The obliquity of Enceladus
The extraordinary activity at Enceladus' warm south pole indicates the presence of an internal global or local reservoir of liquid water beneath the surface. While Tyler (2009, 2011) has suggested that the geological activity and the large heat flow of Enceladus could result from tidal heating...
Main Authors: | , , |
---|---|
Format: | Text |
Language: | unknown |
Published: |
arXiv
2015
|
Subjects: | |
Online Access: | https://dx.doi.org/10.48550/arxiv.1512.00285 https://arxiv.org/abs/1512.00285 |
id |
ftdatacite:10.48550/arxiv.1512.00285 |
---|---|
record_format |
openpolar |
spelling |
ftdatacite:10.48550/arxiv.1512.00285 2023-05-15T18:22:13+02:00 The obliquity of Enceladus Baland, Rose-Marie Yseboodt, Marie Van Hoolst, Tim 2015 https://dx.doi.org/10.48550/arxiv.1512.00285 https://arxiv.org/abs/1512.00285 unknown arXiv https://dx.doi.org/10.1016/j.icarus.2015.11.039 arXiv.org perpetual, non-exclusive license http://arxiv.org/licenses/nonexclusive-distrib/1.0/ Earth and Planetary Astrophysics astro-ph.EP Geophysics physics.geo-ph FOS Physical sciences article-journal Article ScholarlyArticle Text 2015 ftdatacite https://doi.org/10.48550/arxiv.1512.00285 https://doi.org/10.1016/j.icarus.2015.11.039 2022-04-01T11:32:48Z The extraordinary activity at Enceladus' warm south pole indicates the presence of an internal global or local reservoir of liquid water beneath the surface. While Tyler (2009, 2011) has suggested that the geological activity and the large heat flow of Enceladus could result from tidal heating triggered by a large obliquity of at least 0.05°-0.1°, theoretical models of the Cassini state predict the obliquity to be two to three orders of magnitude smaller for an entirely solid and rigid Enceladus. We investigate the influence of an internal subsurface ocean and of tidal deformations of the solid layers on the obliquity of Enceladus. Our Cassini state model takes into account the external torque exerted by Saturn on each layer of the satellite and the internal gravitational and pressure torques induced by the presence of the liquid layer. As a new feature, our model also includes additional torques that arise because of the periodic tides experienced by the satellite. We find that the upper limit for the obliquity of a solid Enceladus is 0.00045 degrees and is negligibly affected by elastic deformations. The presence of an internal ocean decreases this upper limit by 13.1%, elasticity attenuating this decrease by only 0.5%. Since the obliquity of Enceladus cannot reach Tyler's requirement, obliquity tides are unlikely to be the source of the large heat flow of Enceladus. More likely, the geological activity at Enceladus' south pole results from eccentricity tides. Even in the most favorable case, the upper limit for the obliquity of Enceladus corresponds to about two meters at most at the surface of Enceladus. This is well below the resolution of Cassini images. Control point calculations cannot be used to detect the obliquity of Enceladus, let alone to constrain its interior from an obliquity measurement. Text South pole DataCite Metadata Store (German National Library of Science and Technology) South Pole |
institution |
Open Polar |
collection |
DataCite Metadata Store (German National Library of Science and Technology) |
op_collection_id |
ftdatacite |
language |
unknown |
topic |
Earth and Planetary Astrophysics astro-ph.EP Geophysics physics.geo-ph FOS Physical sciences |
spellingShingle |
Earth and Planetary Astrophysics astro-ph.EP Geophysics physics.geo-ph FOS Physical sciences Baland, Rose-Marie Yseboodt, Marie Van Hoolst, Tim The obliquity of Enceladus |
topic_facet |
Earth and Planetary Astrophysics astro-ph.EP Geophysics physics.geo-ph FOS Physical sciences |
description |
The extraordinary activity at Enceladus' warm south pole indicates the presence of an internal global or local reservoir of liquid water beneath the surface. While Tyler (2009, 2011) has suggested that the geological activity and the large heat flow of Enceladus could result from tidal heating triggered by a large obliquity of at least 0.05°-0.1°, theoretical models of the Cassini state predict the obliquity to be two to three orders of magnitude smaller for an entirely solid and rigid Enceladus. We investigate the influence of an internal subsurface ocean and of tidal deformations of the solid layers on the obliquity of Enceladus. Our Cassini state model takes into account the external torque exerted by Saturn on each layer of the satellite and the internal gravitational and pressure torques induced by the presence of the liquid layer. As a new feature, our model also includes additional torques that arise because of the periodic tides experienced by the satellite. We find that the upper limit for the obliquity of a solid Enceladus is 0.00045 degrees and is negligibly affected by elastic deformations. The presence of an internal ocean decreases this upper limit by 13.1%, elasticity attenuating this decrease by only 0.5%. Since the obliquity of Enceladus cannot reach Tyler's requirement, obliquity tides are unlikely to be the source of the large heat flow of Enceladus. More likely, the geological activity at Enceladus' south pole results from eccentricity tides. Even in the most favorable case, the upper limit for the obliquity of Enceladus corresponds to about two meters at most at the surface of Enceladus. This is well below the resolution of Cassini images. Control point calculations cannot be used to detect the obliquity of Enceladus, let alone to constrain its interior from an obliquity measurement. |
format |
Text |
author |
Baland, Rose-Marie Yseboodt, Marie Van Hoolst, Tim |
author_facet |
Baland, Rose-Marie Yseboodt, Marie Van Hoolst, Tim |
author_sort |
Baland, Rose-Marie |
title |
The obliquity of Enceladus |
title_short |
The obliquity of Enceladus |
title_full |
The obliquity of Enceladus |
title_fullStr |
The obliquity of Enceladus |
title_full_unstemmed |
The obliquity of Enceladus |
title_sort |
obliquity of enceladus |
publisher |
arXiv |
publishDate |
2015 |
url |
https://dx.doi.org/10.48550/arxiv.1512.00285 https://arxiv.org/abs/1512.00285 |
geographic |
South Pole |
geographic_facet |
South Pole |
genre |
South pole |
genre_facet |
South pole |
op_relation |
https://dx.doi.org/10.1016/j.icarus.2015.11.039 |
op_rights |
arXiv.org perpetual, non-exclusive license http://arxiv.org/licenses/nonexclusive-distrib/1.0/ |
op_doi |
https://doi.org/10.48550/arxiv.1512.00285 https://doi.org/10.1016/j.icarus.2015.11.039 |
_version_ |
1766201590524411904 |