Dressing for Winter Astronomy
Published on Nov 18, 2006 at 12:16 am.
4 Comments.
Filed under amateur astronomy.
I think that I may have posted something like this last year on my old blog. Well, it bears repeating.
We are having a big star party this weekend. Naturally, this is supposed to be one of the coldest nights of the season. Now, cold weather and astronomy go together. The cold drives a lot of water vapor out of the atmosphere. The high pressure that often follows cold fronts also yields cloud-free skies. Put the two together, and you have perfect sky conditions. Only, it is cold.
I find that most of my students, being city folk, have absolutely no idea how to handle the cold. After all, in the city, you are never far from a nicely heated warm building. In the city, things are always scheduled indoors during less than nice weather. And, city people are not outdoors much after dark.
Astronomers, though, are fequently nowhere near nice warm buildings, are outdoors late at night, are out in the country, and of course are outside. Night is the coldest time of the day. In the fall and winter months, the temperature tends to plunge at sunset. And, of course, the best and clearest nights are the coldest. This is a recipe for disaster for city folk.
First of all, at night, it is much colder than during the day. When people get ready to dress for the outdoors, they tend to think of how they’d dress to walk from the car to a building during the day. At night, you don’t have the Sun heating you. Also, astronomy is a rather quiet and calm thing to do. You are just standing at the telescope. This isn’t like skiing, where you are moving around and being active. Standing at the telescope you don’t generate nearly as much heat. Worse, the best astronomy is done without obstructions blocking the horizon. But, those obstructions also block wind. So, you are going to be much colder sitting or standing around a telescope than you would be actively moving around in the daylight. Also, the city tends to hold in heat. So, it is generally quite a bit colder in the country than in the city. Expect it to be ten degreed colder in the rural areas than the weather forecast calls for. Expect it to feel a good 20 degrees colder than you are expecting it to feel like in the city. This is the astronomer’s environment.  All too often, students and members of the public come to events like this weekend’s star party ill prepared.
I tell my students and friends to come dressed as if they are going to be going on an Arctic expedition. Really. That isn’t far off of how you should dress for astronomy. Remember, you drove for an hour or two to get to a remote site. It is good for astronomy because it is remote. That means no warm buildings to run to if you get cold. It also means that you are a long way from warm clothes if you didn’t bring enough. If you bring too many warm clothes, then you don’t have to wear them all, or you can take some off. However, if you didn’t bring enough, you will be miserable, and there will be nothing that you can do about it other than leave. So, don’t hesitate to pack the car with extra hats, gloves, jackets, parkas, sweaters, blankets, etc.
So, what does the best at keeping you warm? Well, the secret is to dress in layers. This has multiple advantages. First of all, if you are dressed in layers, you can always add or subtract a layer as needed to get comfortable. But, even better, if you have overlapping layers, it is harder for cold air to find its way in to you. But, the best reason is that layers keep you warmer than one thick layer. The reason is that air is a pretty poor conductor of heat. That is how insulation generally works, anyway. You wear big puffy clothes that have lots of air trapped in them. That is your insulation! So, layers have air trapped in them, and also air trapped between the layers. That is more air to act as insulation. People from up north learn this, but folks here in Texas haven’t always figured it out, especially those who have spent all their lives in the city.
So, layers are the key. But, which layers do you want? Just wearing several jackets on top of each other won’t work. You need to cover all parts of your body. But, the most important thing to cover is you head. Your brain is absolutely vital for the operation of your body. So, if you head starts to get cold, your body will adjust blood flow to keep your brain an even temperature. This will even occur at the expense of your extremeties. So, if you head gets cold, then your hands and feet get even colder. The bulk of the heat loss from your body will come from your head. So, wear a hat! The thicker and warmer the hat, the better. I have a down filled rabbit fur lined hat that keeps my head nice and warm even in the coldest weather. But, any hat helps. Next, cover your neck! After all, all the blood going to your head goes through your neck, so if your neck gets cold, so do you. I have a nice thick scarf that does the job. But, even just turning up your collar helps. And, don’t worry how you look. After all, if you are doing astronomy, it is dark anyway, right?
Second to your head, your torso is the next most important thing to keep warm. Wear multiple layers. Wear a sweater, a vest, and a jacket or parka. The longer coats work best, as they cover more, and then tend to also overlap your pants. You don’t want all the layers to have a joint at the same spot, or the cold air will get in that weak area. People often wear heavy coats, but you should not forget the other layers that go with that.
Gloves are good. Mittens are better. But, remember that if you are doing anything serious at the telescope, you need to be able to adjust the focus, change eyepieces, write things down, etc. So, I have found that thinner gloves work better than the thick ones. You have to take the thick ones off to do anything, exposing bare skin to the cold. Thin gloves you can wear and do everything that you need to do. Some people wear very thing gloves under heavy mittens. Remember, though, that if you are wearing a hat, you hands will be warmer than they would be otherwise, anyway.
Coats and glove, and even sometimes hats are about as far as most city people go. But, that leaves half of you exposed to the cold. You’ll be losing heat through your legs and feet. Long underwear helps absolutely wonders with the legs. Best is to wear loose heavy pants of jeans over the long underwear (loose to trap air). If it is really cold, then ski pants or ski bibs can go on over the pants. Some students have worn extra loose jeans over their pants, adding layers.
Then, don’t forget the feet. That is normally where you first feel the cold. Your toes get cold, and then you are miserable. The first line of defense is heavy shoes and socks. Better would be two or three pairs of socks, preferably with at least one pair being extra thick thermal socks. Even better would be insulated boots. Remember, if you are wearing boots, that tucking your pants into them keeps cold air from going up your pants legs. Yeah, it looks silly, but remember it is dark out! Besides, after everyone else is freezing and miserable, they’ll not be thinking that you look funny any more.  If you don’t have insulated boots, you can wrap bubble wrap around your feet, or even garbage bags. OK, it looks stupid, but do you care after everyone else has gone home because they were miserable?
And, don’t forget that there are other non-clothing things that help. I’ve had a few students come wearing sleeping bags. The unzip the bottom so that they can walk, and the top so they can look out. It looks sort of like a walking cocoon, but who cares? Blankets are wonderful, too. Pretty much anything that acts as a barrier to the cold air helps. And, then you can also buy chemical heating packs. Activate them, and shove them in your shoes or gloves and they warm you.
Hot drinks also help. Heat is heat. So, eating or drinking anything hot helps. Of course this means that you need an insulated cup and a thermos, but those are not hard to come by. Hot chocolate or hot cider also give an energy boost, allowing your body to generate more of its own heat. But, beware of alcohol. It can make you feel warmer, but it is all an illusion. Alcohol really makes you lose heat faster, only you don’t realize it at first. So, stay away from it if you want to keep warm.
So, there you have some hints to keeping warm while doing astronomy in the winter. It works. I’ve been out in VERY cold temperatures — so cold that ice formed on the outside of my clothing, but I was quite comfortable in my massive warm clothes. It can be done. And if someone like me, who grew up on the Texas Gulf Coast, where it seldom gets below freezing, can do it, anyone can. If you are cold, you can’t enjoy skywatching. But, if you are dressed appropriately, you can enjoy astronomy no matter how cold it gets (within reason, of course).
-Astroprof
profgrrrrl on November 18, 2006 at 9:46 pm: 1
Merely from a fashion standpoint, I simply couldn’t be an astromer
[hee]
Astroprof on November 19, 2006 at 5:10 am: 2
Some of us do dress a little better when not observing.
nutty on January 11, 2007 at 12:29 pm: 3
what’s an ‘astromer’?
nutty bubble on December 12, 2007 at 7:18 pm: 4
oooooooooooookkkkkkkkkkkkkkk