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

Comments and questions about the APOD on the main view screen.
omurchubp

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

Post by omurchubp » Mon Sep 30, 2013 2:38 pm

I can quite clearly see the silouettes of Yogi bear
& Boo Boo against the night sky. They're having a party.

Seriously ... I vote combination of aurora, reflected light
from tide & camera lens effects.

Roland

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

Post by Roland » Mon Sep 30, 2013 2:55 pm

I see something between airglow and aurora. I saw a couple of edges that look like aurora, but the rest of the time it was more like airglow. Is it possible that the two are related? Is airglow what aurora becomes farther away from the poles where the magnetic lines run parallel to the earth surface?

scopegal

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

Post by scopegal » Mon Sep 30, 2013 2:59 pm

I agree with the notion of this phenomena being an auroral display. After all we are at solar maximum (or very very near). While I could not find any archived data to indicate a well timed flare or other event, I think it is likely that such an occurance took place. When the video was shot it was very early in the morning when the green came around and it happened so randomly that an Aurora just makes sense to me.

Mokurai
Asternaut
Posts: 6
Joined: Sun Nov 04, 2012 2:44 pm

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

Post by Mokurai » Mon Sep 30, 2013 3:07 pm

Ah, collective intelligence, the dream of Doug Engelbart, who invented most of modern computing. In his honor, One Laptop Per Child teaches astronomy and everything else to millions of children, and enables them to collaborate to solve the problems of the world.
Click to play embedded YouTube video.

Rathkennamike

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

Post by Rathkennamike » Mon Sep 30, 2013 3:15 pm

The patches are obviously cloud, It would be common for cloud to form on a rising tide.
The green colour is most likely an effect of the recording process or the imaging equipment in combination with the ambient light. Or it could be that the water vapour in the cloud will filter out red light at certain angles. :idea:

jisles

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

Post by jisles » Mon Sep 30, 2013 3:19 pm

Looks to me like aurora.

maunakea

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

Post by maunakea » Mon Sep 30, 2013 3:27 pm

That green glow has a cloud-like structure and behavior. I'm going to go with noctilucent clouds.

Greenman

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

Post by Greenman » Mon Sep 30, 2013 3:29 pm

A morning version of the green flash perhaps?

User avatar
JohnD
Tea Time, Guv! Cheerio!
Posts: 1577
Joined: Wed Feb 16, 2005 2:11 pm
Location: Lancaster, England

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

Post by JohnD » Mon Sep 30, 2013 3:30 pm

geckzilla wrote: Surely you don't think a pipeline that exploded 1500 miles away the night after the video was shot had anything to do with it?
No, the night OF the video.
Which, quoting APOD, "ran from 9:30 pm August 11 to 3:00 am the next morning" The 12th.
John

sschroeder

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

Post by sschroeder » Mon Sep 30, 2013 3:33 pm

Looks like light reflecting off noctilucent clouds to me. The green also seems to be somewhat enhanced by camera artifact as the colors seem to be a bit off throughout the video.

ganoudij
Asternaut
Posts: 1
Joined: Mon Sep 30, 2013 2:56 pm

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

Post by ganoudij » Mon Sep 30, 2013 3:33 pm

The camera is facing south towards Nova Scotia. Hopewell Rocks is around latitude 48N near mid latitude for aurora activity (50-60N). I think the green light is being reflected by the north moving clouds from behind the camera. This theory is supported by the increased illumination on the foreground rock after the illumination on the clouds starts to fade. The tide is coincidental but the water at the shoreline is also reflecting the light from the clouds and aurora. More research needs to be done to see if there was any reported aurora on Monday, August 12th, 2013 between 1:00 and 3:00 AM in the area. Spaceweatherlive.com gives a 10% chance of minor activity that night for mid-latitudes.

Edited Post: I checked on the wind direction during this time frame (Fundy Park) and it is primarily out of the North (NE to NW). I think this is most likely air-glow moving north. Not clouds, which should be moving south, southeast or southwest. There are high altitude clouds on the horizon, which could have a similar color but unable to make them out with the resolution on the video. The illumination on the foreground rock seems to be from the sky behind or above the camera not from water ... it is way too bright to be a green reflection from the water, which would probably absorb some of the wavelength anyway. Cameras of course see more than the human eye in a 30 second exposure so the effect wouldn't have to be as bright as it might seem.
Last edited by ganoudij on Mon Sep 30, 2013 6:50 pm, edited 5 times in total.

fivver

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

Post by fivver » Mon Sep 30, 2013 3:45 pm

In your APOD description you opine that it could be something artificial or natural or something else entirely. I'd be interested in what that something else could be. :lol2:

Jim Nelson

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

Post by Jim Nelson » Mon Sep 30, 2013 3:49 pm

This phenomenon occurs around sunrise at which time up is the general direction Earth is moving in it's orbit. Since it resembles an aurora is it possible there's an aspect of the solar wind or a CME we're running into that's unaffected by the magnetic field.

Kingy

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

Post by Kingy » Mon Sep 30, 2013 3:50 pm

Perhaps aurora reflecting off or through noctilucent clouds.

cdavenport1941

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

Post by cdavenport1941 » Mon Sep 30, 2013 3:52 pm

Notice that the green glow coincides with the rising tide. Perhaps reflected color from algae in the water?

Horse782

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

Post by Horse782 » Mon Sep 30, 2013 3:56 pm

Simply looks to me as being a weak version of the norther lights. considering the date and time, the sun would have been rising in a couple hours so charged particals from the sun would have been starting to cascade through the atmospher from over the horizan, normaly only visable in more northern areas where the magnetic field is more consentrated by the poles but lets not forget, this is the bay of fundy, and the tide rushes in same time as the green appears.... the moons gravety acted as a "boost" causing the magnetic field in the area to bunch togeather, thus concentrating the charged particals. the same as up north when the lines of our magnetic feild start drawing closer togeather to merge at the poles, drawing these particals togeather and giveing us our norther lights. also worth noting is the increased activity of the sun this year (solar flairs) thus giving more of these charged particals then normal.

that would be my uneducated best guess!

derp82

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

Post by derp82 » Mon Sep 30, 2013 4:01 pm

Better question would be... why did the user upload the video at 360p? If he's taking long exposures, he has to have a camera capable of producing a 720p or higher video in post production. 1080p is only 2 megapixels.

Gorrak

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

Post by Gorrak » Mon Sep 30, 2013 4:07 pm

The Tide doesn't come in until the end of the video. Hopewell Rocks have the fastest/highest tides in the world. When the tide comes in here, it can go as high as the trees on the rocks in less than an hour. This location is also on a Bay, so I'm not sure if that would change the algea conditions.

Having grew up in the area, and spent many late nights camping out near these rocks, I've never seen or heard of the sky doing this... So my guess is this is a camera defect of some kind. We get some nice color in the sky at dusk, but nothing like this lighting up the night.

Henry Selvey

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

Post by Henry Selvey » Mon Sep 30, 2013 4:23 pm

I would guess that it is a form of auroral display. It certainly is the most normal green of such. The reflection theory sounds a little far-fetched to me and the photographic theories are quite beyond me. It certainly does not have the characteristic wavy appearence of an aurora, but I would not take that as ruling out auroras. I have only observed auroras several times in my life, but on the first occasion it was very diffuse and it took several of us quite some time to figure out what we were witnessing. Nevertheless, the first time I saw it, the aurora did in time show bands and waves which is what gave it away to us. I believe that matthank's explanation (pg 1) is rather compelling and could have easily produced the same appearence at the earlier stages of my first viewing of the auroral phenomenon.

welaing

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

Post by welaing » Mon Sep 30, 2013 4:24 pm

I saw something like this in northern Wisconsin in Summer 1998, and the press reported it had been caused by a magnetar event.

robamiller

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

Post by robamiller » Mon Sep 30, 2013 4:34 pm

I don't know about this image, but in Spokane WA in August 2013 we had several thunderstorms. One occurred during the Perseid Meteor shower and I saw some pretty fantastical things. I have captured some video I can post, but to summarize, there were several instances of blue/green aurora-looking patches of sky, unusual lightning patterns, and instances of bright red traces. I can't help but feel the timing of the storm with the meteor shower was somehow responsible for the anomalies I witnessed that night.

eLamanented

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

Post by eLamanented » Mon Sep 30, 2013 4:52 pm

Could it be a reflection of an algae bloom, it seems to move along as the tide roles in.

47.81 N 122.37 W
Asternaut
Posts: 1
Joined: Mon Sep 30, 2013 4:33 pm

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

Post by 47.81 N 122.37 W » Mon Sep 30, 2013 4:54 pm

While the green looks similar to aurora I've captured on still photography from just north of Seattle, it's hard to imagine seeing that much aurora color facing south or southwest from the camera's latitude.

my near-newb thoughts...

aurora: not convinced
equipment artifact: likely
other stuff: no idea

kw5kw

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

Post by kw5kw » Mon Sep 30, 2013 5:01 pm

I agree that if it appears on frames at about 25 seconds its is an unwanted by product of the camera's sensor. To keep this from being a factor reduce time from a 30 second exposure to a 20 second exposure.

MD IRELAND

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

Post by MD IRELAND » Mon Sep 30, 2013 5:03 pm

Could this be an Auora reflecting off very high very light clouds??