I should have put a more 'stand out' kind of title on this topic.
Maybe something like "Life Discovered on Mars!".

You need to take a close look, do an enlargement beyond that provided
by JPL, and really look at it.  The picture is a distant shot of a
valley or hillside, not a closeup of Spirit Rover tread marks.

http://marsrovers.jpl.nasa.gov/gallery/all/2/n/633/2N182561246ESFAEVO


tomcat