The results of the remote probing of the moon by means of infrared and microwave emissions and by radar are reviewed. Also, we discuss how the various observational results can help to explain physical parameters of the lunar surface, such as thermal and electrical conductivities, dielectric constant, density, particle sizes in the lunar regolith, depth of the surface layer, roughness of the surface, variation of these parameters from point to point on the surface, and amount of heat generated in the lunar interior. 190 T. HAGFORS ' at several different phase angles in order to obtain maps of isotherms on the moon. The resolution used was 25 seconds of arc as compared with the diameter of the moon which is about 30 minutes of arc. The data in the figure were obtained from the thermal contours at a few different phase angles. The data ascribed to Saari and Shorthill [1967] were obtained in a wavelength interval from 10 to 12t• with an instrument having an angular resolution of 8 seconds of arc. The post-sunset data were obtained by Murray and Wildey [1964] at 8-13t• with a resolution of 26 seconds of arc and by Shorthill and Saari [1965] at 10-12tz with their higher resolution instrument. The pre-sunrise observations are particularly difficult to make because of the high sensitivity required. Having special instrumentation Low [ 1965] was able to determine the pre-sunrise temperature by scanning over the cold limb of the moon at a wavelength of 20t•. He found an average pre-dawn temperature of 90øK and also observed colder localized areas with temperatures down to 70øK.