火星の雪の深さの季節的な変動
D E Smith1, M T Zuber, G A Neumann
1Laboratory for Terrestrial Physics, NASA/Goddard Space Flight Center, Greenbelt, MD 20771, USA.
Science (New York, N.Y.)
|December 12, 2001
まとめ
火星 火星 火星 火星
科学分野:
- 惑星科学は惑星科学である.
- 地質物理学 地質物理学とは地質物理学です.
背景:
- 火星の季節的な二酸化炭素循環は,表面の上昇と惑星の平ら化に影響を与えます.
- 以前の研究では,これらの時間的な変化の正確な測定が欠けていました.
研究 の 目的:
- 火星の季節的な高さの変化を定量化するために.
- 季節的に堆積した二酸化炭素の密度を測定する.
- 火星の重力と地形学の関係を調査する.
主な方法:
- マース・オービター・レーザー・アルティメーター (MOLA) の地形データを,火星・グローバル・サーベイヤー (MGS) の宇宙船で利用した.
- 分析されたMGSドップラー追跡残留は,火星の平ら化の時間的変動を測定するために.
- 季節的な二酸化炭素の交換と相関する標高の変化.
主要な成果:
- 火星の高緯度 (80度以上) で (1.5-2メートル) の有意な標高変化を測定した.
- 北半球の秋に予期せぬ亜化期が観測され,南半球の砂嵐と一致した.
- 季節的に堆積した二酸化炭素の平均密度を910 +/- 230 kg/m3に制限した.
結論:
- 季節的な二酸化炭素の堆積と昇華は,火星上の測定可能な高さの変化を引き起こします.
- 火星の乾氷の密度は,地上の雪よりもかなり高い.
- 火星の重力と平ら化の時間的変動は,表面プロセスと関連しています.
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