Ancient theory

Many might believe that these alien encounters and sightings are the stories of the modern age. This certainly is a misconception though. There are various sights, artifacts, cave drawings, places and monuments which suggest that planet earth was visited millions of years ago by extra-terrestrial beings. It is been suspected that the whole human race is in fact the descendants of these beings. 

 Some writers have proposed that intelligent extraterrestrial beings have visited Earth in antiquity or prehistory and made contact with humans. Such visitors are called ancient astronauts or ancient aliens. Proponents suggest that this contact influenced the development of human cultures, technologies and religions. A common variant of the idea is that deities from most, if not all, religions are actually extraterrestrials, and their technologies were taken as evidence of their divine status. These proposals have been popularized, particularly in the latter half of the 20th century, by writers such as Erich von Däniken, Zecharia Sitchin, Robert K. G. Temple, David Icke and Peter Kolosimo, but the idea that ancient astronauts actually existed is not taken seriously by most academics, and has received little or no credible attention in peer reviewed studies. Ancient astronauts have been widely used as a plot device in science fiction.

Image- Stone Carvings Found in Persepolis, Iran. the Image Depicts the Sumerian God Anunaki. Note that the Sumerians were the first civilizations on the earth to develop written records. In this picture the God is shown to be inside some type of a machine which is shown to have wings suggesting it's ability of flight. another alternate explanation is that the God has the Lower half body of a Bird.

Image- This is the Picture of the 'Dogu' figurine from Japan. it is dated back to some 1000 BC. if you look closely, it is a figure of a human-like being who is seen to be wearing goggles or some sort of an eye gear. when you see it's overview you might notice that this looks like some astronaut who is Wearing a spacesuit.

Image- The Nazca Lines of Peru. These lines are made in the middle of nowhere. These lines are perfectly straight, some of which run up to 80 kilometers long. There are also Very Huge Drawings of animals. birds and fishes on this site. some of them are about 500 Sq. kilometers in area and can only be seen from air. it was nearly impossible to create them without aerial surveillance. They are suspected to be the Landing Strips of the Ancient Alien Spaceships.

Image- One more misc. image suggesting ancient astronauts. [PS- If you know the names and origins of these images, please post it in the comments.]