  Time-resolved femtosecond x-ray diffraction patterns from laser-excited
molecular iodine are used to create a movie of intramolecular motion with time
and space resolution of $30~$fs and $0.3$ \AA . The high spatial fidelity is
due to interference between the moving excitation and the static initial charge
distribution. This x-ray interference has not been employed to image internal
motion in molecules before. The initial state is used as the local oscillator
for heterodyne amplification of the excited charge distribution to retrieve
real-space movies of atomic motion on \AA ngstrom and femtosecond scales.
Coherent vibrational motion and dispersion, dissociation, and rotational
dephasing are all clearly visible in the data, thereby demonstrating the
stunning sensitivity of heterodyne methods.
