It was rather difficult to find the Nielsen figures back in 2005, since in the 1970s there was much less coverage of the Nielsen ratings than today, and I wasn’t able to find a listing for the January 5, 1973 10 P.M. Nielsen ratings—which, due to the slowness of data collection back then, were not be published until several weeks after the fact. Just guessing what day a newspaper might have chosen to report the ratings (typically about two weeks later) is confusing, made worse by the fact that most versions of the Nielsen ratings published then recorded only regularly scheduled recurring shows, not one-off specials.
Anyway, it turns out that the Columbia Journalism Review reported the ratings figures for In Search of Ancient Astronauts in a 1977 piece blasting NBC for foisting biased pseudo-history on an unsuspecting American public. According to Timothy Hackler, 28 million Americans watched In Search of Ancient Astronauts in its first airing, with millions more seeing the program over the next few years, after it was syndicated to local television stations in the lead up to the launch of its spin-off, In Search Of.... Its first-night ratings were about the same as the viewership for Sanford & Son, which aired earlier the same night, and it had more viewers than the Wonderful World of Disney. Hackler went on to report that within 48 hours of the program’s broadcast, Bantam Books had sold 250,000 new copies of Chariots of the Gods.
Those are astonishing numbers by any account, but in 1973 they are close to dumbfounding. In 1973, the U.S. population was 212 million people, which means that 13% of all Americans watched the show, and of that audience, one out of every 100 viewers bought the book within 48 hours of the special’s airing. And it aired at 10 P.M. on a Friday night, which even in the 1970s was one of the lower-rated network time slots. That night, the special aired opposite Love, American Style and a 1966 Steve McQueen movie, The Sand Pebbles.
Those numbers really put in perspective the sheer impact that In Search of Ancient Astronauts had in legitimizing the ancient astronaut theory, something that later documentaries and books were not able to replicate. Ancient Aliens, for example, peaked with a weekly audience of 2.2 million viewers in 2011, in a country of 312 million people—0.7% of the population. For the History Channel, that was a huge hit, but it pales in comparison to its predecessor.
Hackler’s piece does a good job of summarizing the sheer violation of ethical norms expected of broadcast television in the 1970s, when it was still shocking to image that anyone would purposely lie on television or leave out part of the story:
NBC has defended its part in the hoax on the grounds that the programs were channeled through the entertainment rather than the news division. But this does not appease NBC’s critics. Ronald Story, author of The Space-Gods Revealed, which was published last year and which systematically debunks van Daniken, has said: “I have a big complaint with the movie and TV producers. They’ve said, in effect, ‘This is fact.’ They’ve presented it as truth. It should have been labeled science fiction.”
William D. Carey, executive director of the [American Association for the Advancement of Science], said in an interview that his organization may establish regional panels to monitor and comment upon science programming. Carey said he was not familiar with the "ancient astronaut" shows, but that an A.A.A.S. committee would scrutinize communications law toward "the possibility of intervening in the licensing of stations" that consistently present inaccurate or deceptive science programs.
By the 1990s, NBC and ABC could both air documentaries that were out and out pseudoscientific propaganda--The Mysterious Origins of Man, The Mystery of the Sphinx, and Chariots of the Gods Revisited—to popular acclaim and critical attack, but with diminishing results. Mysterious Origins of Man, the most successful of the shows (in terms of impact, not ratings), attracted 20 million viewers on NBC both times it aired in 1996, but that was 20 million against a population of 269 million people, just 7.4% of the population, only about half of what In Search of Ancient Astronauts brought in two decades earlier. Mystery of the Sphinx, in 1993, attracted 33 million viewers, around 12% of Americans and closer to the 1973 viewer haul. However, thanks to the rise of the internet, email had made the voices of those in the audience who opposed the message of Mysterious Origins that much louder. Whereas people in 1973, or even 1993, had to take time to write a physical letter and mail it to NBC, the internet meant that this layer of effort was no longer necessary. The Boston Globe reported in 1997 that the producer of the show kept a three-inch-thick binder crammed with printed out copies of the emails he received, outraged that network TV would show such programming:
“Have you no shame?” one asks. Another calls their show a “national embarrassment.” Other messages use these terms: a “steamy pile of rodent remains,” “hooey,” “claptrap,” “drivel.” The [producers] are called “greedheads,” “disgusting panderers,” and “ratings whores.”
That’s perhaps the most insidious thing: There is now so much junk science on TV and expectations have fallen so low, that we now expect such programs to be pandering frauds. And this carries over into other media as well. No one even raised an eyebrow when Ancient Aliens pundit Linda Moulton Howe claimed this week that intelligence agencies are tracking her every move and that extraterrestrials, who secretly control our government, have “resurrection technology” and are reanimating the dead (like in Plan 9 From Outer Space) in order to keep the multiverse from collapsing. Twenty or forty years ago, someone like that couldn’t make those claims and be taken seriously on television; today it’s practically a requirement to hold similar ideas if you want to be on cable TV.