An early port of Partiview for OS X has been announced by the American Museum of Natural History. Partiview is a very cool planetarium program that is part of their Digital Universe project.
The gui is still primitive and you may want to avoid it if you aren't comfortable with the command line, but this will be a neat thing in the schools and for amateurs.
http://tingilinde.typepad.com/starst...iew_for_o.html