The purpose of this article is to explore the challenging context surrounding the non-appropriation principle as recent developments in space law take an unexpected turn towards accelerated commercialization and blurring ethical principles. By analyzing the reinterpretation of the “res communis” regime of outer space, the reader understands that this regime is in transition and gradually slides towards private property rights and trends despite the non-appropriation principle. This raises questions as to competition law rights between private stakeholders (firstcomers vs newcomers) and potential monopolies restricting access to critical resources and services. Such commercial activity must further be closely monitored since it might involve modifying the core identity of a celestial body per se, as in the case of terraforming. Space ethics could provide guidance against such scenarios until an appropriate regulatory regime is agreed upon at the international level. Last, proper antitrust regulation is vital for a prosperous Mars settlement.