Originally launched for the first time successfully on September 12 1997, the Mars Global Surveyor has given Nasa much more than its expectations by living beyond its primary mission which was intended to end in January of 2002. Remaining in good condition as of this point, Nasa has extended its mission for a third time through 2006 and believe if funding is allocated the Surveyor could remain in space around Mars' orbit for another five to ten years. On September twelfth of this year, the Global Surveyor passed Viking I as the longest lived spacecraft in Mars space mission history.

Among the discoveries made by the Surveyor, the most dramatic since its mission began was a discovery of a fossilized river delta in a crater known as "Eberswalde". This delta proved the existence of water flow among Mars at one time, resulting in the production of sedimentary rock as found by Spirit and Opportunity.

The most exciting recent discovery has been that of the formation of new gullies on Mars. This evidence has changed the estimates of the age of Mars. In addition, the Mars Global Surveyor discovered a shrinking of the southern polar ice cap of three feet a year. This proved to Nasa that Mars is undergoing more frequent changed than previously believed. In addition, the Surveyor has gathered data on

New technology has allowed Nasa to increase its utilization of the Surveyor in ways never dreamed of at the onset of its mission. Resolution of its cameras made it possible to determine that boulders no larger than one to two meters exist in ripples caused by a catastrophic flood. This technique, is known as "compensated pitch and roll targeted observation". In May of this year, the Surveyor again made history by being the first spacecraft to ever take images of other spacecraft in orbit, taking images of the European Space Agency's Mars Express and NASA's Mars Odyssey.

Nasa - National Mars Exploration Program - http://www.nasa.gov/home/: :

1) One Mars Orbiter Takes First Photos of Other Orbiters
2) Mars Orbiter Sees Rover Tracks Among Thousands of New Images
3) Nasa Press Releases September 20, 2005
4) Recent Changes on Mars Seen by Mars Global Surveyor Michael C. Malin and Kenneth S. Edgett, Malin Space Science Systems, September 2005

About the Author

David Craig Nasa and General Astronomy Inofrmation M.S. Physics - University of Minnesota B.S. Computer Science - University of Oregon