Ancient Astronauts - Did Real Aliens Mold Our Civilization?

There are many people, some scientists included, who believe firmly that our civilization as we know it was influenced by ancient encounters with extraterrestrial life. In 1966 a book entitled "Intelligent Life in the Universe" was published. It was written by two astrophysicists named I.S. Shklovski and Carl Sagan. It stated that "scientists and historians should seriously consider the possibility that extraterrestrial contact occurred during recorded history. The scientists argued that "sub-light speed interstellar travel by extraterrestrial life was a certainty when considering technologies that were established or feasible in the late '60s that repeated instances of extraterrestrial visitation to Earth were plausible" This of course, sparked much controversy.