火星の大気中のメタンの検出
Vittorio Formisano1, Sushil Atreya, Thérèse Encrenaz
1Istituto di Fisica dello Spazio Interplanetario INAF-IFSI, Via del Fosso del Cavaliere 100, 00133 Rome, Italy. formisan@nike.ifsi.rm.cnr.it
まとめ
メタンは火星の大気中に検出されており,そのレベルは惑星全体で著しく変化しています. この発見は,火星のメタンの生物学的および地質学的源の両方の可能性を開きます.
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
- 大気化学 大気化学
背景:
- メタンは潜在的なバイオシグネチャーガスです.
- 火星でのメタンの以前の検出は暫定的なものだった.
- メタンの源を理解することは,火星の居住可能性の評価の鍵です.
研究 の 目的:
- 火星の大気中のメタンの検出を報告する.
- メタンの世界の平均値と変動度を定量化するために.
- 火星のメタンの潜在的な源について議論する.
主な方法:
- 火星エクスプレス宇宙船に搭載された惑星フーリエスペクトロメーター (PFS) を利用した.
- メタンの吸収特性を特定し,定量化するために分析されたスペクトルデータ.
- 火星表面のメタンの分布をマッピングしました.
主要な成果:
- 火星の大気中のメタンの存在が確認されました.
- 世界平均メタンの混合比率は10 +/- 5 parts per billion by volume (ppbv) であった.
- 重要な空間的変動が観察され,混合比率は0~30ppbvであった.
結論:
- 検出されたメタンは,火星上で地質学的または潜在的に生物学的活動が進行していることを示唆しています.
- 潜在的な源には,微生物の生命,水熱プロセス,または地球外からの影響が含まれます.
- 火星メタンの起源を特定するためにさらなる調査が必要です.
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