Ice Caps

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On Mars there is an ever present water cycle . We can see evidence of this in the ice caps. Above you can see the north polar minimums and maximums. In the winter the ice caps are large, and in the summer they grow very small. The ice caps on Mars are made of a mixture of frozen water and dry ice (frozen carbon dioxide). A key to one process of terraforming would be to melt the ice caps. The Mariner 9 and Viking orbiters photographed layered terrain whose age has been estimated at less than a few million years. The nearly uniform thickness and spacing of the layers suggests they were formed by atmospheric sedimentation processes (dust settling out of the atmosphere) modulated by periodic climate changes. Most planetary scientists believe that the Martian surface has not always been in the same orientation with respect to its axis of spin. This Polar Wandering Theory explains that the north and south poles appear to have wandered all over the planets crust. Certain regions of the crust that are now far from the poles would at some time in the past have been within the polar regions. Click here for a picture extensively layered deposits at at the rim of the south pole.

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