Analysis of cosmic materials: Results on carbon and silicate laboratory analogues

Carbon and silicates are two of the main components of cosmic dust. They change nature through different evolutionary phases, according to the cosmic environment and the experienced processing. To understand the evolution of cosmic materials the study of "laboratory analogues" represents a powerful tool. In this context, systematic analyses are performed at the cosmic physics laboratory of Naples on solid particles, synthesised and processed under carefully controlled conditions. Different kinds of carbon and silicate samples are produced under various environmental conditions and exposed to processes (e.g. thermal annealing, UV irradiation and ion bombardment). The comparative analysis of the results allows us to link intrinsic properties (such as chemical composition and structure) to the optical behaviour of grains. This study offers the opportunity to interpret observations concerning the composition of small bodies in the Solar System, such as spectroscopic results obtained for comets by the Infrared Space Observatory (ISO). Several open questions remain, however, unsolved and await results from new laboratory experiments. ©1999 COSPAR. Published by Elsevier Science Ltd.