"Here's a question. Go to the link cabojoe gave, click on the image that shows the small crater. What is it about the human brain that makes that crater look like a bump, but if you turn the picture upside down, it looks like a crater? Where did we get the inability to see craters correctly if they are lit "wrong"? And why?"
Funny, I noticed that too.. I am an avid viewer or space pictures.. I always notice that a depression can look like a raised area, and vice versa, if it is lit a certain way..
It is very strange, interesting you brought it up. I thought I was the only one...
I remember thinking.. "Olympus Mons is that big hole in the ground?"
LOL
Bones
It isn't the human brain, it's the loss of depth perception...shadow cast from/shadow cast onto look the same because you have no way of seeing the third dimension.
(Photo interpretation was a fun thing...but apt to be embarrassing)