Insights for hydrated sulfuric acid on Europa's surface from a combined orbital – experimental approach.

IF 2.5 2区物理与天体物理 Q2 ASTRONOMY & ASTROPHYSICS

Icarus Pub Date : 2025-03-11 DOI:10.1016/j.icarus.2025.116543

T.W. Hayes , S. Li

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引用次数: 0

Abstract

Europa's non-water ice component may come from its interior ocean or from exotic processes (e.g. surface irradiation and/or impacts). We investigate these possible sources globally using all high spatial resolution (<25 km/pixel) data acquired by the Near-Infrared Mapping Spectrometer (NIMS) onboard Galileo, which is more advantageous than previous studies that only used few selected high spatial resolution datasets, or those with global coverage yet low spatial resolution. We find that the slopes of NIMS spectra from 1.3 to 2.2 μm show the same hemispheric dichotomy displayed by incident radiation fluxes, with trailing hemisphere spectral slopes being much more negative, or “bluer”, than those of the leading hemisphere. Spectral slopes are also bluer locally in older terrains, further suggesting a surface exposure-age dependence. In our examined endmember library, only sulfuric acid octahydrate (H₂SO₄ • 8H₂O, “SAO”) can explain this blue slope. Water ice – SAO ice mixtures show blue slope strength increases with SAO abundance. We attribute the behavior of Europa's NIMS spectral slopes to indicate the likely presence of hydrated sulfuric acid. Weak blue slopes in Europa's endogenic features suggest minor SAO abundances.

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来源期刊

Icarus 地学天文-天文与天体物理

CiteScore

6.30

自引率

18.80%

发文量

356

审稿时长

2-4 weeks

期刊介绍： Icarus is devoted to the publication of original contributions in the field of Solar System studies. Manuscripts reporting the results of new research - observational, experimental, or theoretical - concerning the astronomy, geology, meteorology, physics, chemistry, biology, and other scientific aspects of our Solar System or extrasolar systems are welcome. The journal generally does not publish papers devoted exclusively to the Sun, the Earth, celestial mechanics, meteoritics, or astrophysics. Icarus does not publish papers that provide "improved" versions of Bode''s law, or other numerical relations, without a sound physical basis. Icarus does not publish meeting announcements or general notices. Reviews, historical papers, and manuscripts describing spacecraft instrumentation may be considered, but only with prior approval of the editor. An entire issue of the journal is occasionally devoted to a single subject, usually arising from a conference on the same topic. The language of publication is English. American or British usage is accepted, but not a mixture of these.