DARTの動力衝突によるディモルフォスの軌道周期の変化
Cristina A Thomas1, Shantanu P Naidu2, Peter Scheirich3
1Northern Arizona University, Flagstaff, AZ, USA. cristina.thomas@nau.edu.
Nature
|March 1, 2023
まとめ
ダブル・アステロイド・リダイレクト・テスト (DART) ミッションでは小惑星の軌道が成功しました. ダイモルフォスの軌道期間が 予想より大幅に短縮されました
科学分野:
- 惑星科学
- 天体力学
- 衝撃物理
背景:
- ダブル・アステロイド・リダイレクション・テスト (DART) ミッションは,小惑星の傾斜のための運動インパクター技術をテストすることを目的とした.
- この前例のない実験の標的は 小惑星ディディモスの月である ディモルフォスでした
- 衝突前の軌道のパラメータは 長年の光曲線観測を用いて 精密に決定されました
研究 の 目的:
- ダイモルフォスの軌道周期の変化を,DARTの動力衝突の後に報告する.
- 小惑星の軌道を分析する
- 弾力移転の強化におけるエジェクトの役割を調査する.
主な方法:
- 衝突前の軌道パラメータを 正確に決定するために 光曲線観測を利用した.
- 衝突後の軌道周期の変化を測定するために,地球ベースの光曲線とレーダー観測を使用した.
- インパクトダイナミクスを分析し,モメンタム強化要因を考慮した.
主要な成果:
- ディモルフォスの軌道周期は -33.0 ± 1.0 (3σ) 分変化した.
- 2つの独立した観測方法 (光曲線とレーダー) は,周期変化に対して同一の結果を出した.
- 観測された周期の変化は,完全に非弾力的な衝突で予測されたより大幅に大きかった.
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成功しました
- 軌道周期の変化は,宇宙船のインシデントモメンタムを超えた重要なモメンタム強化を示しています.
- 衝突時に発生したエジェクタは,観測された傾斜に寄与し,モメンタム移転を増加させる上で重要な役割を果たした.
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