Jiejun Jing, currently finishing his Ph.D. at Vrije Universiteit Amsterdam, in the Netherlands, is a worthy recipient of the John C. Jamieson Student Paper Award for his paper titled “Garnet stability in the deep lunar mantle: Constraints on the physics and chemistry of the interior of the Moon,” published in Earth and Planetary Science Letters (584, 117491, 2022).

This paper is his first lead-author publication and was completed against a backdrop of the lockdowns and laboratory restrictions during the pandemic. His work is a textbook example of the power of integrating information from mineral physics with information gathered from high- pressure experiments. The paper outlines a set of high-pressure experiments to delineate the limits of stability of the mineral garnet at hundreds-of-kilometer depth in the mantle of the Moon. This is important because of the large effects garnet can have on both the trace element composition of melts in equilibrium with garnet, and the physical properties of rocks given the comparatively high density of the mineral.

Models developed in Jiejun’s paper quantify both these chemical and physical effects and give a great overview of the various implications of the presence of garnet in the Moon. In addition, the work described in this paper can clearly serve as a basis for a broad range of follow-up work. Jiejun shows that on the basis of their physical properties, lithologies containing a mixture of garnet- bearing and ilmenite-bearing rocks could be a key component of the core-mantle boundary region of the Moon. To date, the physical and chemical properties and evolution of such a lithology have not been assessed quantitatively.

Since the publication of his work, Jiejun has completed experiments on the distribution of elements between minerals and magma in the lunar interior and has started a collaboration with Chinese colleagues studying the composition of samples from the Chang’e 5 sample return mission. Upon completion of his thesis in October 2023, Jiejun intends to continue his work on the Moon, with a

particular focus on physical property measurements of deep Moon materials. With lunar science on the rise across the globe, his future looks bright.

—Stephan Klemme, University of Münster, Münster, Germany

It is my great honor to receive the 2023 John C. Jamieson Student Paper Award, and I am grateful for the recognition of my contributions to the field of lunar science. It is my hope that my paper will serve as a foundation for further research in this field, especially the potential of exploring the physical and chemical properties of the garnet- and ilmenite-bearing lowermost mantle. Since I arrived in Amsterdam at the end of 2019 to start my Ph.D., the global pandemic started and profoundly affected my research plan. Despite this challenge, I was very fortunate to receive support and encouragement throughout this project, and I extend my gratitude to all my colleagues. My first appreciation goes to my supervisor at Vrije Universiteit Amsterdam, Wim van Westrenen. Wim’s brilliance as a scientist is matched by his wonderful supervising skills. I really appreciated his guidance on the path to science and enjoyed every discussion we had on scientific and daily matters. I still remember the afternoon in late 2020 when Wim and I, both wearing face masks, discussed lunar garnet in the lab. It may have been a little late for a Ph.D. student to conceive his first paper idea, nearly in the second year of the Ph.D. The university was almost empty and the pandemic was despairing, but our brainstorming in our lab was exciting and this project was full of hope. That discussion also motivated me to diversify my research tool kit. I began learning the experimental skills of the multianvil press with my colleague Jurriën Knibbe. I also appreciate the patient and kind guidance and help from Jurriën. Many thanks also to Yanhao Lin, as well as the technicians and colleagues from both Vrije Universiteit Amsterdam and Utrecht Universiteit, who helped me complete the experiments, analyses, and writing the paper. In the end, I want to acknowledge Stephan Klemme for his endorsement, and the Mineral and Rock Physics section of AGU for conferring this award upon me. —Jiejun Jing, Vrije Universiteit Amsterdam, Amsterdam