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スプートニク・プラニシアの方向転換は 冥王星に海があることを示唆している
F Nimmo1, D P Hamilton2, W B McKinnon3
1Department of Earth and Planetary Sciences, University of California Santa Cruz, Santa Cruz, California 95064, USA.
Nature
|November 17, 2016
まとめ
冥王星のスプートニク・プラニティア盆は 衝撃の痕跡かもしれない 冥王星の位置からすると 表面下には海が存在し 重力の異常を説明し 冥王星の地質を理解する上で 長期にわたる海が存在することを 示唆しています
科学分野:
- 惑星科学
- 地理学
- 天体生物学
背景:
- 冥王星のスプートニク・プランティアは 惑星の潮軸の近くにある 窒素で覆われた大きな盆地です
- その現在の位置は,潮と回転力による方向転換を示唆しています.
- 盆地には負の地形がありますが,重力の正の異常が再方向化されます.
研究 の 目的:
- スプートニク・プラニシアの形成と現在の状態を調査する
- 盆地の観測された重力異常と位置に必要な条件を決定する.
- 冥王星の地質進化における 潜在的海域の役割を評価する
主な方法:
- 重力異常と地形データの分析
- 衝突盆の形成と惑星の方向転換のモデル化
- 地下海の動態と殻の性質の評価
主要な成果:
- スプートニク・プラニシアの重力異常は 殻の薄れと海洋の上昇によって説明され,衝突の起源と地下海洋を前提としています.
- 地下海洋がなければ 重力の異常を説明するには 信じられないほど厚い窒素層が必要になります
- 耐久性の高い地下海とそれに伴う上昇を維持するために 硬直で伝導性のある氷の殻が必要である.
結論:
- 地下海の存在は スプートニク・プラニシアの特徴の 説明であると考えられます
- 冥王星の地下海は 今日まで存在しているかもしれません
- 窒素の堆積,負荷,そして惑星の方向転換の間の複雑なフィードバックは,冥王星の地質史に影響を与えたかもしれない.
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