Calling it the biggest loophole in the world doesn’t quite capture its reach: Dennis Hope claims that he owns the moon—and our solar system’s planets—due to what the Outer Space Treaty doesn’t say. Mashablereports the treaty has been the guiding document on space law since 1967, and while it bars any country on Earth from laying claim to a heavenly body, it makes no mention of private companies or individuals doing just that. So Hope formed Lunar Embassy Corp, snatched up the property rights to the moon and more, and has been selling off one-acre lots since. Though Yahoo shines a light on Hope’s offerings (your own piece of the moon will cost just $19.99 an acre; Mars will run you slightly more at $22.49), it’s far from the first time he’s been in the news. He was featured in the documentary Lunarcy!, out last month on Epix, notes the Hollywood Reporter, and he’s talked to media before. As National Geographic previously reported, Hope thinks he has solid ground to stand on: He registered his moon claim with the UN in 1980, and got no answer, which he thinks means it’s a go. And while there’s still plenty of real estate to be had, Hope has sold more than a nominal amount of each: 600 million moon acres (about 7.5% of it) and 325 million Mars acres. He says two former US presidents are landowners as well as 250 “very well known celebrities,” as are two US hotel chains. But Hope does draw the line somewhere: The Apollo landing sites are off-limits.