Stephen J. Mackwell currently serves as director of the Lunar and Planetary Institute in Houston, Texas, and is an adjunct professor in the Department of Earth Science at Rice University, USA. Amy A. Simon-Miller is the associate director for Strategic Science at NASA Goddard in Maryland, USA. Jerald W. Harder is an instrument scientist for the Spectral Irradiance Monitor (SIM) on the NASA-sponsored Solar Radiation and Climate Experiment (SORCE). Mark A. Bullock is the Planetary Physics Section manager at the Southwest Research Institute, located in Boulder, Colorado, USA.