Abstract

Observations of zodiacal light polarization in the antisolar hemisphere performed by the Helios 1 and 2 spaceprobes were searched for variations and anomalies reported earlier from ground-based photometry. No change in polarized intensity or direction of polarization was found, the upper limit of a few S 10 or a few degrees simply decreasing with improving signal-to-noise ratio, with no obvious lower bound. The polarization pattern was found symmetric to the antisolar point. The angle of polarization is perpendicular to the scattering plane except for the viewing directions closest to the antisolar point (β = ±16°, ∊ = 161°) where there is a tendency for negative polarization. This impressively regular behaviour of zodiacal light polarization leaves no basis for exciting peculiarities and sheds some doubt on the reliability of those observations, which led to such claims.