APOD: Artificial Night Sky Brightness (2023 Mar 08)

[APOD Robot]

Artificial Night Sky Brightness

Explanation: Where have all the dim stars gone? From many places on the Earth including major cities, the night sky has been reduced from a fascinating display of thousands of stars to a diffuse glow through which only a few stars are visible. The featured map indicates the relative amount of light pollution that occurs across the Earth. The cause of the pollution is artificial light reflecting off molecules and aerosols in the atmosphere. Parts of the Eastern United States and Western Europe colored red, for example, have an artificial night sky glow over ten times that of the natural sky. In any area marked orange or red, the central band of our Milky Way Galaxy is no longer visible. The International Dark Sky Association suggests common types of fixtures that provide relatively little amounts of light pollution.

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[zendae]

I do wonder if some of the red and orange colors are a bit skewed to the bright side. I am ~ 30 miles northwest of Philly, and on this map well-ensconced in the red/orange. There are a lot of Mayberry RFD type locales here - I have cornfields of hundreds of acres right across the street - and we most definitely can see the Milky Way during clear low humidity nights, especially in winter. Andromeda is visible with binoculars. I think there must be lots of pinpoints of non-red/orange scattered about that don't show up on these maps.

[AVAO]

Artificial Night Sky Brightness

Explanation: Where have all the dim stars gone? From many places on the Earth including major cities, the night sky has been reduced from a fascinating display of thousands of stars to a diffuse glow through which only a few stars are visible. The featured map indicates the relative amount of light pollution that occurs across the Earth. The cause of the pollution is artificial light reflecting off molecules and aerosols in the atmosphere. Parts of the Eastern United States and Western Europe colored red, for example, have an artificial night sky glow over ten times that of the natural sky. In any area marked orange or red, the central band of our Milky Way Galaxy is no longer visible. The International Dark Sky Association suggests common types of fixtures that provide relatively little amounts of light pollution.

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This Day in APOD

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Interesting that the desert region around Kirkuk, Baghdad to Basra is one of the absolutely brightest areas worldwide...

[Ann]

Wow. Note that the eastern half of the United States is bright, whereas the western part of the U.S. is mostly dark. (And please tell me what happened to Canada?)

As a non-American who never studied American history (well, I know of Mayflower 1620, the Declaration of Independence of 1776 and the Civil War of 1861-65 and the shooting of Lincoln in 1865, but not that much else), I immediately though of the Louisiana Purchase (of 1803). That was when the U.S. bought, in one fell swoop, the entire western half of what is now the United States, right?

The Louisiana Purchase. Illustration: William Morris

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Eh, no. Because the Louisiana Purchase was the purchase (by the 13 original states?) of what is now sort of the middle third part of the present U.S.

I guess it was Lewis and Clark that helped the U.S. gain control of the far, far, far wild West, right?

Lois and Clark. Oops, wrong illustration.

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Lewis and Clark, also known as Meriwether and William. Are you sure, Meriwether, that you didn't blunder onto the Rocky Mountains during your long walks through the forests of Middle Earth?

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Anyway. It looks to me as if the western part of the United States still isn't fully settled.

Ann

[FrankTKO]

(And please tell me what happened to Canada?)

90% of Canadians live within 240 km (150 miles) of the US border. The three largest cities, Toronto, Montreal and Vancouver are within 50 km of the border.

[DeWitte]

Where is the all the light coming from in western North Dakota?
The light pattern is as large as Denver and the front range of Colorado, but this is a rural sparsely populated area.

[Astronymus]

Light pollution is the reason I basicly gave up an astronomy as a hobby...

[Stringy]

Where is the all the light coming from in western North Dakota?
The light pattern is as large as Denver and the front range of Colorado, but this is a rural sparsely populated area.

https://earthobservatory.nasa.gov/image ... rth-dakota

[zendae]

Ann said:
"Anyway. It looks to me as if the western part of the United States still isn't fully settled."

Ann, here is an interesting map of the U.S., with each state resized by ratio to its population.

https://www.iflscience.com/heres-what-a ... sity-42032

There are a couple mistakes in the discussion below the map. New York should be New Jersey. Alaska is NOT 1.7 sq km lol...

[orin stepanek]

And it look's as the brightest (Most lit country) is India! And some
of Europe!