Book excerpt: What would the remains of an advanced extraterrestrial civilization look like? How can we determine if strange-looking formations or regular-seeming landforms on the surface of another world are artificial or not? In The Cydonia Controversy, imaging specialist Mark Carlotto not only updates his conclusions about various unusual features in the Cydonia region of Mars, including the famous "Face", but also lays the groundwork for an exciting new science -- exoarcheology.