  Recent Pan-STARRS data show that the leading arm from the globular cluster
Palomar 5 (Pal 5) appears shorter than the trailing arm, while simulations of
Pal 5 predict similar angular extents. We demonstrate that including the
spinning Galactic bar with appropriate pattern speeds in the dynamical modeling
of Pal 5 can reproduce the Pan-STARRS data. As the bar sweeps by, some stream
stars experience a difference in net torques near pericenter. This leads to the
formation of apparent gaps along Pal 5's tidal streams and these gaps grow due
to an energy offset from the rest of the stream members. We conclude that only
streams orbiting far from the Galactic center or streams on retrograde orbits
(with respect to the bar) can be used to unambiguously constrain dark matter
subhalo interactions. Additionally, we expect that the Pal 5 leading arm debris
should re-appear south of the Pan-STARRS density truncation.
