InSightによる火星のスピン状態と深層構造
Sébastien Le Maistre1,2, Attilio Rivoldini3, Alfonso Caldiero3,4
1Royal Observatory of Belgium, Brussels, Belgium. sebastien.lemaistre@oma.be.
Nature
|June 14, 2023
まとめ
インサイトミッション
科学分野:
- 惑星科学
- 地理学
- 天文地質学
背景:
- 火星の内部構造と大気の理解は その形成と進化の鍵です
- 惑星の内部は直接アクセスできないので,地球物理データを解釈するのは困難です.
- NASAのインサイトミッションは 地震と無線科学の重要なデータを提供しました
研究 の 目的:
- 火星の核,マントル,大気の基本的な性質を決定する.
- 火星の核とマントルの特徴を分けて ラジオサイエンスのデータを使って
- 火星内部の異常や 回転速度を調査する
主な方法:
- 火星の惑星の回転を正確に測定する
- 正常モードでの共鳴の検出
- インサイトの追跡データを分析した.
主要な成果:
- 液体コアの半径 (1,835 ± 55 km) と密度 (5,9556,290 kg m−3) を決定した.
- 核-マントルの境界で特徴的な密度増加 (1,6902,110 kg m−3).
- 固体の中核と 明らかにした核の形状は マントルの質量異常を示しています
- 火星の回転速度が ゆっくりと加速している証拠を見つけた
結論:
- インサイトミッションのデータは 火星の内部構造の詳細な特徴づけを可能にしました
- 結果は火星のマントルの内部に 質量異常があることを示唆しています
- 観測された回転加速は,内部動力学や大気/氷冠の変化と関連している可能性があります.
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