1. Space Sciences Laboratory; University of California; Berkeley California USA
2. Department of Physics and Astronomy; University of Iowa; Iowa City Iowa USA
3. Institute of Geophysics and Planetary Physics; University of California; Los Angeles California USA
4. Institute of Space and Astronautical Science; Sagamihara Kanagawa Japan
5. Herzberg Institute of Astrophysics; National Research Council; Ottawa Ontario Canada
6. Department of Earth and Planetary Sciences; Kyushu University; Fukuoka Japan