  In the solar neighborhood, where the typical relaxation timescale is larger
than the cosmic age, at least 10\% to 15\% of Sun-like stars have planetary
systems with Jupiter-mass planets. In contrast, dense star clusters,
charactered by frequent close encounters, have been found to host very few
planets. We carry out numerical simulations with different initial conditions
to investigate the dynamical stability of planetary systems in star cluster
environments.
