火星の上層大気圏で原子デウテリウムが検出されました
V A Krasnopolsky1, M J Mumma, G R Gladstone
1Department of Physics, Catholic University of America, Washington, DC 20064, USA. VKras@lepvx3.gsfc.nasa.gov
まとめ
火星 火星 火星 火星
科学分野:
- 惑星科学は惑星科学である.
- 大気科学 大気科学
- アストロケミストリー アストロケミストリー
背景:
- 火星の大気組成と進化を理解することは,その居住可能性の鍵です.
- 火星の水と大気中のガスにおけるデウテリウム (重水素) と水素の比率は,水失量と大気中のプロセスについての洞察を提供します.
研究 の 目的:
- 火星の大気中のデウテリウムライマンアルファ線強度を測定するために.
- デウテリウム結合分子水素 (HD) と分子水素 (H2) の比率を決定する.
- 水 (HDO/H2O) と HD/H2 分割を比較し,火星の大気中のプロセスを理解する.
主な方法:
- ハッブル宇宙望遠鏡による高解像度スペクトロスコピーを利用しました.
- 火星の大気中のデウテリウムライマンアルファ線の強度を測定した.
主要な成果:
- デウテリウムライマンアルファ線が23 +/- 6レイリーで検出されました.
- 計算されたHD/H2比は1.5 +/- 0.6 x 10(-4) である.
- 見つかったHD/H2はHDO/H2Oより11倍小さく,分断の熱力学的制御を示しています.
結論:
- 火星のHD/H2分割は熱力学的に制御されるが,動力学的に制御されない.
- 分子水素 (H2) は,その長い大気中の寿命のために,水と比較してデウテリウムに著しく枯渇しています.
- 観測された同位体の分断は,約5メートルの厚さの交換可能な水氷の惑星規模の貯蔵庫を示唆しています.
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