Work

Spatially Resolved Visible Wavelength Spectroscopy of the Galilean Moons With VLT/MUSE

Year: 2025

Type: article

Abstract: We present observations of all four Galilean satellites using spatially resolved visible wavelength (475–935 nm) spectroscopic observations with the ground‐based VLT/MUSE + AOF facility in 2019. A range of features in the observed reflectance spectra were compared to laboratory measured spectra, and mapped to understand the spatial distributions (at 300 km spatial resolution) of different compositional species on the moons' surfaces, providing near‐global context for future observations. The 485 nm spectral slope on Io is consistent with the presence sulfur materials such as , with stronger slopes on the trailing hemisphere and at high latitudes. Io's 560 nm absorption band is strongest at high latitudes, and shows an enhancement in the Pele plume deposit, consistent with the presence of . The similar 530 nm absorption band on Europa is constrained to the trailing hemisphere, and also appears consistent with sulfur materials. On Ganymede, a proxy for the 577.3 nm molecular oxygen absorption was found to be strongest at low‐mid latitudes, particularly around the trailing hemisphere, with a potential slight southward bias. This distribution appears consistent with the hypothesis that Ganymede's closed magnetic field line region allows stable bubbles of to exist in Ganymede's surface ice.

Source: Journal of Geophysical Research Planets

DOI: 10.1029/2024je008511

Authors: Oliver R. T. King, Leigh N. Fletcher, Fraser Clarke, Andrea Hidalgo

Institutions: University of Leicester, University of Oxford

Language: English

Topic: Astro and Planetary Science

Subfield: Astronomy and Astrophysics

Field: Physics and Astronomy

Domain: Physical Sciences

Open Access status: hybrid

Estimated APC paid: $4,070

Funder: European Research Council