  The Centaurs are a population of small, planet-crossing objects in the outer
solar system. They are dynamically short-lived and represent the transition
population between the Kuiper belt and the Jupiter family short-period comets.
Dynamical models and observations of the physical properties of the Centaurs
indicate that they may have multiple source populations in the trans-Neptunian
region. It has been suggested that the inclination distribution of the Centaurs
may be useful in distinguishing amongst these source regions. The Centaurs,
however, undergo many close encounters with the giant planets during their
orbital evolution; here we show that these encounters can substantially
determine the inclination distribution of the Centaurs. Almost any plausible
initial inclination distribution of a Kuiper belt source results in Centaurs
having inclinations peaked near 10-20 degrees. Our studies also find that the
Kuiper belt is an extremely unlikely source of the retrograde Centaur that has
been observed.
