QUESTION: 
When Mars Global Surveyor maps Mars, will you study the areas of pictures 
taken by the Viking mission to see if there has been any changes.

ANSWER from Cathy Davis on January 2, 1997:
Yes. Although, we will have a camera that has different spatial 
resolution than the Viking missions. A major interest is to see 
what, if any, changes have occurred in the last 20 years.