Subject: Why does the Earth spin on its axis?

I'm the mother of a very curious 5-year-old daughter, who asked me a 
question I cannot answer. She is studying the planets and solar system in her 
Montessori class, and wants to know why the Earth rotates on its axis each day.
 I'm sure that's a subject my teachers covered in elementary school, but I'll 
be darned if I can remember. Can you help?



P.S. Thanks very much for setting up this Web site. I plan to visit it often, 
and will bring along my daughter!

Re: Why does the Earth spin on its axis?