December presents a captivating celestial display, inviting stargazers to enjoy a variety of bright stars and notable astronomical events. As the month unfolds, the constellation Orion takes center stage, illuminated by its striking stars, including Aldebaran, Pollux, Procyon, Sirius, and the magnificent Jupiter. For those keen to observe, the Geminid meteor shower, one of the year’s most anticipated astronomical phenomena, will peak on the night of December 13-14.
During the initial half of the month, observers can catch a glimpse of Mercury appearing prominently in the dawn sky. The best viewing occurs between December 5 and 10, when this swift planet shines brightly low in the southeastern horizon, roughly an hour before sunrise. In contrast, Mars and Venus remain hidden, too close to the sun to be seen.
The Geminid meteor shower promises a spectacular show, with optimal viewing conditions expected due to a dark, nearly moonless sky. Stargazers can expect to see up to 80 meteors per hour, particularly from rural locations. The meteors will appear to radiate from near Orion, but they can be seen across the entire sky. To enjoy the best experience, viewers should find a dark spot away from city lights.
Notable Astronomical Events
In addition to the meteor shower, December offers several other intriguing astronomical events. On December 3, the nearly full moon will obscure members of the Pleiades star cluster from approximately 19:00 to 21:00 CST. A pair of binoculars will enhance visibility of this event.
The full moon, known as the Cold Moon, rises on December 4, marking the peak of its brightness. Following that, on December 9, the waning moon will pass close to Regulus, Leo’s brightest star, creating an occultation visible from parts of Greenland, Iceland, and northern Canada.
The star Algol, located in the constellation Perseus, will also undergo a notable eclipse this month. Observers can witness the star reach its minimum brightness on December 17 around 21:30 CST. This phenomenon occurs every 2.9 days when its dimmer companion star passes in front of it, resulting in a drop in brightness of about 70%, making it easily noticeable to the naked eye.
Another highlight of December is the winter solstice on December 21, the shortest day and longest night of the year. Following this, the annual Ursid meteor shower will peak on the night of December 21-22, yielding 5 to 10 meteors per hour radiating from the Little Dipper.
Finding Your Way in the Night Sky
To aid in identifying celestial bodies, the free Stellarium Mobile app, available for both Android and iPhone, is a valuable tool for locating and recognizing current planets and constellations. Users can set the app to night mode and point their devices skyward for guidance.
Those interested in a detailed sky map and calendar can access resources at www.skymaps.com/downloads.html. For updates, alerts on auroras, and news related to astronomy, following Astro Bob on Facebook can provide timely information.
As December progresses, the International Space Station will also be visible in the early morning sky from December 15-31. Stargazers can log onto Heavens-Above.com to find specific flyover times for their location or download NASA’s Spot the Station app for updates.
Clear skies are anticipated throughout the month, making December an excellent time for both seasoned astronomers and those new to stargazing to immerse themselves in the wonders of the universe.
