Experimental simulation of cometary surfaces using volatile-rich analogue materials

Abstract

Cometary surfaces are shaped through the process of activity when the comet approaches the sun and the sublimation of volatiles removes dust and gases. Recently, the ESA Rosetta mission showed the geomorphologic diversity of comet 67P/Churyumov-Gerasimenko in great detail (Fig. 1), giving us the opportunity to investigate the sublimation processes on small Solar System bodies by means of geomorphologic analyses of the surface . In order to understand how these processes alter the surface appearance, we investigate the morphologic evolution of sublimating cometary surfaces in the laboratory of the IGEP department at TU Braunschweig. The focus lies on the evolution of different morphologies that were found on comet 67P/Churyumov-Gerasimenko, such as fractur es and debris deposits [1,2]. We consider the composition and initial geometry of the samples and variable insolation flux. Different sample compositions and geometries are prepared to model the interaction of volatile-dust mixtures with vacuum conditions. The results will not only provide information on the material properties and parameters (e.g. cohesion, tensile strength) of comets, but will also enable us to Analyse the morphologic evolution of cometary surfaces.