SCHIAPARELLI HEMISPHERE, ENHANCED COLOR. This mosaic shows exaggerated colors that allow us to see subtle cloud and surface features. The center of this image is near the impact crater Schiaparelli (latitude -3 deg., longitude 343 deg.)/P>

The large circular area with a bright yellow color (in this rendition) is known as Arabia. The boundary between the ancient, heavily-cratered southern highlands and the younger northern plains occurs far to the north (latitude 40 deg.) on this side of the planet, just north of Arabia. The dark streaks with bright margins emanating from craters in the Oxia Palus region (to the left of Arabia) are caused by erosion and-or deposition by the wind. The dark blue area on the far right, called Syrtis Major Planum, is a low-relief volcanic shield of probable basaltic composition. Bright white areas to the south, including the Hellas impact basin at lower right, are covered by carbon dioxide frost.

* Mosaic limits are approximately latitude -60-to-60 degrees, longitude 280-to-30 degrees. Mosaic is composed of 100 red/violet Viking Orbiter images, digitally combined by orthographic projection at a scale of 1 km/pixel. Images acquired in 1980 during mid-northern summer on Mars (Ls=89 deg.). Color variations enhanced 2x; large-scale brightness variations (mostly due to sun-angle variations) normalized by large-scale filtering.