イトカワの塵粒子の表面で観測された初期の宇宙気象
T Noguchi1, T Nakamura, M Kimura
1College of Science, Ibaraki University, 2-1-1 Bunkyo, Mito, Ibaraki 310-8512, Japan. tngc@mx.ibaraki.ac.jp
Science (New York, N.Y.)
|August 27, 2011
まとめ
宇宙気象,小惑星の表面の変化は,小惑星イトカワからの粒子で確認されました. この発見は,S型小惑星と隕石のスペクトルの違いを説明するのに役立ちます.
科学分野:
- 惑星科学は惑星科学である.
- 宇宙化学 (コスモケミストリー)
- 地質学 地質学 地質学
背景:
- 普通のコンドライトの反射スペクトルは,S型小惑星とは異なる.
- この不一致は,空気の無い天体の表面の変化である宇宙気象に起因する.
- ハヤブサミッションは,S型小惑星25143イトカワからサンプルを回収した.
研究 の 目的:
- イトカワ粒子の宇宙気象の証拠を調査するために.
- S型小惑星の表面変化のメカニズムを理解するために.
主な方法:
- 顕微鏡とスペクトロスコーピーを用いて帰還した小惑星粒子の分析.
- 表面の変化とナノ粒子形成の識別と特徴付け.
主要な成果:
- 10個のイトカワ粒子のうち5つの表面の変化が観察されました.
- オリヴィン,ピロキセン,プラジオクラゼの表面層 (5-15 nm) で発見された硫黄含有鉄分豊富なナノ粒子は,蒸気堆積を示唆しています.
- 硫黄のないFe豊富なナノ粒子は,フェルマグネシアンシリケートの中でより深く (<60 nm) 発見され,メタミク化とFeの局所的減少を示唆しています.
結論:
- S型小惑星イトカワ粒子の宇宙気象の直接的な証拠が見つかりました.
- 観測された表面の変化とナノ粒子の組成は,宇宙の気象化プロセスに関する洞察を提供します.
- この発見は,小惑星と隕石の関係を理解するのに役立ちます.
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