ヒューゲンズ探査機がタイタンの表面に降下する際に,雨,風,霧が降った
M G Tomasko1, B Archinal, T Becker
1Lunar and Planetary Laboratory, University of Arizona, 1629 E. University Blvd, Tucson, Arizona 85721-0092, USA.
Nature
|December 2, 2005
まとめ
タイタン (Titan) タイタン (Titan) タイタン (Titan)
科学分野:
- 惑星科学は惑星科学である.
- 天体生物学 アストロバイオロジー
- 大気科学 大気科学
背景:
- タイタンの大気はメタンの変換を示しており,表面または地下のメタン貯蔵庫があることを示唆しています.
- 過去のカッシーニ軌道探査機の測定では,地球表面の貯水池は検出されなかった.
- タイタンの大気中のメタンとスモッグは,表面観測を遮る.
研究 の 目的:
- ヒューゲンズ探査機のデータを用いてタイタンの表面構成と地質学的特徴を調査する.
- 液体炭化水素貯蔵庫と過去の液体活動に関する証拠を探す.
- タイタンの大気の霧と表面のスペクトル特性を分析するために.
主な方法:
- ハイゲンズ探査機下降イメージ/スペクトル放射計からのスペクトルと高解像度の画像の分析.
- 降下中と着陸後,地表の特徴を観測する.
- 赤外線反射スペクトルと大気中の霧粒子密度の測定.
主要な成果:
- 画像は,古代の液体の流れの痕跡を明らかにし,地球に似た排水システムがあり,暗い低地へと導いた.
- 着陸後の画像では,乾燥した河床が写っていた.
- 表面スペクトルでは,有機物質 (トリン) と水氷が示され,近赤外線では原因不明の青い斜面が示されました.
- ハーゼ粒子の密度は表面に向かってわずかに増加し,メタンの相対湿度は50%でした.
結論:
- タイタンの表面は,河川システムを含む,過去の液体活動の証拠を示しています.
- 表面の組成は,有機物質,水氷,および未知の物質のユニークな混合物です.
- この発見は,タイタンの複雑な地質学的プロセスと大気相互作用を示唆している.
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