ストラトスフィアの粒子における4Heの検出は,地球外生命体の起源の証拠を示しています
R S Rajan1, D E Brownlee, D Tomandl
1Department of Terrestrial Magnetism, Carnegie Institution of Washington, Washington, D.C. 98195, USA.
Nature
|May 12, 1977
まとめ
科学者たちは,平流圏の粒子に高濃度のヘリウム-4 (4He) を検出し,それらを真の微小隕石であると確認しました. この発見は,地球外生命体の起源を示し,地球に侵入する際の大気温は最小限にあることを示している.
科学分野:
- 宇宙塵の研究 宇宙塵の研究
- 惑星科学は惑星科学である.
- 大気化学 大気化学
背景:
- 微小隕石は,大気圏に入ると生き残ると予測される小さな惑星間粒子です.
- ストラトスフィアの粒子の最近の収集は,原始的な隕石と一致する元素の組成により,地球外の起源を示唆しています.
研究 の 目的:
- ストラトスフィアの粒子の組成を調べ,その微小隕石の状態を確認するためです.
- 採集した粒子の太陽風への曝露と最小の大気温上昇の証拠を特定するために.
主な方法:
- 2年間にわたってマイクロメートルの大きさの平流層粒子の収集.
- 原始的な隕石と比較するための元素組成分析.
- 粒子内のヘリウム-4 (4He) 濃度の検出.
主要な成果:
- ヘリウム-4 (4He) の高い濃度は,幾つか平流圏の粒子で検出されました.
- 4Heの存在は,太陽風にさらされていることを示唆しています.
- ヘリウム保持は,粒子が大気圏に入るときに重大な摩擦加熱を受けなかったことを示しています.
結論:
- 検出されたヘリウム-4は,平流圏の粒子が真の微小隕石であることを確認しています.
- これらの粒子は,地球外物質の証拠を提供し,地球の大気との相互作用は最小限にある.
- この発見は,微小隕石の生存に関するウィップルの予測を裏付けている.
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