MGS Image # M0301474 mc18
Other than resizing, this image has not been enhanced or altered in any way. It was cropped directly from the image provided by Malin Space Science Systems.
Download it yourself at http://www.msss.com/moc_gallery/ab1_m04/images/M0301474.html
The face-like feature is located at the northern rim of a crater near Nirgal Vallis.
The entire image width is shown here, a distance of 2.87 km.
MGS MOC was at an altitude of 374.05 km.
The face has many details including two eye sockets (possibly filled with some sand), forehead, brow, hair, ear, detailed nose with two nostrils, mouth, chin, cheekbones, and goatee, all in appropriate location, shape, and proportion. Although face-like features can sometimes be seen in naturally formed landscapes, for some researchers this type of detail and proportion arouses suspicians of artificiality.
Image courtesy of NASA/JPL/MSSS