When was the first artificial Earth satellite launched?

The codename for this satellite is “The simplest satellite-1”. It was called “PS-1” for short. It was launched into orbit a long time ago, specifically on the fourth of October one thousand nine hundred and fifty-seven. It was launched from the Baikonur cosmodrome. But then it was also called “Tyura-Tam”. The authorities of the Soviet Union renamed the cosmodrome in order to hide its location. After all, the city of Baikonur is not very close to the cosmodrome. Well, the first artificial Earth satellite completed its flight on January 4, 1958.