エウロパの表面にある過酸化水素

R W Carlson¹, M S Anderson, R E Johnson

¹Jet Propulsion Laboratory, California Institute of Technology, Pasadena, CA 91109, USA. rcarlson@lively.jpl.nasa.gov

Science (New York, N.Y.)

|March 26, 1999

まとめ

ガリレオ宇宙船からのスペクトルは,欧州の表面で過酸化水素を明らかにしています. この発見は,強烈な粒子放射が,氷の月の上で化学物質を作り出すという理論を支持する.

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
スペクトロスコーピーは,スペクトロスコーピーを用います.

背景:

木星の氷の月であるヨーロッパは,地球外生命の探求における主要なターゲットです.
ヨーロッパの表面の組成を理解することは,その居住性を評価するために極めて重要です.
エネルギー粒子爆撃は,惑星系における氷の体の化学に影響を与える重要なプロセスです.

研究の目的:

スペクトルデータを用いて,ヨーロッパの表面構成を分析する.
エウロパの表面に存在する特定の化学物質の種類を特定し,定量化するために.
エウロパの表面を形作る放射溶解などの化学プロセスを調査する.

主な方法:

ガリレオ宇宙船を用いて,欧州の主要な反木星四角の空間的に解明された赤外線および紫外線スペクトルの取得.
化学化合物を特定するためにスペクトル内の吸収特性の分析.
観測されたスペクトル特性の比較と過酸化水素と水氷の実験室測定.

主要な成果:

水素過酸化物 (H2O2) に起因する独特の吸収特性の検出.
表面の過酸化水素濃度の推定値は,水氷に比べて約0.13%である.
観測されたH2O2の豊富さは,放射性分解生成の予測と一致しています.

結論:

ヨーロッパの表面にはかなりの量の過酸化水素が含まれており,おそらく放射分解によって形成されている.
この研究は,放射分解がヨーロッパの表面化学に影響を及ぼす支配的なプロセスであることを確認しています.
これらの発見は,ユーロパの潜在的居住可能性と天体生物学的な重要性に意味を持っています.

キーワード:

非プログラム的なものです.

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