APOD: A Total Lunar Eclipse Corona (2021 Jun 09)

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APOD: A Total Lunar Eclipse Corona (2021 Jun 09)

Post by APOD Robot » Wed Jun 09, 2021 4:08 am

Image A Total Lunar Eclipse Corona

Explanation: This moon appears multiply strange. This moon was a full moon, specifically called a Flower Moon at this time of the year. But that didn't make it strange -- full moons occur once a month (moon-th). This moon was a supermoon, meaning that it reached its full phase near its closest approach to the Earth in its slightly elliptical orbit. Somewhat strange, a supermoon appears a bit larger and brighter than the average full moon -- and enables it to be called a Super Flower Moon.  This moon was undergoing a total lunar eclipse. An eclipsed moon can look quite strange, being dark, unevenly lit, and, frequently, red -- sometimes called blood red. Therefore, this moon could be called a Super Flower Blood Moon. This moon was seen through thin clouds. These clouds created a faint corona around the moon, making it look not only strange, but colorful. This moon was imaged so deeply that the heart of the Milky Way galaxy, far in the background, was visible to its lower right. This moon, this shadow, this galaxy and these colors were all captured last month near Cassilis, NSW, Australia -- with a single shot. (Merged later with two lower shots that better capture the Milky Way.)

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Re: APOD: A Total Lunar Eclipse Corona (2021 Jun 09)

Post by JohnD » Wed Jun 09, 2021 10:13 am

Apod, are you purposely trying to be annoying, after our criticism of your 'Face on Jupiter' pic, yesterday?

A 'Flower' moon? The moon has no flora, never has, never will. A 'Super' moon? That does NOT "appear a bit larger and brighter than the average full moon" - it is 7% wider than an average full moon, which the unaided eye cannot discern. And a 'blood' moon? When the moon has no fauna, with or without a heamoglobin circulation, never has, never will.
This is a clever, well executed, and beautiful picture it doesn't need all that fanciful stuff, that has opened Apod to the woo-woo, hand waving, so well expressed by "good website".
John

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Re: APOD: A Total Lunar Eclipse Corona (2021 Jun 09)

Post by Chris Peterson » Wed Jun 09, 2021 1:09 pm

JohnD wrote:
Wed Jun 09, 2021 10:13 am
Apod, are you purposely trying to be annoying, after our criticism of your 'Face on Jupiter' pic, yesterday?

A 'Flower' moon? The moon has no flora, never has, never will. A 'Super' moon? That does NOT "appear a bit larger and brighter than the average full moon" - it is 7% wider than an average full moon, which the unaided eye cannot discern. And a 'blood' moon? When the moon has no fauna, with or without a heamoglobin circulation, never has, never will.
This is a clever, well executed, and beautiful picture it doesn't need all that fanciful stuff, that has opened Apod to the woo-woo, hand waving, so well expressed by "good website".
John
I take it as a light-hearted acknowledgment of the cultural role the Moon has long played.
Chris

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Re: APOD: A Total Lunar Eclipse Corona (2021 Jun 09)

Post by JohnD » Wed Jun 09, 2021 1:49 pm

Light-hearted? "When I hear the word 'Culture' I reach for my revolver!"

The beauty of science is overwhelming - there is no need to embellish and decorate it with whimsy!

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Re: APOD: A Total Lunar Eclipse Corona (2021 Jun 09)

Post by De58te » Wed Jun 09, 2021 1:56 pm

I only can remember the name of September's full moon, Harvest Moon, mainly because I worked on the farm. Who knows maybe the Flower Moon is named for such a reason that nurseries are selling flowers right now to plant in your garden. If this gets your dander up, I wonder what were you thinking when March's full moon is known as the Worm Moon?

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Re: APOD: A Total Lunar Eclipse Corona (2021 Jun 09)

Post by Chris Peterson » Wed Jun 09, 2021 2:01 pm

JohnD wrote:
Wed Jun 09, 2021 1:49 pm
Light-hearted? "When I hear the word 'Culture' I reach for my revolver!"

The beauty of science is overwhelming - there is no need to embellish and decorate it with whimsy!
The beauty of nature is found in both science and culture.

Not every APOD is intended to deliver rigorous science. And I think that's good. The Moon is a powerful symbol to humans, central to our cultures for tens of thousands of years. This is seen in many places, including the folk names we assign.
Chris

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Re: APOD: A Total Lunar Eclipse Corona (2021 Jun 09)

Post by Ann » Wed Jun 09, 2021 2:16 pm

Beautiful APOD.

It's interesting to compare the size of the non-overexposed Moon with some of the best-known deep-sky targets of our galaxy. We can see that the Moon seems to be (apparently) a bit larger than most of the well-known sights in Sagittarius and Scorpius. Only the Large and Small Sagittarius Clouds definitely occupy a larger patch of sky than old Luna. It's fun to see the Moon and its halo overwhelm the colorful clouds of upper Scorpius.

But ah, Moon, dear old Luna. You are big and hugely important to us. But on a cosmic scale, you just don't know how tiny you are! And you don't even know that you don't know, since you've got rocks for a brain!

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Re: APOD: A Total Lunar Eclipse Corona (2021 Jun 09)

Post by orin stepanek » Wed Jun 09, 2021 2:56 pm

Ann wrote:
Wed Jun 09, 2021 2:16 pm
Beautiful APOD.

It's interesting to compare the size of the non-overexposed Moon with some of the best-known deep-sky targets of our galaxy. We can see that the Moon seems to be (apparently) a bit larger than most of the well-known sights in Sagittarius and Scorpius. Only the Large and Small Sagittarius Clouds definitely occupy a larger patch of sky than old Luna. It's fun to see the Moon and its halo overwhelm the colorful clouds of upper Scorpius.

But ah, Moon, dear old Luna. You are big and hugely important to us. But on a cosmic scale, you just don't know how tiny you are! And you don't even know that you don't know, since you've got rocks for a brain!

Ann
Yes; that Luna is tiny compared to the universe is true! To me it is a Hugh part oh our lives! Today's APOD is quite beautiful! I may not use it as an background unless I tip it 90 degrees!
MultiEclipse_Eder_960.jpg
I got kitty today; Purr :lol2:
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Re: APOD: A Total Lunar Eclipse Corona (2021 Jun 09)

Post by neufer » Wed Jun 09, 2021 3:15 pm

JohnD wrote:
Wed Jun 09, 2021 1:49 pm

"When I hear the word 'Culture' I reach for my revolver!"
  • "When I hear the word 'Corona' I reach for my mask!"
JohnD wrote:
Wed Jun 09, 2021 1:49 pm

The beauty of science is overwhelming - there is no need to embellish and decorate it with whimsy!
https://en.wikipedia.org/wiki/Lord_Peter_Wimsey wrote:
<<Lord Peter Death Bredon Wimsey DSO (later 17th Duke of Denver) is the fictional protagonist in a series of detective novels and short stories by Dorothy L. Sayers. The family coat of arms is blazoned as "Sable, 3 mice courant, argent; crest, a domestic cat couched as to spring, proper". The family motto, displayed under its coat of arms, is "As my Whimsy takes me." A dilettante who solves mysteries for his own amusement, Wimsey is an archetype for the British gentleman detective. Lord Peter is often assisted by his valet and former batman, Mervyn Bunter.

Born in 1890 and ageing in real time, Wimsey is described as being of average height, with straw-coloured hair, a beaked nose, and a vaguely foolish face. Reputedly his looks were patterned after those of academic and poet Roy Ridley, whom Sayers briefly met after witnessing him read his Newdigate Prize-winning poem "Oxford" at the Encaenia ceremony in July 1913. Wimsey created a spectacularly successful publicity campaign for Whifflet cigarettes while working for Pym's Publicity Ltd, and at age 40 was able to turn three cartwheels in the office corridor, stopping just short of the boss's open office door. Among Lord Peter's hobbies, in addition to criminology, is collecting incunabula, books from the earliest days of printing. He is an expert on matters of food (and especially wine), male fashion, and classical music. He excels at the piano, including Bach's works for keyboard instruments. One of Lord Peter's cars is a 12-cylinder ("double-six") 1927 Daimler four-seater, which (like all his cars) he calls "Mrs Merdle" after a character in Charles Dickens's Little Dorrit who "hated fuss".

Lord Peter Wimsey's ancestry begins with the 12th-century knight Gerald de Wimsey, who went with King Richard the Lionheart on the Third Crusade and took part in the Siege of Acre. This makes the Wimseys an unusually ancient family, since "Very few English noble families go that far in the first creation; rebellions and monarchic head choppings had seen to that", as reviewer Janet Hitchman noted in the introduction to Striding Folly.>>
https://en.wikipedia.org/wiki/Roger_Penrose wrote:
Click to play embedded YouTube video.
<<Sir Roger Penrose Kt OM FRS (born 8 August 1931) is a British mathematical physicist, mathematician, philosopher of science and Nobel Laureate in Physics. He is Emeritus Rouse Ball Professor of Mathematics at the University of Oxford, an emeritus fellow of Wadham College, Oxford, and an honorary fellow of St John's College, Cambridge, and University College London. Penrose has made contributions to the mathematical physics of general relativity and cosmology. He has received several prizes and awards, including the 1988 Wolf Prize in Physics, which he shared with Stephen Hawking for the Penrose–Hawking singularity theorems, and one half of the 2020 Nobel Prize in Physics "for the discovery that black hole formation is a robust prediction of the general theory of relativity".

:arrow: "Fashion, Faith, and Fantasy in the New Physics of the Universe" is a book by mathematical physicist Roger Penrose, released in September 2016. The book is based on his lectures that he gave at Princeton University in 2003. A reviewer of Publishers Weekly stated "Acclaimed English mathematical physicist Penrose ... gets to the heart of modern physics’ problem with subjectivity in this insightful and provocative pop-sci title... He writes with clarity and authority in this dense but rewarding discussion of scientific stumbles in the search for truth."
https://www.goodreads.com/review/show/1939231290 wrote:
<<Roger Penrose is 85, and a lot of the material in his new ["Fashion, Faith, and Fantasy"] book has previously appeared in The Road to Reality and Cycles of Time. By all rights it should be awful, but in fact it's pretty good; none of the standard rules ever seem to apply to him. At the end, he complains in a slightly surprised tone that he's never understood why people call him a maverick. In fact, he has very conservative views on physics. He almost makes it sound plausible. Then, on the final page, he tells you about his father's strong belief that Shakespeare's plays were written by Edward de Vere, the Earl of Oxford. As he says goodbye, he recommends in passing the original book on the subject, by J. Thomas Looney.>>
Art Neuendorffer

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Re: APOD: A Total Lunar Eclipse Corona (2021 Jun 09)

Post by JohnD » Wed Jun 09, 2021 4:23 pm

"wHimsy", neufer, wiv an 'H', and no 'e'!

And the Lord Peter, however much Sayers gave him the manners and appearance of an upper-class 'silly ass' (a donkey-type ass!), or how he has been portrayed by actors, has the incisive, intelligent and dare I say, scientific mind, that made him a true successor to Holmes, as consulting detectives. No whimsy there!

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Re: APOD: A Total Lunar Eclipse Corona (2021 Jun 09)

Post by johnnydeep » Wed Jun 09, 2021 7:27 pm

Chris Peterson wrote:
Wed Jun 09, 2021 2:01 pm
JohnD wrote:
Wed Jun 09, 2021 1:49 pm
Light-hearted? "When I hear the word 'Culture' I reach for my revolver!"

The beauty of science is overwhelming - there is no need to embellish and decorate it with whimsy!
The beauty of nature is found in both science and culture.

Not every APOD is intended to deliver rigorous science. And I think that's good. The Moon is a powerful symbol to humans, central to our cultures for tens of thousands of years. This is seen in many places, including the folk names we assign.
Not to mention that not all the frequenters of APOD are scientists or even necessarily well-versed in science. Some just come to see beautiful, if sometimes whimsically described and presented, pictures. But even in those cases, the embedded links almost always provide some rigorous science fare for those so inclined.
"To Boldly Go......Beyond The Fields We Know."

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Re: APOD: A Total Lunar Eclipse Corona (2021 Jun 09)

Post by VictorBorun » Wed Jun 09, 2021 7:58 pm

A kid's problem on optics: is red side out? Is red side in?

They say the white light is a mix that can be made warm (red or at least yellowish) or cool (violet or at least bluish) by positive or negative wavelength discrimination.
So the moon's corona in the posted pic is red side out, violet-blue side in and has a yellowish-against-bluish border in-between.

Why then is the low-sun sky painted inversely: warm colors are closer to sun, cool ones are farther from sun?

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Re: APOD: A Total Lunar Eclipse Corona (2021 Jun 09)

Post by Chris Peterson » Wed Jun 09, 2021 8:51 pm

VictorBorun wrote:
Wed Jun 09, 2021 7:58 pm
A kid's problem on optics: is red side out? Is red side in?

They say the white light is a mix that can be made warm (red or at least yellowish) or cool (violet or at least bluish) by positive or negative wavelength discrimination.
So the moon's corona in the posted pic is red side out, violet-blue side in and has a yellowish-against-bluish border in-between.

Why then is the low-sun sky painted inversely: warm colors are closer to sun, cool ones are farther from sun?
I'm not convinced this is actually a corona, which should be brightest at the center and decrease in brightness radially outward. This looks like some sort of simpler scattering effect. The ring appearance is just odd. Or maybe it's just some weird processing... note that the star density is much lower inside the ring than further out, which it shouldn't be unless that region was darkened with some kind of mask.
Chris

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Re: APOD: A Total Lunar Eclipse Corona (2021 Jun 09)

Post by Fred the Cat » Wed Jun 09, 2021 9:51 pm

Makes you wonder what it looked like before we observed and measured the light in the camera?

Has anyone ever put a mirror on one side of the two slits then measured what came back through? Of course, using a mirror seems to have potential flaws too. :?
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Re: APOD: A Total Lunar Eclipse Corona (2021 Jun 09)

Post by neufer » Wed Jun 09, 2021 10:23 pm

Chris Peterson wrote:
Wed Jun 09, 2021 8:51 pm
VictorBorun wrote:
Wed Jun 09, 2021 7:58 pm

A kid's problem on optics: is red side out? Is red side in?

They say the white light is a mix that can be made warm (red or at least yellowish) or cool (violet or at least bluish) by positive or negative wavelength discrimination.
So the moon's corona in the posted pic is red side out, violet-blue side in and has a yellowish-against-bluish border in-between.

Why then is the low-sun sky painted inversely: warm colors are closer to sun, cool ones are farther from sun?
I'm not convinced this is actually a corona, which should be brightest at the center and decrease in brightness radially outward. This looks like some sort of simpler scattering effect. The ring appearance is just odd. Or maybe it's just some weird processing... note that the star density is much lower inside the ring than further out, which it shouldn't be unless that region was darkened with some kind of mask.
  • The aureole centre [artificially darkened here] is fringed yellow and red because it extends furthest in these colours. The first ring's blue-violet inner edge is made of extreme violet to blue with just a little green. The dim outer red is tinged with next dimmer ring's violet.
https://www.atoptics.co.uk/droplets/corcols.htm wrote:
<<Corona colours are iridescent, redolent of soap bubbles and peacock tails. A corona's size in any single colour is proportional to the light wavelength. The red corona is almost twice as large as the extreme violet one. In the white light corona all the coronas of the individual spectral colours are superimposed. The aureole centre is nearly white. Its edge is fringed yellow and red because it extends furthest in these colours. The first ring's blue-violet inner edge is made of extreme violet to blue with just a little green. The greens at each ring centre are subdued where blue to orange all mix. The outer red is tinged with next ring's violet.>>
https://en.wikipedia.org/wiki/Corona_(optical_phenomenon) wrote:
<<In meteorology, a corona (plural coronae) is an optical phenomenon produced by the diffraction of sunlight or moonlight (or, occasionally, bright starlight or planetlight) by individual small water droplets and sometimes tiny ice crystals of a cloud or on a foggy glass surface. In its full form, a corona consists of several concentric, pastel-colored rings around the celestial object and a central bright area called aureole. The aureole is often (especially in case of the Moon) the only visible part of the corona and has the appearance of a bluish-white disk which fades to reddish-brown towards the edge. The angular diameter of a corona depends on the sizes of the water droplets involved; smaller droplets produce larger coronae. For the same reason, the corona is the most pronounced when the size of the droplets is most uniform. Coronae differ from halos in that the latter are formed by refraction (rather than diffraction) from comparatively large rather than small ice crystals.>>
Art Neuendorffer

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Re: APOD: A Total Lunar Eclipse Corona (2021 Jun 09)

Post by Chris Peterson » Wed Jun 09, 2021 10:33 pm

neufer wrote:
Wed Jun 09, 2021 10:23 pm
Chris Peterson wrote:
Wed Jun 09, 2021 8:51 pm
VictorBorun wrote:
Wed Jun 09, 2021 7:58 pm

A kid's problem on optics: is red side out? Is red side in?

They say the white light is a mix that can be made warm (red or at least yellowish) or cool (violet or at least bluish) by positive or negative wavelength discrimination.
So the moon's corona in the posted pic is red side out, violet-blue side in and has a yellowish-against-bluish border in-between.

Why then is the low-sun sky painted inversely: warm colors are closer to sun, cool ones are farther from sun?
I'm not convinced this is actually a corona, which should be brightest at the center and decrease in brightness radially outward. This looks like some sort of simpler scattering effect. The ring appearance is just odd. Or maybe it's just some weird processing... note that the star density is much lower inside the ring than further out, which it shouldn't be unless that region was darkened with some kind of mask.
  • The aureole centre [artificially darkened here] is fringed yellow and red because it extends furthest in these colours. The first ring's blue-violet inner edge is made of extreme violet to blue with just a little green. The dim outer red is tinged with next dimmer ring's violet.
Ah, missed that. Thanks. Of course, if the source light is mainly red, we'd not expect to see any color fringes as we normally would in a corona. Rather like a rainbow at sunset shows only the red band.
Chris

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Re: APOD: A Total Lunar Eclipse Corona (2021 Jun 09)

Post by VictorBorun » Thu Jun 10, 2021 4:06 pm

Let's face it: more scattered, at greater angles, are photons with wavelengths closer to the particles that do the scattering.

For the low-sun sky the particles are the air molecules that are smaller than the visual wavelength range. Therefore the shortest wavelengths are scattered most, hence the deep blue is opposite to sun.

For the compact coronae the particles are the ice micro-crystals that are larger than the visual wavelength range. Therefore the longest wavelengths are scattered most, hence the ring is red side out .

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Re: APOD: A Total Lunar Eclipse Corona (2021 Jun 09)

Post by Chris Peterson » Thu Jun 10, 2021 10:53 pm

VictorBorun wrote:
Thu Jun 10, 2021 4:06 pm
Let's face it: more scattered, at greater angles, are photons with wavelengths closer to the particles that do the scattering.

For the low-sun sky the particles are the air molecules that are smaller than the visual wavelength range. Therefore the shortest wavelengths are scattered most, hence the deep blue is opposite to sun.

For the compact coronae the particles are the ice micro-crystals that are larger than the visual wavelength range. Therefore the longest wavelengths are scattered most, hence the ring is red side out .
It's more complicated than that, because the colors are the result of diffraction, not scattering.
Chris

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Re: APOD: A Total Lunar Eclipse Corona (2021 Jun 09)

Post by VictorBorun » Fri Jun 11, 2021 4:22 pm

Chris Peterson wrote:
Thu Jun 10, 2021 10:53 pm
VictorBorun wrote:
Thu Jun 10, 2021 4:06 pm
more scattered, at greater angles, are photons with wavelengths closer to the particles that do the scattering.
It's more complicated than that, because the colors are the result of diffraction, not scattering.
OK, let's use 2 terms for 2 situations:
1) the particles are larger that the visual range wavelengths, and the longer waves are diffracted at a greater angles;
2) the particles are smaller that the visual range wavelengths, and the shorter waves are scattered at a greater angles.