September 17, 2020

John Taylor Wasson, Emeritus Professor in UCLA’s Department of Earth, Planetary, and Space Sciences, passed away peacefully at his long-time home in Los Angeles on September 8, 2020, at the age of 86. He had suffered a stroke in January, but had courageously battled back, improving in many ways, before his sudden passing. John was passionate about meteorites and what their properties reveal about the formation and early evolution of the Solar System.  Over a research career spanning six decades, he left a rich legacy of contributions to meteoritics and planetary science.

John was born on the 4th of July 1934, in the rural hamlet of Springtown, Arkansas, the only child of Harlan and Ruth Wasson. He milked cows and carried out country chores but was also an outstanding student. He attended the University of Arkansas from 1951 to 1955. When it was time to choose a graduate school, MIT offered $10 more per month than Harvard, so Crimson got the boot.  Only three years later John received his PhD in Chemistry, with his now famous independent streak facilitated by loose supervision from his thesis advisor, Charles Coryell.

Just twenty-four years of age, the newly minted Dr. Wasson wanted to see Europe and so he accepted a one-year postdoc at the Technische Hochschule, Munich, working in nuclear physics. Although he spent much time copying papers on meteorites, time enough was found to meet his future wife, a beautiful humanities student named Gudrun Hanewald. He also started a project using a form of activation analysis. The first of some 260 scientific publications by John Wasson appeared in 1960, “Messung der Einfangsgamma- und Röntgenspektren von Sm und Gd” (about the energies of gamma- and x-rays from neutron-irradiated samarium and gadolinium); a single page, entirely in German.

In September 1959, John accepted a 3-month postdoc from Coryell back at MIT, but only while final arrangements were made for him to fulfill an obligation to the U.S. Air Force. He had participated in ROTC as an undergraduate and owed the Air Force at least two years of service. For 3½ years he worked at Air Force Cambridge Research Laboratories, just a few kilometers from MIT.  John lingered there as Gudrun, whom he’d married in 1960, completed her PhD at nearby Harvard. His Air Force boss was Ed Martell, a former student of Willard Libby, the Nobel laureate who would later spearhead the hiring of Wasson by UCLA. Martell’s group was mainly concerned with studying radionuclides in the stratosphere that were produced by nuclear-bomb tests.

His Air Force service satisfied, in 1963 John returned to German-speaking Europe to do a second postdoc at Bern, nominally supervised by the ailing Fritz Houtermans.  There, he published his first work in cosmochemistry, a long paper in Icarus entitled “Radioactivity in interplanetary dust”.  He also coauthored a paper involving neutron activation analysis and started meteorite research in earnest. His first daughter, Christina, was born in Bern in 1964.

In 1964, John was hired to the faculty at UCLA, appointed to both the Department of Chemistry and the Institute of Geophysics and Planetary Physics, then directed by Libby. John later related that his recruitment was almost exclusively due to Libby, and that John was not required to give a seminar before winning the offer. (He admitted that this omission might have helped his chances.)

At UCLA, John immediately gave full rein to his passion for meteoritics. His twelfth publication (1965), entitled simply “Boron in iron meteorites,” was based on colorimetric analysis, and soon after he published his first two papers applying neutron activation analysis, most notably a paper in Science reporting concentration data for three elements, Ni, Ga and Ge, in one iron meteorite. This was followed by a 1967 Geochimica et Cosmochimica Acta paper that represented major progress for classification and interpretation of iron meteorites. The striking trace-element records of fractional crystallization in asteroidal cores had begun to emerge. John realized much work lay ahead and, anticipating that future, titled his paper “The chemical classification of iron meteorites: I. A study of iron meteorites with low concentrations of gallium and germanium.” That GCA/iron classification series would eventually reach XII (in 1998) and were followed by other papers on trace elements in irons. John and Gudrun’s second daughter, Kerstin, was born in 1968.

In 1969 John was chosen to be one of the few scientists allocated Apollo 11 lunar samples. Over the next 15 years he and his colleagues, including Paul Warren, produced a series of important papers on siderophile and volatile trace elements in lunar samples. It was also in 1969 that Allende fell, and John managed to scoop up 45 kilograms for UCLA. For the rest of his life he continued to expand the UCLA meteorite collection, now the fifth largest in the U.S.

In the early 1970s, John’s postdoc Phil Baedecker wrote a software package, “Spectra”, that enabled a gradual shift away from the arduous radiochemical form of neutron activation in favor of instrumental neutron activation analysis (INAA). John’s first book, “Meteorites: Classification and Properties,” appeared in 1974. A year later postdoc Ed Scott and John published a landmark paper distinguishing two broad categories of iron-meteorite groups, later termed “magmatic” and “non-magmatic” (i.e., not fractionally crystallized) irons.

The Meteoritical Society always was an important part of John’s scientific life.  In 1980 he served as President of the MetSoc.  He then served five years as Editor of Meteoritics, beginning in 1987, during which time he oversaw a tremendous enhancement of the quality and stature of the Society’s journal (now the prestigious Meteoritics and Planetary Science).  The 1980s also saw a great expansion in the breadth of John’s scientific contributions as he and his colleagues published important papers on a variety of topics, including the origin of lunar KREEP, reduction and metamorphism in chondritic meteorites, and terrestrial accretion. Student Frank Kyte and John confirmed and later expanded upon the 1980 Alvarez paradigm that iridium can be exploited as a recorder of accretion, including the Cretaceous–Paleogene boundary (marking the dinosaur-killer event). John’s second book appeared in 1985: “Meteorites: Their Record of Early Solar-System History”. This decade yielded important papers on the compositions of chondrites (especially carbonaceous chondrites), chondrules, and “non-magmatic” irons.  

John was awarded the MetSoc’s highest honor, the Leonard Medal, in 1992. In the early 1990s, he continued his studies of chondrites, mainly with Greg Kallemeyn. Later in the decade came several important papers on the origin of chondrules and on redox processes in chondrites. Still in the 1990s, John began his studies on the layered tektites of southeast Asia.

In 2003, John was awarded the U.S. National Academy of the Sciences' triennial J. Lawrence Smith Medal for “important studies on the classification, origin, and early history of iron meteorites and chondritic meteorites, and on the mode of formation of chondrules.” In the 2000s John made further contributions on iron meteorites and complex processes involved in the formation of chondrites.

In 2011, the mineral wassonite (TiS), indicative of extremely reducing conditions, was formally approved. In 2013, with key assistance from Alan Rubin, and spurred by a major donation from Arlene and Ted Schlazer, John established the UCLA Meteorite Gallery, offering thousands of visitors the chance to encounter meteorites and to learn more about the solar system. After John formally retired from UCLA in 2015, he still remained active in research, cycling to his office nearly every day and continuing INAA studies on iron meteorites. Long-time friends were not surprised when, after his stroke in January 2020, John wanted nothing more than to return to his meteorite research, which by enthusiasm and willpower he managed to an admirable extent.

John’s other passions included tennis. He was a very good player, even into his eighties. John’s favorite causes, suitable for donation in his name, include the Meteorite Gallery at UCLA, and the Flint Creek Preserve in Arkansas.

Paul Warren, Alan Rubin, Kevin McKeegan
Department of Earth, Planetary and Space Sciences
University of California Los Angeles

Categories: In Memoriam