Water on MarsAlmost all water on Mars today exists as ice, though it also exists in small quantities as vapor in the atmosphere. What was thought to be low-volume liquid brines in shallow Martian soil, also called recurrent slope lineae, may be grains of flowing sand and dust slipping downhill to make dark streaks. While most water ice is buried, it is exposed at the surface across several locations on Mars. In the mid-latitudes, it is exposed by impact craters, steep scarps and gullies.
Impact eventAn impact event is a collision between astronomical objects causing measurable effects. Impact events have physical consequences and have been found to regularly occur in planetary systems, though the most frequent involve asteroids, comets or meteoroids and have minimal effect. When large objects impact terrestrial planets such as the Earth, there can be significant physical and biospheric consequences, though atmospheres mitigate many surface impacts through atmospheric entry.
CORONA (satellite)The Corona program was a series of American strategic reconnaissance satellites produced and operated by the Central Intelligence Agency (CIA) Directorate of Science & Technology with substantial assistance from the U.S. Air Force. The CORONA satellites were used for photographic surveillance of the Soviet Union (USSR), China, and other areas beginning in June 1959 and ending in May 1972. In 1957, the Soviet Union launched Sputnik 1, the first artificial Earth satellite.
Cold WarThe Cold War was a period of geopolitical tension between the United States and the Soviet Union and their respective allies, the Western Bloc and the Eastern Bloc. The term cold war is used because there was no large-scale fighting directly between the two superpowers, but they each supported opposing sides in major regional conflicts known as proxy wars. The conflict was based on the ideological and geopolitical struggle for global influence by these two superpowers, following their roles as the Allies of World War II that led to victory against Nazi Germany and Imperial Japan in 1945.
