The Geographic Distribution of Dense-phase O₂ on Ganymede
Abstract
Ground-based spectroscopy of Ganymede's surface has revealed the surprising presence of dense-phase molecular oxygen (O₂) via weak absorptions at visible wavelengths. To date, the state and stability of this O₂ at the temperatures and pressures of Ganymede's surface are not understood. Its spatial distribution in relation to albedo, expected temperatures, particle irradiation patterns, or composition may provide clues to these unknowns. We present spatially resolved observations of Ganymede's surface O₂ obtained with the Hubble Space Telescope and construct the first comprehensive map of its geography. In agreement with the limited spatially resolved data published previously, our map suggests that the condensed O₂ is concentrated at the low to midlatitudes of the trailing hemisphere, a distribution that may reflect influences of Ganymede's intrinsic magnetic field on the bombardment of its surface by Jovian magnetospheric particles. Overlapping regions from different observations within this data set also show evidence for moderate temporal variability in the surface O2, but we are unable to distinguish between potential causes with the available data.
Additional Information
© 2021. The Author(s). Original content from this work may be used under the terms of the Creative Commons Attribution 4.0 licence. Any further distribution of this work must maintain attribution to the author(s) and the title of the work, journal citation and DOI. Received 2021 May 5; revised 2021 June 17; accepted 2021 June 17; published 2021 July 30. Based on observations made with the NASA/ESA Hubble Space Telescope, obtained from the Data Archive at the Space Telescope Science Institute, which is operated by the Association of Universities for Research in Astronomy, Inc., under NASA contract NAS5-26555. These observations are associated with program #7444 and #15789. This work is also based on new observations associated with program #15925. Support for programs #15925 and #15789 was provided by NASA through a grant from the Space Telescope Science Institute, which is operated by the Association of Universities for Research in Astronomy, Inc., under NASA contract NAS5-26555. This work was also supported by NASA Headquarters under the NASA Earth and Space Science Fellowship Program (grant 80NSSC17K0478). We would like to acknowledge John R. Spencer for his role in producing the 1999 observations used in this study. Facility: HST(STIS). - Software: astropy (Astropy Collaboration et al. 2013).Attached Files
Published - Trumbo_2021_Planet._Sci._J._2_139.pdf
Accepted Version - 2106.10565.pdf
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Additional details
- Alternative title
- The Geographic Distribution of Dense-phase O2 on Ganymede
- Eprint ID
- 110243
- Resolver ID
- CaltechAUTHORS:20210813-181157415
- NAS5-26555
- NASA
- 80NSSC17K0478
- NASA Earth and Space Science Fellowship
- Created
-
2021-08-16Created from EPrint's datestamp field
- Updated
-
2021-08-16Created from EPrint's last_modified field
- Caltech groups
- Division of Geological and Planetary Sciences