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彗星67P/チュリュモフ・ゲラシメンコは,過去4年間に蓄積された塵の層を放出しています
Rita Schulz1, Martin Hilchenbach2, Yves Langevin3
1European Space Agency, Scientific Support Office, Keplerlaan 1, Postbus 299, 2200 AG Noordwijk, The Netherlands.
Nature
|January 28, 2015
まとめ
彗星67P/チュリュモフ・ゲラシメンコから収集された彗星の塵粒は,ふわふわした集積体であり,彗星組成の以前のモデルに異議を唱え,惑星間塵粒子の原材料であることを示唆しています.
科学分野:
- 宇宙塵の研究 宇宙塵の研究
- 彗星科学 彗星科学
- 惑星科学 惑星科学
背景:
- 彗星は,塵と凍ったガスからなる氷の体です.
- 彗星の塵粒子は,周日点の近くから流された塵の多い地殻から発生すると考えられている.
- 地球で発見された惑星間塵の粒子は,彗星の起源であると考えられています.
研究 の 目的:
- 彗星67P/チュリュモフ・ゲラシメンコからの塵粒の組成と構造を分析するために.
- 彗星塵の起源と性質を決定する.
- 彗星塵の構造と組成に関する既存のモデルをテストする.
主な方法:
- 彗星67P/Churyumov-Gerasimenkoからの塵粒の収集と分析.
- 粒子の大きさ,多孔性,表面組成の顕微鏡検査.
- 採集された粒子を惑星間塵粒子と既存の彗星モデルと比較.
主要な成果:
- 50ミクロメートルを超える粒子は,50%以上の多孔性でふわふわしていて,より小さな粒子の集積を示唆しています.
- 穀物の表面はナトリウムが豊富で,彗星の隕石にナトリウムが豊富に含まれていることが説明できる.
- この発見は,有機マントルと氷を持つシリケートコアとしての彗星塵のモデルに異議を唱えている.
結論:
- 彗星67Pからの彗星塵粒は,惑星間塵粒子の原材料である可能性が高い.
- 彗星の塵のついた地殻は,物質の流出を調節する役割を果たします.
- 彗星塵の組成は,これまでモデル化されていたよりも複雑で,太陽系形成にも影響がある.
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