An Energetic Eruption With Associated SO 1.707 Micron Emissions at Io's Kanehekili Fluctus and a Brightening Event at Loki Patera Observed by JWST

An Energetic Eruption With Associated SO 1.707 Micron Emissions at Io's Kanehekili Fluctus and a Brightening Event at Loki Patera Observed by JWST

de Pater, I. (TU Delft Astrodynamics & Space Missions; University of California)
Lellouch, Emmanuel (Observatoire de Paris)
Strobel, Darrell F. (Johns Hopkins University)
de Kleer, Katherine (California Institute of Technology)
Fouchet, Thierry (Observatoire de Paris)
Wong, Michael H. (Department of Astronomy; University of California)
Holler, Bryan J. (Space Telescope Science Institute)
Cazaux, S.M. (TU Delft Astrodynamics & Space Missions)
Moeckel, Chris (University of California)

2023

We observed Io with the James Webb Space Telescope (JWST) while the satellite was in eclipse, and detected thermal emission from several volcanoes. The data were taken as part of our JWST-ERS program #1373 on 15 November 2022. Kanehekili Fluctus was exceptionally bright, and Loki Patera had most likely entered a new brightening phase. Spectra were taken with NIRSpec/IFU at a resolving power R ≈ 2,700 between 1.65 and 5.3 µm. The spectra were matched by a combination of blackbody curves that showed that the highest temperature, ∼1,200 K, for Kanehekili Fluctus originated from an area ∼0.25 km² in size, and for Loki Patera this high temperature was confined to an area of ∼0.06 km². Lower temperatures, down to 300 K, cover areas of ∼2,000 km² for Kanehekili Fluctus, and ∼5,000 km² for Loki Patera. We further detected the a¹Δ ⇒ X³Σ⁻ 1.707 µm rovibronic forbidden SO emission band complex over the southern hemisphere, which peaked at the location of Kanehekili Fluctus. This is the first time this emission has been seen above an active volcano, and suggests that the origin of such emissions is ejection of SO molecules directly from the vent in an excited state, after having been equilibrated at temperatures of ∼1,500 K below the surface, as was previously hypothesized.

Io
JWST
spectra
volcanic activity

http://resolver.tudelft.nl/uuid:ee810d23-cfb4-4bd7-8e02-6527250decdc

https://doi.org/10.1029/2023JE007872

2169-9097

JRG Planets, 128 (8)

Institutional Repository

journal article

© 2023 I. de Pater, Emmanuel Lellouch, Darrell F. Strobel, Katherine de Kleer, Thierry Fouchet, Michael H. Wong, Bryan J. Holler, S.M. Cazaux, Chris Moeckel, More Authors