The good news about winter is that the skies are dark longer than they are bright (for those of us north of the equator); the bad news about winter is that it cold, often frightfully so, at night. More good news: when a cold front blows through, sometimes accompanied by bad weather, it’s not uncommon to have very clear skies behind the front. Astronomers say that the ‘transparency’ of the sky is good. What’s often not good is the steadiness of the air in the atmosphere, which astronomers call the ‘seeing’. Poor seeing makes stars look like blobs and planets look like bigger blobs.