In a picture of Mars taken by the Viking 1 orbiter in 1976 (inset), sunlight caught this hill in a way that it made it look like a shadowy face. Here, the European craft Mars Express reveals it is nothing more than a lumpy rock — as scientists argued all along.

Credit: ESA/DLR/FU BERLIN/MSSS NASA/JPL

In 1998 and 2001, NASA's Mars Global Surveyor took high-resolution pictures of the outcrop, but failed to quell speculation by some that the feature was a relic of a martian civilization.

Gerhard Neukum, principal investigator for the Mars Express camera, says he received hundreds of e-mails asking for new pictures. “Some of them even said 'NASA is lying, we want the truth'.” He says the conspiracy theorists went quiet after the release of the image shown here, constructed using data gathered on 29 December 2004 and 22 July 2006.

The hill, imaged with a resolution of 13.7 metres per pixel, is a few kilometres wide and was probably shaped by erosion.