A hybrid simulation of Mercury's magnetosphere for the MESSENGER encounters in year 2008

The latest measurements from the two encounters of the MESSENGER spacecraft in year 2008 have discovered several interesting features of the magnetosphere of Mercury. We have performed high-resolution 3D hybrid model calculations to simulate the solar wind interaction with the Hermean magnetosphere during the first two Mercury encounters of the MESSENGER spacecraft in 2008. It is found that the global structure of the Hermean magnetosphere is significantly controlled by the direction of the interplanetary magnetic field. The bow shock size and shape and the magnetotail configuration have very large differences in these two encounters with northward-pointing and southward-pointing interplanetary magnetic field, respectively. Comparisons are also given with the observed magnetic field profiles and the computational results. In general, good agreement can be found including the interesting feature of the relatively thick magnetopause current layer at outbound measurements. Our work shows that 3D hybrid simulation is a promising method to study in detail the Hermean magnetosphere in parallel with the post-MOI observations of the MESSENGER spacecraft and the Bepi-Colombo mission in future.

[1]  A. L. Broadfoot,et al.  Mariner 10 - Mercury atmosphere , 1976 .

[2]  L. Blomberg,et al.  Magnetosphere–Exosphere–Surface Coupling at Mercury , 2007 .

[3]  Thomas E. Moore,et al.  A quantitative model of the planetary Na + contribution to Mercury’s magnetosphere , 2003 .

[4]  T. Bagdonat,et al.  Plasma environment of magnetized asteroids : a 3-D hybrid simulation study , 2006 .

[5]  K. Kabin,et al.  On the space environment of Mercury , 2004 .

[6]  B. Anderson,et al.  Kinetic instabilities in Mercury's magnetosphere: Three‐dimensional simulation results , 2009 .

[7]  Richard D. Starr,et al.  Mercury's Magnetosphere After MESSENGER's First Flyby , 2008, Science.

[8]  Pekka Janhunen,et al.  Modelling the solar wind interaction with Mercury by a quasi-neutral hybrid model , 2003 .

[9]  Petr Hellinger,et al.  Structure of Mercury's magnetosphere for different pressure of the solar wind: Three dimensional hybrid simulations , 2006 .

[10]  S. Solomon,et al.  Modeling of the magnetosphere of Mercury at the time of the first MESSENGER flyby , 2010 .

[11]  W. Ip,et al.  MHD simulations of the solar wind interaction with Mercury , 2002 .

[12]  Ulrich R. Christensen,et al.  A deep dynamo generating Mercury’s magnetic field , 2006, Nature.

[13]  James A. Slavin,et al.  The Structure of Mercury's Magnetic Field from MESSENGER's First Flyby , 2008, Science.

[14]  W. Ip.  Dynamics of electrons and heavy ions in Mercury's magnetosphere , 1987 .

[15]  Kenneth G. Powell,et al.  Interaction of Mercury with the Solar Wind , 1998 .

[16]  T. Bagdonat,et al.  Hybrid simulation of weak comets , 2004 .

[17]  S. Krimigis,et al.  Magnetosphere, Exosphere, and Surface of Mercury , 1987 .

[18]  Uwe Motschmann,et al.  From a Weak to a Strong Comet — 3D Global Hybrid Simulation Studies , 2002 .

[19]  D. Gubbins.  Speculations on the origin of the magnetic field of Mercury , 1977 .

[20]  C. Russell,et al.  Global hybrid simulations of solar wind interaction with Mercury: Magnetosperic boundaries , 2006 .

[21]  G. Siscoe,et al.  Variations in the solar wind stand‐off distance at Mercury , 1975 .

[22]  Helmut Lammer,et al.  Surface-Exosphere-Magnetosphere System Of Mercury , 2005 .

[23]  C. Russell,et al.  The magnetosphere of Mercury , 1988 .

[24]  N. Ness,et al.  Magnetic Field Observations near Mercury: Preliminary Results from Mariner 10 , 1974, Science.

[25]  E. Kallio,et al.  Surface conductivity of Mercury provides current closure and may affect magnetospheric symmetry , 2004 .