Much work has been done on measuring the brightness of the zodiacal light and its polarization. Unfortunately the scattering function of a particle depends on its complex index of refraction, its shape, and its size; the brightness and polarization of the zodiacal light therefore depends on the distribution of the sizes, the physical composition, and the spatial distribution of the scatterers. Thus a number of model distributions that explain the same data are derived [Giese, 1963; Powell et al., 19676]. Observations suggest that the particles are concentrated in the ecliptic and that their density falls off far from the sun. Independent observations of radio and photographic meteors and larger objects suggest that the zodiacal light is produced by micrometeoroids with masses of a microgram or smaller, i.e., diameters of 100 μ or smaller.