Natalia Artemieva¹, Robert Luther², Andrea Schmalen², Kai Wuennemann³ and Detlef Koschny⁴, (1)Planetary Science Institute Tucson, Tucson, AZ, United States, (2)Museum für Naturkunde, Berlin, Germany, (3)Museum fuer Naturkunde, Berlin, Germany, (4)European Space Agency, Villanueva De La Can, Spain