radio_wave has definitions from the field of physics
[ noun ] (physics) an electromagnetic wave with a wavelength between 0.5 cm to 30,000 m

Used in print

(Cornell H. Mayer, "Radio Emission of the Moon...)

Piddington and Minnett explained their observations by pointing_out that rocklike materials which are likely to make_up the surface of the moon would be partially transparent to radio_waves , although opaque to infrared_radiation .

Since the absorption of radio_waves in rocklike material varies with wave_length , it should be possible to sample the temperature variation at different depths beneath the surface and possibly detect changes in the structure or composition of the lunar surface material .