Who owns the moon?
Who owns the moon? A space lawyer answers
Did the Stars and Stripes on the moon signify the establishment of an American colony?
Of course, claiming new national territories had been very much a European habit, applied to non-European parts of the world. In particular the Portuguese, the Spanish, the Dutch, the French and the English created huge colonial empires. But while their attitude was very Europe-centric, the legal notion that planting a flag was an act of establishing sovereignty quickly stuck and became accepted worldwide as part and parcel of the law of nations.
Still, the simple answer to the question of whether Armstrong and Aldrin by way of their small ceremony did transform the moon, or at least a major part thereof, into U.S. territory turns out to be “no.” They, nor NASA, nor the U.S. government intended the U.S. flag to have that effect.
Most importantly, that answer was enshrined in the 1967 Outer Space Treaty, to which both the United States and the Soviet Union as well as all other space-faring nations, had become a party. Both superpowers agreed that “colonization” on Earth had been responsible for tremendous human suffering and many armed conflicts that had raged over the last centuries. They were determined not to repeat that mistake of the old European colonial powers when it came to decide on the legal status of the moon; at least the possibility of a “land grab” in outer space giving rise to another world war was to be avoided. By that token, the moon became something of a “global commons” legally accessible to all countries – two years prior to the first actual manned moon landing.