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Board of Trustees

Dr. Tim Hunter

Tim Hunter, M.D., Chair

Hunter obtained a B.A. degree from DePaul University in 1966 and the M.D. degree from Northwestern University in 1968. He also received a Bachelor of Science degree in mathematics from the University of Arizona in 1980. Currently, he is a Professor in the Department of Radiology in the College of Medicine at the University of Arizona. Tim Hunter has been an amateur astronomer since 1950. With James McGaha, he operates Grasslands Observatory in Sonoita, Arizona. He recently completed a Masters degree (MSc) in Astronomy from Swinburne University.  Since 1986, he has been interested in the growing problem of light  pollution. In 1987, Tim Hunter and Dr. David Crawford founded the International Dark-Sky Association, Inc., to promote quality outdoor lighting and combat the effects of light pollution.

Dr. Candace P. Kohl

Candace P. Kohl, Ph.D., Vice-Chair

Kohl received a B.A. degree in Chemistry from Carleton College in 1969 and a Ph.D. in Chemistry from the University of California, San Diego in 1975. Her studies involved measurement of cosmic ray produced radioactivity in lunar samples and meteorites as well as studies of impact craters. She was one of the original developers of the technique using in-situ produced radioactivity in terrestrial rock to study geomorphology. She is active in science outreach and is on the board of several fund raising organizations for science scholarships. She has been honored by the designation of Minor Planet 4899 Candace. She volunteers with international science efforts and organizations promoting women in science.

Joseph K. Alexander

Joseph K. Alexander

Joseph K. Alexander is a private consultant in science and technology policy. He was a Senior Program Officer with the National Academies Space Studies Board (SSB) from 2005 until 2013, and he served as SSB Director from 1998 until November 2005. Prior to joining the National Academies, he was Deputy Assistant Administrator for Science in EPA’s Office of Research and Development. From 1993 to 1994, he was Associate Director of Space Sciences at the NASA Goddard Space Flight Center. He served concurrently as Acting Chief of the Laboratory for Extraterrestrial Physics. From 1987 until 1993, he was Assistant Associate Administrator for Space Sciences and Applications in the NASA Office of Space Science and Applications. He also served from 1992 to 1993 as Acting Director of Life Sciences in OSSA. Prior positions have included Deputy NASA Chief Scientist, Senior Policy Analyst at the White House Office of Science and Technology Policy, and research scientist at the Goddard Space Flight Center.

Dr. William K. Hartmann

William K. Hartmann, Ph.D.

Hartmann is a founder and Senior Scientist of the Planetary Science Institute. He and Don Davis (see below) are known for developing, at PSI, the current theory of the origin of the Moon by a large planetesimal impact into the forming Earth. Hartmann's current work involves development of the "PSI isochron system" of counting impact craters to infer ages of various planetary surface units. Hartmann holds a Ph.D. in Astronomy and M.S. in Geology from the University of Arizona. He was the first winner of the Carl Sagan Award from the American Astronomical Society, a winner of the G.K. Gilbert award from the Geological Society of America, and a co-winner of the Runcorn-Florensky medal from the European Geophysical Union. In addition to his planetary work, he is known for his astronomical paintings and popular writing, including textbooks, popular science, and two published novels.

Dr. Mark Sykes

Mark V. Sykes, Ph.D., J.D.

Sykes is the C.E.O. and Director of the Planetary Science Institute. He studies asteroids, comets and interplanetary dust, using both  ground-based and space-based telescopes, primarily in the thermal infrared. He is the discoverer of cometary dust trails and many extended structures arising from asteroid collisions within the zodiacal cloud. He is the former Chair of the Division for Planetary Sciences of the American Astronomical Society, and was made a Fellow of the American Association for the Advancement of Science for his science advocacy. He has been honored by the designation of Minor Planet 4438 Sykes. Mark received his Ph.D. in Planetary Sciences in 1986 and 1998 from the University of Arizona (and is admitted to the Arizona Bar). Mark is also a professional musician, performing more than 25 seasons with the Arizona Opera Company, where he sings in the chorus. He is a member of the American Guild of Musical Artists.

Dr. Michael Belton

Michael J.S. Belton, Ph.D.

Belton has been involved in the study of planetary objects throughout his entire career. Upon receiving his doctorate’s degree in 1964, Belton moved to the Kitt Peak National Observatory and joined the “Space Division.” He remained at Kitt Peak until 2000, when le left the observatory to set up Belton Space Exploration Initiatives, LLC. He continues to hold the rank of Emeritus Astronomer at the Observatory. Belton is a past chair of the Division for Planetary Sciences of the American Astronomical Society (AAS) and for a short period was a vice-president of the AAS. Most recently he chaired the first “decadal” study of Solar System Exploration for the national Research Council and a NASA Workshop on the “Scientific Requirements for Mitigation of Hazardous Comets and Asteroids.” He has published more than 290 articles on research topics in planetary science and, in 1995, he was warded the Gerard P. Kuiper Prize in Planetary Science by the American Astronomical Society. Also in recognition of his work, minor planet 3498 has been named for him.

Dr. Michael Belton

Kathryn Schmoll

Schmoll has a B.S. in Public Administration from Indiana University and is a graduate of the Harvard Business School Advanced Management Program. Awards include: the William Jump award for outstanding public service; the NASA outstanding Leadership Medal; the Presidential Rank of Meritorious Executive; and, Outstanding Achievement Award from Women in Aerospace. She is a member of the Network of Earthquake Engineering Simulators Board of Trustees Audit and Finance Committee.


Trustees Emeritus

Dr. Brent A. Archinal

Brent A. Archinal, Ph.D.

Archinal received his Ph.D. from Ohio State University in 1987. For 13 years he was employed at the U. S. Naval Observatory and did research into methods for more accurately determining the Earth's orientation and improving the coordinate systems of the Earth and sky. In 1997 he helped establish the International Celestial Reference Frame, to which all other reference frames are now referred. Since 2000 he has been working as a Geodesist with the Astrogeology Science Center of the U. S. Geological Survey in Flagstaff. In 2006 August, he became Chair of the IAU/IAG Working Group on Cartographic Coordinates and Rotational Elements,  which is responsible for establishing the coordinate systems of all solar system bodies. He is a MER Athena and Huygens DISR Science Team member. His research centers on improving the coordinate systems for the other bodies of the solar system so that they can be accurately mapped. He has revised the coordinate reference frames for Io, Mars, and the Moon. As an active amateur astronomer, Archinal is the author of "The Non-existent Star Clusters of the RNGC" (The Webb Society), and co-author of the book "Star Clusters"

Dr. Donald Davis photo

Donald R. Davis, Ph.D.

Davis is a Founder and Senior Scientist of the Planetary Science Institute. He is a Trustee Emeritus of the PSI Board of Trustees on which he served for 15 years. In addition to his leadership of the Institute as co-founder and Director for over 30 years, he has made many contributions to planetary science including advancing our knowledge of asteroids and the origin of the Moon.

Dr. John Mason photo

John L. Mason, Ph.D.

Mason received a B.S .degree in Meteorology from the University of Chicago in 1944 and a Ph.D. in Chemical Engineering from Caltech in 1950. He currently consults for Applied Research & Technology, a California LLC, on the design of energy-efficient pumps and compressors. He is a fellow of the Society of Automotive Engineers (SAE), and was SAE's 1990 president. He is a member of the National Academy of Engineering. John Mason is a Trustee Emeritus of the Planetary Science Institute.

Past Board Members


Name Joined (Office)
2016 Brent Archinal 2002
2016 Benjamin W. Smith, J.D. 2002 (Secretary 2013-2016)
2012 Michael G. Gibbs 2009 (Secretary 2010-2013)
2010 Donald R. Davis * 1996  
2010 John L. Mason 1995 (Secretary 1998-2009)
2010 David H. Levy * 1999 (Vice-Chair 2000-2004, Chair 2005-2007)
2007 Carolyn S. Shoemaker * 2000  
2005 Byron D. Groves 1997 (Chair 1999-2004)
2004 Robert J. Parks 1998 (Treasurer 2000-2004)
2004 Dennis L. Matson * 1995  
2004 Humberto Campins * 2003  
2003 Alex Berman 2000  
2002 Wesley T. Huntress * 2000  
1999 George S. Holditch 1995 (Treasurer 1995-1999)
1998 Michael Berns 1995 (Vice-Chair 1995-1998)
1998 Walter Hansch 1995  
1998 Kip Kinnings 1995 (Secretary 1997, Chair 1998)
1997 Douglas B. Nash * 1995 (Chair 1995-1997)
1997 Eugene M. Shoemaker * 1997  
1996 Michael Udkovich 1995 (Secretary 1995-1996)

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