From The New York Times:
Fifty years ago, before most people living today were born, the beep-beep-beep of Sputnik was heard round the world. It was the sound of wonder and foreboding. Nothing would ever be quite the same again — in geopolitics, in science and technology, in everyday life and the capacity of the human species.
The Soviet Union had launched the first artificial satellite, a new moon, on Oct. 4, 1957. Climbing out of the terrestrial gravity well, rising above the atmosphere and into orbit, Sputnik crossed the threshold into a new dimension of human experience. People could now see their kind as spacefarers. Their enhanced mobility might someday prove as liberating as the first upright steps of hominid ancestors long ago.
More here.