MacTutor
4th October
On this day in 1957, the Soviet Union launched Sputnik 1, the first artificial earth satellite. It circled the earth every 96 minutes in an elliptical orbit. Pravda noted that
... theoretical work by Nikolay Ivanovich Muskhelishvili has made a fundamental contribution to this great victory.On this day in 2010 Google released a Doodle celebrating the first day of the Gregorian calendar (In fact the first day of the Gregorian calendar was 5th October 1582).