The face on mars is a natural landformation. People beleive it was made by aliens but it was not mars like earth has mesa's and they are huge rock formations like mountain and it was proven thanks to newer images with higher resolution.

It was first discovered by a ship called viking 1 who was taking pictures of mars to see where it's sister ship viking 2 could land and it captured The Huge Face but due to low resolution they could not make it all the way out and they believed that it was a sculpture of a egyptian pharo.

But in the last paragraph it says "What the picture actually shows is the martian equivalent of a butte or mesa landforms common to earth around the american midwest". Which may be because The Red Planet once had water and caused the rocks to decay in a wierd way making The Huge Face.