Note to users. If you're seeing this message, it means that your browser cannot find this page's style/presentation instructions -- or possibly that you are using a browser that does not support current Web standards. Find out more about why this message is appearing, and what you can do to make your experience of our site the best it can be.

Science 1 May 2009:
Vol. 324. no. 5927, pp. 606 - 610
DOI: 10.1126/science.1172011
Prev | Table of Contents | Next

Reports

MESSENGER Observations of Magnetic Reconnection in Mercury’s Magnetosphere

James A. Slavin,1,* Mario H. Acuña,2,{dagger} Brian J. Anderson,3 Daniel N. Baker,4 Mehdi Benna,2,5 Scott A. Boardsen,1,5 George Gloeckler,6,7 Robert E. Gold,3 George C. Ho,3 Haje Korth,3 Stamatios M. Krimigis,3,8 Ralph L. McNutt, Jr.,3 Jim M. Raines,6 Menelaos Sarantos,1 David Schriver,9 Sean C. Solomon,10 Pavel Trávnícek,9,11 Thomas H. Zurbuchen6

Solar wind energy transfer to planetary magnetospheres and ionospheres is controlled by magnetic reconnection, a process that determines the degree of connectivity between the interplanetary magnetic field (IMF) and a planet’s magnetic field. During MESSENGER’s second flyby of Mercury, a steady southward IMF was observed and the magnetopause was threaded by a strong magnetic field, indicating a reconnection rate ~10 times that typical at Earth. Moreover, a large flux transfer event was observed in the magnetosheath, and a plasmoid and multiple traveling compression regions were observed in Mercury’s magnetotail, all products of reconnection. These observations indicate that Mercury’s magnetosphere is much more responsive to IMF direction and dominated by the effects of reconnection than that of Earth or the other magnetized planets.

1 Heliophysics Science Division, NASA Goddard Space Flight Center, Greenbelt, MD 20771, USA.
2 Solar System Exploration Division, NASA Goddard Space Fight Center, Greenbelt, MD 20771, USA.
3 Johns Hopkins University Applied Physics Laboratory, Laurel, MD 20723, USA.
4 Laboratory for Atmospheric and Space Physics, University of Colorado, Boulder, CO 80303, USA.
5 Goddard Earth Science and Technology Center, University of Maryland, Baltimore County, Baltimore, MD 21228, USA.
6 Department of Astronomy, University of Maryland, College Park, MD 20742, USA.
7 Department of Atmospheric, Oceanic and Space Sciences, University of Michigan, Ann Arbor, MI 48109, USA.
8 Academy of Athens, Athens 11527, Greece.
9 Institute of Geophysics and Planetary Physics, University of California, Los Angeles, CA 90024, USA.
10 Department of Terrestrial Magnetism, Carnegie Institution of Washington, Washington, DC 20015, USA.
11 Astronomical Institute, Academy of Sciences of the Czech Republic, Prague 14131, Czech Republic.

{dagger} Deceased.

* To whom correspondence should be addressed. E-mail: james.a.slavin{at}nasa.gov

Read the Full Text


THIS ARTICLE HAS BEEN CITED BY OTHER ARTICLES:
Magnetic Twisters on Mercury.
K.-H. Glassmeier (2009)
Science 324, 597-598
   Abstract »    Full Text »    PDF »
MESSENGER Observations of Mercury's Exosphere: Detection of Magnesium and Distribution of Constituents.
W. E. McClintock, R. J. Vervack Jr, E. T. Bradley, R. M. Killen, N. Mouawad, A. L. Sprague, M. H. Burger, S. C. Solomon, and N. R. Izenberg (2009)
Science 324, 610-613
   Abstract »    Full Text »    PDF »


To Advertise     Find Products

Science. ISSN 0036-8075 (print), 1095-9203 (online)