The Cannibalistic Chaos Within Planetary Systems

Our solar system is well behaved: The set of planets follows near-circular orbits around the sun that don’t cross paths or change much. Even the occasional asteroid collisions are relatively peaceful compared to the havoc that likely exists in some of the more than 3,000 planetary systems discovered in our galaxy to date. Somewhere in the Milky Way, a planet could be headed on a collision course with its host star. 

Migrating Planets