October is the first full month of fall and includes the traditional Halloween holiday. As with numerous other holidays, there are known astronomical connections with it going back beyond the contemporary costumes, jack-o-lanterns and trick-or-treaters.
Halloween is a seasonal holiday, but how did it come to be?
Our four seasons are traditionally marked by the two equinoxes and two solstices. In our modern world, they mark the starting date of our seasons. Equinoxes mark spring and fall and the solstices mark summer and winter. Thus last month, the equinox on Sept. 22 marked the beginning of autumn in the northern hemisphere, and spring in the southern hemisphere.
Lesser known are four other dates midway between the seasonal equinoxes and solstices. These are referred to as “cross-quarter days.” According to Bruce McClure (EarthSky.org), These dates have been handed down to our modern era where they currently are celebrated as minor holidays on Groundhog Day (February 2), May Day (May 1), Lammas (August 1) and Halloween (October 31).
According to LiveScience.com, Ohio State astronomer Richard Poggee traces the origins of Halloween back to civilizations living in the British islands in the pre-Christian era. For the Celts and Druids — not to mention Shinto Japanese as well — these cross-quarter days were not the midpoints of each season. No, quite the opposite was the case. In these ancient cultures, the seasons began on the cross-quarter days and the Equinoxes and Solstices marked their midpoints, in contrast to our currently observed custom.
The Celts celebrated a sacred fall festival known as Samhain, meaning summer’s end. For the Celts, Samhain was like New Year’s Eve. Occurring in late October it was likely also meant to celebrate the harvest.
The Celtic observation is described by Luke Gilkerson (ExperienceAstronomy.com) as occurring like this in the green hills of Ireland: They believed that during…