On Oct. 10, 1967, the international Outer Space Treaty was ratified.
This treaty established a set of rules regulating how different countries can explore and use outer space. Specifically, it says "the exploration and use of outer space shall be carried out for the benefit and in the interests of all countries and shall be the province of all mankind." The treaty dictates that no one can claim territory in outer space and that other celestial bodies must be used "exclusively for peaceful purposes." More than 100 countries have ratified the treaty today.