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Old 15-02-2019, 11:26 AM
Tropo-Bob (Bob)
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What caused this?

I have seen this affect before but never as strongly. The glow continued from the Western Horizon, through overhead, all the way down to the Eastern Horizon. It did lose its intensity, but nevertheless it was easily visible. I felt like I was on Saturn looking outwards towards the rings!

I guess it must have been the Sun illuminating dust high in the atmosphere. It was dry and hot yesterday, like inland heat. However, given all the recent floods, I just struggle to think that it is inland dust.
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Old 15-02-2019, 11:50 AM
JA
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Hello Bob,

I think it's the sun (from at/just below the horizon) streaming through a gap/s in the clouds OR possibly reflecting upwards off low level cloud and illuminating the sky near dusk. I have an old photograph (from film!) near dusk which shows multiple such orange/red streams through the clouds, but your image has an interesting and more stark red/blue contrast, perhaps due to longer exposure & ISO

Best
JA

Last edited by JA; 15-02-2019 at 12:08 PM.
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Old 15-02-2019, 11:55 AM
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sil (Steve)
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But its coloured, so I think more rays through low clouds lighting up vapour not yet strong enough to form clouds. Very striking.
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Old 15-02-2019, 03:46 PM
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Smoke from the many bushfires may be part of the answer☺
Alex
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Old 15-02-2019, 04:07 PM
astro744
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Looks like anti-crepuscular rays. See https://www.atoptics.co.uk/atoptics/anti1.htm
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Old 17-02-2019, 10:51 AM
Tropo-Bob (Bob)
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Thanks for the replies.

I am still confused, as what I saw was simple one streak, or one ray; it was not a group of rays.
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Old 17-02-2019, 12:59 PM
gaseous (Patrick)
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Zodiacal light?
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Old 17-02-2019, 01:43 PM
astro744
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Quote:
Originally Posted by Tropo-Bob View Post
Thanks for the replies.

I am still confused, as what I saw was simple one streak, or one ray; it was not a group of rays.
There are two others in your image. One to the right half way between the main one and the telegraph pole. Another to the left of the main one above the palm. The latter is is extremely faint.

Have a look at all the images and explanations at the link I sent previously. Anti-crepuscular rays can vary in appearance and sometime you only see one main one although the others are there but much fainter. They are caused by light scattering from ice crystals and dust. The angle between the ray, you and the anti-solar point would likely influence the appearance of a particular ray but also the amount and size of the ice crystals and dust in the air.

Above I was only referring the the first image which has three rays that I can detect. I just looked at your original post and the second attached image shows a ray at a different angle. Was this taken from the same location at the approximately the same time? Where they eminate from is called the anti-solar point. Was the Sun behind you?

Last edited by astro744; 17-02-2019 at 01:59 PM. Reason: Added para.
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Old 17-02-2019, 05:47 PM
Tropo-Bob (Bob)
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Quote:
Originally Posted by astro744 View Post
There are two others in your image. One to the right half way between the main one and the telegraph pole. Another to the left of the main one above the palm. The latter is is extremely faint.

Have a look at all the images and explanations at the link I sent previously. Anti-crepuscular rays can vary in appearance and sometime you only see one main one although the others are there but much fainter. They are caused by light scattering from ice crystals and dust. The angle between the ray, you and the anti-solar point would likely influence the appearance of a particular ray but also the amount and size of the ice crystals and dust in the air.

Above I was only referring the the first image which has three rays that I can detect. I just looked at your original post and the second attached image shows a ray at a different angle. Was this taken from the same location at the approximately the same time? Where they eminate from is called the anti-solar point. Was the Sun behind you?
The first image was looking at the Western Horizon after sunset. The second image was looking the Eastern Horizon, only a few moments later. The orange/pink ray went all the way from the Western to the Eastern Horizon, although it lost its intensity along the way. I have never seen a ray before that goes totally across the sky.
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Old 17-02-2019, 06:48 PM
astro744
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Quote:
Originally Posted by Tropo-Bob View Post
The first image was looking at the Western Horizon after sunset. The second image was looking the Eastern Horizon, only a few moments later. The orange/pink ray went all the way from the Western to the Eastern Horizon, although it lost its intensity along the way. I have never seen a ray before that goes totally across the sky.
OK that makes more sense. The western rays are crepuscular radiating upwards as the sun was just below the horizon. Crepuscular can also radiate downwards if the Sun is behind clouds but still above the horizon. The eastern ray is anti-crepuscular. It is not uncommon to see skywide rays although it is also not that common. I have seen them a few times and wish I had an all sky camera to capture them. Good spotting!

See https://www.atoptics.co.uk/atoptics/skywide.htm
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Old 17-02-2019, 06:59 PM
Tropo-Bob (Bob)
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Quote:
Originally Posted by astro744 View Post
OK that makes more sense. The western rays are crepuscular radiating upwards as the sun was just below the horizon. Crepuscular can also radiate downwards if the Sun is behind clouds but still above the horizon. The eastern ray is anti-crepuscular. It is not uncommon to see skywide rays although it is also not that common. I have seen them a few times and wish I had an all sky camera to capture them. Good spotting!

See https://www.atoptics.co.uk/atoptics/skywide.htm
Thanks Astro744, I am finally getting the idea of Crepuscular and anti-crepuscular rays. Thanks again!
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