Phase function or flux (top) and degree of polarization (bottom) of incident unpolarized light that has been singly scattered by gas molecules (dashed orange) and the irregularly shaped ring particles (Moreno et al. 2006) (solid blue) as functions of the single-scattering angle Θ (Θ = 0° for forward-scattered light). The fluxes have been normalized such that their average overall scattering directions equal one (Hansen & Travis 1974). Positive (negative) polarization indicates a direction of polarization perpendicular (parallel) to the plane through the incident and scattered-light beams.