Can you use your telescope outside in the winter?

Question

I am in a cold climate and sometimes it can get down to -30 C Will this damage my telescope?

Answer 1

Yes, you can use your telescope during the winter. It is the best time for small scopes, because the air is more stable, so there will be much less "twinkling" of stars and such.

But it is important to make sure your telescope has plenty of time to adjust to the outdoor temperatures before you use it. I keep mine in my un-insulated (but locked) garage for that very reason. When I want to take it outside for observing, it is already only a couple of degrees warmer than the ambient temperature. If I'd kept it indoors at 68°F, it might take hours to completely stabilize, and there might be a frost problem.

Answer 2

One important thing that hasn't been mentioned yet:

If you use your telescope on a cold night and then bring it into a warm house, moisture will condense on the optics. It will eventually evaporate, but it's best to avoid this.

To prevent the problem: When you are done observing, cover the optics while you are still outside. (E.g., put your eyepieces into a box, and put the lens cover over the objective lens if you have a refractor. I don't know what kind of telescope you have, but apply whatever covers are available.) After you bring the equipment inside, leave the covers in place until the equipment has warmed to room temperature.

As far as problems during observing, I can think of two (other than personal comfort):

1) The image may be of poor quality until the optical elements cool to the ambient temperature. How long this takes depends on the size of the telescope, the thickness of the mirror or lens, etc. A small telescope acclimates relatively quickly, while a large telescope might take at least a couple of hours.

2) If parts of your telescope require batteries, you may have trouble with battery performance at low temperatures.

As Dave_Stark mentioned, you can reduce the problems of thermal changes by storing your telescope in an unheated location.

Answer 3

Yes, you can as long as you remember that electronics that require power can drain a battery to exhaustion much faster in cold temperatures then they would when it's warm. This is especially true for GOTO telescopes who use significant amounts of power. Bring an extra power tank or battery along, and make sure to have dew heaters on the finder scope, diagonal mirror if your telescope has an open tube and on the corrector or objective lens if you have a catadioptric or refracting telescope. Otherwise frost can form and shut you down for the night. Dress very warmly, as though it's 20 or 30 degree colder than the thermometer indicates because you won't be moving much and generating much heat. Pay particular attention to keeping your head, feet and hands warm. You don't want to touch freezing metal when it's 10 below outside barehanded. Make sure your vehicle is dependable. I advise against going out into the hinterlands in sub-zero cold or cold weather mixed with strong winds because death can occur within minutes out there from hypothermia. When it's 50 below, I would either observe from home, or not at all. That is deadly cold weather to be outside for any reason. Not only that, lubricants can solidify, motors can stop working and batteries can fail in killing cold like that. Not even animals go out in that if they have a choice. It can be really hard to observe when it 20 degree above zero between the gusty wind and the dampness that occurs here in the Southern U.S. Know what the warning signs of hypothermia are also, it can sneak up on you and before you know it, you're in deep trouble. The first sign is suddenly feeling very warm all over, then confusion and disorientation sets in. At least take along a sleeping bag and extra clothes and let someone know where you're going and when you're coming back. Take along a mobile phone too, it could be the difference between getting home and a long unpleasant stay in the frigid outdoors at best. Make sure your vehicle can handle the terrain you're driving over. Needless to say, a small front-wheel drive car will get stuck on ice covered ground full or ruts, which is the norm when you're taking to unpaved roads or worse. Merely freezing temperatures can be accommodated with little difficulty, but be careful. I do more observing in the winter than any other time because the skies are darkest and the nights longest. With dew heaters on my telescope, a powerful battery that can cope with both the cold and the load placed on it and multiple layers of clothing and warm boots suited to the weather, I have no problem observing all night long when the temperatures are near freezing. The coldest weather I ever observed in was around zero degrees, after two hours of which I was forced to quit because my hands and feet started to freeze. Taking a thermos full of coffee or hot chocolate also helps keep you warm, as well as some snacks.

Answer 4

Winter is actually an ideal time to use a telescope. The reason why is that the air is much cooler and therefore much less turbulant, and if the air is less turbulant you'll get sharper images out of your telescope. In other words, the "seeing" is much better in the winter than any other time of year.

Answer 5

You can use you telescope outside in winter but you need to let it acclimate to the temperature.

You biggest problem will be frost, the air you exhale will form a frost on the optics so you may have to shorten you observation time a bit.

Answer 6

But if it's a telescope with a computer and/or electronics, that may well be too cold. It will at least put a heavy burden on the batteries.

Answer 7

Put you telescope outside for about 2 hours before you use it. That will allow all parts of it to contract properly. Wear a MUFFLER!!

Answer 8

The cold shouldn't damage anything. The mirror and lenses are usually thin enough that they won't crack from the temperature differences. (Key word is "usually".)

Answer 9

Probably wont damage it but if the sky isn't clear you might not see anything

Answer 10

No damage. Go ahead.