Join me tonight for the Great World-Wide Star Count

The usual conception of Halloween will includes a full moon, a witch, a black cat or a Jack-o-lantern. Not to burst your bubble but Halloween rarely sports a full moon. In fact the next Halloween to have a full moon won't be until the year 2020.

A better item to associate with Halloween would be the Pleiades star cluster. How could a small star cluster be associated with the spookiness of Halloween you ask?

In ancient times, many cultures around the world, including the Aztec and Mayan civilizations in Mexico and Central America, the Celts in England, and others around the world would set aside a day where the dead were honored and great ceremony was held concerning them.

That day has since developed into what we call Halloween or, to use its more proper name, "All Hallows Eve." This is the day before Nov. 1, All Saints Day. It was believed that on All Hallows Eve the dead came from their graves to visit the living.

On that occasion, in ancient times, the Pleiades would be due south in the sky at midnight. An astronomical object which is due south at midnight is said to have reached culmination, or its highest point in the sky.

In ancient Greece temples and streets were often aligned with the Pleiades being due south at midnight. The Aztecs believed the Earth has been destroyed and recreated several times in its history and each destruction happened when the Pleiades were at culmination.

Today, the Pleiades don't reach midnight culmination on Halloween. Precession -- the wobbling of Earth's axis over thousands of years -- has shifted the time when and where stars are visible. Time zones and Daylight Savings Time haven't helped either. So this year on October 31 the Pleiades will be due south and at their highest point in the sky at about 2 a.m. MDT.

To see the Pleiades, or Seven Sisters, go out about 8:30 p.m. on Oct. 31, and look east. The tiny dipper-shaped cluster will be found about 20 degrees, about the width of two clinched fists held at arms length, above the horizon.

Initially, when viewed without optical aid, you might see only six stars. When viewed through binoculars many more stars are seen; in a moderate to large telescope it might, I say might, be possible to catch a glimpse of the blue haze of the nebula in which these stars reside.

If you want to see the moon on Halloween, look southwest about 6:30 p.m.; its very slender crescent is located below bright Venus and just above the star Antares in Scorpius, the Scorpion. Don't wait too long, as the moon will set at about 6:30 p.m.

SKY WATCH: Now, for all you hardy star gazers, if you would like to join me tonight (Thursday) for the Great World-Wide Star count, be at the Dundy County/Stratton high school football stadium grandstand in Benkelman at about 7 p.m. Bring binoculars if you have them, and don't forget the observation guide (which you can download from www.windows.ucar.edu/starcount). We will be attempting to observe the stars in the constellation Cygnus, the Swan positioned high overhead. While I agree the football stadium is not the best dark-sky place to observe from, the point of this exercise is to see how many stars are visible from any given location -- light polluted or not. And you can repeat the exercise in darker locals if you wish. Dress warm for the occasion and if it is cloudy, well, never mind. If it is cloudy we might try it again on Saturday evening, Nov. 1, same time, same place.

NEXT TIME: More astronomical blathering.