APOD: A Blue-Banded Blood Moon (2021 Dec 01)

[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.

<< Previous APOD

This Day in APOD

Next APOD >>

[Ann]

A red sunset on the Earth, with blue sky above the red horizon.

---

A Blue-Banded Blood Moon. Image Credit: Angel Yu

---

As it is on the Earth, so it is in the heavens.

Ann

[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.

[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.

[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

[VictorBorun]

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?

[jasonpatterson]

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.

[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?

[Cousin Ricky]

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.

[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!

[Chris Peterson]

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.

[johnnydeep]

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.

[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

[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

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

[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.

[alter-ego]

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
Although to be honest, I do twinge a bit when I hear "blood" in food names.

[JohnD]

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

[johnnydeep]

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. ]

[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!"

[johnnydeep]

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.

[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/

[neufer]

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

[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!"

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.

[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

[johnnydeep]

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!