APOD: Mysterious Green Patches on the Sky (2013 Sep 30)

[Beyond]

"When you hear hoofbeats think horses, not zebras."

I'm being pedantic but zebras are horses and this statement is also biased against people who observe hoofbeats in Africa or at a zoo. Perhaps it would be more appropriate to say when you hear hoofbeats it's probably not Sleipnir.

WOW Datsa lotta hoof beats

[bystander]

I'm being pedantic but zebras are horses and this statement is also biased against people who observe hoofbeats in Africa or at a zoo. Perhaps it would be more appropriate to say when you hear hoofbeats it's probably not Sleipnir.

Zebras are not horses any more than donkeys are horses. While they are all equines and of the same family and genus, they are distinct subgenera and species. This would be like saying lions, tigers, and leopards are all the same because they are all felines (Genus Panthera).

"details, details, details ..."

[Fundyfog]

Regarding the Aurora Borealis, yes, it can be seen this far south but only rarely, and never if you are not looking towards the north.

Curt, I will have to disagree with you on the last part of your statement. I have photographs of the Aurora Borealis taken here in New Brunswick only a couple hours drive from Hopewell Cape where the lights stretched across the night sky all they way to the south east and west. I would have to look them up but I seem to remember it being about mid-October in 2006. But regardless, I would have to agree that it is probably not the Northern Lights in this case.

The source photographer said he had set up two LED lights, which you can plainly see the effects of. But there are also more distant light sources from across the Petitcodiac River, and background light from the nearby communities, including the City of Moncton. Time lapse photography, especially at night, has a wonderful way of capturing events the human eye did not or could not see. It also may represent those events in a manner that doesn't allow us to clearly interpret their source. (Dust particles illuminated by a flash have fooled countless people into believing they've photographed ghosts.) In addition to the incoming tide, wind, and the passing of time there are a number of variables that the camera didn't capture: temperature and atmospheric moisture are a couple for example. The clouds in the photos could very likely be fog and there is no easy way to tell its altitude. My theory is that it is a combination of the long exposure capturing the lights from various sources reflecting off what may be low, early morning fog. Why is it green? My best guess: maybe the combination of a long exposure, the orange glow of background light and the blue/white glow of the LEDs mixing and reflecting off the surrounding rocks, incoming brown muddy tidal water and low fog. It would be interesting if someone could reproduce it.

[geckzilla]

I'm being pedantic but zebras are horses and this statement is also biased against people who observe hoofbeats in Africa or at a zoo. Perhaps it would be more appropriate to say when you hear hoofbeats it's probably not Sleipnir.

Zebras are not horses any more than donkeys are horses. While they are all equines and of the same family and genus, they are distinct subgenera and species. This would be like saying lions, tigers, and leopards are all the same because they are all felines (Genus Panthera).

"details, details, details ..."

Well, I do consider lions, tigers, and leopards (and bobcats, and panthers, and, and...nevermind) to all be cats.

Zebras, donkeys and horses are so similar they are capable of reproduction with one another! Granted, they're sterile hybrids, but I see nothing wrong with classifying things together especially with the genetic evidence backing it up.

[Jails]

Green it's the first and last couleur reflected in the atmosphère.
It is a solar wind. Too light to rise in the range of colors.
It is because the magnetic shield is too low.
Normally the green does not observe easily

More the wind to solar is loaded in particle ionized.
More we rise in the spectre of colors.
It is as a caress. If it was stronger or than we would have film in infrared.
We would have seen a aurora borealis.

[Kevin Snair]

Wow ..... what an amazing variety of theories.

I am certainly willing and interested in trying to reproduce the shoot as an experiment to see if we get similar results. It would be a while before I could do it though. Our tides vary in height from 32 feet to 46 feet. To reproduce the scenario, I would need an almost new moon, tides at a similar height, similar air temp, the same size waves, and the same water temp. Seeing that we have only 13 or 14 new moons per year, and Autumn is upon us, it will be another 8 or 9 months before there is even a chance of similar conditions.

Thanks to everyone who has contributed to this discussion.

[geckzilla]

Wow ..... what an amazing variety of theories.

I am certainly willing and interested in trying to reproduce the shoot as an experiment to see if we get similar results. It would be a while before I could do it though. Our tides vary in height from 32 feet to 46 feet. To reproduce the scenario, I would need an almost new moon, tides at a similar height, similar air temp, the same size waves, and the same water temp. Seeing that we have only 13 or 14 new moons per year, and Autumn is upon us, it will be another 8 or 9 months before there is even a chance of similar conditions.

Thanks to everyone who has contributed to this discussion.

Hey Kevin, any chance we could see a couple of stills in the meantime at high resolution to see how it looks without all the video compression?

[BielakAttack]

From a amateur astronomers standpoint I can see why this would look like an Aurora, even though to me it looks more like clouds. Not saying they are clouds, especially since the known clouds of the video move perpendicular. Airglow is another, though more unlikely probability.

Coming from a hobbyist photographers perspective, I know that standard LED lights, fluorescent lights and natural daylight have similar color warmth. In night shots when using back-lighting from LED sources I would sometimes have to alternate between my custom preset for fluorescent and my preset for daylight, depending on the color warmth of the reflection, which changes quite frequently when changing positions. The way I would know is; when the overall hue would look too green, I would know that I need to change the white balance to my fluorescent preset, and problem solved. If its too blue, I need to change it to daylight. It is very possible that the incoming tide or fog caused a "cooling" of the color warmth by changing the reflective light, requiring a change in the white balance. Right before posting this I went back and rewatched the video. Notice the blue wash at the beginning? That was more drastic because the light source was a little bit bigger than the LED's.

However, it could be something way more interesting. But since the rock walls and trees also change green, I'd point my finger of blame at the boring change in white balance.

[Dr.Bob]

I don't think it's aurora, looks too cloud like. It also looks like its emanating from the rock/trees to me.. Most curious! Where's Spock when you need him?

[Nitpicker]

Seems to be looking about NE (based on sky motion) from a latitude of N46. Can Aurora Borealis be observed from so far South?

Based on the topography of the location if the camera had been pointing NE much of what you would be able to see is the cliff wall. That said, the camera seems to be pointed mostly towards the south as it is looking out into the bay, possibly SW from approx location 45º49'01.66"N 64º34'29.32"W. Regarding the Aurora Borealis, yes, it can be seen this far south but only rarely, and never if you are not looking towards the north.

"When you hear hoofbeats think horses, not zebras."

Thank you Curt, but you are almost 200 posts and two corrections too late. I was first corrected by alter-ego at about post #32, and I conceded my silly mistake soon afterwards, here:
http://asterisk.apod.com/viewtopic.php? ... 5&start=36

My mistake was caused by not reading the details provided by the photographer closely enough, not having any special knowledge of the exact bay/cliff, and also my unjustified assumption that Perseus would be in or near the field of view. If one looks NE from this approximate location, at the time and date in question, the orientation of the galactic plane is not too dissimilar from that seen when looking southward. Granted, the well-known appearance of the centre of the galaxy should have been a dead giveaway, but we're all stupid from time to time. I don't think I heard any hoofbeats.

[norman]

Let's not forget the Shag harbour incident

[Kevin Snair]

Here are links to two stills. One is prior to the arrival of the green. The other during.

Http://www.creativeimagery.ca/Persieds_367.jpg
Http://www.creativeimagery.ca/Persieds_424.jpg

[Nitpicker]

Norman, you might be able to solve the Shag Harbour Incident by trolling.

[Beyond]

Norman, you might be able to solve the Shag Harbour Incident by trolling.

ha-ha, good suggestion, but they took off a l-o-n-g time ago.

[neufer]

I'm being pedantic but zebras are horses and this statement is also biased against people who observe hoofbeats in Africa or at a zoo. Perhaps it would be more appropriate to say when you hear hoofbeats it's probably not Sleipnir.

Zebras are not horses any more than donkeys are horses. While they are all equines and of the same family and genus, they are distinct subgenera and species. This would be like saying lions, tigers, and leopards are all the same because they are all felines (Genus Panthera).

Zebras, donkeys and horses are so similar they are capable of reproduction with one another! Granted, they're sterile hybrids, but I see nothing wrong with classifying things together especially with the genetic evidence backing it up.

• Horses & dogs have true withers; zebras & asses don't.

<<The withers is the ridge between the shoulder blades of a four-legged mammal. In many species it is the tallest point of the body, and in horses and dogs it is the standard place to measure the animal's height (in contrast, cattle are normally measured to the top of the hips).

In dogs, the height of the withers is often used to determine the dog's jump height in various dog sports. It is also often a determining factor in whether the dog conforms to the show-quality standards for its breed.

Zebras have very low withers, making it far more difficult for a saddle to stay in place.

Asinus is a subgenus of Equus that encompasses several subspecies of Equidae commonly known as asses, characterized by long ears, a lean, straight-backed build, lack of a true withers, a coarse mane and tail, and a reputation for considerable toughness and endurance.>>

[geckzilla]

There are a lot of superficial differences. They're still all categorized as horses (equus). The word "horse" as we usually use it refers to the animal more specifically called the domestic horse. I told you I was being pedantic.

[Chris Peterson]

Horses & dogs have true withers; zebras & asses don't.

Not so.

All four legged mammals have withers. Some animals, such as horses and dogs, have higher thoracic dorsal spinal processes than other animals, producing more pronounced (or obviously taller) withers. But to suggest that some withers are more "true" than others is wrong, or at least, very poor wording.

[geckzilla]

Here are links to two stills. One is prior to the arrival of the green. The other during.

Http://www.creativeimagery.ca/Persieds_367.jpg
Http://www.creativeimagery.ca/Persieds_424.jpg

Thanks for those. It's a lot more clear, but still mysterious. Hmm. All I can think of at the moment is that if we really want to solve this one easy way to eliminate the possibility of it being created by the instrument would be to use two cameras at the same time and compare the data between them. If both show the same anomaly then it must be a real thing.

[neufer]

Horses & dogs have true withers; zebras & asses don't.

Not so.

All four legged mammals have withers. Some animals, such as horses and dogs, have higher thoracic dorsal spinal processes than other animals, producing more pronounced (or obviously taller) withers. But to suggest that some withers are more "true" than others is wrong, or at least, very poor wording.

• MIce have withers?

HAMLET. The Mouse-trap. Marry, how? Tropically. This play

• . is the image of a murder done in Vienna: Gonzago is
  . the duke's name; his wife, Baptista: you shall see
  . anon; 'tis a knavish piece of work: but what o'
  . that? your majesty and we that have free souls,
  . it touches us not: let the galled jade wince,
  . our withers are unwrung.

----------------------------------------------------------
Withers, n. pl. [Properly, the parts which resist the pull or strain in drawing a load; fr. OE. wither resistance.] The ridge between the shoulder bones of a horse, at the base of the neck.
----------------------------------------------------------
Wither, v. i. [OE. wideren; probably the same word as wederen to weather; or cf. G. verwittern to decay, to be weather-beaten.]

• 1. To fade; to lose freshness; to become sapless; to become sapless; to dry or shrivel up.
  2. To lose or want animal moisture; to waste; to pin away, as animal bodies.
  3. To lose vigor or power; to languish; to pass away. Names that must not wither." Byron.

[BoilerMaker]

Me, I am going with, there was something in the meteors, This year I have noticed more than a few meteors with a greenish burn. Enough small particles left from a burned out meteor shower could have been the cause. What turns green when burned?

[Beyond]

Withers... The ridge between the shoulder bones, at the base of the neck.
Who would know more about Withers, than Josephine The Plumber, played by Jane Withers.
Jane's Withers came in handy when she had to haul around the really big can of Comet.

thCAGI8B5L.jpg (7.96 KiB) Viewed 55358 times

[Nitpicker]

Beyond, that's a terrible segue back to astronomy. You Oort to know better.

[Beyond]

Gee, i thought i was being rather Sirius.

[Nitpicker]

Me, I am going with, there was something in the meteors, This year I have noticed more than a few meteors with a greenish burn. Enough small particles left from a burned out meteor shower could have been the cause. What turns green when burned?

Wow, I don't think that possibility has been mentioned yet. I have no idea how plausible it is, but I give credit for originality at this late stage.

[geckzilla]

MIce have withers?

Obviously a glitch in the matrix.