  We study the incompressible limit of solutions to the compressible barotropic
Navier-Stokes system in the exterior of a bounded domain undergoing a simple
translation. The problem is reformulated using a change of coordinates to fixed
exterior domain. Using the spectral analysis of the wave propagator, the
dispersion of acoustic waves is proved by the means of the RAGE theorem. The
solution to the incompressible Navier-Stokes equations is identified as a
limit.
