Post #3501

The rotation rates of the planets around their axis relative to the stars (sidereal days) 🌍 Planets rotate because they were formed from moving material. Momentum must be conserved, so the planets acquired their own rotation. The bigger the planet, the more material it took to create it. And the more material, the greater the rate of rotation. (Note the rotation rate of Jupiter, Saturn). © James O'Donoghue