91É«ÇéƬ

Surprisingly, NASA doesn’t appear to have produced an official explanation
of the face, but the producers of Astronomy Picture of the Day, one of whom
works at NASA, show one of the pictures at
http://antwrp.gsfc.nasa.gov/apod/ap950722.html
and dismiss it as a Martian hill whose illusory face-like
appearance depends on viewing angle and angle of illumination.