火星的红色峭壁

西西

  

Explanation: How did these layers of red cliffs form on Mars? No one is sure. The northern ice cap on Mars is nearly divided into two by a huge division named Chasma Boreale. No similar formation occurs on Earth. Pictured above, several dusty layers leading into this deep chasm are visible. Cliff faces, mostly facing left but still partly visible from above, appear dramatically red. The light areas are likely water ice. The above image spans about one kilometer near the north of Mars, and the elevation drop from right to left is over a kilometer. One hypothesis relates the formation of Chasma Boreale to underlying volcanic activity.

  
  图片说明：火星上的红色峭壁如何形成的？无人知详。火星北半球的冰冠几乎被宏伟的博勒拉峡谷一劈为二。地球找不到类似的情形。上图中，尘土叠层一直延伸到峡谷深处。大部分峡谷面向左边，不过部分仍然可以从上面看见，呈现醒目的红色。发亮的部分可能是水冰。上图在火星北半球，绵延约一公里，从右向左的海拔落差超过一公里。有一种猜测认为博勒拉峡谷的成形与火山的地下活动有关。