Computer Sciences Corporation, 7700 Hubble Drive, Lanham, MD 20706, USA
Johns Hopkins University, Applied Physics Laboratory, Laurel, MD 20723, USA
Johns Hopkins University, Applied Physics Laboratory, Laurel, MD 20723, USA
Carnegie Institution of Washington, Department of Terrestrial Magnetism, Washington, DC 20015, USA
The Catholic University of America, Department of Physics, Washington, DC 20064, USA
Smithsonian Institution, Natural History Museum, Washington, DC 20013, USA
University of Arizona, Lunar and Planetary Laboratory, Tuscon, AZ 85721, USA
University of Arizona, Lunar and Planetary Laboratory, Tuscon, AZ 85721, USA
The Catholic University of America, Department of Physics, Washington, DC 20064, USA; Carnegie Institution of Washington, Department of Terrestrial Magnetism, Washington, DC 20015, USA