We provide an introduction and overview about the initial Submillimetre Wave Instrument (SWI) characterization, operation, and in-flight calibration during the Lunar Earth Gravity Assist (LEGA) campaign of the Juice (Jupiter icy moons) spacecraft. A preliminary analysis on the frequency calibration is provided. For detailed analyses on total power and beam calibration and the observation and operations planning we refer to three other SWI papers prepared for this special issue of Annales Geophysicae (ANGEO).

Long-term analysis of 16 solar eclipses over south-central Chile using historical ionograms (1958–2024). Layer-dependent ionospheric responses were quantified, and fragile analog records were rescued and digitized, providing unique insights into eclipse-induced ionospheric variability.

Waves on the boundary of our magnetic shield, the magnetosphere, act as a source of electrical currents in space that flow between outer space and the ionised top of our atmosphere. We develop a simple numerical model of how these waves couple to different regions of geospace to determine their likely impacts in the context of space weather and how these vary with conditions. We find the waves’ impacts can be significant, though are typically highly localised.

The dayside auroral region is a highly dynamic region of the ionosphere that is influenced by the coupling between the solar wind, magnetosphere, and ionosphere. In this paper, we illustrate this dynamic nature and present a quantitative analysis of both altitudinal and latitudinal variation within the region. In addition, ionospheric parameters on closed field lines, along the open-closed field line boundary and in the polar cap are statistically compared.

Using mid-infrared data acquired by Moons and Jupiter Imaging Spectrometer (MAJIS) aboard the European Space Agency’s JUpiter ICy moons Explorer (JUICE) spacecraft during the 2024 lunar flyby, we retrieved lunar surface temperature and effective emissivity at high spatial and spectral resolution. By comparing three independent thermal-retrieval methods, we confirmed the main mare–highland contrasts and showed how roughness and observing geometry shape the infrared signal, providing a methodological test case for future MAJIS studies of Jupiter’s icy moons.

Comprehensive analysis of geomagnetic storms from 23–25 March, 23–25 April, 4–6 November 2023, and  10–13 May 2024, reveals that solar wind parameters, geomagnetic activity, Joule heating, and Prompt Penetration Electric Fields significantly influence ionospheric Total Electron Content variations, Equatorial Ionization Anomaly crest formations, and post-sunset plasma irregularities. The storms highlighted the importance of inter-hemispheric asymmetries in Joule Heating, which affected the distribution and magnitude of ionospheric disturbances.

During its first Earth flyby, the JUpiter Icy Moons Explorer (Juice) spacecraft acquired observations over the Western Pacific. We identify several gaseous compounds (O₂, H₂O, CO₂, O₃, CH₄, N₂O), liquid/ice clouds over the ocean and atmospheric waves at high altitudes. We find good agreement with similar observations of Earth-orbiting PRISMA spectrometer. This study helps in planning future observations from the Moon and Jupiter Imaging Spectrometer (Majis) when it comes to the Jupiter system.

The Submillimetre Wave Instrument (SWI) aboard the Juice mission is a sophisticated and first-of-its-kind payload. SWI is designed to support the diverse science objectives of the Juice mission targeting Jupiter's middle atmosphere, icy-moon's exospheres as well as near sub-surface thermophysical properties. This presents significant planning, operations and commanding challenges which are described in this paper in the context of the Lunar and Earth Gravity Assist (LEGA).

Terrestrial lightning has been spectroscopically observed from Juice (JUpiter ICy moons Explorer) spacecraft, for the first time from space in a wide wavelength range. Though not detected by ground sensors, Juice confirmed neutral atomic oxygen and nitrogen emissions, with energies and temperatures consistent with average lightning. This observation is a benchmark for Jupiter, a primary Juice target, where simultaneous hydrogen emissions in different wavelengths could identify lightning.

Auroras, the natural lights seen in Earth's sky near the poles, are shaped by both Earth's and the solar wind's magnetic fields, as well as charged solar particles. This study examines how auroras change when the solar wind's magnetic field is dawn-dusk oriented. Daytime observations are challenging due to sunlight, so we developed a method to further separate auroras from background light. In summer, auroras shift east or west with/against the solar wind's magnetic field.

In this paper, we propose a method for identifying anomalous electromagnetic phenomena in the ionosphere before earthquakes, contributing to earthquake prediction research. By analyzing satellite data from the China Seismo-Electromagnetic Satellite and applying a decomposition technique, we identify significant electric-field disturbances prior to the May 11, 2023, Tonga Islands earthquake, supporting studies of seismic precursors.