  Circumbinary Planets (CBPs) can be misaligned with their host binary stars.
Orbital dynamics, simulations, and recent observations of proto-planetary disks
all suggest that the planet can stably orbit in a plane perpendicular to that
of an eccentric host binary star (i.e., a polar orbit). No solid claim of
detection of such a configuration has been made; the nine systems detected by
the transit technique are nearly coplanar, but their discovery is also biased
towards that configuration. Here, we develop Eclipse Timing Variations (ETVs)
as a method to detect misaligned CBPs. We find that since apsidal motion
(periastron precession) of the host binary is prograde for a coplanar planet
and retrograde for a polar planet, the mean eclipse period of primary and
secondary eclipses differ in a way that distinguishes those configurations.
Secondly, the Eclipse Duration Variations (EDVs) vary in a way that can confirm
that inference, over and against a polar model. Thirdly, the relative phasing
of primary and secondary ETVs on the planet's orbital timescale also
distinguishes the two configurations, which we explain analytically and
quantify through a grid of numerical models. We apply these methods to
Kepler-34, a transiting planet known to be nearly coplanar by detailed
photodynamic modeling. In this system, we find that the binary eclipse times
alone suffice to distinguish these orbital configurations, using the effects
introduced here. Our work provides a tool for discovering potential polar CBPs,
or misaligned CBPs of milder inclinations, from the existing ETV dataset of the
Kepler, as well as future observations by TESS or PLATO.
