Lunar Surface Characteristic Indicated by the March, 1960, Eclipse and Other Observations.

The variation in lunar brightness temperature during the total eclipse of March 13, 1960, was found to be about 10 or less at 8.6-mm wave length. This result, when combined with prior data for this and other wave lengths, indicates that the average, or typical, lunar surface structure is stratified in at least two, and possibly three, layers. The topmost layer is about 0.5 cm in depth and seems to resemble ordinary sand in vacuo, the intermediate layer may be several centimeters or more in depth and is most notably characterized by a high electric conductivity, while the lowermost stratum of indefinite depth is more like rock.