  Meteor showers on the Earth occur at well known times, and are associated
with the decay of comets or other minor bodies whose orbital paths pass close
to the Earth's trajectory. On the surface, determining the closest proximity of
two orbital paths appears to be a computationally intensive procedure. This
paper describes a simple geometric method for determining the proximity between
the orbital paths of two bodies (i.e., a comet and a planet) in the solar
system from the known ephemerides of the objects. The method is used to
determine whether or not meteor showers on other planets in the solar system
could be associated with any of 250 known comets.
