Partial Test Ban Treaty in the context of "Comprehensive Nuclear-Test-Ban Treaty"

Nuclear fallout is residual radioisotope material that is created by the reactions producing a nuclear explosion or nuclear accident. In explosions, it is initially present in the radioactive cloud created by the explosion, and "falls out" of the cloud as it is moved by the atmosphere in the minutes, hours, and days after the explosion. The amount of fallout and its distribution is dependent on several factors, including the overall yield of the weapon, the fission yield of the weapon, the height of burst of the weapon, and meteorological conditions.

Fission weapons and many thermonuclear weapons use a large mass of fissionable fuel (such as uranium or plutonium), so their fallout is primarily fission products, and some unfissioned fuel. Cleaner thermonuclear weapons primarily produce fallout via neutron activation. Salted bombs, not widely developed, are tailored to produce and disperse specific radioisotopes selected for their half-life and radiation type.

The anti-nuclear movement is a social movement that opposes various nuclear technologies. Some direct action groups, environmental movements, and professional organisations have identified themselves with the movement at the local, national, or international level. Major anti-nuclear groups include Campaign for Nuclear Disarmament, Friends of the Earth, Greenpeace, International Physicians for the Prevention of Nuclear War, Peace Action, Seneca Women's Encampment for a Future of Peace and Justice and the Nuclear Information and Resource Service. The initial objective of the movement was nuclear disarmament, though since the late 1960s opposition has included the use of nuclear power. Many anti-nuclear groups oppose both nuclear power and nuclear weapons. The formation of green parties in the 1970s and 1980s was often a direct result of anti-nuclear politics.

Scientists and diplomats have debated nuclear weapons policy since before the atomic bombings of Hiroshima and Nagasaki in 1945. The public became concerned about nuclear weapons testing from about 1954, following extensive nuclear testing including the Castle Bravo disaster. In 1963, many countries ratified the Partial Test Ban Treaty which prohibited atmospheric nuclear testing.

Space law is the body of law governing space-related activities, encompassing both international and domestic agreements, rules, and principles. Parameters of space law include space exploration, liability for damage, weapons use, rescue efforts, environmental preservation, information sharing, new technologies, and ethics. Other fields of law, such as administrative law, intellectual property law, arms control law, insurance law, environmental law, criminal law, and commercial law, are also integrated within space law.

The origins of space law date back to 1919, with international law recognizing each country's sovereignty over the airspace directly above their territory, later reinforced at the Chicago Convention in 1944. The onset of domestic space programs during the Cold War propelled the official creation of international space policy (i.e., the International Geophysical Year) initiated by the International Council of Scientific Unions. The Soviet Union's 1957 launch of the world's first artificial satellite, Sputnik 1, directly spurred the United States Congress to pass the Space Act, thus creating the National Aeronautics and Space Administration (NASA). Because space exploration required crossing transnational boundaries, it was during this era where space law became a field independent from traditional aerospace law.