Properties of the Lunar Surface as Revealed by Thermal Radiation

Thermal radiation from the moon has been previously measured by both optical and microwave techniques, and this has led several workers to estimate the thermal properties of the lunar surface. Using the assumption that the thermal properties are proportional to the temperature, the uniform surface corresponding to the observed optical values is calculated. Possible mixed surfaces are also evaluated. These are examined to estimate the likely variation in microwave radiation, and by comparison with observed results it is shown that the most probable surface consists partly of rock or gravel overlain by a thin layer of fine dust, and partly of areas with dust extending to beyond the depth from which the microwave radiation emanates.