December begins the period we think of as winter's skies. We talk about how the stars are so much brighter in winter, and we think it's because the skies are clearer, more transparent, in cold weather. The reality is much simpler - there are just more bright stars visible in winter. So, what's up in December?
Start with one of the two most recognized constellations in the skies: Orion. The Belt and Sword of Orion are easily seen this month, almost due south at mid-month. The middle star in the belt looks just a little fuzzy if you're not using telescopes or binoculars. Through binoculars or even a small telescope, it's revealed as the great Orion Nebula. The brightest star in Orion, on the left shoulder, is called Betelgeuse. It's actually a variable star - while it's always bright, it's light varies slightly. So that while it's classified as the brightest star in Orion, Rigel, to the lower right of the Belt and Sword, is sometimes just a bit brighter. Here's a great photo and constellation map of Orion - be sure to move your mouse over the photo!
Below and to the left, or east, of Orion is a very bright star. That's Sirius, the brightest star in our skies. It's in the constellation Canis Major, the "Greater Dog" - Orion is accompanied by two hunting dogs (although Canis Minor is more difficult to find).
One last constellation note - as Christmas approaches, you may notice, fairly low in the northwest, a pattern of stars in the shape of an upright cross. That's Cynus, the Swan. But it's better known as the Northern Cross, and December is it's last bit of visibility until summer. Catch it early in the evening - by 9 PM, it's too low to be seen from most locations.
There's not really much in the way of planets this month - Saturn is rising in the east, but it's better left for January. There is a meteor shower the night of December 13-14, the Geminids - so named because they generally originate from the area near the constellation Gemini, just to the east of Orion. If you want to see meteors, stay up until well after midnight or wake up in the early morning for the best chances. The Moon will reappear on the evening of December 14, low in the west after sunset - although you can see a think sliver of the just-past-New Moon in the late afternoon of the 13th if you have a clear western horizon. So, take a break from Christmas shopping and partying for a few minutes some night, and take look up. And if you have any questions, post them in the comments for this post, and I'll do my best to answer them.