How this is possible:
American Dennis M. Hope, spotting a loophole in The Outer Space Treaty of 1967, filed a declaration of ownership for Earth's Moon and the planets Mars, Venus, Mercury, Jupiter, Saturn, Uranus, Neptune, Pluto as well as their respective moons, on November 22, 1980.
This declaration of ownership was initially filed at the San Francisco County offices and then filed with the U.S.A., U.S.S.R., and the General Assembly of the United Nations. A copy of this declaration is included with every property purchased. He has granted MoonEstates.com the exclusive rights to sell extra-terrestrial land in the United Kingdom.