メッセンジャー (MESSENGER) は,水星のイオン化エクソスフィアとプラズマ環境の組成に関する観測を行った
Thomas H Zurbuchen1, Jim M Raines, George Gloeckler
1Department of Atmospheric, Oceanic and Space Sciences, University of Michigan, 2455 Hayward Street, Ann Arbor, MI 48109-2143, USA. thomasz@umich.edu
Science (New York, N.Y.)
|July 5, 2008
まとめ
メルキュール メルキュール メルキュール メルキュール メルキュール
科学分野:
- 惑星科学は惑星科学である.
- 宇宙物理学 宇宙物理学
- プラズマ物理学 プラズマ物理学
背景:
- 水星の宇宙環境は,太陽風の相互作用と外層のイオン化によるイオンで満たされています.
- 以前の観測では,水星の外層にあるナトリウム (Na+),酸素 (O+),およびカリウム (K+) イオンを示していた.
研究 の 目的:
- メッセンジャーのデータを用いて,水星の磁気圏におけるイオンの構成と分布を分析する.
- 水星のプラズマ環境内のイオンの起源とエネルギー化を調査する.
主な方法:
- MESSENGER宇宙船の観測から得られるイオン量とイオンフローの分析.
- イオン種を特定するために,電荷あたりの質量 (m/q) のスペクトルデータの解釈.
主要な成果:
- 硫黄 (S+) と硫化水素 (H2S+) イオンが検出され, (S+ + H2S+) / (Na+ + Mg+) = 0.67 +/- 0.06.06 となります.
- m/q = 18 の水族イオンを特定し,Na+ + Mg+ に相対して 0.20 +/- 0.03 の濃度で測定した.
- 重い種を含む水銀由来イオンが磁気圏を満たしていることが観察されました.
結論:
- S+,H2S+,水族イオンの存在は,水星の外層組成の理解を広げています.
- 双重イオン化された種は,水星の磁気圏内の有意な電子エネルギー化 (<1 keV) を示唆しています.
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