Whitepaper #034 in the Decadal Survey for Solar and Space Physics (Heliophysics) 2024-2033. Main topics: basic research. Additional topics: planetary ionospheres / upper atmospheres; ground-based missions/projects; space-based missions/projects; planetary magnetospheres.
This paper describes the scientific motivation for the NASA HMCS study of the MIO mission, which involves a relativistic-electron accelerator operated in the equatorial magnetosphere. MIO will reveal the connections between magnetospheric phenomena and ionospheric phenomena enabling the magnetospheric drivers of various aurora, ionospheric phenomena, and field-aligned currents to be determined.