In Memoriam: Robert O. Pepin, 1933–2023

Credit: University of Minnesota.

Robert Osborne Pepin, planetary scientist and professor emeritus at the University of Minnesota, passed away on January 6 at the age of 89. Pepin was the director of the Lunar Science Institute (now the Lunar and Planetary Institute) from 1974 to 1977. In 1976, Pepin initiated the Basaltic Volcanism Study Project (BVSP), which gathered a broad group of scientists to compare the nature, composition, and timing of volcanism on Earth, the Moon, Mercury, and Mars. This required a close look at lunar samples in a much broader planetary context.

Pepin received his Ph.D. in physics from the University of California, Berkeley in 1964. Pepin joined the University of Minnesota as a Research Associate in 1965 and joined the faculty as an assistant professor in 1966. He was a Professor of Physics from 1975 until his retirement in 2008. Pepin’s research focused on mass spectrometry. He was a leader in using the isotopes of rare gases to probe the geology of our solar system, including meteorites, lunar rocks returned during the Apollo missions (in which he played a leading role), and interplanetary dust returned from missions in the early 2000s.

He was recognized with a host of awards, most recently the Fred Whipple Award from the American Geophysical Union in 2020. After retirement he continued to work as a consultant to NASA on the Mars rover missions as well as other projects.

Pepin’s career included service to the university as director of the Institute of Technology (now the College of Science and Engineering) Honors Program from 1989 to 2007. In addition to his research accolades, he received several teaching awards, including the Morse-Alumni Award for Contributions to Undergraduate Education.

Professor Paul Crowell, Head of the School of Physics and Astronomy, said of Pepin, “Bob loved his work and particularly the University of Minnesota and its students. Many of us worked with Bob while teaching the first-year honors course. His rapport with students was extraordinary. He was a gentle and kind human being and an eternal optimist, which was evident in my most recent conversation with him last week. We will miss him greatly.”

— Text courtesy of the University of Minnesota