The Agreement Governing the Activities of States on the Moon and Other Celestial Bodies, commonly called the Moon Agreement or Moon Treaty, was adopted by the UN General Assembly on 5 December 1979 and entered into force on 11 July 1984 after its fifth ratification. It is the last of the five core UN space treaties developed through the Committee on the Peaceful Uses of Outer Space (COPUOS).
The agreement extends and elaborates principles from the 1967 Outer Space Treaty. Key provisions include:
- Peaceful use: The Moon must be used exclusively for peaceful purposes; military bases, weapons testing, and the placement of nuclear or other weapons of mass destruction in lunar orbit or on the surface are prohibited.
- Non-appropriation: Neither the surface nor the subsurface of the Moon, nor any part of it or natural resources in place, can become property of any state, organization, or person.
- Common heritage of mankind: Article 11 declares the Moon and its natural resources the common heritage of mankind and calls on states parties to establish an international regime to govern the exploitation of those resources when such exploitation is about to become feasible.
- Scientific freedom and transparency: States must inform the UN Secretary-General of activities and share scientific results.
The treaty is widely considered a failed instrument because none of the major spacefaring powers — the United States, Russia, China, Japan, India, or the United Kingdom — are parties. Its ratifying states are mostly non-spacefaring, which limits its practical force. France has signed but not ratified.
The "common heritage" clause is the central reason for non-accession: spacefaring states and private industry view it as incompatible with commercial resource extraction. National laws such as the US Commercial Space Launch Competitiveness Act (2015) and the Artemis Accords (2020), which permit private appropriation of space resources, represent an alternative legal direction that several states are now pursuing instead.
Example
In 2020, Saudi Arabia withdrew from the Moon Agreement — becoming the first state party to do so — shortly before the Artemis Accords on lunar resource use were opened for signature.
Frequently asked questions
They object to Article 11's 'common heritage of mankind' principle, which they argue would require an international regime to govern and share lunar resources, conflicting with national and commercial extraction plans.
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