Department of Terrestrial Magnetism, Carnegie Institution of Washington, 5241 Broad Branch Road, NW, Washington, DC 20015 United States
Department of Chemistry and Biochemistry, Arizona State University, P.O. Box 871404, Tempe, AZ 85287 United States
Department of Earth, Atmospheric and Planetary Sciences, Massachusetts Institute of Technology, 77 Massachusetts Ave., Cambridge, MA 02139 United States