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ABSTRACT The Juno spacecraft, which is in a polar orbit around Jupiter, is providing direct measurements of the planet’s magnetic field close to its surface1. A recent analysis of

observations of Jupiter’s magnetic field from eight (of the first nine) Juno orbits has provided a spherical-harmonic reference model (JRM09)2 of Jupiter’s magnetic field outside the planet.

This model is of particular interest for understanding processes in Jupiter’s magnetosphere, but to study the field within the planet and thus the dynamo mechanism that is responsible for

generating Jupiter’s main magnetic field, alternative models are preferred. Here we report maps of the magnetic field at a range of depths within Jupiter. We find that Jupiter’s magnetic

field is different from all other known planetary magnetic fields. Within Jupiter, most of the flux emerges from the dynamo region in a narrow band in the northern hemisphere, some of which

returns through an intense, isolated flux patch near the equator. Elsewhere, the field is much weaker. The non-dipolar part of the field is confined almost entirely to the northern

hemisphere, so there the field is strongly non-dipolar and in the southern hemisphere it is predominantly dipolar. We suggest that Jupiter’s dynamo, unlike Earth’s, does not operate in a

thick, homogeneous shell, and we propose that this unexpected field morphology arises from radial variations, possibly including layering, in density or electrical conductivity, or both.

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OTHERS THE ANOMALOUS STATE OF URANUS’S MAGNETOSPHERE DURING THE VOYAGER 2 FLYBY Article Open access 11 November 2024 IN SITU EVIDENCE OF THE MAGNETOSPHERIC CUSP OF JUPITER FROM JUNO

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Bolton, S. J. et al. The Juno mission. _Space Sci. Rev_. 213, 5–37 (2017). Article  ADS  Google Scholar  Download references ACKNOWLEDGEMENTS All authors acknowledge support from the Juno

project. K.M.M. is supported by the US Department of Defense (DoD) through the National Defense Science and Engineering Graduate Fellowship (NDSEG) programme and L.K. through a US National

Science Foundation Graduate Fellowship. REVIEWER INFORMATION _Nature_ thanks C. Jones and the other anonymous reviewer(s) for their contribution to the peer review of this work. AUTHOR

INFORMATION AUTHORS AND AFFILIATIONS * Department of Earth and Planetary Sciences, Harvard University, Cambridge, MA, USA Kimberly M. Moore, Rakesh K. Yadav, Laura Kulowski, Hao Cao & 

Jeremy Bloxham * NASA/GSFC, Greenbelt, MD, USA John E. P. Connerney & Stavros Kotsiaros * Space Research Corporation, Annapolis, MD, USA John E. P. Connerney * University of Maryland,

College Park, MD, USA Stavros Kotsiaros * National Space Institute, Technical University of Denmark, Kongens Lyngby, Denmark John L. Jørgensen & José M. G. Merayo * Division of

Geological and Planetary Sciences, California Institute of Technology, Pasadena, CA, USA David J. Stevenson * Southwest Research Institute, San Antonio, TX, USA Scott J. Bolton * Jet

Propulsion Laboratory, California Institute of Technology, Pasadena, CA, USA Steven M. Levin Authors * Kimberly M. Moore View author publications You can also search for this author inPubMed

 Google Scholar * Rakesh K. Yadav View author publications You can also search for this author inPubMed Google Scholar * Laura Kulowski View author publications You can also search for this

author inPubMed Google Scholar * Hao Cao View author publications You can also search for this author inPubMed Google Scholar * Jeremy Bloxham View author publications You can also search

for this author inPubMed Google Scholar * John E. P. Connerney View author publications You can also search for this author inPubMed Google Scholar * Stavros Kotsiaros View author

publications You can also search for this author inPubMed Google Scholar * John L. Jørgensen View author publications You can also search for this author inPubMed Google Scholar * José M. G.

Merayo View author publications You can also search for this author inPubMed Google Scholar * David J. Stevenson View author publications You can also search for this author inPubMed Google

Scholar * Scott J. Bolton View author publications You can also search for this author inPubMed Google Scholar * Steven M. Levin View author publications You can also search for this author

inPubMed Google Scholar CONTRIBUTIONS K.M.M. and J.B. wrote the manuscript and performed the data analysis. K.M.M., J.B., J.E.P.C., S.K., J.L.J. and J.M.G.M. contributed to discussions of

the data analysis, and K.M.M., R.K.Y., L.K., H.C., J.B. and D.J.S. contributed to discussions of the dynamo implications. All authors contributed to editing and revising the manuscript.

J.E.P.C. is principal investigator of the Juno magnetometer investigation, S.J.B. is principal investigator of the mission and S.M.L. is project scientist of the mission. CORRESPONDING

AUTHOR Correspondence to Jeremy Bloxham. ETHICS DECLARATIONS COMPETING INTERESTS The authors declare no competing interests. ADDITIONAL INFORMATION PUBLISHER’S NOTE: Springer Nature remains

neutral with regard to jurisdictional claims in published maps and institutional affiliations. RIGHTS AND PERMISSIONS Reprints and permissions ABOUT THIS ARTICLE CITE THIS ARTICLE Moore,

K.M., Yadav, R.K., Kulowski, L. _et al._ A complex dynamo inferred from the hemispheric dichotomy of Jupiter’s magnetic field. _Nature_ 561, 76–78 (2018).

https://doi.org/10.1038/s41586-018-0468-5 Download citation * Received: 09 April 2018 * Accepted: 26 July 2018 * Published: 05 September 2018 * Issue Date: 06 September 2018 * DOI:

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currently available for this article. Copy to clipboard Provided by the Springer Nature SharedIt content-sharing initiative KEYWORDS * Jupiter * Juno Orbit * Dynamo Region * Spherical

Harmonic Reference Model * Field Morphology