小惑星2008 TCの衝突と回復 ((3))
P Jenniskens1, M H Shaddad, D Numan
1SETI Institute, Carl Sagan Center, 515 North Whisman Road, Mountain View, California 94043, USA. Petrus.M.Jenniskens@nasa.gov
Nature
|March 28, 2009
まとめ
科学者たちは,脆弱な小惑星とユニークな隕石を結びつけました. アルマハタ・シッタ隕石の回収された断片は,これまでコレクションで表現されていなかった,珍しい,多孔性のウレイライト組成物を明らかにした.
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)
- 隕石学は,隕石についてです.
背景:
- 小惑星は,母体との直接的なリンクがないため,スペクトル特性によって分類されます.
- 2008年に発見された小惑星2008 TC3は,平らな反射スペクトルを示した.
- 2008 TC3は大気圏に入ると分解し,回収可能な断片を残さないと予想されていた.
研究 の 目的:
- 小惑星とその隕石の断片の間の明確なリンクを確立するために.
- 小惑星2008 TC3.3から回収された隕石の組成と性質を特徴づける.
- 小惑星のスペクトルタイプと隕石のクラスをつなぐために.
主な方法:
- 小惑星2008 TC3.3の発見と追跡
- 小惑星の軌道に沿った隕石の断片 (アルマハタ・シッタ) の回収.
- 小惑星と回収された隕石の両方の光譜分析.
- 隕石サンプルのペトログラフィックおよび化学分析.
主要な成果:
- 合計3.95kgの47個の隕石の断片が回収され,大気圏への侵入後に生き残ったことを確認しました.
- 分析により,隕石はポリミクトウレイライトであり,超細い粒,多孔性,および大きな炭酸性含有物によって特徴付けられていることが明らかになった.
- 組み合わせたスペクトルデータは,親小惑星をF級小惑星として特定しました.
- F級小惑星2008 TC3と,暗い,炭素に富んだ異常なウレイライト隕石との間に,確固たる関連が確立されました.
結論:
- この研究は,小惑星2008 TC3とアルマハタ・シッタ隕石落下を成功裏に結びつけ,F級小惑星との最初の直接的なつながりを示しました.
- 回収された隕石は異常なウレイライトであり,以前は隕石コレクションに含まれていなかった繊細で炭素に富んだ物質です.
- この発見は,小惑星の多様性,そして原始的な太陽系材料の組成に関する私たちの理解を広げています.
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