I live in the Netherlands and recently I have been seeing an orange glow in the sky at night, in the northwestern direction. What is the cause of this? And why is it in the northwestern direction (I have seen it a couple of times recently, all in the same general direction).
What kind of Orange and how much of the sky did it fill?
Low pressure sodium lights are common in lighting cities and highways. Is there a big city/freeway northwest of you? I suppose under the right conditions you could see sky glow from a large city a long way away.
If you are at a very dark clear site (unlikley in the Netherlands) it could be zodiacal light - sunlight reflecting off the dust that fills the solar system. Although I don't know you could see it with the naked eye at a regular site