Although stories about aliens have never been officially confirmed, their existence has been widely speculated upon.
Many people believe that from outer space have visited us for centuries. Some say that life on Earth “out there” and was seeded here. Others say that aliens have what happens on Earth, and are responsible for quite a few legends, and that the ancient Greek and Roman gods, the fairies and dwarfs in many classical tales, were in fact “space people” living here. Still say that aliens were responsible for the growth of highly evolved civilizations which have perished, including the Incan and Mayan civilizations and the legendary Atlantis.
A lot of ancient civilizations, the Egyptians, Hindus, Greeks, and Mayans, have left writings and which indicate contacts with superior beings “from the stars.” Many believe that the aliens are here to help us, while others hold that the aliens intend us . Still others think that most aliens visit Earth to study us like our scientists study primitive natives and animals, and have no interest in helping us .
It is difficult to comment conclusively on these theories in general, apart from saying that any and all of them might be possible. Maybe time will tell.