We left footprints, flags, and flotsam and jetsam on the moon, but something we did not leave is an economy. Private companies and governments are now hard at work to change that.

This week on “Marketplace Morning Report,” we’re sharing multiple views on an emerging lunar economy, how it might work, and if it's even a good idea. We’re launching the mini series with Matt Weinzierl, an economist and senior associate dean for faculty development and research at the Harvard Business School. He’s also co-author of “Space to Grow: Unlocking the Final Economic Frontier.”

Weinzierl recently discussed the present and future moon economy with Marketplace’s David Brancaccio. The following is an edited transcript of their conversation.

David Brancaccio: So there's a space economy that's taking off, as it were, burgeoning, but there's no moon economy yet. Does it look like the moon's going to get one, you think?

Matt Weinzierl: There's certainly reasons to go to the moon that go back to national prestige, national security, some of the reasons we've always gone to space. There are some particular areas of the moon that are particularly valuable for doing more things in space, which is part of what we're trying to do. Those areas have water ice or continuous exposure to the sun for solar energy. But the new thing, and it may be part of what you're getting at, is that some companies are raising money to go actually do things on the moon for profit, whether it's mining the lunar soil or providing services to other customers on the lunar surface. And that's really what's the big change in space for the last couple decades is this rising commercialization.

Brancaccio: Yeah, I saw there's a company called Interlune that has a contract to deliver three precious liters of helium-3. So, I mean, that starts to sound like mining, but we're already talking private sector here. This won't be like the people who got to the moon in the first place with humans — the U.S. government ran that program.

Weinzierl: Yes, that's right, and it's actually a pretty nuanced story. And so I think it's important maybe for your listeners, too, to know that this is not really about the privatization about the space economy. It's really, we like to talk about it as the commercialization. So it's not that the government's getting out of space. Government is still likely to be the main customer, especially for risky and difficult things like creating a permanent presence on the moon. But what is interesting is that they've brought in a whole set of market forces to those relationships, and, as part of that, the government's been encouraging companies that help provide the public services in space to also develop commercial customers on the side.

Brancaccio: What they found up there was a lot of moon dust. It's called regolith. That's not in short supply on the moon, and there are companies looking at if you could turn it into something valuable, what might be done with it?

Weinzierl: That's right. And, you know, I think the general lesson there too is that, as we open up these possibilities, ideas come from sort of everywhere. That's part of the beauty of the market. You get startups and their backers willing to take longshot bets on ideas that might seem sort of impractical, but, you know, mining the moon, mining asteroids is an idea humans have had for as long as we've been going to space. It is now legally acceptable, as well, based on some relatively recent U.S. law. So it might be in our future, sooner than we would expect.

Brancaccio: U.S. law — I mean, there would be critics who would say, "Do we get to decide, as Americans?"

Weinzierl: The governing space treaty — the governing international law for space is called the Outer Space Treaty — passed in 1967, and it's very clear that countries cannot claim sovereignty over any territory in space or any celestial object. But it's not as clear on whether companies or countries can claim a property right over resources in space, and the United States unilaterally passed legislation in 2015 giving U.S. companies the right to claim just such property rights. And that, of course, was controversial, and probably remains controversial among many, but other countries have adopted similar legislation, and we'll see, of course, once people actually do start mining these resources, how that all plays out.