The 1967 treaty that bars national appropriation of outer space and celestial bodies, keeps states responsible for their private space activities, and limits military use of the Moon and other bodies.
In more detail
Formally the Treaty on Principles Governing the Activities of States in the Exploration and Use of Outer Space, it entered into force on 10 October 1967 and had 118 States Parties on 1 January 2026. Article II rules out sovereignty claims; Article VI requires authorisation and supervision of private actors; Article VIII leaves jurisdiction over launched objects with the state of registry.