  We study at the microscopic level the dynamics of a one-dimensional
gravitationally interacting sticky gas. Initially, N identical particles of
mass m with uncorrelated, randomly distributed velocities fill homogeneously a
finite region of space. It is proved that at a characteristic time a single
macroscopic mass is formed with certainty, surrounded by a dust of non
extensive fragments. In the continuum limit this corresponds to a single shock
creating a singular mass density. The statistics of the remaining fragments
obeys the Poisson law at all times following the shock. Numerical simulations
indicate that up to the moment of macroscopic aggregation the system remains
internally homogeneous. At the short time scale a rapid decrease in the kinetic
energy is observed, accompanied by the formation of a number sqrt(N) of
aggregates with masses sqrt(N).
