QUESTION:
In the image of the rock dubbed "Flat Top," there appears to be another
smaller rock to the upper right with similar characteristics (flatness,
amount of dust on top, at about the same height). Is it possible to
determine if this piece broke away from flat top?  Or determine if it is
part of flat top, but the rock in between has been eroded away?  Many thanks
for your time and energy in the matter.

ANSWER from Ted Roush on July 15, 1997:
Even if a human were on Mars, it would be very difficult to determine if
"flat top" and the rock you are refering to were once contiguous.  Even if
they had the same elemental composition, which could be determined by the
APXS, this simply implies that they were formed from the same materials. 
One would need to observe a "perfect" match along the appropriate edges. 
Perhaps if there were a distinctive "feature" that was obviously continued
on each individual rock one could make a better case for both samples having
once been contiguous.  There really isn't a ready mechanism of
preferentially erroding the putative "rock inbetween" while leaving behind
the other rocks.