1. Two mechanisms of solar-wind proton entry deep into the near-Moon wake revealed by SELENE (Kaguya)
- Author
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Nishino, Masaki N., Fujimoto, Masaki, Maezawa, Kiyoshi, Saito, Yoshifumi, Yokota, Shoichiro, Asamura, Kazushi, Tanaka, Takaaki, Tsunakawa, Hideo, Shibuya, Hidetoshi, and Matsushima, Masaki
- Abstract
第42回 月・惑星シンポジウム(2009年8月5-7日, 宇宙航空研究開発機構宇宙科学研究本部), The 42nd ISAS Lunar and Planetary Symposium (August 5-7, 2009. Institute of Space and Astronautical Science, Japan Aerospace Exploration Agency (JAXA)), Sagamihara, Kanagawa Japan, We study solar wind (SW) intrusion into the near-Moon wake using plasma data obtained by the SELENE (KAGUYA) spacecraft. It has been known that SW protons flowing around the Moon access the central region of the distant lunar wake, while SW intrusion deep into the near-Moon wake has never been expected. Here we review two mechanisms (which we call type-I and type-II, respectively) of SW proton entry deep into the near-Moon wake, using plasma and magnetic field data obtained by the SELENE spacecraft at 100 km height from the lunar surface. The key process of the type-I entry is acceleration of the SW protons by the ambipolar electric field around the wake boundary. This entry mechanism lets the SW protons come fairly deep into the wake (solar zenith angle (SZA) 150 degrees) at 100 km height. On the other hand, the type-II entry is based on the SW proton scattering on the dayside; SW protons are once scattered at the lunar dayside surface, picked-up by the SW motional electric field, and finally access the deepest wake (150, 形態: カラー図版あり, 形態: CD-ROM1枚, 著者人数: 13人, Physical characteristics: Original contains color illustrations, Number of authors: 13, Note: One CD-ROM, 資料番号: AA0064739022
- Published
- 2009