Over the last two decades, there has come about a recognition that chaotic
dynamics is pervasive in the solar system. We now understand that the orbit
s of small members of the solar system-asteroids, comets, and interplanetar
y dust-are chaotic and undergo large changes on geological time scales. Are
the major planets' orbits also chaotic? The answer is not straightforward,
and the subtleties have prompted new questions.