OMEGA/Mars Expressによって観測された火星の北極帽の夏の進化
Y Langevin1, F Poulet, J-P Bibring
1Institut d'Astrophysique Spatiale, CNRS-Université Paris Sud, 91405 Orsay, France. yves.langevin@ias.u-psud.fr
Science (New York, N.Y.)
|February 19, 2005
まとめ
鉱物学,水,氷,活動 (OMEGA) 観測所 (Observatoire pour la Minéralogie, l'Eau, les Glaces, et l'Activité) は,火星の水氷を監視し,小粒の凍結から大粒の氷への移行を観察しました. 観測期間中,地表氷の塵による汚染は最小限にとどまった.
科学分野:
- 惑星科学 惑星科学
- アストロジオロジー アストロジオロジー
- リモートセンシング (リモートセンサー)
背景:
- 火星の極地層は,氷の面積と性質の季節的な変化を示しています.
- 表面氷のダイナミクスを理解することは,火星の気候の歴史を解釈する上で極めて重要です.
研究 の 目的:
- 火星の北極地域における水氷と氷粒の大きさの時間的進化を監視するために.
- 表面氷のアルベドの変化と塵の汚染を評価する.
主な方法:
- OMEGAの可視赤外線画像スペクトロメーターを使用して,広範な観測を行いました.
- 2004年後半 (Ls 93-127°) に火星の北緯度 (北緯70度以上) からのデータを分析した.
- 監視された地表水氷の範囲,粒子の大きさ,およびアルベドの時間経過.
主要な成果:
- 極地上の明るい,小粒子の凍りから,より大きな粒子の氷への移行が観察されました.
- 大粒結晶の氷が支配する周辺地域のアルベドの上昇を観測した.
- モデルに依存する評価では,氷の塵の汚染が低いことが示された.
結論:
- 火星の北極帽は,季節的に凍結と氷粒の性質に大きな変化を経験します.
- アルベドの変動は,氷粒の大きさや分布の変化と関連しています.
- 火星の表面水の氷は,この期間中に限られた塵の汚染を示しています.
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