Ask A Scientist© Astronomy Archive

Author:      mark
Why does the Earth spin?  What makes it spin?

Response #:  1 of 1
Author      jasjeet s bagla
Earth spins because (presumably) the cloud from which it condensed had some
rotation.  As it condensed, it spun up because something called the angular
momentum is conserved.  If you pour some water in to a sink, you would have
noticed that it spins up as it approaches the outlet, this is another
example of spinning up.  If a body is spinning then it must keep on doing so
forever, unless some force acts on it.  That is why the Earth keeps on
spinning - you do not need a force to keep it going.