中文翻譯:
你知道嗎？在火星的北極圈旁邊，有一個神秘的螺旋形！每年冬天，火星的北極會增添一層約一米厚的冰，這是來自稀薄空氣中的二氧化碳凍結而成的。這層新的冰層會覆盖住全年都存在的水冰層。當強風從北極的中心吹來時，這些風會因為火星的轉動而旋轉，這樣就形成了有趣的螺旋形狀。這幅圖片是由歐洲太空總署的火星快車（Mars Express）拍攝的，還有來自美國NASA的火星全球勘測者（Mars Global Surveyor）激光高度計的數據，讓我們了解到更多有關火星的故事！
原文:
Why is there a spiral around the North Pole of Mars? Each winter this pole develops a new outer layer about one meter thick composed of carbon dioxide frozen out of the thin Martian atmosphere. This fresh layer is deposited on a water-ice layer that exists year round. Strong winds blow down from above the cap’s center and swirl due to the spin of the red planet — contributing to Planum Boreum’s spiral structure. The featured image is a perspective mosaic generated in 2017 from numerous images taken by ESA’s Mars Express and elevations extracted from the laser altimeter aboard NASA’s Mars Global Surveyor mission.
來源:NASA每日圖片
