小惑星 (1) セレスの水蒸気源を特定した
Michael Küppers1, Laurence O'Rourke1, Dominique Bockelée-Morvan2
1European Space Agency, European Space Astronomy Centre, PO Box 78, Villanueva de la Cañada 28691, Spain.
Nature
|January 24, 2014
まとめ
科学者たちは,小惑星セレスから発する水蒸気を検出し,小惑星帯が乾燥した地域であるという伝統的な見解に異議を唱えました. この発見は,潜在的に亜高層化や冷凍火山化を通じて,ベルト内に氷の体が存在する可能性を示唆しています.
科学分野:
- 惑星科学は惑星科学である.
- 天文学 天文学
- 天体生物学 アストロバイオロジー
背景:
- 従来の"スノーライン"モデルは,太陽系天体を乾燥した内部体と氷の表面体に分けます.
- 小惑星帯のオブジェクトは通常,乾燥していると考えられていますが,最近の発見は,水氷と水素化ミネラルの存在を示唆しています.
- 以前の研究ではセレスの周りに水蒸気があると示唆されていたが,決定的な証拠は得られなかった.
研究 の 目的:
- 小惑星セレスの周りの水蒸気の存在を確認するためです.
- セレスの水蒸気放出源と特性を調査する.
- セレス上の水蒸気が太陽系形成と進化に及ぼす影響を理解する.
主な方法:
- 繊細な観測器具を使って水蒸気を検出しました.
- 水分子のシグネチャーを特定するためにスペクトルデータを分析した.
- セレスの表面上の水蒸気源の空間的分布をマッピングしました.
主要な成果:
- セレスの周りの水蒸気の検出が確認され,少なくとも毎秒10^26の分子の生成率が確認されました.
- 主に中緯度の地域における,局所的な水蒸気排出源を特定した.
- 観測された現象は,彗星のような昇華または冷凍火山活動と一致しています.
結論:
- セレスは水蒸気の活発な源であり,アクセシブルな揮発物の存在を示しています.
- この発見は,伝統的な乾燥小惑星帯のパラダイムに異議を唱え,氷の体移動のモデルをサポートしています.
- セレスの水蒸気排出は,亜鉛化や冷凍火山などの地下プロセスによって引き起こされ,内部活動と潜在的な居住可能性の洞察を提供している可能性があります.
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