水星の複雑なエクソスフィア:MESSENGERの第3回フライトバイの結果
Ronald J Vervack1, William E McClintock, Rosemary M Killen
1Johns Hopkins University Applied Physics Laboratory, Laurel, MD 20723, USA. Ron.Vervack@jhuapl.edu
Science (New York, N.Y.)
|July 22, 2010
まとめ
MESSENGERは水星の磁気尾にイオン化されたカルシウムを検出し,内部フォトイオンコンベクションを示唆した. ナトリウム,カルシウム,マグネシウムの明確な外層分布は,水星の薄い大気の複雑な制御プロセスを示している.
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
- スペクトル顕微鏡検査です.
背景:
- 水星は薄いエクソスフィアとダイナミックな磁気圏を持っています.
- 以前の観測では,宇宙外生物の存在が示唆されていたが,詳細な空間情報や構成情報には欠けていた.
研究 の 目的:
- 水星のエクソスフィアと磁気圏の組成と分布を調査する.
- フォトイオン化や磁気圏の輸送など,エクソスフィアの種を制御するプロセスを理解する.
主な方法:
- メッセンジャー宇宙船の水銀大気と表面組成スペクトロメーター (MASCS) を利用.
- エクソスフィアの元素を特定し,定量化するために,フライトバイの際のスペクトル放射を分析する.
主要な成果:
- イオン化されたカルシウム放出の検出 1-2 水銀の半径は尾に向かって,フォトイオンの尾の磁気圏のコンベクションをサポートします.
- ニュートラルなナトリウム,カルシウム,マグネシウムの高度分布は,水星の極点上にある.
- 2つの成分ナトリウム分布と非対称なマグネシウム分布の証拠.
結論:
- 磁気圏のコンベクションは,水星の磁気圏内での光イオンの輸送に重要な役割を果たします.
- 種特有の複数のプロセスが,水星のエクソスフィアの元素の分布を統制する.
- エクソスフィアの複雑さは,個々の種とその相互作用の詳細な研究を必要とします.
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