Short‐Term Variability of Jupiter's Satellite Footprints as Spotted by JWST
Open Access
- 3 March 2026
- journal article
- Published by American Geophysical Union (AGU) in Geophysical Research Letters
- Vol. 53 (5)
Abstract
We present the main Alfvén wing (MAW) spots of Io and Europa as observed by the Near‐Infrared Spectrograph onboard the James Webb Space Telescope. These auroral footprint features have been measured previously, but only in emission. Here, the derived ionospheric emission, temperature and column density are reported, as well as spectral radiance. At the Io footprint, temperatures are 670–900 K, excluding a spatially confined cold structure (538 17 K), localized to the MAW spot, with high densities (0.98 0.43 × ). There are suggestions of a similar, less extreme population associated with the Europa footprint. However, temperatures at Io's MAW spot show significant variability within different observational exposures, indicating precipitation energy changes, sampling various regions of the ionosphere's altitudinal temperature profile. This work provides a new window into understanding the auroral processes driven by moon‐magnetosphere interactions in the Jovian system.Keywords
Funding Information
- Northumbria University
- Science and Technology Facilities Council (ST/W001527/2)
- Science and Technology Facilities Council (ST/W00089X/1)
- Science and Technology Facilities Council (ST/X003426/1)
- Science and Technology Facilities Council (ST/X508548/2)
- Space Telescope Science Institute (NAS5‐03127)
- Space Telescope Science Institute (JWST‐GO‐03665.002‐A)
- National Aeronautics and Space Administration (80NSSC23K1637)
- Natural Environment Research Council (NE/W002914/1)
This publication has 54 references indexed in Scilit:
- Alfvén Waves Related to Moon–Magnetosphere Interactions2024
- Overview of Moon–Magnetosphere Interactions2021
- A New Model of Jupiter's Magnetic Field From Juno's First Nine OrbitsGeophysical Research Letters, 2018
- The tails of the satellite auroral footprints at JupiterJournal of Geophysical Research: Space Physics, 2017
- Juno‐UVS approach observations of Jupiter's aurorasGeophysical Research Letters, 2017
- Jupiter's equatorward auroral features: Possible signatures of magnetospheric injectionsJournal of Geophysical Research: Space Physics, 2014
- Mapping the electron energy in Jupiter's aurora: Hubble spectral observationsJournal of Geophysical Research: Space Physics, 2014
- Longitudinal modulation of the brightness of Io's auroral footprint emission: Comparison with modelsJournal of Geophysical Research: Space Physics, 2013
- Cassini UVIS observations of the Io plasma torus.I. Initial resultsIcarus, 2004
- A Baseline Spectroscopic Study of the Infrared Auroras of JupiterIcarus, 1997