On October 4, 1957 the Soviet Union successfully launched the first unmanned satellite in the history of space exploration. Sputnik's launch shocked many around the globe, especially America who saw themselves as technologically superior to the Soviet Union. With this event, the Soviet union was able to get the upper hand in their arms race with the United States. Sputnik proved outer space is reachable by humans.
The embarrassment of the United States after Sputnik galvanized them to launch their own artificial satellite, the Explorer I, on January 31, 1958. The ensuing space race would be one the highest period of scientific research and discovery