The Darkness Returns

[mcrossley]

Today, for the first time in a while I notice that North Cheshire will have some true darkness tonight.

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[RayProudfoot]

Technical darkness perhaps Mark. Sadly I've not seen a truly dark sky for decades and I guess that Manchester still spoils your northern view.

I read an article in a paper recently about a new observatory in Chile and apparently the skies are that transparent the Milky Way casts a shadow. Can you imagine what those skies must look like?

[mcrossley]

Two friends of mine went to South Africa a few years ago to do some observing. They ended up at the SALT establishment, they too found the milky way cast a shadow on the wall. They came to view the milky way as light pollution in its own right! Plus the gegenschein, zodiacal light, and air glow was clearly visible. They were fooled on the first night when they woke up to 'dark skies', it was clouds blocking out the starlight!

I have seen the gegenschein from Galoway, Scotland which is also very dark when the air is clear. It was quite noticeable, and mistaken for a hazy cloud at first, until we noticed it only moved with the stars!

[RayProudfoot]

Milky Way light polluter? Blimey, I've heard it all now. There are a few dark skies locations in the UK. I must try to visit one before Old Nick comes calling.

I've never seen the Zodiacal Light sadly. Not sure I've seen Mercury either. But I have seen a total solar eclipse which I think beats everything. Sadly, there aren't many visible in Europe after the March 2015 one but that's too far north and at sea so I won't bother.

Enjoy your observing. Reasonable chance it will be clear tonight.

[Intheswamp]

In the fall of 1995 (I can't really call her a lady) Opal landed on the northwest gulf coast of Florida...Hurricane Opal...her eye, according to tracking, passed pretty much directly over my house. She turned out the lights over a pretty good swath of south Alabama for a lengthy period of time...from a couple of days to over a month in some places Though there was tremendous damage to property from Opal there was a silver lining to it if you looked for it. With the grid blown down there was very little light pollution for a few days and the winds blowing in hard and northward cleaned the atmosphere *greatly*!!! I had never seen the stars like we saw them after that storm...the air was fresh and clear!!! And during the days....some deep blue skies...I guess the gases in the atmosphere could reflect the blue light waves and there wasn't much pollution there to conceal them...???? Anyhow, the stars were SHARP!!!

The Milky Way casting a shadow.... I'm blessed to live where I can't see a streetlight. It is relatively dark at my property though to the east I can see the weak glow of our local town and to the north I can sometimes sense the pollution from up north. But, I can walk out and look up and get lost in the Milky Way. The next really clear, moonless night I'm going out and look for a shadow. I'm not in an exotic location, just the nondescript little hills of south Alabama, but...I'll take it.

Ed

ETA: Had to correct the spelling of "stars" from "starts" to "stars".

[mcrossley]

The next really clear, moonless night I'm going out and look for a shadow.

Try a hand close to a white wall. If Jupiter is up it too can cast a visible shadow.

[mcrossley]

And during the days....some deep blue skies...I guess the gases in the atmosphere could reflect the blue light waves and there wasn't much pollution there to conceal them...???? Anyhow, the starts were SHARP!!!

When all the planes were grounded after 9/11, people across the USA reported how dark blue the skies were during the day, and skies clear at night - those aircraft pump soo much water and gases into the upper atmosphere they create the milky white-blue skies we are just used to now -
I think it is frightening to think about it!

[Intheswamp]

Now that you mention it the skies did seem "different" right after the terrorist attacks. I don't know whether that feeling was the lack of seeing any planes aloft (though we don't have a high traffic count here), the clearing of the atmosphere, or the psychological impact of knowing there were no airplanes flying/polluting the skies.

To clarify, the gases I spoke of were of the natural kind. In regards to clear skies, the stuff we're spewing into the atmosphere creates a very foggy window for us. As long as the storms that come in are lightweights with little damage they do a pretty good job of clearing the atmosphere for a while...the problem is that we can't pick how strong they will be or not be.

Ed