When I was young I really wanted to see this movie. I never did, nor did I read the book all the way through, though mom had it in the home library. I did like a lot of the pictures. As a kid, I wanted to believe in these things. Seeing it now older eyes, I am more annoyed by it than anything. It send the trend for all the "In Search of.." movies that followed, mostly from good ol' Sun Classics, in which they talk a lot about sea monsters, yetis, UFOs and the like and NEVER once find any real evidence to prove such things existed. By age 10i think I knew everything any of these types of movies would say, as most of them covered the same ground as the rest of them.
And yet I never stopped watching them. How many of them did Peter Graves end up hosting? I didn't hate them by any means, but they always seemed to promise things and then never delivered. Not once did they find true evidence to back up any of the claims the movies actually sort of made.
And this one is REALLY boring. It also has a dopey early 70s soundtrack that is also quite distracting from Rod Serling's decent narration. It apparently was shown on TV in 1973 as "In Search of Ancient Astronauts" which is credited with starting the fun "In search of..." series.
Time has not been kind to this movie, since most of the claims can be proven false now, or already have been. The moa on Easter Island, for one example. The Pyramids of Egypt for another. It mostly serves as a warning that a good marketer will make money off people who want to believe these things exist and have happened. I'm not saying this planet has never been visited by aliens, but there's sure no proof in this movie. I'm glad I didn't see it as a kid.
It is still better than THE LATE, GREAT PLANET EARTH, and even at 88 minutes I want my time back.