Alexander Lukin, Space Research Institute, Moscow, Russia, Evgeny V Panov, Space Research Institute, Austrian Academy of Sciences, Graz, Austria, Anton Artemyev, University of California Los Angeles, Earth, Planetary, and Space Sciences, Los Angeles, CA, United States, Anatoli A Petrukovich, Space Research Institute RAS, Moscow, Russia and Rumi Nakamura, Space Reserach Institute, Austrian Academy of Sciences, Graz, Austria