The Moon, long an object of fascination and exploration, is now also seen as a place to make money.The big picture: 50 years ago during the Apollo 11 mission, humans were drawn to our nearest cosmic neighbor by scientific curiosity and the desire to demonstrate technological prowess and geopolitical power. But now there’s a financial incentive for the entrepreneurially minded.Companies focusing on "interplanetary" opportunities have received $192 million in investment over the last 10 years, mostly for the development of lunar rovers and landers, according to a new report from Space Angels.The sector is an emerging one in the space industry, which drew about $22.3 billion in investment into 476 space companies during the same time.The pitch: NASA, Jeff Bezos and others envision the Moon as a place to harvest water that can be broken down for rocket fuel and used for missions deeper into space.That fuel, in theory, would eventually be cheaper to make in space than propellant launched from Earth.Platinum and other rare metals could also lie beneath the Moon's surface and potentially be mined in the future.To make that happen, the lunar surface needs to be prospected and infrastructure — roads, launch pads and power — would have to be set up to support permanent human operations.That exploration and development phase is expensive and creates an opportunity for companies.The driver is government money and support. That will likely be the case for at least the next 10–15 years, says industry analyst Carissa Christensen of Bryce Space and Technology. "The interest and intellectual investment in ISRU is more than what you might think based on the bottom line economics of what a lunar economy might be in the near term," she says.What’s happening: NASA — which plans to land people on the Moon by 2024 — is already awarding contracts for the private development of robotic lunar landers and concept studies for landing systems that could help perform research and bring people down to the surface.So far, NASA has awarded one Gateway contract to Maxar to build the propulsion element.The agency is also exploring whether private companies like Lockheed Martin, Boeing and Sierra Nevada can help to build its Gateway — a small station around the Moon that will be used to stage missions down to the surface. Some of the world's top researchers in lunar ISRU — in situ, or on site, resource utilization — outlined what the Moon has to offer in the way of markets and products, at a workshop at the Universities Space Research Association headquarters this week.What they're saying: There are still open questions about what resources are on the Moon, the scale and price point of Moon-made fuel that warrants investment and, aside from governments, what the long-term market would be for products and services.And there are cautionary tales about the difficulties of doing business in space. But optimists like investor Chad Anderson of Space Angels say that market is unlimited. He points to Astrobotic, which received a NASA contract to build a lunar lander, but also has revenue in the form of a sponsorship from DHL and media companies that want to broadcast video from the surface of the Moon.Yes, but: "The mission of ISRU is to sustain life, not make a profit," says Clive Neal, an engineering professor at the University of Notre Dame and organizer of this week's workshop. ISRU's proponents say the real value is its potential role in allowing us to not only take ourselves off our home planet but thrive there, in an entirely new niche for human life. Go deeper: All the Moon landings, from Luna to Apollo to Chang'ePoll: The Moon is a young person's gameWe don’t know how much water is on the MoonBlue Origin details plans to get NASA to the Moon by 2024What's in a moonshotHow NASA's Moon missions got their names