初期の太陽系における隕石ナノダイアモンドの in situ 形成の可能性
Z R Dai1, J P Bradley, D J Joswiak
1School of Materials Science and Engineering, Georgia Institute of Technology, Atlanta, Georgia 30332, USA.
Nature
|July 12, 2002
まとめ
かつて隕石や彗星に豊富に存在すると考えられていたプレソラーナノダイアモンドは,惑星間塵の中で驚くほど稀である. これはそれらの起源に異議を唱え,一部が他の星の周りにではなく,太陽系の内側で形成される可能性があることを示唆しています.
科学分野:
- 宇宙化学 (コスモケミストリー)
- 惑星科学は惑星科学である.
- 天文学 天文学
背景:
- プレソーラー粒子は,恒星形成と太陽系の初期進化の洞察を提供します.
- 隕石からのナノダイアモンドは,最も豊富に存在するプレソーラー粒子の1つと考えられていた.
研究 の 目的:
- 惑星間塵粒子 (IDP) のナノダイアモンドの豊富さを調査する.
- プレソラーナノダイアモンドの起源と分布を再評価する.
主な方法:
- 繊細で炭素が豊富な惑星間塵の粒子の分析.
- IDPにおけるナノダイアモンドの豊富さの比較と隕石や彗星のサンプル.
主要な成果:
- ナノダイアモンドは分析されたIDPには存在しないか,または非常に枯渇している.
- これは,ナノダイアモンドが彗星のような原始的な太陽系外部の物質に豊富に存在するという期待に反している.
結論:
- いくつかのナノダイヤモンドは,太陽系内部の内部で形成され,独占的にプレソーラーではありません.
- また,プレソラーナノダイアモンドの分布は,太陽中心の距離とともに減少し,太陽系初期輸送の理解が不完全であることを示す可能性があります.
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