Candice J Hansen, Planetary Science Institute Tucson, Tucson, AZ, United States, Shawn Brueshaber, Western Michigan University, Kalamazoo, MI, United States, Glenn Orton, Jet Propulsion Laboratory, Pasadena, CA, United States, Thomas Momary, NASA Jet Propulsion Laboratory, California Institute of Technology, Pasadena, CA, United States and Scott J Bolton, Southwest Research Institute, San Antonio, TX, United States