Ask A Scientist© Astronomy Archive

Author:      rick kiper
Why does Venus rotate in a direction opposite the other planets?

Response #:  1 of 2
Author:      samuel p bowen
Class, this is a very good question.  There is no good reason for the direc-
tion of rotation of any of the planets except what the motion of the matter
locally that formed the planet was.  It is actually surprising that so many
of the other planets have similar rotations directions.  Since there are
only very small forces that slow planets down, the rotations we see tell us
something about the early motion of the matter in the local region.  It is
really fun to ask interesting questions.  This is what scientists spend most
of their time doing.  Keep up the good work.  

Response #:  2 of 2
Author:      daniel n koury jr
The latest ideas I have read about are that planets from dust particles and
similar things hitting each other and sticking together till they get bigger
and bigger.  A planet like Venus probably got to be it is present size from
the collision of smaller "planets".  The last two small planets to collide
in forming the planets we see today determine it is rotation by how they
happen to hit each other.  This is the best idea we have right now, but
maybe someday you or someone like you will come up with a better one.