  We consider weak solutions of the spatially inhomogeneous Landau equation
with hard potentials ($\gamma \in (0,1]$), under the assumption that mass,
energy, and entropy densities are under control. In this regime, with arbitrary
initial data, we show that solutions satisfy pointwise Gaussian upper and lower
bounds in the velocity variable. This is different from the behavior in the
soft potentials case ($\gamma <0$), where Gaussian estimates are known not to
hold without corresponding assumptions on the initial data. Our upper bounds
imply weak solutions are $C^\infty$ in all three variables, and that
continuation of solutions is governed only by the mass, energy, and entropy.
