In April 2003, the Mars Global Surveyor (MGS) Mars Orbiter Camera (MOC) operations team completed the validation and archiving of MOC data acquired between February and July 2002. This was a period that included the end of northern winter and the start of spring in that hemisphere. This composite of MOC daily global images, acquired in early May 2002, shows what the planet looked like in early northern spring. The retreating north polar seasonal carbon dioxide frost cap is seen at the top of this view. Other white features in the image are clouds of water ice crystals in the martian atmosphere. The left half of this picture shows the Tharsis region, which includes several very large volcanoes. Olympus Mons, the largest martian volcano, is as wide as the Hawaiian Island chain is long; it is the dark, somewhat circular feature at the far left. Toward the lower right, the system of deep Valles Marineris chasms can be seen.