On July 20, 2019, a half-century will have passed since Apollo 11 astronauts Neil Armstrong and Edwin “Buzz” Aldrin became the first humans to walk on the moon. More than just an excuse to celebrate an epochal achievement, the 50th anniversary is also an opportunity to reflect on the Apollo program’s complex origins and legacy—and on how lunar exploration in general has changed our understanding not only of the moon, but also of Earth and ourselves.

To that end, a huge number of commemorative media and memorabilia are already appearing on screens and shelves around the world, with even more to follow in coming months. Of the books in this overwhelming flood, one stands out for the understated elegance of its prose and the profoundly wide-angle view it offers of its subject: Oliver Morton’s The Moon: A History for the Future. Only one of the book’s eight chapters is explicitly devoted to the Apollo missions, but the tome, in its entirety, places humanity’s lunar forays into new, thought-provoking contexts guaranteed to surprise and delight even the most knowledgeable space buff.

Scientific American spoke with Morton, a writer and editor at the Economist, about the motivations for future lunar voyages, how to responsibly conduct them and why the moon should make us all reconsider what it means to live on Earth.

[An edited transcript of the conversation follows.]

Why write this book right now? Is it just the 50th anniversary of the first human lunar landing, or is it more than that?

It’s two things. The 50th anniversary of Apollo 11 is important, particularly for people like me in their mid-50s, because it’s quite remarkable to realize that of all the things we thought back then about the extraordinary future, one thing we didn’t think about was that by 1972 human journeys to the moon would be over and that no one would go back. But the other thing, of course, is that it’s quite clear now that people are going to go back. I believe there are more people on Earth today who will walk on the moon than who have walked on the moon.

There are many proffered reasons for going back: doing interesting science or the possibility of using resources there. And of course, there’s the matter of “great power” geopolitics and the symbolism involved in being there, overhead in the skies of everyone on Earth. I don’t exactly applaud that, but I can see the reality of it. But when it comes down to it, the real reason for going back is that people in general have more power now, and getting to the moon is less difficult than it used to be. In the 1960s it took the supreme efforts of the world’s preeminent superpower to put people on the moon. And that’s just not the case anymore. The attitude is shifting from being “Why go to the moon?” to “Hey, why not?”

So it’s worth thinking again about what it is that the moon means to people and what it could come to mean to people as we return.

Well, what does the moon mean to you? You discuss the spectrum of attitudes toward the moon a great deal in the book: Some people want the “sky moon”—just something to see in the sky. Others want the “rock moon,” an object to be scientifically studied or mined for resources. Or “a moon that is at one with their Earth,” a place one might routinely visit that, although exotic, is really not so out of this world. Which moon do you want?

I am somewhat confused about the moon. But I think what most fascinates me about the moon is its sheer unworldliness, the way it makes you think about [what] it is to be a world like Earth, and [what] the moon is deprived [of]. Thinking about the moon hard made me realize how extraordinary it is that on Earth, if you put something down, Earth will move it away from you—wind will blow it away, rain will wash it away. Eventually, a mountain range will rise up, or a sea will open, and that something will tumble down. On the moon—unless it’s unhappy enough to be at ground zero for another asteroid strike—you put something down, and it stays down. Nothing much happens. The lack of anything on the moon really puts one’s sense of what it is to be a “world” into question. A question that simply speculating about one’s feet on the moon, or about the moon becoming something other than a rock in the sky, doesn’t quite reach.

Earlier this year, Vice President Mike Pence announced NASA is going to somehow get U.S. astronauts back to the lunar surface by 2024. What do you think about that? Who do you think will be there next, and when and why?

What I think is that things are moving considerably faster than I would have expected when I began writing this book! I believe the next people to land on the moon will probably be American. Quite how they’ll do so, I’m not sure. It’s fairly unlikely that NASA will do it by 2024, as Pence suggested, partly because NASA has various handicaps in the “resource” sense of the word—it is carrying unnecessary weight in terms of being required to use a very large, very expensive, as yet unfinished NASA-developed booster, the Space Launch System, rather than alternatives such as SpaceX’s Falcon Heavy or perhaps the new rocket being developed by Jeff Bezos’s Blue Origin, the New Glenn. And I think that's a genuine problem for NASA, as well as this idea of building a little space station—the lunar Gateway—around the moon before going back down to the surface, which is not something that has a great deal of support outside of NASA and the contractors who are building this thing.

Meanwhile the Chinese seem to be planning to go, too, but they are in no rush. It would be a significant effort, and I think China sees human lunar landings as something that would just be “nice to have.” But China’s interest kind of forces America’s hand, in that there is a symbolism to being the first on the moon that is lost if someone else goes up there, and you’re not there, too. There’s a real aspect of “great power” rivalry here.

One thing I enjoyed about the book was your unflinching discussion of the profound social inequalities often associated with space exploration. You grapple with a perennial criticism of the Apollo program—that it was an overly expensive distraction from more pressing problems on Earth. And you write about how those missions and the prosperity that made them possible in the first place are inseparable products of historical injustices, from the obliteration of Native American populations to the slave trade.

Yes, it’s important to remember that Apollo was not universally popular, even among Americans, even at the time. I suppose the most famous example is Gil Scott-Heron’s song “Whitey on the Moon.” You know, “A rat done bit my sister Nell, with Whitey on the moon.” Hugely though I respect NASA’s astronauts of the 1960s and 1970s, they were all middle-aged white men, mostly from the officer class—that’s not “humanity” as the term is usually construed! One uncontestably interesting thing about a return to the moon is the opportunity it presents for more of “humanity”—women, people of color, people of developing nations, people of a wider range of ages, and so on—to actually go there.

And the idea that Apollo was a distraction from Earth is quite a strong one, particularly in the context of global ecological change, climate change especially. But being able to go into space helped alert people to those problems. At the same time, if all you can do with the moon is watch Earth heat up from a distance, that’s not so great. One could argue, and I might, that sending humans to the moon is still too expensive—but it’s a tiny fraction of what we spend on many other things, and what we should be spending on problems such as climate change. If I had to choose between spending really effectively on climate change or spending profligately on missions to the moon, well, I’d be hard-pressed to choose the moon. But I don’t think that’s really the choice the world is facing at the moment. I don’t think the costs of human missions to the moon and of dealing with climate change are remotely of the same scale.

Somewhat relatedly, then, do we need to be concerned about protecting the environment of the moon? If so, how?

I’d like people to plan and perform their lunar missions in ways that don’t leave behind a terrible amount of mess. At the same time, the amount of mess that humans could make on the moon, compared with the messes we can and do make on Earth, is always going to be absolutely trifling. For the time being, I’d certainly suggest that people avoid visiting the obvious heritage sites, such as the Apollo 11 and Apollo 17 landing locations.

The situation has become more complex since the days of Apollo, though, because there’s now a strong consensus that interesting volatiles—water ice, in particular—are stored in shadowed craters at the moon’s poles. That water ice could be used for, among other things, producing rocket fuel, which has many people excited. I’d like to see some discussion of an international agreement to cover the use of those potential resources, because right now, I don’t believe there are any meaningful constraints on what anyone can do with them. I wouldn’t want anything needlessly punitive, and we don’t need every molecule of ice that’s ever settled in a crater to be preserved as is. But the discussion is important, because we don’t really know yet the extent of the water-ice deposits there, and we also don’t know the trade-off between using them as a physical resource versus using them as a scientific resource. We have no real sense yet of what information from lunar and even earthly history is stored in those ices.

Speaking of science, what do you think would be the most compelling scientific reason to go to the moon now?

To me, the most compelling thing is the possibility of finding samples from the very early Earth on the moon. Some scientists have called the moon “Earth’s attic,” because for billions of years, it has been collecting material ejected from our planet by impacts and other processes. The arguments for all this remain somewhat theoretical, but there really should be quite a significant number of extremely old Earth rocks up there, on the lunar surface, from parts of our planet’s history we can’t otherwise directly study. Similarly, there might be a much smaller amount of rocks from early Venus there, from back when that world may have been much more Earth-like, which would be really fascinating to study. And frankly, it’s much easier to gather up and sort through moon rocks by the ton than to retrieve any rocks at all from present-day Venus, the surface of which is very hard to get to and even harder to return from.

I also find something poetic and scientific about the notion of doing radio astronomy from the moon’s far side, which, because it always faces away from Earth, is the only place within light-years where such observations could be unaffected by our planet’s electromagnetic babble. There are radio-based studies of the early universe that, at the moment, scientists can only imagine performing from that vantage point. Most of my thinking about the moon involves using it to gaze back at, and better understand, Earth, so the idea that it could be a platform for looking farther out to the universe’s beginnings is one that similarly pleases me.