  Previous studies of cometary impacts in the outer Solar System used the
spatial distribution of ecliptic comets (ECs) from dynamical models that
assumed ECs began on low-inclination orbits (<5 deg) in the Kuiper belt. In
reality, the source population of ECs - the trans-Neptunian scattered disk -
has orbital inclinations reaching up to ~30 deg. In Nesvorny et al. (2017), we
developed a new dynamical model of ECs by following comets as they evolved from
the scattered disk to the inner Solar System. The model was absolutely
calibrated from the population of Centaurs and active ECs. Here we use our EC
model to determine the steady-state impact flux of cometary/Centaur impactors
on Jupiter, Saturn, Uranus, and their moons. Relative to previous work (Zahnle
et al. 2003), we find slightly higher impact probabilities on the outer moons
and lower impact probabilities on the inner moons. The impact probabilities are
smaller when comet disruption is accounted for. The results provide a modern
framework for the interpretation of the cratering record in the outer Solar
System.
