The landform on Mars is quite interesting, and there could be many thoughts on how it came to be. With already known knowledge and knowledge that is soon to come, people like to guess. With the already known knowledge, we know so far that aliens have not been found on Mars yet, therefore they couldn't have possibly made a mark.

Like Earth, Mars is a planet just with different features. Our earth forms mountains and hills due to erosion and our plate tectonics. It's naturaly formed by the planet. No living organism created the rocky mountains. So with that, it is able to be assumed that Mars can form it's own hills and mountains as well.

Something else that is credible is that no life form has been found on Mars yet. Who knows if Mars has erosion or layers under it's surface that is able to move? On

Mars, there is no life that could have possibly created such a piece of art. Earth itself makes beautiful art like the Grand Canyon and

Niagra Falls. Naturaly, these landforms formed by Earth. Nobody knows exactly if Mars is able to do that, but with the relyablility we have today it has not proven that any life form could have created the Face on Mars.

If these markings were to be made by some kind of living organism, we almost certainly would know about it. Especialy with all of the high technology we have today, we would be able to see any kind of life. Maybe if we explored undernethe the surface of Mars, then we could get more information to see if Mars could have created it or if these aliens are living undernethe.

It's a great way to assume how it happened by comparing Mars to Earth, but it could also be irrelevent. Earth, unlike Mars, has an atmosphere. It keeps in heat, but changes. Earth also has water and life. If this were to be a cause of the rocks, hills, and mountains, then it could be said that the face on Mars was not created by erosion, water, or anything like that. It takes a lot of studing and even more knowledge to figure it out, but aliens don't seem to be logical quite yet.