まとめ
表面の酸化は火星の水 (H2O) を大幅に枯渇させ,以前考えられていたよりも早く除去します. このプロセスは,地質的な時間における火星の土壌と氷蓋の水の利用可能性に影響を及ぼした可能性があります.
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
- 地質化学 地質化学
背景:
- エクソスフィアの脱出は,火星での不可逆的な水失失いの主要なメカニズムと考えられていた.
- 以前の推定では,水分失失失率が1平方センチメートルあたり約10〜8分子/秒であった.
研究 の 目的:
- 表面の酸化による火星の大気からの水分喪失の割合を定量化するために.
- この損失率を外層の脱出と比較し,火星の水の歴史におけるその重要性を評価する.
主な方法:
- 火星の大気組成と表面過程の分析.
- 表面酸化と水分損失に関与する化学反応のモデリング.
主要な成果:
- 表面の酸化は,火星の大気から酸素と水素を,秒あたり平方センチメートルあたり10〜8〜10〜11分子の速度で除去します.
- これは,均一な損失を想定して,地質時間における10〜25〜10〜28g/cm2のH2O分子 (10〜2〜10〜5g/cm2) の純損失に対応する.
- 表面酸化による計算された損失率は,外層の脱出による損失を大幅に上回ります.
結論:
- 表面の酸化は,以前は過小評価され,火星の大気中の水の不可逆的な沈み方を表しています.
- このプロセスは,地球上の水資源の形成において,外層圏の脱出よりも重要な役割を果たしたのかもしれない.
- 表面の酸化は,火星のレゴリットと極地の氷冠に水の存在に影響を与えたかもしれない.
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