Whitepaper #389 in the Decadal Survey for Solar and Space Physics (Heliophysics) 2024-2033. Main topics: space weather applications; basic research. Additional topics: space weather research/applications/operations pipeline; planetary ionospheres / upper atmospheres.
Solar and stellar ultraviolet occultations provide a capability essential for advancing our understanding of the thermosphere. Advances over the past decade have demonstrated the power of occultations for measuring density, temperature and waves. Additionally, occultation instruments are readily miniaturized, making them ideal candidates for space weather monitoring sensors.