Martian Bow Shock and Magnetic Pile-Up Barrier Formation Due to the Exosphere Ion Mass-Loading
Bow shock, formed by the interaction between the solar wind and a planet, is generated in different patterns depending on the conditions of the planet. In the case of the earth, its own strong magnetic field plays a critical role in determining the position of the bow shock. However, in the case o...
| Main Authors: | , , , , , , |
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| Format: | Article |
| Language: | English |
| Published: |
The Korean Space Science Society
2011-03-01
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| Series: | Journal of Astronomy and Space Sciences |
| Subjects: | |
| Online Access: | http://ocean.kisti.re.kr/downfile/volume/kosss/OJOOBS/2011/v28n1/OJOOBS_2011_v28n1_17.pdf |
| Summary: | Bow shock, formed by the interaction between the solar wind and a planet, is generated in different patterns depending
on the conditions of the planet. In the case of the earth, its own strong magnetic field plays a critical role in determining
the position of the bow shock. However, in the case of Mars of which has very a small intrinsic magnetic field, the
bow shock is formed by the direct interaction between the solar wind and the Martian ionosphere. It is known that the
position of the Martian bow shock is affected by the mass loading-effect by which the supersonic solar wind velocity
becomes subsonic as the heavy ions originating from the planet are loaded on the solar wind. We simulated the Martian
magnetosphere depending on the changes of the density and velocity of the solar wind by using the three-dimensional
magnetohydrodynamic model built by modifying the comet code that includes the mass loading effect. The Martian
exosphere model of was employed as the Martian atmosphere model, and only the photoionization by the solar radiation
was considered in the ionization process of the neutral atmosphere. In the simulation result under the normal solar
wind conditions, the Martian bow shock position in the subsolar point direction was consistent with the result of the
previous studies. The three-dimensional simulation results produced by varying the solar wind density and velocity
were all included in the range of the Martian bow shock position observed by Mariner 4, Mars 2, 3, 5, and Phobos 2. Additionally,
the simulation result also showed that the change of the solar wind density had a greater effect on the Martian
bow shock position than the change of the solar wind velocity. Our result may be useful in analyzing the future observation
data by Martian probes. |
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| ISSN: | 2093-5587 2093-1409 |