In the heavily cratered southern highlands, repeated wind erosions and depositions could create the greatly eroded landscape seen in Figure 5.10. This frame is about 43 km across.

An aeolian surface on Mars sometimes can also appear as an etched surface as indicated in Figure 5.11. In addition, wind eroded parallel ridges, called yardang on Earth, can also be found on Mars (Figure 5.12).

For a comparison, yardangs of the Iranian desert on Earth as observed from LandSat photos are shown in Figure 5.13. Notice the linear features between this image and that of the previous image. A picture of the geology in this area as observed from a low-altitude airplane is given in Figure 5.14. Indeed, the linear features in Figure 5.12 are likely yardangs that resemble inverted keels of sailboats that are arranged parallel to each other.