1. Department of Physics and Astronomy; University of Kansas; Lawrence Kansas USA
2. Department of Physics and Astronomy; Benedictine College; Atchison Kansas USA
3. Space Science and Engineering Division; Southwest Research Institute; San Antonio Texas USA
4. Johns Hopkins University Applied Physics Laboratory; Laurel Maryland USA
5. Institute for Astronomy and Space Physics; COCICET/University of Buenos Aires; Buenos Aires Argentina
6. Mullard Space Science Laboratory; University College London; London UK
7. Centre for Planetary Sciences; University College London/Birkbeck; London UK