What strange quirks of fate gets us all where we end up being. When I took a teaching position with San Diego State in the Spring of 1963 the department had just initiated a fledgling MS program and had enrolled the first six graduate students. Before long I met Nathan Ayer and John (aka., Jack) Holden, one third of the program. We became instant friends. Completely unbeknownst to me, Robert Dietz was employed at the Naval Electronics Laboratory in the Point Loma District of San Diego. Nate and John were two of his assistants. The three of us immediately shared intense interests. Long involved discussions of impact structures, craters, astroblemes and speculations regarding the Moon and other planets got under way almost any time we got together.

            Nate almost seemed to live around the department. Whenever I desired conversation, I'd descend into "The Catacombs" (the graduate student offices in the basement) and there would be Nate sitting amidst his piles of collected books listening to classical music and working on his thesis. Nate's study involved Meteor Crater of Arizona, the same impact structure as that of the classic study of Eugene Shoemaker. Nate was interested in shock metamorphic effects on detrital zircon grains. These grains were derived primarily from the Coconino Sandstone, a pre-impact bedrock unit in the area. It seemed that normal Coconino zircon grains were colored to one degree or another, but in the impact site grains taken from pieces of the Coconino ejecta were clear. Obviously, he was dealing with a shock-metamorphic effect, but was the coloration loss due to heating or due to intense short-term pressure change. It was an interesting problem, certainly one that had never occurred to me.

            John was more interested in sea-floor spreading and tectonics, both fascinating topics in themselves. But if any conversion drifted into planetary things, he was sure to have input. Plus, John had a unique talent for illustration of almost any concept. As any discussion unfolded, John's sketched illustrations of maps, faces, cross sections, craters and a whole variety of doodles would appear on napkins, waste paper or any other medium that happened to be around. John was Robert Dietz's illustrator, plus he was the department cartoonist and many of his efforts adorned the hall bulletin boards. Every geologist who saw his artwork was greatly amused and some of his cartoons ultimately made it into well respected geology textbooks. (for a couple examples of Holden cartoons, click here. )

            John and Nate greatly aided my understanding of the Earth as a planet. I didn't realize it at the time, but it's true. Remember, this was in the days prior to the concept of plate tectonics. Virtually no geologists were thinking along planetary lines at this time. But we were. I remember when the first Mariner flyby images returned and showed Mars to be cratered like the Moon. The images first appeared in the evening newspaper. Nate and I ran into one another the next morning and we both broke into a big smile. We knew craters would dot that planetary landscape. Everyone else was surprised.

            Although I listened to countless "Dietz stories," I only met Bob Dietz on one occasion. Nate introduced us. He shook my hand and said hello, but you could see from his eyes that his thoughts were totally elsewhere, perhaps lost on some distant astrobleme. "Well," said Nate, "That's Dietz." For a Holden cartoon of Dietz, click here.