Cassini in situ observations of long-duration magnetic reconnection in Saturn’s magnetotail

Arridge, Christopher Stephen and Eastwood, J.P. and Jackman, Caitriona M. and Poh, Gang-Kai and Slavin, J. A. and Thomsen, M. F. and André, Nicolas and Jia, X. and Kidder, A. and Lamy, L. and Radioti, Aikaterini and Reisenfeld, Dan and Sergis, Nicholas and Volwerk, M. and Walsh, A.P. and Zarka, P. and Coates, A. J. and Dougherty, M. K. (2016) Cassini in situ observations of long-duration magnetic reconnection in Saturn’s magnetotail. Nature Physics, 12 (3). pp. 268-271. ISSN 1745-2473

[thumbnail of csa_nphys_diffusionregion_rep]
PDF (csa_nphys_diffusionregion_rep)
csa_nphys_diffusionregion_rep.pdf - Accepted Version
Available under License Creative Commons Attribution.

Download (7MB)


Magnetic reconnection is a fundamental process in solar system and astrophysical plasmas, through which stored magnetic energy associated with current sheets is converted into thermal, kinetic and wave energy. Magnetic reconnection is also thought to be a key process involved in shedding internally produced plasma from the giant magnetospheres at Jupiter and Saturn through topological reconfiguration of the magnetic field. The region where magnetic fields reconnect is known as the diffusion region and in this letter we report on the first encounter of the Cassini spacecraft with a diffusion region in Saturn’s magnetotail. The data also show evidence of magnetic reconnection over a period of 19 h revealing that reconnection can, in fact, act for prolonged intervals in a rapidly rotating magnetosphere. We show that reconnection can be a significant pathway for internal plasma loss at Saturn. This counters the view of reconnection as a transient method of internal plasma loss at Saturn. These results, although directly relating to the magnetosphere of Saturn, have applications in the understanding of other rapidly rotating magnetospheres, including that of Jupiter and other astrophysical bodies.

Item Type:
Journal Article
Journal or Publication Title:
Nature Physics
Uncontrolled Keywords:
ID Code:
Deposited By:
Deposited On:
23 Dec 2015 09:19
Last Modified:
17 Sep 2023 01:45