In Memoriam: Bevan M. French (March 8, 1937–May 10, 2025)

Bevan French (Figure 1) is most widely known for his pioneering work in planetary science and the field of impact cratering. He was one of the early workers on terrestrial impact materials along with Gene Shoemaker, Robert Dietz, Nick Short, Richard Grieve, Mike Dence, Dieter Stöffler, Ed Chao, and others. Throughout his career, Bevan was a champion for impact science, particularly centered on petrography and geologic observations at terrestrial craters. His 1998 book, Traces of Catastrophe, published by the Lunar and Planetary Institute in Houston, is still used today in classrooms across the world as one of the standard introduction texts for impact cratering.

Bevan French was born on March 8, 1937, in East Orange, NJ, USA. At age 15, he was already actively involved in collecting rare minerals at Franklin, NJ, for his own mineral studies group. A few years later, in 1954, his minerals got him into the Top 40 of the Westinghouse Science Talent Search, which also led to a summer job at the National Bureau of Standards during the same year. He obtained an A.B. degree in geology from Dartmouth College, Hanover, NH, USA (1958), a M.S. in geochemistry from the California Institute of Technology, Pasadena, CA, USA (1960), and a Ph.D. in geology at The Johns Hopkins University, Baltimore, MD, USA (1964), with a thesis titled “Stability of Siderite, FeCO₃, and Progressive Metamorphism of Iron Formation,” on metamorphic petrology of iron formations in the Minnesota Iron Range. At a geological conference in Minneapolis in the mid-60s, Bevan gave a talk about his thesis work which attracted a smart lady geologist who was working for an iron-mining company. Two years later, in 1967, they married. Mary-Hill French became a close partner in editing Bevan's manuscripts and joined in all the travels around the world, in a total of 32 different countries (Figure 2). Bevan joked about robbing the cradle: Bevan was much younger. Together, they supported young investigators interested in terrestrial impacts until her passing in 2019 at the age of 102.

Amusingly, Bevan's work in the 1960s on the Iron Range was done well before recognition of the Sudbury as an impact structure and the subsequent discovery of Sudbury ejecta in the Iron Range. In recent years, Bevan joked about how, 50 years later, he was returning to his geologic roots with renewed interest in Sudbury and associated rocks on the Canadian Shield. Bevan's work on Sudbury, starting in the mid to late 1960s, was essential in confirming the impact origin of this structure. Starting with his pioneering work on shock-metamorphic studies, especially on quartz, in the later 1960s, he then collaborated with several colleagues to provide evidence for the impact origin of several other promising structures around the world, such as Rochechouart, B.P., Oasis, Tenoumer, Aouelloul, Araguainha, and Serra da Canghala. His impact pedigree is actually shared: he is a distant cousin of Don Gault, another pioneer in impact studies, and he would greet Don as “cuz” at conferences.

After graduating from Johns Hopkins Bevan quickly turned toward planetary science and joined NASA Goddard Space Flight Center in 1964. There he continued working on impact cratering and co-convened a conference on terrestrial impacts and co-edited with Nicholas M. Short the “Shock Metamorphism of Natural Materials” monograph, the so-called “green bible of impact cratering,” where much of the establishing work of impact cratering was presented. In 1968 he was on leave as a visiting professor at Dartmouth College (NH, USA), to teach courses on igneous petrology and terrestrial impact structures. Bevan then joined the Apollo Program as a co-investigator on Apollo 11 and 12 samples, and as a trainer for astronauts of the Apollo 16 and 17 missions. He was involved in some of the first publications on lunar glasses in the early 1970s and continued to also work on lunar materials. In 1991, he co-edited, with Grant Heiken and Dave Vaniman, the classic publication “Lunar Sourcebook: A user's guide to the Moon,” a one-volume reference encyclopedia of scientific and technical information about the Moon.

Bevan spent a few years (1972–1975) away from NASA as a Program Director of Geochemistry at the National Science Foundation (NSF) before returning back to NASA Headquarters in 1975. At NASA, Bevan had many roles (Figure 3), including Discipline Scientist for Planetary Materials (administering research on lunar samples, meteorites, and cosmic dust), Advanced Programs Scientist, and Discipline Scientist for Special Projects, as well as Program Scientist for the Mars Observer mission. He also represented NASA at the 1977 tri-agency meeting establishing the U.S. Antarctic Meteorite Program (known as ANSMET) and longstanding partnership between NASA, NSF, and the Smithsonian Institution. To work in science administration was certainly ademanding job—on the one side you have greedy scientists who want more and more money to study little gray rocks from outer space. On the other side, you are harassed by science-illiterate politicians like the infamous Senator Proxmire, who awarded a so-called “Golden Fleece” to Bevan's program for the “useless expenditure of Federal Funds” to spend 2.8 million dollars to “construct an addition to the lunar laboratory to house 100 pounds of moon rocks.” Some things never seem to change.

Bevan officially retired from NASA in 1994 and quickly returned to terrestrial impact structures, first as a visiting professor at the University of Vienna (1994; returning in 1997 and 2001) and later as a research collaborator in the Smithsonian Institution Departments of Mineral Sciences (1994–2004) and Paleobiology (2004–2022). Even during his tenure at NASA, he stayed involved in impact research. For example, he closely followed the debate on the K–T boundary impact (now K–Pg), well before Chicxulub had been identified as the source crater. He encouraged a more detailed look at the Manson impact structure (in Iowa, USA), which resulted in a comprehensive book publication. Originally, it was assumed to be about 65 million years old, but then an older formation age was determined.

He has made important contributions to the study of the Vredefort impact structure in South Africa, the Bushveld Complex, and the discussion on Early Archean spherule layers, for which he pointed out the dilemma (still not really solved): spherules are rather rare around younger impacts but dominate ejecta deposits in the Early Archean. He has also worked on a variety of other impact structures, such as Gardnos in Norway, Woodleigh in Australia, Decorah (Iowa, USA), Rock Elm (Wisconsin, USA), and again on Sudbury.

He and Mary-Hill were strong supporters of students interested in impact geology, whether through hands-on tutorials at their home or research seed grants at Brown University and at the Carnegie Institution, specifically for studies of terrestrial impacts. Bevan and Mary-Hill traveled extensively to many conferences and participated in field excursions all around the world (Figures 4 and 5). In recognition of his eminent contributions to planetary sciences and impact cratering in particular, Bevan was awarded the Barringer Medal from the Meteoritical Society in 2002 (Figure 6). He followed this award up with a somewhat autobiographical review paper in 2004, published in Meteoritics and Planetary Science, and later wrote (together with one of us; C.K.) a widely cited review paper on the criteria to be used to identify geological structures or materials as being of impact origin.

Although Bevan never formally advised students' theses or dissertations, he was a great mentor to many of us (young and old) in the community. He gave personal tutorials to young researchers about recognizing shock-metamorphic features. Through long, detailed conversations at conferences, phone conversations, and written discussions, Bevan left his mark on the entire impact community. He had a large network of international collaborators and was very much entrenched in the scientific community, as is also evident from the number of memorials he wrote for former colleagues.

Beyond science, Bevan enjoyed many things, including classical music and reading (mystery and humor being high on his lists of favorites). Bevan's dry wit and creative abilities often brought smiles to our community. Two prime examples were his original song—and performance—of “The Man Passing by on his Way to the Moon,” for the retirement of Eugene Shoemaker, and his Barringer Medal Award speech titled “The importance of being cratered.” Lately, he spent a lot of his time organizing his books and reprints, as well as his large sample collection, housed in the basement of his home in Chevy Chase (MD, USA). Just before his sudden passing, he was polishing his final paper about Sudbury (Figure 7). We have lost an absolute giant in the field of impact cratering research, very influential for some of us to come into the field, and a wonderful person and gentleman.