  The presence of gaseous giant planets whose orbits lie in extreme proximity
to their host stars ("hot Jupiters"), can largely be accounted for by planetary
migration, associated with viscous evolution of proto-planetary nebulae.
Recently, observations of the Rossiter-McLaughlin effect during planetary
transits have revealed that a considerable fraction of detected hot Jupiters
reside on orbits that are misaligned with respect to the spin-axes of their
host stars. This observational fact has cast significant doubts on the
importance of disk-driven migration as a mechanism for production of hot
Jupiters, thereby reestablishing the origins of close-in planetary orbits as an
open question. Here we show that misaligned orbits can be a natural consequence
of disk migration. Our argument rests on an enhanced abundance of binary
stellar companions in star formation environments, whose orbital plane is
uncorrelated with the spin axes of the individual stars. We analyze the
dynamical evolution of idealized proto-planetary disks under perturbations from
massive distant bodies and demonstrate that the resulting gravitational torques
act to misalign the orbital planes of the disks relative to the spin poles of
their host stars. As a result, we predict that in the absence of strong
disk-host star angular momentum coupling or sufficient dissipation that acts to
realign the stellar spin axis and the planetary orbits, the fraction of
planetary systems (including systems of hot Neptunes and Super-Earths), whose
angular momentum vectors are misaligned with respect to their host-stars should
be commensurate with the rate of primordial stellar multiplicity.
