Mars Global Surveyor
Mars Orbiter Camera (MOC)

MOC Begins Third Mars Year in Mapping Orbit

MGS MOC Releases MOC2-321 to MOC2-324, 12 December 2002

The Mars Global Surveyor (MGS) Mars Orbiter Camera (MOC) "officially" began its mapping mission on 9 March 1999, after MGS had spent about a year and a half slowly changing its orbit to its final nearly-circular, nearly-polar position approximately 380 km (236 mi) above the martian surface. When mapping began, it was summer in the martian northern hemisphere, and winter in the south. One of the primary objectives of MOC was to observe Mars for one full Mars year, documenting changes in its weather and seasonal patterns of polar cap growth and retreat. On 24 January 2001, MOC completed its first Mars year--about 687 Earth days--as the planet returned to the exact same time of year (in northern summer) that it had been at the start of mapping.

This week, MGS and MOC completed an unprecedented second Mars year of daily global monitoring and detailed observations of the red planet. On 12 December 2002, Mars returned to the exact same position in its orbit around the sun (or equivalently, the exact same time of the martian year) as it was on 9 March 1999 and 24 January 2001. MGS has now entered its third Mars year, and critical monitoring of weather patterns continues, along with on-going efforts to gather high resolution images of future spacecraft landing sites, provide detailed studies of geologic features, and observe phenomena that change--like wind streaks--over time.

Current plans call for MGS and MOC to remain active through October 2004. Between now and then, and in addition to its own scientific duties, the spacecraft will play a small but extremely important role in supporting the upcoming Mars Exploration Rover (MER) mission by providing a radio relay for data being transmitted during the critical entry, descent and landing phase of each of the rovers. Additionally, MGS may be used to augment science data return. These functions will use the French-supplied Mars Relay and the MOC's computer buffer. A proposal is presently being prepared to further extend the MGS mission to provide another full Mars year of weather observations, to support landing site studies for NASA's 2007 and 2009 Mars missions, to scout locations for future detailed studies by the Mars Reconnaissance Orbiter's (MRO) advanced instrumentation, and to provide critical observations supporting MRO's 6-month long aerobraking period.

In the interim, MOC continues, every day, to acquire dazzling images of the martian surface. As we now begin a third Mars year observing the planet from the mapping orbit, we present (below) a sampling of recent images and mosaics assembled by MOC scientists at Malin Space Science Systems.

N. Polar Storms

Athabasca Floods

N. Polar Dunes

Northern Plains

Images Credit: NASA/JPL/MSSS
Caption by: K. S. Edgett and M. C. Malin, MSSS

Malin Space Science Systems, Inc.