ヨーロッパの差別化された内部構造: 2つのガリレオの遭遇から得られた推論
J D Anderson1, E L Lau, W L Sjogren
1Jet Propulsion Laboratory, California Institute of Technology, Pasadena, CA 91109-8099, USA.
まとめ
ガリレオ宇宙船のデータは,ヨーロッパを明らかにしています.
科学分野:
- 惑星科学は惑星科学である.
- 地質物理学 地質物理学とは地質物理学です.
- 天体生物学 アストロバイオロジー
背景:
- 木星の衛星であるヨーロッパは,地球外生命の主要な候補である.
- エウロパの内部構造を理解することは,その居住性を評価する上で極めて重要です.
研究 の 目的:
- ヨーロッパの外部の重力場を決定する.
- 月の内部構造と組成を推論する.
主な方法:
- ガリレオ宇宙船の無線キャリア波からのドップラーデータの分析.
- 2つのヨーロッパ出会い (E4とE6) の測定結果.
主要な成果:
- ユーロパは,水の氷と液体の厚い外殻 (100〜200 km) を所有しています.
- 月の深い内部は,密度が4000kg/m3を超えている.
- 岩層マントル (30003500 kg/m3) に囲まれた金属の核 (半径はユーロパの約40%) が内部構成の可能性がある.
結論:
- エウロパの構造は,氷の殻の下には地表の下の海があることを示唆しています.
- 金属コアの存在は,磁場の可能性によって支持されています.
- これらの発見は,ヨーロッパが生命を宿す可能性に影響を及ぼします.
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