Lunar electromagnetic environment revealed by SELENE (Kaguya)

2018 Fiscal Year Final Research Report

• Project/Area Number: 26400477
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Multi-year Fund
• Section: 一般
• Research Field: Space and upper atmospheric physics
• Research Institution: Nagoya University
• Principal Investigator: NISHINO MASAKI 名古屋大学, 工学研究科, 特任講師 (50466794)
• Research Collaborator: SAITO Yoshifumi 宇宙航空研究開発機構, 宇宙科学研究所, 教授 (30260011) ; HARADA Yuki 京都大学, 大学院理学研究科, 助教 (90823386)
• Project Period (FY): 2014-04-01 – 2019-03-31
• Keywords: 月面環境学 / 月プラズマ / SELENE / 太陽風 / 太陽風・月相互作用 / 波動粒子相互作用

Outline of Final Research Achievements

We studied unsolved physical mechanism of interactions between the solar wind and the Moon, using observational data by the lunar orbiter Kaguya (SELENE). Main results are (1) signature of strong magnetic anomaly in the lunar wake, (2) variations of the lunar surface potential in the terrestrial foreshock, (3) discovery of the decrease in the interplanetary magnetic field intensity around the Moon, and (4) identification of excitation mechanism of electrostatic solitary waves around the Moon. In addition, we proposed a new model of the lunar wake boundary, based on the observations. These results would become the basis of the lunar environmental studies in both aspects of science and engineering, and can be widely applicable to other rocky (exo)planets and small bodies.

Free Research Field

月面環境学、磁気圏プラズマ物理学

Academic Significance and Societal Importance of the Research Achievements

本研究は月周回衛星Kaguya(SELENE)の観測データを用いて月面の電磁環境を推定したものであり、理工の両面において将来の月面探査の基礎データとなるものである。また、月と太陽風の相互作用のうち未解明であった現象の物理メカニズムを明らかにすることが出来たが、これは月以外の天体(水星や小天体等)にも広く応用することが可能である。