QUESTION: 
How many pictures do you think you will get in the two years of mapping
Mars by MGS?

ANSWER from Charles Whetsel on November 3, 1997:
The Mars Global  Surveyor spacecraft has  two main camera  systems:  A
"wide-angle" system for taking low-resolution images that are  similar
to  the  weather  map  pictures  you  see  of  the  earth on TV, and a
"narrow-angle" camera that takes  detailed geological pictures of  the
surface of  Mars, like  a spy  satellite.   Once it  reaches the final
mapping orbit, MGS will  be able to send  down a "global" weather  map
once per day, and will take  at least 2-3 narrow angle images  on each
orbit (every 2 hours), or 20-30 pictures per day (Some months will  be
better than others, since  the camera can work  at a higher rate  when
the  earth  and  Mars  are  closer  together).    In  the   elliptical
aerobraking orbits,  we can  generally take  only one  wide and narrow
angle image per  orbit, depending on  the orbit period,  which is much
less than we will be able to do once we are the final orbit.