DARTミッションのモメンタム転送 ダイモルフォス小惑星の動力衝突
Andrew F Cheng1, Harrison F Agrusa2, Brent W Barbee3
1Applied Physics Laboratory, Johns Hopkins University, Laurel, MD, USA. andy.cheng@jhuapl.edu.
Nature
|March 1, 2023
まとめ
NASAのダブル・アステロイド・リダイレクション・テスト (DART) ミッションでは小惑星の傾斜が成功しました. ダイモルフォスの動力衝突は 噴出物を発生させ 惑星防衛のモメンタム移転を大幅に強化した
科学分野:
- 惑星科学
- 天体物理学
- 航空宇宙工学
背景:
- NASAのダブル・アステロイド・リダイレクト・テスト (DART) ミッションは惑星防衛のテストとして設計された.
- 二重小惑星ディディモスの月体である ダイモルフォス小惑星の 動力衝突でした
- このミッションは 惑星防衛に適したスケールで 超高速衝突実験を初めて行いました
研究 の 目的:
- 小惑星の傾斜の有効な方法として 動力衝突を検証する
- 動力衝突の際に小惑星に伝わるモメンタムを定量化する.
- 小惑星の軌道を 変えるためのDARTミッションの 効果を評価するために
主な方法:
- 衝突後のディディモス系のバイナリ軌道期間の変化の分析.
- ディモルフォスの軌道の軌道速度の瞬時の変化の計算.
- 噴射反転と小惑星の密度に基づいてモメンタム強化因数 (β) の決定.
主要な成果:
- ディモルフォスの軌道速度成分が2. 70 ± 0. 10mm/sの瞬時減少を測定した.
- ダイモルフォスの質量と密度によって,モメンタム強化因数 (β) が2. 2から4. 9の範囲であることが判明した.
- これらの結果は,DART宇宙船のインシデントモメンタムよりも,エジェクトからのモメンタム移転がかなり大きいことを示しています.
結論:
- DARTの動力衝突は ダイモルフォス小惑星の方向転換に 非常に効果的でした
- 衝撃で発生したエジェクタからの反発は,モメンタム移転を強化する上で重要な役割を果たしました.
- この発見は,小惑星の傾斜と惑星防衛のための有望な戦略として, 動力衝突技術を検証しています.
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