Colour-enhanced 'fish-eye' view of Mars. Mosaic of images made by the Viking Orbiter, centred on the large Schiaparelli impact crater. This point perspective image simulates a 'fish-eye' lens view from a spacecraft about 2500 km above the surface, and covers an area of about 60 degrees latitude by 60 degrees longitude. The dark patch running across the disc consists of the Sinus Meridiani (left of centre) and Sinus Sabeus (right). The dark colour is thought to be due to ancient basaltic rock. The white area at bottom right is the vast Hellas impact basin, filled with seasonal carbon dioxide frost. The pale streaks near the craters at top left are wind-blown dust deposits.