The first artificial satellite sent into space was Sputnik 1. Launched by the Soviet Union on October 4, 1957, it marked a significant milestone in the space race during the Cold War era. Sputnik 1 was a spherical satellite with four long antennas, and its successful launch signified the beginning of the exploration of outer space. The satellite transmitted radio pulses that could be detected by ground stations, capturing the world's attention and leading to advancements in technology and scientific research. Sputnik 1 is often credited with igniting public interest in space science and exploration, laying the groundwork for future space missions.