Very interesting topic; reminded me of a picture I pulled off the nasa website some time ago….
http://photojournal.jpl.nasa.gov/cat...umber=pia09160
Download the hi-rez version to this pic; open it.
Make your own assertions on how this looks; I’m sure people on this forum could tie this to more things then I could. Zoom in towards the top of the apparent “head” and check out the hatch. Symmetrically both doors are the same size, also notice to the right of the hatch doors the heavy shadow line, this shows that the hatch is lower on the surface. Bet you could fit a pretty big ship through those doors, no?