Van Allen Lecture: Nature’s Palette

Abstract:

Like an artist’s palette, Nature has a set of common physical processes to employ to make a magnetosphere. The nature of a particular work of art depends on how much of each of the colors is used and how they are combined on the canvas. In much the same way, the nature of a magnetosphere is determined by the particular properties of a given planet and how those properties influence the dynamical significance of the various processes. We will examine some of the processes in Nature’s palette and see how their importance varies from magnetosphere to magnetosphere within our own solar system. Comparing actual realizations of magnetospheres to which we have in-situ access enables us to see the interplay between the physical processes and the peculiar conditions of each body. As we contemplate the extra-solar planets we are now discovering, we need to consider other possible combinations of colors from this palette: What other wonderful and exotic magnetospheres might exist throughout the universe?