x-irradiation, standing, and heating. The albedo and spectrum of the soil differed significantly from expected values.