QUESTION:
I noticed that on some photos, the ground reflected differently. Is taht
because of the different build up of the rocks, or is this merely a result
of reflection of the sun?

ANSWER from Jack Farmer on July 19, 1997:
I assume this question concerns the images obtained by Pathfinder. Although
one must be careful about colors and reflections as you suggest, there are
real color differences in the rocks at the landing site that likely relate
to differences in chemical composition as well as mode of formation. The
APXS measurements of three rocks now confirm there are a range of
compositions present.