Journal article
In Situ Evidence of a Twisted Loop-like Magnetic Flux Rope at Mars: A MAVEN and Tianwen-1 Close Conjunction
Astrophysical journal. Letters, Vol.1008(1), L24
09/01/2026
DOI: 10.3847/2041-8213/ae9aa0
Abstract
Magnetic flux ropes are twisted magnetic field lines that are commonly observed in space and astrophysical plasmas. At Mars, these structures are especially interesting because the planet does not have a global magnetic field like Earth, but instead has remanent magnetic fields preserved in its crust. In this study, we report a close conjunction observation by MAVEN and Tianwen-1 of a magnetic flux rope within the Martian ionosphere. The two spacecraft observed closely related magnetic signatures at near-identical locations and altitudes, allowing us to examine the spatial structure of the event. Our analysis suggests that the observed flux rope may have a loop-like geometry, with magnetic-field lines connected to the Martian dayside ionosphere at both ends. This structure may have formed or evolved through ionospheric instabilities under unusually low solar-wind dynamic pressure or internal reconnection between neighboring crustal magnetic fields. This event shows that Mars may produce a loop-like magnetic flux rope that resembles, in geometry, twisted magnetic loops seen in the solar atmosphere, providing a useful connection between planetary and solar plasma processes.
Details
- Title: Subtitle
- In Situ Evidence of a Twisted Loop-like Magnetic Flux Rope at Mars: A MAVEN and Tianwen-1 Close Conjunction
- Creators
- Yuanzheng 渊正 Wen 文Jasper S. Halekas - University of IowaTakuya 拓也 Hara 原Han-Wen 涵文 Shen 沈Shaosui 绍穗 Xu 徐Chi 驰 Zhang 张Thomas E. Cravens - University of KansasJunfeng QinJiawei 佳维 Gao 高Charles F. Bowers - University of MichiganLong 龙 Cheng 程Kathleen. G. Hanley - University of California SystemDavid A. Brain - University of Colorado SystemDavid L. Mitchell - University of California SystemChristian X. Mazelle - Université Fédérale de Toulouse Midi-PyrénéesJared R. Espley - Goddard Space Flight CenterJames P. McFadden - University of California SystemShannon M. Curry - University of Colorado System
- Resource Type
- Journal article
- Publication Details
- Astrophysical journal. Letters, Vol.1008(1), L24
- DOI
- 10.3847/2041-8213/ae9aa0
- ISSN
- 2041-8205
- eISSN
- 2041-8213
- Publisher
- IOP
- Grant note
- National Aeronautics and Space Administration (NASA): NNH10CC 04C
Y. Wen acknowledges insightful discussions with Dr. Janet G. Luhmann. We acknowledge NASA and the MAVEN mission for support through grant NNH10CC04C to the University of Colorado and by subcontract to Space Sciences Laboratory, University of California, Berkeley. Y.W. is partly supported by the Ballard and Seashore Fellowship from the University of Iowa. The research described in this Letter utilizes publicly available data from the MAVEN Science Data Center, https://lasp.colorado.edu/maven/sdc/public/data/sci/, and NASA Planetary Data System, https://pds-ppi.igpp.ucla.edu/, including data from the MAG (J. E. P. Connerney 2017), STATIC (J. P. McFadden 2026), SWIA (J. S. Halekas 2024), SWEA (D. L. Mitchell 2017) instruments. The Tianwen-1/MOMAG data are publicly available at Lunar and Planetary Data Release System, https://moon.bao.ac.cn/, and the MOMAG official website, https://space.ustc.edu.cn/dreams/tw1_momag/?magdata=cal. Part of this work is supported by the French space agency CNES for the observations obtained with the SWEA instrument. We also acknowledge the anonymous reviewer for constructive comments that helped improve our manuscript. We dedicate this Letter to the MAVEN mission, in recognition of its extraordinary contributions to Mars science and its enduring legacy in advancing humanity's understanding of the Martian upper atmosphere, ionosphere, magnetosphere, and solar-wind interaction.
- Language
- English
- Date published
- 09/01/2026
- Academic Unit
- Physics and Astronomy
- Record Identifier
- 9985222738702771
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