An Improbable Collaboration

Abstract

Fifty years of collaboration between the authors are reviewed. Common themes cover magnetospheric magnetohydrodynamic phenomena: MHD waves, wave‐particle interactions, circulation, global modes and field line resonances in the terrestrial context, and magnetosphere‐moon interactions, transport processes, instabilities, and global structure in the magnetospheres of giant planets. Over the period reviewed, instrumentation has improved, particularly in particle detectors, and interpretations that seemed radical when first suggested are now supported by measurements and seem commonplace.Plain Language SummaryThe authors have worked together for almost 50 years. They met when the existence of the magnetosphere, the volume surrounding the Earth in space that is structured by its planetary magnetic field, had been established for only a decade. They have succeeded since then in showing that, in a field where new discoveries were regularly happening, there is a very useful role for people who, paying attention to the strengths and weaknesses of instrumentation, can move back and forth between theory, simple modeling, data analysis, and back to theory. Magnetohydrodynamics, a theoretical tool that simplifies the description of space plasmas by focusing on averaged responses, has been their key discipline, but some of their key contributions have elucidated the critical role of the energetic particles that depart from average behavior. Through a mix of theory, interpretation of observations, and even leading spacecraft instrument teams, the authors have contributed to understanding most aspects of the large‐scale behavior of the magnetospheric systems at Earth, Jupiter, and Saturn.Key PointsOutline of development of many aspects of basic field and particle interactions in magnetospheresTheories of linear and nonlinear magnetospheric MHD waves and wave‐particle interactionsMHD of giant planet magnetospheres and magnetosphere‐moon interactions