Dining & Nightlife | Astronomy

Halloween is on its way and happens to be an astronomically significant holiday. The reason is that it falls on the last of the four Cross Quarter days of the Solar Calendar. A Cross Quarter day is a day that comes midway between an Equinox and a Solstice; in the case of Halloween, midway between the Autumnal Equinox and the Winter Solstice. For pre-Christian Celts and other ancient cultures, Cross Quarter days marked the beginnings and ends of the seasons; Equinoxes and Solstices took place right in the middle. This differs from our own calendar, in which the beginnings and ends of seasons correspond to Equinoxes and Solstices. Nevertheless, vestiges of ancient Cross Quarter celebrations remain with us today. Among such vestiges are the celebrations of Groundhog Day on February 2, May Day on May 1, Lammas Day on August 1 and, of course, Halloween on October 31.

Halloween is also associated with the Pleiades star cluster, which, in olden times, rode highest in the sky at the end of October. During those times, the Pleiades were considered to be harbingers of cataclysmic events, including the return of the dead, as were comets and eclipses. Today, the Pleiades reach their highest point in the sky during November.

* Jupiter will be bright and easy to spot throughout October. Look for it in eastern skies during the early evening hours. Jupiter reaches opposition (most full illumination) on October 29.
* Neptune and Uranus will also be visible in the early evening, but these more-distant planets require a telescope to be fully appreciated.
* Comet Elenin, recently discovered by Leonid Elenin, a Russian amateur, will approach Earth most closely on October 16. It should be visible in binoculars, but far more interesting views can be had with a telescope and, perhaps, some imaging gear.
* The Orionid meteor shower is expected to peak on October 21, but the shower is irregular and may reach its peak earlier. Expect about 20 meteors per hour with best viewing after midnight.