Ancient Astronaut theory is based on the idea aliens have visited the Earth in the past. The only evidence we have we can use to support ancient astronaut theory are strange artifacts, unexplained feats achieved in the past, and artifacts of suspicous origin.
It is known that primitive humans are intrigued by those who travel through the sky with advanced technologies, and believe them to be gods. In WWII soldiers were stationed on remote islands, the people on these islands were still essentially in the stone age, and reacted to the technologically superior soldiers as being gods. Some scientist believe this may be the foundation for most religions, that aliens with advanced technology being made into gods by primitive man.
Gods are countlessly refered to have come from the heavens in flying machines. Just as astronauts travel to other worlds in space crafts today. From scrolls to ancient clay tablets, their are recordings of gods coming to Earth from space in what could be called space crafts created by many different cultures.
By literally taking ancient mythology and legend you can decipher how they could be communicating that ancient astronauts had visited Earth. Ancient legends describe creatures or gods coming down to Earth on balls of fire launching and landing in crashes of thunder. Aliens visiting Earth in spaceships. Many artistic depictions of ancient legend show what could clearly be interpreted as a spaceship or otherwise compared to a spaceship.
Ancients maps and charts of Earth show a very clear depiction of what certain areas of the world look like from space, the detailed specific nature of these maps is baffling, and it could be believed that aliens could have formed these charts, having been able to see Earth from space.
Many people believe that ancient aliens had to have built many ancient structures, for humans would have taken many years and many more people to be able to construct such structures, more years than in the time periods current historians believe they did. Some structures are created with such percision, that it is believed that only advanced technology could they have been created.
Strange beings, depicted with some human likeness, with qualities of animals, coming to Earth from Space on the outside and inside of ancient structures across the world support Ancient Astronaut theory. Even pictures of these gods within what can appear to be rockets, piloting them into the heavens can be found. The odd shapes of the heads of gods could be attributed to the shape of the ancient astronaut's breathing apparatus.
Many of the creatures or gods are desribed of having supernatural powers, being able to control ancient energies such as mana. Gods are depicted to come from space and visit all over Earth to help the prehistoric humans of Earth. Worshipped by the men the Gods became legend that we now read today.
Modern technology found long ago, dating back thousands of years before invention, brings up questions of ancient astronauts. Signs inscribed in deserts that lead to landing strips that date back thousands of years ago, signs unrecognizeable from the ground, they were made for air travel. Air ports for ancient astronauts, located in desserts.
"Chariot of the Gods" by Erich von Däniken