APOD: Dark Skies: Turn on the Night (2019 May 16)

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APOD Robot
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APOD: Dark Skies: Turn on the Night (2019 May 16)

Post by APOD Robot » Thu May 16, 2019 4:08 am

Image Dark Skies: Turn on the Night

Explanation: Have you ever experienced a really dark night sky? One common and amazing feature is the glowing band of our Milky Way galaxy stretching from horizon to horizon. If you live in or near a big city, though, you might not know this because city lights reflecting off the Earth's atmosphere could only allow you to see the Moon and a few stars. Today, however, being UNESCO's International Day of Light, the International Astronomical Union is asking people to Turn on the Night by trying to better understand, and in the future better reduce, light pollution. You can practice even now by going to the main APOD website at NASA and hovering your cursor over the [url=https://apod.nasa.gov/apod/image/1905/T ... </a>Before image</a>. The <a href="image/1905/TotnAfter_Dai_3000.jpg]After[/url] picture that comes up is a panorama of four exposures taken with the same camera and from the same location, showing what happened recently in China when people in Kaihua County decided to turn down many of their lights. Visible in the Before picture are the stars Sirius (left of center) and Betelgeuse, while visible in the After picture are thousands of stars with the arching band of our Milky Way Galaxy. Humanity has lived for millennia under a dark night sky, and connecting to it has importance for both natural and cultural heritage.

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Re: APOD: Dark Skies: Turn on the Night (2019 May 16)

Post by Boomer12k » Thu May 16, 2019 8:54 am

I live in a mobile home park. Lots of yard lights.
I live a bit out of town, but still to the north are the city lights.

I still get images of M51... from the Driveway...

But, yes...could be better... but then we would all be mugged by the druggie neighbors...

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Ann
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Re: APOD: Dark Skies: Turn on the Night (2019 May 16)

Post by Ann » Thu May 16, 2019 9:34 am

Well done, Boomer! :D

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orin stepanek
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Re: APOD: Dark Skies: Turn on the Night (2019 May 16)

Post by orin stepanek » Thu May 16, 2019 10:52 am

8-) Nice :clap: :thumb_up:
Orin

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Chris Peterson
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Re: APOD: Dark Skies: Turn on the Night (2019 May 16)

Post by Chris Peterson » Thu May 16, 2019 12:50 pm

Boomer12k wrote:
Thu May 16, 2019 8:54 am
I live in a mobile home park. Lots of yard lights.
I live a bit out of town, but still to the north are the city lights.

I still get images of M51... from the Driveway...
One reason that imaging is popular with amateur astronomers is that you can operate under much brighter skies. With an image you can subtract out the background and stretch the contrast. Our eyes can't do that. I can see M51 through binoculars at my dark location. I doubt you can. Above all, light polluted skies kill visual astronomy (or simply the human experience of a starry sky).
Chris

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Re: APOD: Dark Skies: Turn on the Night (2019 May 16)

Post by Chris Brownewell » Thu May 16, 2019 6:10 pm

I'm not at all in favor of light pollution, but the after picture seems to suggest that if you turned off your lights you'd be able to see Barnard's Loop in Color with the unaided eye.......probably not happening no matter what you do.

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Re: APOD: Dark Skies: Turn on the Night (2019 May 16)

Post by BDanielMayfield » Thu May 16, 2019 9:13 pm

Chris Brownewell wrote:
Thu May 16, 2019 6:10 pm
I'm not at all in favor of light pollution, but the after picture seems to suggest that if you turned off your lights you'd be able to see Barnard's Loop in Color with the unaided eye.......probably not happening no matter what you do.
No 'probably' about it, as no unaided human eye can see the color in even the brightest nebula from even the darkest sites.

Looks like three or four people didn't get the memo. :lol2:
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Re: APOD: Dark Skies: Turn on the Night (2019 May 16)

Post by thearborist » Thu May 16, 2019 9:44 pm

Am I missing something? The After image shows the stars and Orion constellation higher in the sky than the Before image, indicating the After image was taken first. Barring a temporal inversion in only part of the galaxy, this seems anomalous. Any thoughts?

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Re: APOD: Dark Skies: Turn on the Night (2019 May 16)

Post by alter-ego » Fri May 17, 2019 5:11 am

thearborist wrote:
Thu May 16, 2019 9:44 pm
Am I missing something? The After image shows the stars and Orion constellation higher in the sky than the Before image, indicating the After image was taken first. Barring a temporal inversion in only part of the galaxy, this seems anomalous. Any thoughts?
Looks like the session started after the lights were turned off, but it was desired to show the lights-on condition as before the lights off condition. The after image was taken about 30 minutes before the before image. Funny, we always see before/after comparisons, never in the after/before order. The representation is accurate wrt sky darkness, just not wrt time. Not being that familiar with constellation orientation, most people wouldn't notice the temporal reversal anyway.
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Re: APOD: Dark Skies: Turn on the Night (2019 May 16)

Post by khh » Sun May 19, 2019 11:11 am

Strong virtue signals were picked up by monitoring satellites.

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Re: APOD: Dark Skies: Turn on the Night (2019 May 16)

Post by geckzilla » Sun May 19, 2019 3:04 pm

khh wrote:
Sun May 19, 2019 11:11 am
Strong virtue signals were picked up by monitoring satellites.
Gimme those data, I have to independently confirm this finding.

...Hey, these aren't virtue signals. It's just interference. Looks like it's coming from your location, actually. Might want to fix that.
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