Sputnik 1 ("Elementary Satellite 1") was the first artificial Earth satellite. The Soviet Union launched it into an elliptical low Earth orbit on 4 October 1957. It orbited for three weeks before its batteries died and then orbited silently for two months before it fell back into the atmosphere. It was 58 cm (23 in) in diameter and a polished metal sphere with four external radio antennas to broadcast radio pulses. Its radio signal was easily detectable by radio amateurs, and the 65° inclination and duration of its orbit made its flight path cover virtually the entire inhabited Earth. The satellite's unanticipated success precipitated the American Sputnik crisis and triggered the Space Race, part of the Cold War. The launch was the beginning of a new era of political, military, technological and scientific developments. The name "Sputnik" is Russian for spouse/traveling companion or satellite when interpreted in an astronomical context.