It is logically impossible for aliens to create what we call The Face. Although we do not know if such life forms exist, it still could not happen. It would take hundreds, or even thousands of lightyears to travel to the Milkyway galaxy. Extra-terrestrials would most likely have the same life-span as us, or slighty shorter/longer. So they probably couldn't survive the whole trip to our galaxy.

Even though no one knows how The Face was made, there are some more possible explanations. Strong winds could have eroded the surface of Mars and carried its contents to another location miles away from where they originally were.

Some lighter winds could have made indents on the flat part, giving it "facial features."

We have no evidence that truly proves that aliens are real. Many pictures that people show of their "encounter" just for attention. Others are just hoaxes. On the other hand, we were not there with those people to know that it wasn't true. Yet the lack of evidence says that they don't exist.

How would aliens even know what a human face looks like? They probably would have no idea (if they existed, that is). In the passage it says that The Face resembles an Egyptian pharoh. I don't think that aliens could understand what that was and leave an imprint on Mars that resembles a pharoh.

What kind of technology would they be using? A large laser? Technology/weapons that advanced don't exist yet, so it could not happen. It would most likely take a very long time since it is nearly two miles long. To be honest, I don't think anyone would have the patience to do that. Not even aliens. It could take months or possibly a year, depending on how detailed it is.