Abstract
In terms of orbital dynamics, planetary and debris discs in general are very fragile entities. Gravitational interactions with other nearby stars can generate changes in the orbital parameters of planets. The Milky Way has different environments, some of which might generate extreme planetary orbits, diminishing or even removing completely the possibility for habitability. In this work we have studied gravitational effects caused by stellar encounters with the appropriate masses, velocities and stellar densities, representing different Galactic environments, using a simple model of a planetary system (test particle discs).
