Szalay, J R; Allegrini, F; Ebert, R W; Bagenal, F; Bolton, S J; Fatemi, S; McComas, D J; Pontoni, A; Saur, J; Smith, H T; Strobel, D F; Vance, S D; Vorburger, A; Wilson, R J (2024). Oxygen production from dissociation of Europa's water-ice surface. Nature astronomy, 8(5), pp. 567-576. Nature Publishing Group 10.1038/s41550-024-02206-x
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Jupiter's moon Europa has a predominantly water-ice surface that is modified by exposure to its space environment. Charged particles break molecular bonds in surface ice, thus dissociating the water to ultimately produce H2 and O2, which provides a potential oxygenation mechanism for Europa's subsurface ocean. These species are understood to form Europa's primary atmospheric constituents. Although remote observations provide important global constraints on Europa's atmosphere, the molecular O2 abundance has been inferred from atomic O emissions. Europa's atmospheric composition had never been directly sampled and model-derived oxygen production estimates ranged over several orders of magnitude. Here, we report direct observations of H2+ and O2+ pickup ions from the dissociation of Europa's water-ice surface and confirm these species are primary atmospheric constituents. In contrast to expectations, we find the H2 neutral atmosphere is dominated by a non-thermal, escaping population. We find 12 ± 6 kg s-1 (2.2 ± 1.2 × 1026 s-1) O2 are produced within Europa's surface, less than previously thought, with a narrower range to support habitability in Europa's ocean. This process is found to be Europa's dominant exogenic surface erosion mechanism over meteoroid bombardment.
Item Type: |
Journal Article (Original Article) |
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Division/Institute: |
08 Faculty of Science > Physics Institute 08 Faculty of Science > Physics Institute > Space Research and Planetary Sciences |
UniBE Contributor: |
Vorburger, Audrey Helena |
Subjects: |
500 Science > 520 Astronomy 500 Science > 530 Physics 600 Technology > 620 Engineering |
ISSN: |
2397-3366 |
Publisher: |
Nature Publishing Group |
Language: |
English |
Submitter: |
Pubmed Import |
Date Deposited: |
29 May 2024 15:44 |
Last Modified: |
29 May 2024 22:57 |
Publisher DOI: |
10.1038/s41550-024-02206-x |
PubMed ID: |
38798715 |
Uncontrolled Keywords: |
Magnetospheric physics Rings and moons |
BORIS DOI: |
10.48350/197146 |
URI: |
https://boris.unibe.ch/id/eprint/197146 |