Dear Colleagues, We are pleased to invite you to submit an abstract to our session at the International Mineralogical Association 2026 Meeting (IMA 2026), in Nanjing, China, August 20–24, 2026: "Fluids and melts in planetary interiors: properties, generation, transport and consequences – a session in honor of Bjørn Mysen". Fluids and melts are fundamental agents in the transport of energy and matter within and between the internal layers of rocky planets, such as Earth and Mars. Their physical and chemical properties influence critical geochemical and geophysical processes, including mantle rheology, element and heat transfer, volatile cycling, atmosphere/hydrosphere formation, ore deposit generation, and volcanic dynamics. This session aims to showcase the latest research on the properties, mobility, and transport of melts and fluids across scales—from micro to planetary—with a special emphasis on Earth’s mantle. We welcome contributions from diverse disciplines, including geochemical, geological, and geophysical observations, laboratory-based geochemical and petrological studies, and experimental and numerical modeling approaches. This session is held in honor of Bjørn Mysen, recipient of the 2025 IMA Medal for Excellence, whose pioneering work has advanced our understanding of these processes. Please submit your abstract via the IMA 2026 website. For more information, visit our session page: https://ima2026.nju.edu.cn/52/ca/c65014a807626/page.psp The abstract deadline is March 15, 2026. We look forward to your contributions and to engaging discussions at IMA 2026! Best regards, The conveners Xiaozhi Yang (Nanjing University) Charles Le Losq (Institut de Physique du Globe de Paris) Qunke Xia (Zhejiang University) Eiji Ohtani (Tohoku University) Long Li (University of Alberta) Jannick Ingrin (Université Lille) Naoko Takahashi (Tohoku University) Jun Tsuchiya (Osaka University) Sylvie Demouchy (Université Clermont Auvergne) — Naoko Takahashi Department of Earth Science, Graduate School of Science, Tohoku University 6-3 Aramaki Aza Aoba, Aoba-ku, Sendai, Miyagi, 980-8578 Japan Email: ntakahashi@tohoku.ac.jp