Dennis Hope, self-proclaimed Head Cheese of the Lunar Embassy, will promise you the moon. Or at least a piece of it. Since 1980, Hope has raked in over $9 million selling acres of lunar real estate for $19.99 a pop. So far, 4.25 million people have purchased a piece of the moon, including celebrities like Barbara Walters, George Lucas, Ronald Reagan, and even the first President Bush. Hope says he exploited a loophole in the 1967 United Nations Outer Space Treaty, which prohibits nations from owning the moon.

Because the law says nothing about individual holders, he says, his claim—which he sent to the United Nations—has some clout. “It was unowned land,” he says. “For private property claims, 197 countries at one time or another had a basis by which private citizens could make claims on land and not make payment. There are no standardized rules.”

Hope is right that the rules are somewhat murky—both Japan and the United States have plans for moon colonies—and lunar property ownership might be a powder keg waiting to spark. But Ram Jakhu, law professor at the Institute of Air and Space Law at McGill University in Montreal, says that Hope’s claims aren’t likely to hold much weight. Nor, for that matter, would any nation’s. “I don’t see a loophole,” Jakhu says. “The moon is a common property of the international community, so individuals and states cannot own it. That’s very clear in the U.N. treaty. Individuals’ rights cannot prevail over the rights and obligations of a state.”

Jakhu, a director of the International Institute for Space Law, believes that entrepreneurs like Hope have misread the treaty and that the 1967 legislation came about to block property claims in outer space. Historically, “the ownership of private property has been a major cause of war,” he says. “No one owns the moon. No one can own any property in outer space.”

Hope refuses to be discouraged. And he’s focusing on expansion. “I own about 95 different planetary bodies,” he says. “The total amount of property I currently own is about 7 trillion acres. The value of that property is about $100 trillion. And that doesn’t even include mineral rights.”