The onset of winter heralds many things amateur astronomers love: maximum darkness, high Full Moons, and Orion the Hunter at its summit. Add to these the sights and sounds of the Christmas season. Bah, humbug!
Don't get me wrong. I like even the tackiest commercialism of Christmas. It's astronomy, however, that puts me in a bad mood this time of year. You see, I live in Milwaukee, and, like most locations in the northern U.S., winter brings bitter cold and the cloudiest skies this side of Venus.
Why do I live in Milwaukee? Because, long ago, someone wiser than me decided Astronomy magazine should be based here. Subsequently, we've moved to Waukesha, which lies about 15 miles west of Milwaukee. Our competitor magazine operates out of the Boston area - also under the murk.
I have an idea. Let's move these magazines from their current locations to San Diego and Tucson, and we'll give the other guys first choice!
Oh, well, make the best of a bad situation is what I've heard. Fair enough. I own lots of warm winter clothing and several dew heaters. I don't mind braving the cold to observe. But you can't observe when clouds cover the sky.
If you encounter similar circumstances, I have a bit of advice: Always be ready to observe. This breaks down into two aspects: mental and physical.
Mentally, it's no problem to follow this advice. If you're like me and thousands of other amateur astronomers, you're hooked on weather broadcasts, Internet weather sites, and Attilla Danko's Clear Sky Clock home page, found at www.cleardarksky.com. Also, long stretches of cloudy nights make amateurs so hungry to observe that we'll head out on even marginal nights.
Physically, there's only one thing you really have to do in cold weather: pre-chill your telescope. A warm telescope in cold weather delivers awful images. Instead of faint objects and delicate planetary details, you'll see magnified views of heat streaming off your optics and horribly twinkling images. If you don't already store your scope in an unheated area (or if you're not using a permanent observatory), move at least your optical tube to an unheated porch or garage if there's even a slight chance of the weather clearing. The absolute minimum chill time is 2 hours, but 4 hours is better.
Remember, when you're done observing and you bring your telescope indoors, leave the covers off all optics. (2 to 4 hours will usually do the trick.) Dew will form on a cold telescope, and covered optics will trap it. I've heard many stories of mold forming on objectives and eyepieces because they were capped.
Keep these things in mind, and you'll maximize your winter observing. How much you enjoy it depends mostly on how warm your clothing keeps you.