Insights on collisionless shock physics from the Magnetospheric Multiscale (MMS) mission at Earth

Abstract

We briefly summarize some of the latest, impactful results concerning the nature and physics of collisionless shock waves as observed by NASA’s Magnetospheric Multiscale (MMS) mission. MMS routinely observes Earth’s bow shock and also infrequently captures interplanetary shocks at 1 AU. With the four, identical observatories outfitted with a comprehensive payload of state-of-the-art plasma instrumentation, MMS offers unprecedented capabilities for studying the micro-to-global-scale nature of shocks in near-Earth space. New results highlighted include: the global energy budget and energy partitioning at Earth’s bow shock; complexity and significance of the quasi-parallel shock regime and the ion foreshock;  the acceleration of ions to >1 MeV and electrons to relativistic (>100 keV) energies; and kinetic-scale dynamics of shock fronts including reconnection and We finish with new results of an ongoing large-scale, statistical study of Earth’s bow shock empowered by machine learning applied to the full MMS dataset. We finish with a discussion of the upcoming MMS orbital configurations in regards of new studies plus idealized concepts for future missions to study collisionless shocks.