  In contrast to molecular gases, granular gases are characterized by inelastic
collisions and require therefore permanent driving to maintain a constant
kinetic energy. The kinetic theory of granular gases describes how the average
velocity of the particles decreases after the driving is shut off. Moreover it
predicts that the rescaled particle velocity distribution will approach a
stationary state with overpopulated high-velocity tails as compared to the
Maxwell-Boltzmann distribution. While this fundamental theoretical result was
reproduced by numerical simulations, an experimental confirmation is still
missing. Using a microgravity experiment which allows the spatially homogeneous
excitation of spheres via magnetic fields, we confirm the theoretically
predicted exponential decay of the tails of the velocity distribution.
