Earth Planets Space, Vol. 50 (Nos. 6, 7), pp. 465-471, 1998
MPI K. Baumgärtel Aeronomie, D-37191 Katlenburg-Lindau, Germany
(Received October 7, 1997; Revised March 17, 1998; Accepted March 17, 1998)
Abstract: We discuss some aspects of the study of the Zodiacal cloud based on brightness observations. The discussion of optical properties as well as the spatial distribution of the dust cloud show that the description of the dust cloud as a homogeneous cloud is reasonable for the regions near the Earth orbit, but fails in the description of the dust in the inner solar system. The reasons for this are that different components of the dust cloud may have different types of orbital evolution depending on the parameters of their initial orbits. Also the collisional evolution of dust in the inner solar system may have some influence. As far as perspectives for future observations are concerned, the study of Doppler shifts of the Fraunhofer lines in the Zodiacal light will provide further knowledge about the orbital distribution of dust particles, as well as advanced infrared observations will help towards a better understanding of the outer solar system dust cloud beyond the asteroid belt.