1. Department of Physics and AstronomyUniversity of Texas at San Antonio San Antonio Texas USA
2. Space Science and Engineering DepartmentSouthwest Research Institute San Antonio Texas USA
3. Johns Hopkins University Applied Physics Laboratory Laurel Maryland USA
4. Planetary Science Institute Tucson Arizona USA
5. Lunar and Planetary Institute, Universities Space Research Association Houston Texas USA
6. NASA Goddard Space Flight Center, Planetary Geodynamics Laboratory Greenbelt Maryland USA