On Ganymede’s Magnetic Quadrupolar Strength
Ganymede is the only moon in our solar system known to have a large-scale intrinsic magnetic field, likely generated in the moon’s metallic core. Initial analyses of Galileo spacecraft measurements concluded that Ganymede’s intrinsic magnetic field is dominated by a magnetic dipole and that quadrupo...
| Main Authors: | , , , , |
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| Format: | Article |
| Language: | English |
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IOP Publishing
2023-01-01
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| Series: | The Planetary Science Journal |
| Subjects: | |
| Online Access: | https://doi.org/10.3847/PSJ/acde7f |
| _version_ | 1827392119390601216 |
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| author | A. M. Plattner C. L. Johnson M. J. Styczinski S. D. Vance A. C. Mills |
| author_facet | A. M. Plattner C. L. Johnson M. J. Styczinski S. D. Vance A. C. Mills |
| author_sort | A. M. Plattner |
| collection | DOAJ |
| description | Ganymede is the only moon in our solar system known to have a large-scale intrinsic magnetic field, likely generated in the moon’s metallic core. Initial analyses of Galileo spacecraft measurements concluded that Ganymede’s intrinsic magnetic field is dominated by a magnetic dipole and that quadrupolar contributions are exceptionally weak. These findings have influenced the development of models for Ganymede’s core dynamo over the past two decades, some concluding that Ganymede’s dynamo is limited to the innermost part of Ganymede’s core. Here, we reassess Ganymede’s internal field contributions based on the magnetic measurements from close Galileo flybys of Ganymede (G1, G2, G7, G8, G28, and G29), adding the recent Juno flyby. We find that presently available data cannot constrain Ganymede’s quadrupole moment, as we demonstrate by constructing models with a range of quadrupole moments, including relative values comparable to those at the Earth. As a consequence, global analysis of available data cannot constrain the spatial limits of Ganymede’s core dynamo. Incorporating ocean induction for a range of Ganymede ocean models indicates that ocean induction may be present, but that available magnetic data cannot discern between end-member cases for Ganymede ocean models. |
| first_indexed | 2024-03-08T17:25:24Z |
| format | Article |
| id | doaj.art-2afb59d269ac4d299d8f04cbf0751e0b |
| institution | Directory Open Access Journal |
| issn | 2632-3338 |
| language | English |
| last_indexed | 2024-03-08T17:25:24Z |
| publishDate | 2023-01-01 |
| publisher | IOP Publishing |
| record_format | Article |
| series | The Planetary Science Journal |
| spelling | doaj.art-2afb59d269ac4d299d8f04cbf0751e0b2024-01-02T19:53:25ZengIOP PublishingThe Planetary Science Journal2632-33382023-01-014713410.3847/PSJ/acde7fOn Ganymede’s Magnetic Quadrupolar StrengthA. M. Plattner0https://orcid.org/0000-0001-5154-1833C. L. Johnson1M. J. Styczinski2https://orcid.org/0000-0003-4048-5914S. D. Vance3https://orcid.org/0000-0002-4242-3293A. C. Mills4Department of Geological Sciences, University of Alabama , Tuscaloosa, AL 35487, USA ; amplattner@ua.eduDepartment of Earth, Ocean and Atmospheric Sciences, University of British Columbia , Vancouver, BC V6T 1Z4, Canada; Planetary Science Institute , Tucson, AZ 85719, USAJet Propulsion Laboratory, California Institute of Technology , Pasadena, CA 91109, USAJet Propulsion Laboratory, California Institute of Technology , Pasadena, CA 91109, USADepartment of Geosciences, Baylor University , Waco, TX 76798, USAGanymede is the only moon in our solar system known to have a large-scale intrinsic magnetic field, likely generated in the moon’s metallic core. Initial analyses of Galileo spacecraft measurements concluded that Ganymede’s intrinsic magnetic field is dominated by a magnetic dipole and that quadrupolar contributions are exceptionally weak. These findings have influenced the development of models for Ganymede’s core dynamo over the past two decades, some concluding that Ganymede’s dynamo is limited to the innermost part of Ganymede’s core. Here, we reassess Ganymede’s internal field contributions based on the magnetic measurements from close Galileo flybys of Ganymede (G1, G2, G7, G8, G28, and G29), adding the recent Juno flyby. We find that presently available data cannot constrain Ganymede’s quadrupole moment, as we demonstrate by constructing models with a range of quadrupole moments, including relative values comparable to those at the Earth. As a consequence, global analysis of available data cannot constrain the spatial limits of Ganymede’s core dynamo. Incorporating ocean induction for a range of Ganymede ocean models indicates that ocean induction may be present, but that available magnetic data cannot discern between end-member cases for Ganymede ocean models.https://doi.org/10.3847/PSJ/acde7fGanymedeMagnetic fieldsPlanetary cores |
| spellingShingle | A. M. Plattner C. L. Johnson M. J. Styczinski S. D. Vance A. C. Mills On Ganymede’s Magnetic Quadrupolar Strength The Planetary Science Journal Ganymede Magnetic fields Planetary cores |
| title | On Ganymede’s Magnetic Quadrupolar Strength |
| title_full | On Ganymede’s Magnetic Quadrupolar Strength |
| title_fullStr | On Ganymede’s Magnetic Quadrupolar Strength |
| title_full_unstemmed | On Ganymede’s Magnetic Quadrupolar Strength |
| title_short | On Ganymede’s Magnetic Quadrupolar Strength |
| title_sort | on ganymede s magnetic quadrupolar strength |
| topic | Ganymede Magnetic fields Planetary cores |
| url | https://doi.org/10.3847/PSJ/acde7f |
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