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APOD: Ice Halos by Moonlight (2022 May 14)

Posted: Sat May 14, 2022 4:13 am
by APOD Robot
Image Ice Halos by Moonlight

Explanation: An almost full moon on April 15 brought these luminous apparitions to a northern spring night over Alberta Canada. On that night, bright moonlight refracted and reflected by hexagonal ice crystals in high clouds created a complex of halos and arcs more commonly seen by sunlight in daytime skies. While the colors of the arcs and moondogs or paraselenae were just visible to the unaided eye, a blend of exposures ranging from 30 seconds to 1/20 second was used to render this moonlit wide-angle skyscape. The Big Dipper at the top of the frame sits just above a smiling and rainbow-hued circumzenithal arc. With Arcturus left and Regulus toward the right the Moon is centered in its often spotted 22 degree halo. May 15 will also see the bright light of a Full Moon shining in Earth's night skies. Tomorrow's Full Moon will be dimmed for a while though, as it slides through Earth's shadow in a total lunar eclipse.

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Re: APOD: Ice Halos by Moonlight (2022 May 14)

Posted: Sat May 14, 2022 4:58 am
by Ann
APOD 14 May 2022 Ice Halos by Moonlight Alan Dyer annotated.png

What a beautiful image! I love the name "Parry Arc". Who is Parry? :D

Ann

Re: APOD: Ice Halos by Moonlight (2022 May 14)

Posted: Sat May 14, 2022 5:54 am
by bystander
Ann wrote: Sat May 14, 2022 4:58 am
What a beautiful image! I love the name "Parry Arc". Who is Parry? ...

Sir William Edward Parry, Arctic explorer

Re: APOD: Ice Halos by Moonlight (2022 May 14)

Posted: Sat May 14, 2022 11:56 am
by orin stepanek
LunarHaloComplex1024.jpg
IMG_8741_cSunHaloEdback1024.jpg
Nature is one great artist! 8-) :D

Re: APOD: Ice Halos by Moonlight (2022 May 14)

Posted: Sat May 14, 2022 6:26 pm
by NCTom
Chris,
If I remember correctly, you posted in the not too distant past your own version of this beautiful event. It was one awesome photo.

Re: APOD: Ice Halos by Moonlight (2022 May 14)

Posted: Sat May 14, 2022 8:08 pm
by Ann
I find the photo below very beautiful, and I note that it is from Sweden:


There have been a number of fine halos in Swedish skies. An interesting historical painting is the so called "Vädersolstavlan", "The Weather Sun Painting", which shows a halo display over Stockholm in 1535:

Vädersolstavlan. Artist: Jacob Heinrich Elbfas

Wikipedia wrote:

17th century painting of Stockholm, a copy of the so called Vädersolstavlan, depicting a halo display event in 1535. Cleaned in 1998. The visible haloes are: 22 ° halo, at upper right (should be centered on the Sun) parhelic circle, large white circle (centered on the zenith: appears 'horizontal' in the sky) parhelia including 2 sundogs, 2 120° parhelia and the anthelion (dots on the parhelic circle, resp. nearest to farthest from the Sun) upper tangent arc and possible Parry arc (2 crossing arcs just left of the 22° halo (actually 'above' the 22°, in the sky); not realistically shown) circumzenithal arc, smaller crescent inside the parhelic circle (also centered on the zenith: appears 'horizontal', high in the sky) infralateral arc (bottom right) Note that the whole sky appears strongly tilted in the image: the upper right corner is actually down in the sky (when looking towards the Sun), the zenith is at the center of the circumzenithal arc and parhelic circle. This may result from the artist's choice to represent the display in a realistic orientation relative to the landscape: in this case the sun would have shone from 3/4 back to the right of an observer facing the city. The relative brightnesses of the haloes are quite accurate.
Ann

Re: APOD: Ice Halos by Moonlight (2022 May 14)

Posted: Sat May 14, 2022 9:11 pm
by Chris Peterson
Ann wrote: Sat May 14, 2022 8:08 pm I find the photo below very beautiful, and I note that it is from Sweden:
You have a good combination of things for halos: cold, wet air, low altitude Sun, lots of people with cameras.
There have been a number of fine halos in Swedish skies. An interesting historical painting is the so called "Vädersolstavlan", "The Weather Sun Painting", which shows a halo display over Stockholm in 1535:
Etymology aside, doesn't vädersol translate better as "sundog"?

Re: APOD: Ice Halos by Moonlight (2022 May 14)

Posted: Sun May 15, 2022 4:22 am
by Ann
Chris Peterson wrote: Sat May 14, 2022 9:11 pm
Ann wrote: Sat May 14, 2022 8:08 pm I find the photo below very beautiful, and I note that it is from Sweden:
You have a good combination of things for halos: cold, wet air, low altitude Sun, lots of people with cameras.
There have been a number of fine halos in Swedish skies. An interesting historical painting is the so called "Vädersolstavlan", "The Weather Sun Painting", which shows a halo display over Stockholm in 1535:
Etymology aside, doesn't vädersol translate better as "sundog"?
You're probably right, Chris. But if you ask an average Swede about the word, they will just scratch their heads.

Ann