I really don't think that aliens could have done this. actually i could give you a few reasons why and reason one, that just sounds crazy. Aliens dont exsit.

It's just a natural land form. There are all kinds of dents and holes on these planets. Besides the natural landforms are common enough around Cydonia. "in the article it states, "Thousands of anxious web surfers were wating when the image first appeared on the JPL web site, revealing...a natural landform. There was no alien mounment after all." Reason two is landforms are common around the American west. The test even states, "What the picture actually shows is the Martail equivalent of a butte or mesa-landfors common around the American West." Finally reason 3. If ypu look at the pictures long enough, the longer "the face" has been there there more it transfors into a dent and looks nothing like a face.

I believe its a landform and hopefully these reasons help you beive it too. The scienctists proved has the facts that it is a landform and not a alien face.