There is nothing better sometimes than discover what my ancestors observed around the Equinoxes as a strange or unusual light at dawn on the Equinoxes -
http://earthsky.org/astronomy-essent...-or-false-dawn
Obviously it is an orbital phenomena but the present explanation is hairy and may disguise something more productive and creative in terms of cause. Of course nobody can, out of laziness or worse, look at the orbital motion of the Earth outside celestial sphere framework thereby making proper assessments impossible - for anything and everything !.
The old farmers and fishermen where I grew up marked the event which is probably lost to many nowadays due to artificial light and perhaps to a lesser degree, a society so enamoured by theoretical junk that these events are buried.