I know that we have been to the Moon. So does Buzz Aldrin. But he knows this in a very different way than I do. Aldrin has first hand knowledge of humanity's journey to the Moon, while I must rely on films and books for this knowledge. Aldrin and all the still-living astronauts who have walked on the Moon are in their eighties now, which means that in another couple of decades we can expect to lose, as a species, our first hand knowledge of the Apollo program's accomplishment. We will all then know about it in the same way.
We might say that our knowledge will be "encyclopedic". As Diderot put it,
the purpose of an encyclopedia is to collect knowledge disseminated around the globe; to set forth its general system to the men with whom we live, and transmit it to those who will come after us, so that the work of preceding centuries will not become useless to the centuries to come; and so that our offspring, becoming better instructed, will at the same time become more virtuous and happy, and that we should not die without having rendered a service to the human race in the future years to come.
While I'm sure that my first knowledge of the Moon landing came by word of mouth, my first clear memory of reading about it was in Charlie Brown's Cyclopedia, probably in the fourth grade. I remember very distinctly learning the word "telemetry" in those pages.
Like many boys, I went through a phase of intense interest in space travel. It's strange to consider that, when I was twelve, less time had passed since our last landing on the moon than has now passed since 9/11. I wasn't yet born when Neil Armstrong took his first steps on it, but I was almost two years old when Eugene Cernan took the last step off it. And yet, by the time I was reading about it in the early 1980s, it already seemed part of a distant, almost mythological past. It probably didn't seem that way to my parents, who were in their mid thirties.
Yet somehow, the "space age" never really materialized. Instead of pushing an ever-widening frontier of human exploration outwards, rockets and shuttles have been used mainly to install and maintain an ever-growing network of satellites in Earth's orbit, for research, communications, and surveillance purposes. Part of "knowing" that we went to the Moon is knowing that we soon stopped going there, and that we haven't been back in over four decades. Knowing about the Apollo missions is like knowing about the Vietnam war. Though it has a profound legacy, it's a thing of the past.
Imagine how different it would be if there had been two missions to the Moon every year since 1969. We'd be fast approaching the 100th mission. There would no doubt be permanent structures up there by now, and perhaps crews that worked there as long as they now do on the International Space Station. Knowing that we can get to the moon would feel very different than it does today. It would be part of our active experience.
Sadly, this shared experience would almost certainly include tragedies in which lives were lost. Exploring the Moon is not a low risk activity, after all. Nor would it have been cheap. As far as I can tell, it cost around half a billion dollars in 1972 to carry out a single moon mission. That's a 1 billion dollar annual budget for two missions. Today, we'd be spending 5 or 6 billion dollars a year keeping the program going, all things being equal. And they wouldn't be. Imagine an Apollo program that runs for 40 years, developing new technology and discovering the potential of the Moon's resources. When I was a kid, that's exactly what I was imagining. That image was part of the knowledge that was in circulation. It was what I was learning.