The integral equation approach to the study of interplanetary dust

Some considerations about the zodiacal light brightness integral from the stand point of the theory of integral equations are made. It is shown that for observation directions confined to a plane perpendicular to the ecliptic and passing through the Sun, the Z.L. brightness integral can be formally considered as a first kind integral equation of Volterra type (V.I.E.). In a second step, this equation is transformed into a V.I.E. of the second kind, from which, and under certain assumptions, the spatial distribution of dust out of the ecliptic is obtained.