Skip to Content


David M. Nelson, M.S., M.A. – Data Manager / GIS Analyst / System Administrator

David is a planetary geologist and ArcGIS specialist, having earned a MS in Geology at ASU in 1997 and a MA in Geography also at ASU in 2012. As Data Manager of the RGCPS, he is developing an ArcGIS lab consisting of several Windows workstations and a GIS database consisting of a wide variety of image datasets acquired from current and past planetary missions for mapping and research.

From 1994 to 2003, he was involved in geology-related research, remote sensing, and planetary mapping, working for the late Dr. Greeley. Included in his research, he has used data from several Mars missions including Viking Orbiter, Mars Global Surveyor, and Mars Pathfinder. He also assisted in early mission planning of the European Mars Express mission, the Mars Exploration Rover missions, and several proposed Mars scout missions. At the beginning of 2007, he joined the Lunar Reconnaissance Orbiter Camera team at Arizona State University under Dr. Mark Robinson where he worked for two years in mission preparation, then as a Mission Planner for the first four years of inflight operations. His current role as Data Manager at the RGCPS began at the end of May, 2013.

Professional Staff


Daniel Ball, M.F.A. – Science Photographer

Nathan Cluff – System Administrator & Tech Support

Nathan earned his Bachelor of Applied Science degree in Software and Computing studies from the College of Technology and Innovation at Arizona State University in 2012.  He has been in various technology support roles since his time in the United States Air Force in 1998.  In 2005, he began working in education supporting a large Phoenix based charter school.  Nathan joined the Ronald Greeley Center in the spring of 2016 as a system administrator responsible for updating and configuring the center’s network.

RGCPS Students


“Enzo” Vincenzo Cataldo – Ph.D. Candidate, Geology

Enzo has been accepted to the ASU/SESE Graduate Program in Geology for Fall 2013 and plans to complete a PhD degree. He is now working on a NASA funded project on the mathematical and computer modeling of erosional processes by lava flows on Mars, the Moon and the Earth with Prof. David Williams.
Enzo’s background is in Geology, Petrology and Physical Volcanology. He graduated in Geology from the University of Palermo (Italy) and was later awarded a Master’s in Planetary Science by the University of Lancaster, his thesis work concerning the numerical and physical modeling of explosive volcanic eruptions on Jupiter’s satellite, Io. On that occasion, his main thesis advisor was Prof. Lionel Wilson (Emeritus Professor of Earth and Planetary Sciences, Lancaster University).
Enzo’s leisure time comes in the form of sport activities (mostly running), music and hiking/trekking in the mountains and….good food.


Kyle Mohr – Ph.D. Candidate, Geology

Kyle Mohr grew up in Arizona wandering the desert a child, always admiring the large mountain structures around him. Kyle went on to get his Bachelors of Science in Geophysics at Northern Arizona University. Currently Kyle is working on his Masters degree creating a geologic map of Ascraeus Mons on Mars with Dr. David Williams. Kyle has exceptional experience using ArcGIS software which allowed him to pick up a side project mapping cycloids on Europa. Kyle is also working with Dr. Alyssa Rhoden and Dr. Amanda Clarke on a Ph.D. project looking at the geomorphology of ridges on Enceladus and Europa and comparing them with fissures found on Earth to help better understand plume activity and ridge formation on Icy Satellites. Kyle enjoys hiking and playing hockey in his spare time and spending time with his wife, daughter, and two dogs.


John Christoph – Ph.D. Candidate, Geology


Hourly Workers


Mary Pendleton-Hoffer, D.M.A & M.S. Geology

Mary has been accepted to the ASU/SESE Graduate Program in Geology for Fall, 2009, and plans to complete an MS degree. Her goals include planetary research and science writing. She is a member of the science team for NASA -funded Automatic Landmark Identification (PI: Dr. Kiri Wagstaff, JPL), working on detection of dust devil tracks. Other research interests include: crater morphology comparisons (Venus, Mars, Callisto and Titan); correlating surface and orbital data; developing standard criteria for image comparison; a dust devil history of Gusev Crater, Mars; lava tube morphology (Moon); carbonatites and other unusual volcanics, Earth analog studies, and mapping.
Mary’s background is in music. She attended Texas Tech University, the Royal College of Music and Royal Academy of Music, London, and ASU, completing Bachelor, Master and Doctor of Music degrees, as well as Artist Diplomas in piano and harpsichord performance. She worked for 18 years as an orchestral keyboardist with the Phoenix (AZ) Symphony and the Florida Orchestra (Tampa), and she continues to perform with the Myakka River Piano Trio . Other interests are hiking, gardening, British procedurals, and animals, especially cats.