(Shorti) History--Ancestral Puebloan (Anasazi)

Some traces of the Ancestral Puebloan culture can be found in modern day indigenous tribes like the Hopi, but this is not enough to prove that the this whole civilization just packed their bags and left for another location. Could Cannibalism created by the drought have forced out these people from their beautiful cities…. Or On the other hand, Could they have left with an alien race in a space ship?