Abstract
Our solar system consists of the Sun, nine planets, their satellites, and many small bodies including asteroid and comets. Asteroids and comets are believed to be fossils, which retain the records of planet-forming age fairly well. In order to investigate physical properties of the surface layers of such small bodies, a large number of ground-based observations and laboratory measurements of terrestrial rocks and meteorites have been performed. It is demonstrated from those works that most atmosphereless bodies in the solar system are covered with regolith layers, which were generated by impacts of meteorites. Understanding the light scattering process by such regolith surface is an important subject to estimate the composition and structure. However, it is not established how the scattering properties of an isolated particle are related to the average properties of an ensemble of similar particles in a close-packed powder like regolith. In this paper, we summarize the light scattering properties of small bodies in the solar system by referring to previous works and our laboratory analogue experiments.
