I watched a show about this on the History Channel yesterday and was very intrigued. It's a pretty cool concept. Obviously, there really isn't a way to know for sure whether this could be true or not, but it is nice to be entertained. I for one believe in extraterrestrials. I certainly think this theory could have happened but I can't know for sure. What are others' opinions on this?
P.S. Not sure if this should be in Conspiracy Theories or not.