タイタンの潮

Luciano Iess¹, Robert A Jacobson, Marco Ducci

¹Dipartimento di Ingegneria Meccanica e Aerospaziale, Università La Sapienza, via Eudossiana 18, 00184 Rome, Italy. luciano.iess@uniroma1.it

Science (New York, N.Y.)

|June 30, 2012

まとめ

カッシーニ宇宙船のデータは,タイタンが土星からの周期的な潮のストレスを経験していること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.
アストロジオロジーアストロジオロジー
軌道ダイナミクス軌道ダイナミクス

背景:

タイタンは16日周期で土星を周回し,軌道の偏心度は0.028.08です.
潮力は惑星の体に影響を与え,変形や内部ストレスを引き起こすことが知られている.

研究の目的:

土星の衛星タイタン内での周期的な潮のストレスのシグネチャーを検出および定量化するために.
タイタンの内部構造と構成を,潮力への反応に基づいて調査する.

主な方法:

カッシーニ宇宙船が6回近くを通過した (2006年−2011年) の間における正確な加速測定の分析.
引力場の変動からタイタンの度数-2ラブナンバー (k(2) の決定.

主要な成果:

タイタンの四極重力の周期的な変化,静的値の約4%を検出しました.
恋愛数2度の2つの独立した値を計算した: k(2) = 0.589 ± 0.150 と k(2) = 0.637 ± 0.224 (2σ).

結論:

タイタンの内部は,観測された潮反応を説明するために,軌道時間尺度で変形可能である必要があります.
この発見は,タイタンの内部に地球規模の地下海洋が存在することを強く示唆しています.

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