Board of Trustees

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.

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.

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.

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 J.D.in 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.

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.

Trustees Emeritus

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.

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.