  A gas of inelastic rough spheres admits a spatially homogeneous base state
which turns into a hydrodynamic state after a finite relaxation time. We show
that this relaxation time is hardly dependent on the degree of inelasticity but
increases dramatically with decreasing roughness. An accurate description of
translational-rotational velocity correlations at all times is also provided.
At a given inelasticity, the roughness parameter can be tuned to produce a huge
distortion from the Maxwellian distribution function. The results are obtained
from a Grad-like solution of the Boltzmann-Enskog equation complemented by
Monte Carlo and molecular dynamics simulations.
