Now in its Extended Mission, Mars Global Surveyor (MGS) is into its second Mars year of systematic observations of the Red Planet. With the Extended Mission slated to run through April 2002, the Mars Orbiter Camera (MOC) is being used, among other things, to look for changes that have occurred in the past Martian year. (Because Mars is farther from the Sun than Earth, its year is longer — about 687 Earth days.)