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APOD: A Blue-Banded Blood Moon (2021 Dec 01)
Posted: Wed Dec 01, 2021 5:05 am
by APOD Robot
A Blue-Banded Blood Moon
Explanation: What causes a blue band to cross the Moon during a lunar eclipse? The blue band is real but usually quite hard to see. The featured
HDR image of last week's lunar eclipse, however -- taken from
Yancheng,
China -- has been digitally processed to equalize the Moon's brightness and exaggerate
the colors. The
gray color of the bottom right is
the Moon's natural color, directly illuminated by sunlight. The upper left part of the Moon is not directly lit by the Sun since it is
being eclipsed -- it in the
Earth's shadow. It is faintly lit, though, by sunlight that has passed deep through
Earth's atmosphere. This part of the Moon is red -- and called a
blood Moon -- for the same reason that Earth's sunsets are red: because air scatters away
more blue light than red. The unusual
blue band is different -- its color is created by sunlight that has passed high through Earth's atmosphere, where
red light is better absorbed by ozone than
blue. A
total eclipse of the Sun will occur tomorrow but,
unfortunately, totality be
visible only near the
Earth's South Pole.
Re: APOD: A Blue-Banded Blood Moon (2021 Dec 01)
Posted: Wed Dec 01, 2021 5:26 am
by Ann
As it is on the Earth, so it is in the heavens.
Ann
Re: APOD: A Blue-Banded Blood Moon (2021 Dec 01)
Posted: Wed Dec 01, 2021 5:37 am
by alter-ego
Mmm. Akin to the violet flash at sunset/sunrise here. Seems less complicated to understand. For an observer on the moon, one might call it a blue splash.
Re: APOD: A Blue-Banded Blood Moon (2021 Dec 01)
Posted: Wed Dec 01, 2021 8:08 am
by agardini
Hi; I wish to point out that in the last sentence of the Explanation it is written that an eclipse will occour tomorrow (2 Dec.) rather than on 4 Dec.
Re: APOD: A Blue-Banded Blood Moon (2021 Dec 01)
Posted: Wed Dec 01, 2021 12:34 pm
by JohnD
Oh, for goodness sake! May we - and this astronomy website - please stop using terms such as "Blood Moon".
As shown, APoD is perfectly capable of describing the colours of an eclipsed Moon, without pandering to zombie and vampire fantasists.
Nice pic, by the way!
John
Re: APOD: A Blue-Banded Blood Moon (2021 Dec 01)
Posted: Wed Dec 01, 2021 12:51 pm
by VictorBorun
Ann wrote: ↑Wed Dec 01, 2021 5:26 am
As it is on the Earth, so it is in the heavens.
I wonder why an observer on Moon can see the blue only for a moment between the bright white and the dark red.
I take it the rim of Earth's disk in front of Sun is coloured by the bended rays; more and more bended ones are pale cyanish to blue and less and less bended are yellowish to orange.
When the small disk of Sun is well behind the large disk of Earth all remaining rays are bended greatly. The little light that does pass through must be dark violet, must not it?
Re: APOD: A Blue-Banded Blood Moon (2021 Dec 01)
Posted: Wed Dec 01, 2021 12:59 pm
by jasonpatterson
JohnD wrote: ↑Wed Dec 01, 2021 12:34 pm
Oh, for goodness sake! May we - and this
astronomy website - please stop using terms such as "Blood Moon".
As shown, APoD is perfectly capable of describing the colours of an eclipsed Moon, without pandering to zombie and vampire fantasists.
Nice pic, by the way!
John
I made an account to say exactly this. The universe is fascinating in its own right, it doesn't need silly terms created by the Weather Channel to increase click rates to catch our attention. They can keep their super blood corn moons...
Great APOD, frustrating terminology.
Re: APOD: A Blue-Banded Blood Moon (2021 Dec 01)
Posted: Wed Dec 01, 2021 1:00 pm
by DPAnderson
So is the blue band on this eclipse photo created by the same cause as the "Belt of Venus" we see here on Earth on a clear evening shortly after sunset?
Re: APOD: A Blue-Banded Blood Moon (2021 Dec 01)
Posted: Wed Dec 01, 2021 1:19 pm
by Cousin Ricky
jasonpatterson wrote: ↑Wed Dec 01, 2021 12:59 pm
JohnD wrote: ↑Wed Dec 01, 2021 12:34 pm
Oh, for goodness sake! May we - and this
astronomy website - please stop using terms such as "Blood Moon".
As shown, APoD is perfectly capable of describing the colours of an eclipsed Moon, without pandering to zombie and vampire fantasists.
Nice pic, by the way!
John
I made an account to say exactly this. The universe is fascinating in its own right, it doesn't need silly terms created by the Weather Channel to increase click rates to catch our attention. They can keep their super blood corn moons...
Great APOD, frustrating terminology.
I believe the term was created not by the Weather Channel, but by end-times Christians who take the book of
Revelation literally. Although the world did not end in 2015 as predicted, we are still a species of story tellers, and I think that’s why the term caught on in the general populace.
I have no problem with the term. It acknowledges a dimension of our humanity, we get to tacitly poke fun at the end-times believers, and I get an excuse to sing Prince’s “1999” at karaoke.
An actual problem is APOD’s 2-day space-time anomaly that has the solar eclipse occurring tomorrow.
Re: APOD: A Blue-Banded Blood Moon (2021 Dec 01)
Posted: Wed Dec 01, 2021 1:55 pm
by orin stepanek
I have no trouble with the term Blood Moon; it's
just a color!Today's photo is neat! Just think; if
you live on the moon; it's a solar eclipse
Ah! Poor kitty!
![Sad :(](./images/smilies/icon_sad.gif)
Re: APOD: A Blue-Banded Blood Moon (2021 Dec 01)
Posted: Wed Dec 01, 2021 2:07 pm
by Chris Peterson
JohnD wrote: ↑Wed Dec 01, 2021 12:34 pm
Oh, for goodness sake! May we - and this
astronomy website - please stop using terms such as "Blood Moon".
As shown, APoD is perfectly capable of describing the colours of an eclipsed Moon, without pandering to zombie and vampire fantasists.
Nice pic, by the way!
John
I like the term. Nothing wrong with it. Our language and our culture are richer for such terms. And such terms also serve to make astronomical ideas more accessible to more people.
Re: APOD: A Blue-Banded Blood Moon (2021 Dec 01)
Posted: Wed Dec 01, 2021 3:36 pm
by johnnydeep
Chris Peterson wrote: ↑Wed Dec 01, 2021 2:07 pm
JohnD wrote: ↑Wed Dec 01, 2021 12:34 pm
Oh, for goodness sake! May we - and this
astronomy website - please stop using terms such as "Blood Moon".
As shown, APoD is perfectly capable of describing the colours of an eclipsed Moon, without pandering to zombie and vampire fantasists.
Nice pic, by the way!
John
I like the term. Nothing wrong with it. Our language and our culture are richer for such terms. And such terms also serve to make astronomical ideas more accessible to more people.
Right. Science is, after all, embedded in cultures and societies and the two cross pollinate each other's terms and language. Without such, science would be devoid of poetry, which would be a terrible shame.
Re: APOD: A Blue-Banded Blood Moon (2021 Dec 01)
Posted: Wed Dec 01, 2021 5:12 pm
by RJN
The main NASA APOD text has now been corrected to say that the pending total solar eclipse will be this weekend. I apologize for the oversight. - RJN
Re: APOD: A Blue-Banded Blood Moon (2021 Dec 01)
Posted: Wed Dec 01, 2021 7:17 pm
by JohnD
johnnydeep wrote: ↑Wed Dec 01, 2021 3:36 pm
Chris Peterson wrote: ↑Wed Dec 01, 2021 2:07 pm
JohnD wrote: ↑Wed Dec 01, 2021 12:34 pm
Oh, for goodness sake! May we - and this
astronomy website - please stop using terms such as "Blood Moon".
As shown, APoD is perfectly capable of describing the colours of an eclipsed Moon, without pandering to zombie and vampire fantasists.
Nice pic, by the way!
John
I like the term. Nothing wrong with it. Our language and our culture are richer for such terms. And such terms also serve to make astronomical ideas more accessible to more people.
Right. Science is, after all, embedded in cultures and societies and the two cross pollinate each other's terms and language. Without such, science would be devoid of poetry, which would be a terrible shame.
But, johnny.....
There is no blood on the moon. If you wish to be poetic, the colour of an eclipse is the colour of sunsets, of very early mornings. The poets have said so!
A sloop of amber slips away
Upon an ether sea,
And wrecks in peace a purple tar,
The son of ecstasy. Emily Dickinson, Sunset. That namechecks combinations of red and blue!
And her:
How the old mountains drip with sunset,
And the brake of dun!
How the hemlocks are tipped in tinsel
By the wizard sun! ED The coming of night. She might be describing a lunar sunset (she wasn't)
OR, Robert Frost (I am choosing American Poets, purposely)
The west was getting out of gold,
The breath of air had died of cold,
When shoeing home across the white,
I thought I saw a bird alight.
A brush had left a crooked stroke
Of what was either cloud or smoke
From north to south across the blue;
A piercing little star was through. Looking for a Sunset Bird in Winter.
But I have to admit that the Poet of Poets used a bloody moon as a portent of ill times:
The pale-faced moon looks bloody on the earth,
And lean-looked prophets whisper fearful change. Richard II, Act 2, Scene 4
Certainly the allusion was used much earler than by some recent TV station, or modern apocalypts!
John
Re: APOD: A Blue-Banded Blood Moon (2021 Dec 01)
Posted: Wed Dec 01, 2021 7:56 pm
by De58te
Re John D. A blood moon was written about even earlier than Emily Dickinson or Shakespeare.
Joel, Chapter 2 verse 31.
The Sun shall be turned into darkness and the Moon into BLOOD, before the great and the terrible day of the Lord come.
Re: APOD: A Blue-Banded Blood Moon (2021 Dec 01)
Posted: Thu Dec 02, 2021 4:16 am
by alter-ego
Chris Peterson wrote: ↑Wed Dec 01, 2021 2:07 pm
JohnD wrote: ↑Wed Dec 01, 2021 12:34 pm
Oh, for goodness sake! May we - and this
astronomy website - please stop using terms such as "Blood Moon".
As shown, APoD is perfectly capable of describing the colours of an eclipsed Moon, without pandering to zombie and vampire fantasists.
Nice pic, by the way!
John
I like the term. Nothing wrong with it. Our language and our culture are richer for such terms. And such terms also serve to make astronomical ideas more accessible to more people.
Applies to food to, like blood oranges which I like
![Very Happy :D](./images/smilies/icon_biggrin.gif)
Although to be honest, I do twinge a bit when I hear "blood" in food names.
Re: APOD: A Blue-Banded Blood Moon (2021 Dec 01)
Posted: Thu Dec 02, 2021 10:16 am
by JohnD
De58te wrote: ↑Wed Dec 01, 2021 7:56 pm
Re John D. A blood moon was written about even earlier than Emily Dickinson or Shakespeare.
Joel, Chapter 2 verse 31.
The Sun shall be turned into darkness and the Moon into BLOOD, before the great and the terrible day of the Lord come.
Thank you, De58te! But Shakespeare is my bible!
I'm sure that the Bard was aware of the way the Prophets were as much shamen and magicians, and reworded that verse to put into the mouth of the Earl of Salisbury's Captain, who feared his King was dead, so that all was lost.
But Shakespeare, like us, was not an astrologer, scrying the heavens for prophesies and portents. Despite the geocentic Universe being the received wisdom at that time, he understood the mechanical nature of the planets and stars, as shown by Ulysses' words criticising Agamemnon, who had asked for an oracle:
The heavens themselves, the planets and this centre
Observe degree, priority and place,
Insisture, course, proportion, season, form,
Office and custom, in all line of order.
(Troilus & Cressida, Scene III)
So let us "observe degree, priority and place" when science is the subject. And let us reserve the poetic, apocalytic and sensational for times that need them.
John
Re: APOD: A Blue-Banded Blood Moon (2021 Dec 01)
Posted: Thu Dec 02, 2021 1:42 pm
by johnnydeep
JohnD wrote: ↑Thu Dec 02, 2021 10:16 am
De58te wrote: ↑Wed Dec 01, 2021 7:56 pm
Re John D. A blood moon was written about even earlier than Emily Dickinson or Shakespeare.
Joel, Chapter 2 verse 31.
The Sun shall be turned into darkness and the Moon into BLOOD, before the great and the terrible day of the Lord come.
Thank you, De58te! But Shakespeare is my bible!
...
So let us "observe degree, priority and place" when science is the subject. And let us reserve the poetic, apocalytic and sensational for times that need them.
John
Sure, there are some settings where "pure" science is the subject, but APOD is not one of them.
[ PS - Of almost all the poets I have read the poems of (not a huge number of either, mind you!), I find Emily Dickinson's work the most frequently impenetrable to me. That "SLOOP of amber" poem is a prime example. It reads beautifully to be sure, but damn, girl, you do make it frustratingly difficult to grok. ]
Re: APOD: A Blue-Banded Blood Moon (2021 Dec 01)
Posted: Thu Dec 02, 2021 8:03 pm
by JohnD
Poetry is not for understanding, it is for feeling. Science is the opposite. Just go with the flow, johnny!
Just now in the UK we have a series on BBC TV, "Universe" where that Prodigy (actually he was in another group, D:Ream) Prof.Brian Cox takes us throught the wonders of said Universe. It has outstanding visuals, but woaful explanation of said wonders. It's on the BBC iPlayer but I fear that you-all on t'other side of t'Pond can't watch that, so here's the trailer:
https://www.youtube.com/watch?v=KyeoEqa ... l=BBCEarth
"Amaaaaaaaazing!"
Re: APOD: A Blue-Banded Blood Moon (2021 Dec 01)
Posted: Thu Dec 02, 2021 8:23 pm
by johnnydeep
JohnD wrote: ↑Thu Dec 02, 2021 8:03 pm
Poetry is not for understanding, it is for feeling. Science is the opposite. Just go with the flow, johnny!
Just now in the UK we have a series on BBC TV, "Universe" where that Prodigy (actually he was in another group, D:Ream) Prof.Brian Cox takes us throught the wonders of said Universe. It has outstanding visuals, but woaful explanation of said wonders. It's on the BBC iPlayer but I fear that you-all on t'other side of t'Pond can't watch that, so here's the trailer:
https://www.youtube.com/watch?v=KyeoEqa ... l=BBCEarth
"Amaaaaaaaazing!"
Yup, I'm in NY. "Universe" will probably be shown on PBS at some point, and I'll watch it once it is. Huh - Brian Cox (not to be confused with the Scottish actor of the same name!) is yet another UK "rock star" turned scientist. The preeminent one of course being Brian May. Must be something about that first name...and perhaps also that three letter last name.
![:) :ssmile:](./images/smilies/smile.gif)
Re: APOD: A Blue-Banded Blood Moon (2021 Dec 01)
Posted: Tue Dec 14, 2021 4:31 pm
by bobfosbury
This is a beautiful view of the transmission of sunlight through the ozone layer in the Earth's atmosphere between about 12 and 40 km altitude. The Chappuis band of ozone absorbs a broad band of wavelengths centred close to 600nm and so removes a lot of the orange, yellow and green light to leave blue. As the moon moves from the umbra to the penumbra of the eclipse, the light grazes the Earth at increasing altitudes and, for a short while, passes tangentially through the ozone layer. The process is shown and modelled in the following Flickr post:
https://www.flickr.com/photos/bob_81667/50907803873/
Well done for doing great HDR processing to capture this lovely phenomenon.
Dr Robert A E Fosbury (Bob)
8 Stothert Avenue
Bath BA2 3FF
Astronomer Emeritus, European Southern Observatory
Hon. Prof., UCL Inst. Ophthalmology
ORCID:
http://orcid.org/0000-0001-9975-8003
Photos & spectroscopy:
https://www.flickr.com/photos/bob_81667/
Re: APOD: A Blue-Banded Blood Moon (2021 Dec 01)
Posted: Wed Dec 15, 2021 4:37 pm
by neufer
bobfosbury wrote: ↑Tue Dec 14, 2021 4:31 pm
This is a beautiful view of the transmission of sunlight through the ozone layer in the Earth's atmosphere between about 12 and 40 km altitude. The Chappuis band of ozone absorbs a broad band of wavelengths centred close to 600nm and so removes a lot of the orange, yellow and green light to leave blue. As the moon moves from the umbra to the penumbra of the eclipse, the light grazes the Earth at increasing altitudes and, for a short while, passes tangentially through the ozone layer. The process is shown and modelled in the following Flickr post:
https://www.flickr.com/photos/bob_81667/50907803873/
Well done for doing great HDR processing to capture this lovely phenomenon.
Dr Robert A E Fosbury (Bob)
8 Stothert Avenue
Bath BA2 3FF
Astronomer Emeritus, European Southern Observatory
Hon. Prof., UCL Inst. Ophthalmology
ORCID:
http://orcid.org/0000-0001-9975-8003
Photos & spectroscopy:
https://www.flickr.com/photos/bob_81667/
http://asterisk.apod.com/viewtopic.php? ... 45#p318145
Re: APOD: A Blue-Banded Blood Moon (2021 Dec 01)
Posted: Thu Dec 16, 2021 9:09 am
by JohnD
johnnydeep wrote: ↑Thu Dec 02, 2021 8:23 pm
JohnD wrote: ↑Thu Dec 02, 2021 8:03 pm
Poetry is not for understanding, it is for feeling. Science is the opposite. Just go with the flow, johnny!
Just now in the UK we have a series on BBC TV, "Universe" where that Prodigy (actually he was in another group, D:Ream) Prof.Brian Cox takes us throught the wonders of said Universe. It has outstanding visuals, but woaful explanation of said wonders. It's on the BBC iPlayer but I fear that you-all on t'other side of t'Pond can't watch that, so here's the trailer:
https://www.youtube.com/watch?v=KyeoEqa ... l=BBCEarth
"Amaaaaaaaazing!"
Yup, I'm in NY. "Universe" will probably be shown on PBS at some point, and I'll watch it once it is. Huh - Brian Cox (not to be confused with the Scottish actor of the same name!) is yet another UK "rock star" turned scientist. The preeminent one of course being Brian May. Must be something about that first name...and perhaps also that three letter last name.
Weeeeeeeeeelllllll! Brian May recently completed his PhD on zodiacal dust, a task that took him 33 years, 'cos he had few things to do in between. Brian Cox is a full Professor, of Particle Physics at Manchester, and the Royal Society Professor for Public Engagement in Science. Both men of considerable achievement.
Re: APOD: A Blue-Banded Blood Moon (2021 Dec 01)
Posted: Fri Dec 17, 2021 5:26 pm
by JohnD
Above we discussed the antiquity of astrologers' interest in "Blood-red moons", and biblical references. It goes even further back!
I found by chance a BBC TV programme on YouTube, "The 2000 year old Computer", about the Antikythera Mechanism. That referred to the Seige of Syracuse, 213-212
BC, when a complete Lunar Eclipse, noted to have the "Blood-red" effect, caused the Greek astrologers adviisng the military to predict disaster if their Fleet went to sea against the besieging Romans. This has been cited as a reason why Syracuse fell to the Romans, was sacked, Aristotle was killed and the Atikythera mechanism was onboard a Roman ship, as it was a part of ther spoils of the sack. More, the poly-disciplined college of specialists whose work was featured in the film concluded that it was Arisotle's work that enabled the design of the Mechanism!
I hope that the video is available to American APoDists!
https://www.youtube.com/watch?v=Q124C7W0WYA
John
Re: APOD: A Blue-Banded Blood Moon (2021 Dec 01)
Posted: Fri Dec 17, 2021 7:48 pm
by johnnydeep
JohnD wrote: ↑Fri Dec 17, 2021 5:26 pm
Above we discussed the antiquity of astrologers' interest in "Blood-red moons", and biblical references. It goes even further back!
I found by chance a BBC TV programme on YouTube, "The 2000 year old Computer", about the Antikythera Mechanism. That referred to the Seige of Syracuse, 213-212
BC, when a complete Lunar Eclipse, noted to have the "Blood-red" effect, caused the Greek astrologers adviisng the military to predict disaster if their Fleet went to sea against the besieging Romans. This has been cited as a reason why Syracuse fell to the Romans, was sacked, Aristotle was killed and the Atikythera mechanism was onboard a Roman ship, as it was a part of ther spoils of the sack. More, the poly-disciplined college of specialists whose work was featured in the film concluded that it was Arisotle's work that enabled the design of the Mechanism!
I hope that the video is available to American APoDists!
https://www.youtube.com/watch?v=Q124C7W0WYA
John
It's viewable by me here in NY. I believe I watched a similar Nova or Nature episode that also discussed the Antikythera Mechanism years ago, but this one looks like it's produced by a different group. Thanks - I'll have to watch it this weekend!