We experimentally obtained a direct image of the nuclear wave functions of
{H_2}^+ by dissociating the molecule via electron attachment and determining
the vibrational state using the COLTRIMS technique. Our experiment visualizes
the nodal structure of different vibrational states. We compare our results to
the widely used reflection approximation and to quantum simulations and discuss
the limits of position measurements in molecules imposed by the uncertainty
principle.Comment: 6 pages, 4 figure