Smaller swaths represent images at higher resolution. The selection criteria were to find a place that was relatively flat and relatively smooth, but which displayed characteristics of the south polar layered materials. The base map used here is a mosaic of Viking Orbiter images from the U.S. Geological Survey. The south polar layered deposits are generally devoid of the large craters and hills seen at the Pathfinder site. When the picture on the right was taken, the surface was still mostly covered by winter-time carbon dioxide frost.
Illumination is from the lower right in both pictures.
Two craters are seen in this image, a very rare occurrence on the south polar layered deposits. The shadow of the rims of the craters can be used to determine their depths. Similar calculations for other features in the images indicate that much of the surface is smooth and flat. These pictures show the range of surface texture and morphology that is found within the landing ellipse. All of the frost seen here is expected to be gone by the time the Mars Polar Lander arrives in December 1999.