Some orbits more popular than others in solar systems | Science News | Scoop.it
From www.sciencedaily.com - March 19, 2012 1:14 PM

Computer simulations have revealed a plausible explanation for a phenomenon that has puzzled astronomers: Rather than occupying orbits at regular distances from a star, giant gas planets similar to Jupiter and Saturn appear to prefer to occupy certain regions in mature solar systems while staying clear of others.