I would tell them that it was just a rock as said in the article "huge rock formation" ,i also can prove that it is not an alien because in the article it states that "arrived at the Red Planet in sept 1997..." they went to mars to take pics of the unknown formation to prove to everyon that it was not made by alien the NASA described it as an "natural formation" ,even though this still left others with questions NASA said "the crema on board MGS had to peer through wispy clouds to see the face " which means that the picture wa not as clear as you thought it was with the clouds in the way NASA stated " what the pictuure actually shows is the Martin equivalent of a butte or mesa-landforms common around the American West..." These are all reasons that state that the landform was not created by aliens.