Unveiling plasma energization and energy transport in the Magnetospheric System through multi-scale observations: the science of the ESA M7 Plasma Observatory mission candidate

Plasma energization and energy transport are ubiquitous in cosmic plasmas. The Earth’s Magnetospheric System is a key example of a highly structured and dynamic cosmic plasma environment where massive energy transport and plasma energization occur and can be directly studied through in situ spacecraft measurements. Despite the available in situ observations, however, we still do not fully understand how plasma energization and energy transport work. This is essential for assessing how our planet works, including space weather science, as well as for the comprehension of distant astrophysical plasma environments. In situ observations, theory and simulations suggest that the largest amount of  plasma energization and energy transport occur through the coupling between large, fluid scales and the smaller, ion kinetic scales. Remote observations currently cannot access these scales, and existing multi-point in situ observations do not have a sufficient number of observation points to resolve the fluid-ion scale coupling. Plasma Observatory will be the first mission having the capability to resolve scale coupling in the Earth’s Magnetospheric System through measurements at seven points in space, covering simultaneously the ion and the fluid scales in key regions where the strongest plasma energization and energy transport occur: the foreshock, bow shock, magnetosheath, magnetopause, magnetotail current sheet, and transition region. By resolving scale coupling in plasma processes such as shocks, magnetic reconnection, turbulence, plasma instabilities, plasma jets, field-aligned currents and their combination, these measurements will allow us to address the two Plasma Observatory Science Objectives (SO1) How are particles energized in space plasmas? and (SO2) Which processes dominate energy transport and drive coupling between the different regions of the Earth’s Magnetospheric System? Going beyond the limitations of Cluster, THEMIS and MMS multi-point missions, which can only resolve plasma processes at individual scales, Plasma Observatory will transform our understanding of the plasma environment of our planet with a major impact on the understanding of other planetary plasmas in the Solar System and of distant astrophysical plasmas.