I. Every object in a state of uniform motion tends to remain in that state of motion unless an external force is applied to it. They say the earth keeps spinning because it started spinning and now there is no external force applied to it to stop it. The Sun is an external force. I actually believe that only Stars can make bodies of mass spin. Hence the Earth and other planets like Jupiter have their satellites in a locked position(not spinning). Why doesn't the Sun keep the Earth in a locked position like the Earth keeps the Moon in a locked position? or like Jupiter keeps its satellites in a locked position?