Today:
Looking in the east as midnight approaches, the skies host two trios of vertically-aligned stars. To the right or south of east, a familiar trio marks the belt of Orion, rising a little earlier each evening. Meanwhile a temporary trio shines to the left of east, thanks to the pair of stars we call the Twins of Gemini, joined by the slowly brightening red planet Mars on a line directly below them. They reach high in the south by dawn tomorrow.
Wednesday:
As Hallowe’en approaches, look for the star Algol, the “ghoul” that marks the head of the hideous monster Medusa, a great Hallowe’en costume! Look northeast at 7:30, where the brightest star in Perseus, Mirfak appears (not to be mistaken for the brighter Capella below). To the right of Mirfak, a little lower, shines the spooky Algol.
Thursday:
Hallowe’en’s connection to astronomy comes from its position on the calendar, halfway between the Autumnal Equinox and the Winter Solstice. This mid-point, known as a “cross-quarter day”, began the “dark” half of the year for Celtic people, ending on another season’s mid-point, May 1st, or May Day.