If observed on other planets, the phenomenon might also give clues to the shape of the Sun’s magnetic field as it curls around other bodies in the solar system.
Lilensten and his colleagues observed weak polarization of a red glow that radiates at an altitude of 220 kilometers. The glow results from electrons hitting oxygen atoms. The scientists had suspected that such light might be polarized because Earth’s magnetic field at high latitudes funnels the electrons, aligning the angles at which they penetrate the atmosphere.
Fluctuations in the polarization measurements can reveal the energy of the particles coming from the Sun when they enter Earth’s atmosphere, Lilensten notes. The intensity of the polarization gives clues to the composition of the upper atmosphere, particularly with regard to atomic oxygen. link
Ref: Polarization in aurorae: A new dimension for space environments studies. 2008. Jean Lilensten et al. GEOPHYSICAL RESEARCH LETTERS, VOL. 35, L08804