The in-situ study of solid particles in the solar system

Abstract

In-situ measurements of dust from spacecraft can in principle provide information about dust properties at any given place in the solar system and under conditions that are not reproducible on Earth. Already relatively simple in-situ measurements provide information about the properties of dust particles. Measurements of interplanetary dust have shown for the first time the fluffy and porous structure of interplanetary dust as well as the existence of two dust components with distinctly different properties. Experiments during the missions to comet Halley have shown the cometary dust to consist of two major components to about the same amount: a component that is rich in rock-forming elements and a component that is rich in the elements H, C, N and O. The latter component is assumed to consist of refractory organic material. Although the composition of interstellar dust particles is not directly measured yet, their conditions of entry into the solar system reveal the forces that are acting on them. The forces depend on the properties of dust and allow for a comparison to astrophysical models of dust size, composition and structure. In-situ measurements with improved dust detectors are presently carried out and planned for future missions. The scientific return of these future measurements can be greatly enhanced by combining detailed laboratory studies of the physics and functional principles of the detectors. © 2010 Springer Berlin Heidelberg.