The Ocean Worlds Science Case For The Pollux Spectropolarimeter

Pollux is a candidate European instrument contribution to the Habitable Worlds Observatory (HWO), designed to advance our understanding of the formation and evolution of cosmic structures in the universe, and specifically search signs of life on extrasolar planets.

This high-resolution spectrograph (R > 40,000) with polarimetric capabilities offers nearly continuous and simultaneous coverage from the FUV (∼100 nm) to the NIR (∼1.9 micron), making it a versatile tool for a wide range of scientific investigations from solar system studies to cosmology.

Several Solar System ocean worlds have been the focal point of the scientific community to understand the conditions of their internal saline oceans, as well as the possible emergence of life beyond Earth.

The ocean world science case will leverage Pollux’s UV spectropolarimetric capabilities to investigate surface reflectance and composition, characterize airglow emissions in the environments of giant-planet moons, as well as constrain the microphysical properties of atmospheric aerosols.

Vincent Hue, Bilal Benmahi, Mathieu Barthelemy, Tracy M. Becker, Jean-Claude Bouret, Richard J. Cartwright, Jean-Yves Chaufray, Luca Fossati, Gabriel Giono, Olivier Poch, Ujjwal Raut, Lorenz Roth

Comments: 9 pages, 4 figures, contribution to the Pollux science case for the Habitable Worlds Observatory (HWO)
Subjects: Instrumentation and Methods for Astrophysics (astro-ph.IM); Earth and Planetary Astrophysics (astro-ph.EP)
Cite as: arXiv:2603.11112 [astro-ph.IM] (or arXiv:2603.11112v1 [astro-ph.IM] for this version)
https://doi.org/10.48550/arXiv.2603.11112
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Submission history
From: Vincent Hue
[v1] Wed, 11 Mar 2026 12:00:08 UTC (1,838 KB)
https://arxiv.org/abs/2603.11112
Astrobiology, Astrochemistry, Exoplanet,