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Thread: A light green hue around moon

  1. #1
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    Question A light green hue around moon

    My questions are sincere and I would like to know if anyone else here (aside from twelve y/o daughter and I ) observe or notice a green coloured light hue around the moon two weeks ago?

    The colour of light around the moon was distinctly green - I never mentioned this phenomena to anyone for fear of people thinking that my daughter and I had lost our minds, however, I know what I saw as does my daughter, a light coloured green moon, the colour was very clear.

    I am at loss and would welcome any explanation as to what creates the green in the atmosphere to make the light around the moon appear this colour? thank you.

    Kind regards,
    Blue Earth
    Last edited by Blue Earth; 2009-Apr-16 at 11:19 AM.

  2. #2
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    Blue Earth,
    I don't have a quick answer, but maybe you can give a little more info.

    If it was two weeks ago, the moon was in the first quarter, is that correct? What time of day was it and how high in the sky was the moon? What was the weather like? Was it cloudy at all? And lastly, was the moon itself green, or the light around the moon was green?

    My first guess, particularly if it was the light around the moon, would be some sort of halo.
    At night the stars put on a show for free (Carole King)

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  3. #3
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    Something in the atmosphere was more than likely causing the effect. Living in Whitehorse, Yukon I used to see halos and sun dog all the time from ice crystals in the air. The same effect could be caused from dust or pollutions in the air. Also depending on how low in the sky the moon was it could be just refraction.

    http://www.webexhibits.org/causesofcolor/13D.html

  4. #4
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    From the description so far, I'm thinking an aureole, rather than a halo.

    The aureole is related to the corona. A corona is a diffraction pattern produced by water droplets or amorphous ice crystals which are all about the same size: it forms a ring around the moon with a blue inner edge and a red outer edge, and can be multiple. The aureole is the central part of the corona, usually a pale disc with a reddish edge, which can appear in isolation. If it is produced by droplets of many different sizes, it can be blurred into little more than an amorphous pale patch superimposed on the moon. I've seen aureoles that looked white, pale yellow or pale green.

    Grant Hutchison

  5. #5
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    Come on, somebody has to say it . . .maybe the moon is made of green cheese after all? All seriousness aside though, I'd agree that Grant's on to something - the linked photo sure does look greenish. I've never seen a green aureole yet but I'm hoping to live long enough to see one anyway. I'm sure that neither you nor your daughter is crazy in any case. My only suggestion is that the next time you fear that people will think you're crazy, start lighting up the switchboards and get witnesses - something like that is just too darned cool to keep to your self!
    Last edited by Blue Fire; 2009-Apr-15 at 07:14 PM. Reason: spelling

  6. #6
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    I think the saturation and contrast may have been tweaked a little in my links above.
    Here are aureole photos that more closely approximate the shade in my experience. Notice the faint red outer edge and the pale greenish-yellow centre. The light from the central part of the aureole is composed of superimposed diffraction rings of all spectral shades except that largest red rim: hence the desaturated green appearance.
    The size of the aureole varies according to the mean particle size (small particles give big diffraction patterns). When it's blurred and irregular because of a wide variation in particle size, the red edge becomes harder to notice.

    Grant Hutchison

  7. #7
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    Hello Swift,

    Thank you for your time and replying to my post it is greatly appreciated and I will answer hopefully your questions to the best of my ability. If it helps? I also live in the southern hemisphere in a region called the Bay of Islands in a coastal rural area situated on the east (pacific side) of NZ's north island.

    Quote Originally Posted by Swift View Post
    Blue Earth,
    If it was two weeks ago, the moon was in the first quarter, is that correct?
    The moon was a cresent and gibbous phase on the two (not consecutive) evenings I visually sighted, observed and noticed this unusual phenomena.

    There is no deception to the colour, the appearance of the moon surface was a pale light green and the surrounding light around the moon rim was was a distinct vibrant green.

    The date's this happened (forgive me) would have been between 1 - 4 April 2009. I know it was the week leading up to the weekend that daylight saving finished here in this part of my world being April the 5th. I remember I was not particularly pleased about the idea of turning the clock back one hour and I am still not pleased with it at all

    Quote Originally Posted by Swift View Post
    What time of day was it and how high in the sky was the moon?
    Time and hour of day was evening at approximately 21:30hrs, looking north west the moon would have been approx 45 degree's high in the sky from the horizon (does that sound right(?) sometimes, I think I may not explain things clearly

    Quote Originally Posted by Swift View Post
    What was the weather like? Was it cloudy at all? And lastly, was the moon itself green, or the light around the moon was green?
    It was a clear beautiful autumn night with not much cloud about at all on both evenings I observed and noticed this unusual lunar atmospheric phenomena. The moon and light around the moon was distinctly green in colour.

    At the time I noted this I did also look around at the surrounding stars to see if there was a green hue to their appearance, but, they were to small for me to see any change in the light clearly.

    My daughter came across two green moon articles today whilst doing research online to learn and understand more about this, I will post them soon, thank you again.

  8. #8
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    Quote Originally Posted by rommel543 View Post
    Something in the atmosphere was more than likely causing the effect.
    Hello rommel543,

    I too think that it could only be something in the atmosphere that caused the effect. I know that the moon that its surface is not green in colour, I know this, however on those evenings observed the moon and the moon light was green, no halo, no corona that I recall, it was just green and green around the outer rim/edge of it.

    My daughter and I have searched for an image online that is as close a match in colour to what we saw and came across an image (not of the moon) that shows the colour

    Thank you for help it is appreciated, take care.

  9. #9
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    Quote Originally Posted by grant hutchison View Post
    From the description so far, I'm thinking an aureole, rather than a halo.


    Hello Grant, I am thinking an aureole perhaps also as this would make logical sense to me because it was an atmospheric thing

    Anyway, we are grateful for your time in helping us understand this phenomena, and do appreciate have visited and studied all links in both messages you have kindly posted, a huge, huge thank you take care, kind regards.

  10. #10
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    Quote Originally Posted by Blue Earth View Post
    Anyway, we are grateful for your time in helping us understand this phenomena, and do appreciate have visited and studied all links in both messages you have kindly posted, a huge, huge thank you take care, kind regards.
    Glad to have helped.

    Grant Hutchison

  11. #11
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    Quote Originally Posted by Blue Fire View Post
    Come on, somebody has to say it . . .maybe the moon is made of green cheese after all? All seriousness aside though, I'd agree that Grant's on to something - the linked photo sure does look greenish. I've never seen a green aureole yet but I'm hoping to live long enough to see one anyway. I'm sure that neither you nor your daughter is crazy in any case. My only suggestion is that the next time you fear that people will think you're crazy, start lighting up the switchboards and get witnesses - something like that is just too darned cool to keep to your self!


    Hello Blue Fire,

    Thank you for the smiles and for your suggestion, our 12 y/o enjoyed reading your message ( and all who replied to my post) it helps when someone else is able to explain things abit more clearer or better when mum or dad do some seem to getting thru (grin).

    I encourage my children to develop good observational skills and the importance of recording things - sometimes they remember and sometimes they forget, anyway...

    Your post was a positive nudge and a timely reminder for both my daughter and I to remember to record things the moment anything out of the ordinary happens, we will thank you again, take care.

    PS: Green Moon articles my daughter came across online.

    The New York Times - Archives

    A GREEN CRESCENT MOON.
    From the New-Zealand Times, July 6.

    A bright green moon is not a common phenomenon. Yet this was visible in Willington for about a quarter of an last evening. There was an exceptionally splendid manifestation of the "afterglow" which is so complete an enigma
    to all physicists, and just at the edge of the vivid rosy glow, where it merged into pink and violet, the cresent moon appeared of the most brilliant yet delicate green colour, presenting a most curious and beautiful night. The unwonted spectacle only remained visible a few minutes after 5.P.M.

    The New York Times
    Published: September 19, 1886

    A GREEN MOON.
    From the Virginia (Nev.) Enterprise, Feb.29.

    Last evening there was a beautiful pink after-glow in the west, against which
    loomed the peak of Mount Davidson. At a short distance above the peak, in the midst of the roseate glow, stood the new moon, and above the moon a solitary star. The crescent moon lay on its back, and appeared of a light green. The hue of green was about what is known to artists as malachite. There was no decption about it, as all whose attention was called to the moon at once observed the pale green hue. The phenomenon was doubtless of the same character as the "green suns" of which we have of late heard so much.

    The New York Times
    Published: March 7, 1884

  12. #12
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    Quote Originally Posted by Blue Earth View Post

    Thank you for the smiles and for your suggestion, our 12 y/o enjoyed reading your message ( and all who replied to my post) it helps when someone else is able to explain things abit more clearer or better when mum or dad do some seem to getting thru (grin).

    I encourage my children to develop good observational skills and the importance of recording things - sometimes they remember and sometimes they forget, anyway...
    Glad we could help Blue Earth. We work very hard to keep this forum child friendly. I hope you and your daughter continue your interest in astronomy and science and continue to visit here.
    At night the stars put on a show for free (Carole King)

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  13. #13
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    Quote Originally Posted by rommel543 View Post
    Something in the atmosphere was more than likely causing the effect.
    Hello rommel543, ( I did do a reply post, however it did not appear on board trying again)

    I agree that it was likely something in the atmosphere causing the effect. I
    know that the moon its surface is not green in colour I know this, however, on the evening's I observed this atmospheric optic phenonmena, the surface of the moon and its light was distinctly green in colour.

    We searched online for an image that matched the colour we saw and came
    across this link, although it is not a picture of the moon ( I know (smile) the colour we observed is there, it was a beautiful and an usual thing to see... anyway..

    Thank you for taking time to reply, my daughter and I have enjoyed and
    learned much from everyone (thank you gentlemen) who have kindly
    contributed thoughts and insights to the appearance of the green moon phenomena (smile) take care, kind regards.

  14. #14
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    Quote Originally Posted by Blue Earth View Post
    PS: Green Moon articles my daughter came across online.
    These are interesting, thank you.
    In both cases we have a crescent moon appearing green against, or next to, a red sunset sky. My first thought is that this is a contrast effect: a colourless moon appearing greenish because of surrounding redness. The moon is a great deal brighter than the sky, so scattered red light between our eyes and the moon's disc might not be too noticeable, and the effect of contrast might dominate.
    But I dunno. I've never seen anything like what is described.

    Both stories give enough detail to be pretty sure this isn't a "green flash" effect, unless atmospheric refraction was very unusual. The crescent moon is a fair distance above the horizon in both stories, and the green flash is a horizon effect.

    Both stories also seem quite clear that the sky around the moon is not green, so to that extent it's different from what [b]Blue Earth[/i] reports.

    Grant Hutchison

  15. #15
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    I'm just shooting from the hip here, but perhaps some selective scattering took place. Blue Earth, I wonder if your fall atmosphere can get surges of aerosols or other particulate matter in the atmosphere. [Any of those volcanoes to the NW of you slightly active at all?] You have some mountains in the direction you saw the Moon, that might allow particulate matter to rise to intersect with your 45 deg. angle for the Moon.

    If enough particles are just the right size, they can scatter a certain color more than the others. [The blue halo around the Sun as seen through the Martian atmosphere by the rovers, is one example of this.]

    Or, if the particles were actually a little green and too large for Rayleigh scattering (which would not be surprising), then Mie scattering would fling this green light forward to you.

    It doesn't hurt either that our eyes are most sensitive to the color green, especially in dim light; it's the last color we can see and is now a popular as the paint color for many emergency vehicles.

    It would be interesting to learn what others saw from differnt locations throughout New Zealand.
    We know time flies, we just can't see its wings.

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