"Ancient Aliens" is one of the best shows on television. When it comes to alien contact, this series seems to hit all the bases from dinosaurs to Hitler's Germany.
What is left behind from these "superior" civilizations are huge stone monuments like the pyramids, Easter Island, Stonehenge and Peru's Machu Picchu. Great tourist spots, but nothing spiritually enlightening .
There is also evidence that a high tech anti gravity device was used to fit the stones in place.
Perhaps, of greater interest were the alien contacts with Moses, Mohammad, Joseph Smith, Tesla, and Nazi Germany.
I've also discovered a website on "The Top Ten Alien Mysteries On Planet".
Without a doubt, there has been prolonged alien interference and manipulation of humans on Earth. Some aliens have supported oppressive dictators who used human sacrifice on a regular basis. Others have manipulated DNA to get more compliant worshipers or warriors. Their track record of helping human beings was poor, no cures for diseases, no techology to feed the poor, no education to bring man out of the dark ages.
Jesus Christ on the other hand restored "The Immortal Spiritual Brotherhood Of Melchizedek (i.e. Christ)" to the level of "The Q Continuum".
Ancient Aliens has never taken their viewers to a higher spiritual level. That would be the only criticism that I have of this superior History Channel Series.
It's good to remember the past no matter how bad it appears.