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Updated: Dec 25, 2025

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Scattering And Absorption of Light in Planetary Regoliths
Published on: July 1, 2019
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熱画像で明らかになった原始的な小惑星の多孔性
Tatsuaki Okada1,2, Tetsuya Fukuhara3, Satoshi Tanaka4,5,6
1Institute of Space and Astronautical Science (ISAS), Japan Aerospace Exploration Agency (JAXA), Sagamihara, Japan. okada@planeta.sci.isas.jaxa.jp.
Nature
|March 28, 2020
まとめ
炭素系小惑星リウグ
科学分野:
- 惑星科学
- 小惑星研究
- 太陽系の進化
背景:
- 炭素系 (C型) 小惑星は,惑星の形成を理解するために不可欠な,原始的な太陽系遺物です.
- その物理的性質は,隕石が大気圏に侵入する際の課題により,十分に理解されていない.
研究 の 目的:
- C型小惑星162173リウグの物理的性質と表面構成を調査する.
- リュウグの形成の歴史と内部構造を 制限するためです
主な方法:
- ハヤブサ2宇宙船の熱赤外線画像 (TIR) を使用した地球一回転熱画像.
- 岩石と周囲の表面の温度プロファイルから導かれた熱慣性の分析.
- 表面の特徴と岩石の特性を調べるための近距離熱画像
主要な成果:
- リュウグの表面は低熱慣性 (約. 300tU),多孔な岩石と10cm以上の断片を示唆しています.
- 表面の粗さは,昼間の温度プロフィールに大きな影響を与えます.
- 密度の高い岩石 (熱慣性 > 600 tiu) が観察され,潜在的に外来または凝固した核から発生した.
結論:
- リウグは,高微孔性 (30-50%) と低凝固性を持つ衝突断片から形成された瓦の山である可能性が高い.
- 毛細な岩石と密度の両方の存在は 複雑な形成と進化の歴史を示しています
- 柔らかい宇宙の塵と 密度の高い天体との間に 橋を架けるかもしれない
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