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The common surface features of Mars include dark slope streaks, dust devil tracks, sand dunes, Medusae Fossae Formation, fretted terrain, layers, gullies, glaciers, scalloped topography, chaos terrain, possible ancient rivers, pedestal craters, brain terrain, and ring mold craters. ==Slope streaks== A new phenomenon known as slope streaks has been uncovered by the HiRISE camera on the Mars Reconnaissance Orbiter. These features appear on crater walls and other slopes, and they are thin and many hundreds of metres long. The streaks have been observed to grow slowly over the course of a year or so, always beginning at a point source. Newly formed streaks are dark in colour but fade as they age until white. The cause is unknown, but theories range from dry dust avalanches (the favoured theory) to brine seepage.〔(【引用サイトリンク】publisher=NASA )〕 Examples of dark slope streaks from various parts of Mars are shown below. Click on image to get a better view. File:Tikonravev Crater Floor.JPG|Tikonravev Crater floor in Arabia quadrangle, as seen by Mars Global Surveyor. Click on image to see dark slope streaks and layers. Image:25609layersstreak.jpg|Close-up of some layers under cap rock of a pedestal crater and a dark slope streak, as seen by HiRISE under HiWish program. File:Dark streaks in Diacria.JPG|Dark streaks in Diacria quadrangle, as seen by Mars Global Surveyor. Image:ESP_036956_1895layers.jpg|Layers and dark slope streaks, as seen by HiRISE under HiWish program Esp 036851 1995mesastreaks.jpg|Dark slope streaks on mesa, as seen by HiRISE under HiWish program Location is Amazonis quadrangle. 抄文引用元・出典: フリー百科事典『 ウィキペディア（Wikipedia）』 ■ウィキペディアで「Common surface features of Mars」の詳細全文を読む スポンサード リンク
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