This contribution analyses the gap left by Article VIII of the Outer Space Treaty in matters involving ownership of objects created on celestial bodies and suggests leveraging the Roman law principle of specification to bridge it. Article VIII provides a clear provision: “ownership of objects launched into outer space, including objects landed or constructed on a celestial body, and their component parts is not affected by their presence in outer space or on a celestial body …”. Ownership of an object created in space is therefore possible as long as its ownership was established on Earth. Unfortunately, it leaves open the crucial question for space activities of ownership of objects made of local resources like lunar soil, which have legally no owner. In this case, the specification principle, which has broad application through most national (terrestrial) legal orders, can provide a regime of ownership by stating that created objects belong to the creator when created out of another’s article.