Right: High resolution Mars Global Surveyor view of part of one of these channels.
Click image to view an enlarged version of the close-up on the right.
Viking Orbiter view showing two channel systems in Mars's southern highlands. The area shown is 110 km across. The white outline indicates the area shown in more detail on the right.
High resolution Mars Global Surveyor view of part of one of these channels. The walls of the channel show horizontal stripes, which could either be terraces indicating multi-stage evolution of the valley, or reflect layers in the bedrock through which this channel has been carved.