October skies darker than December skies?

  • Thread starter DaveC426913
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In summary, Dave's hypothesis is that October skies are darker than December skies because it is often rainy in autumn, and the roads reflect vehicle and street lights. The Gegenschein and Zodiacal light are due to dust, and December has a tilted solar plane which makes the sky brighter than October.
  • #1
DaveC426913
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October skies always seem to be very black, whereas December skies seem blue. I don;t know if anyone else has observed this, or whether it's just my imagination.

I have some hypotheses, but none of them seem satisfactory.

- Daylight savings ends in late October. So Oct/Nov skies really are darker than Sept. (but that doesn't explain lighter skies in December)
- It is often rainy in autumn, so the roads reflect vehicle and street lights. And there's (sometimes) snow on the ground in December (though not around here in recent memory).
- Moon is typically in a different phase for a given time of night? (Don't know)
 
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  • #2
We are talking Northern hemisphere of course, and at middle-ish latitudes, but in many parts October is often cloudier than December with more active weather systems around.
So although October days are longer they are frequently dull due to lots of cloud, (I wouldn't quite compare that dullness with black though).
Typically in December there are less active weather systems, so less cloudy days, and there can be extended periods of slow moving high pressure systems leading to calm and cloud free skies.
 
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  • #3
To my horror, I do not seem to have actually specified that I am referring to night skies.

Thanks. That actually a pretty plausible hypothesis.
 
  • #4
Is there any directivity that you have noticed - darker/lighter to the south, north east, west.
Thinking that with the snow on the ground, the Northern Lights, even if you do not see them directly, may reflect back up into the sky.

Also, what about the Gegenschein,
https://en.wikipedia.org/wiki/Gegenschein

Or the Zodiacal light,
https://en.wikipedia.org/wiki/Zodiacal_light

Both due to dust, and since December has you tilted more inline with the solar plane...

There is also Airglow, to brighten up the night sky,
https://en.wikipedia.org/wiki/Airglow

Frankly, how seasonal would any of those be?
 
  • #5
Whoa! Dave. Your eyes must be a lot different than mine. I don't recall ever (and I'm as old as dirt) seeing blue night-time skies in any month. Blue skies are caused by Rayleigh scattering of sunlight--right? There is no sunlight at night--right? Where does the blue come from? Is it subjective?

I wonder if you would see the same monthly difference if you live somewhere else?
 

1. Why are October skies darker than December skies?

October skies are darker than December skies because the tilt of the Earth's axis causes the Northern Hemisphere to be tilted away from the sun during October, resulting in longer nights and shorter days. This decreases the amount of sunlight that reaches the atmosphere, making the skies appear darker.

2. Is there a scientific reason for October skies to be darker than December skies?

Yes, there is a scientific explanation for why October skies are darker than December skies. As mentioned before, the tilt of the Earth's axis affects the amount of sunlight that reaches the atmosphere, resulting in longer nights and darker skies during the month of October.

3. Are there any other factors that contribute to the darkness of October skies?

Yes, there are other factors that can contribute to the darkness of October skies. For example, weather conditions such as clouds or fog can also affect the amount of sunlight that reaches the atmosphere, making the skies appear darker. Additionally, air pollution can also contribute to darker skies by blocking out sunlight.

4. How does the darkness of October skies affect the Earth?

The darkness of October skies does not have a significant impact on the Earth as a whole. However, it can affect certain ecosystems and animals that rely on sunlight for survival. For example, plants may have a harder time photosynthesizing and animals that use sunlight for navigation may experience difficulties.

5. Is there any difference in the darkness of October skies between different locations on Earth?

Yes, the darkness of October skies can vary between different locations on Earth. This is due to factors such as the latitude of the location and local weather conditions. For example, places closer to the equator may experience less of a difference in darkness between October and December due to their proximity to the sun's rays.

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