Image of Mars from 20,000 miles

This image was taken from 20,000 miles by Viking 1 Orbiter. It is a 5 frame mosaic taken during the orbital high point (apoasis) and shows Gangis Chasma in the lower right, which leads into Valles Marineris canyon. In the upper right accordning to NASA scientists the white patch was thougth to be ice fog close to the surface. Another bright patch in the upper right corner was thought to be an ice cloud mving at aproximately 100 mph.