On July 25 1976 probe NASA Viking 1 take a picture at the surface of Mars that some days later would have aroused uneasiness in the public worldwide. The photo in Figure 1, which frame the area to 40.75 ° latitude and 350.54 ° longitude (the so-called zone of Cydonia ), Seemed to restore some semblance of the human face. Several theories developed around this "face on Mars", the most famous of which was that of astrophysics Richard C. Hoagland that The Monuments of Mars: A City on the Edge of Forever ( Monuments of Mars: a city to the brink of infinity , 1987) supported the possibility that the hills 3 km to 1.5 km had been left by ancient Martian civilization As well as other ruins of cities and pyramids detectable on the surface of Red Planet . The Hoagland's theories were not despised: in 1988 he was invited several times by NASA to give lectures in front of thousands of employees on the results of its investigations on the Cydonia. Robert Roe, president of House Committee on Space Science and Applications ( Committee on Science and Space Applications ) Before step down mysteriously had ordered NASA to obtain images at a higher resolution of the Cydonia. In 1993 the probe mission Mars Observer disappeared and could not get those images up to 1998.
However, the long-awaited photos ended up totally cancel the validity of the theory of Hoagland in 1998 and 2001, the probe Mars Global Surveyor In 2002 the probe Mars Odyssey and in 2006 the person Mars Express (ESA) taking photographs unequivocal. In particular, the latest sensor technology was used dell'avanzatissima HRSC (High Resolution Stereo Camera) which allowed to have a resolution in which a pixel represented only 13.7 meters of soil. This allowed even to make a three-dimensional reconstruction of the surface of the planet. The new data made it clear that the similarity with a human face was simply due to Low Resolution original image and a situation shadows particularly due to react to the 20th of sunlight on the horizon than Martian. It also speaks of an interruption of transmission by what seems to be the nostril of the face.