Starship Asterisk*

Posted: **Tue Feb 10, 2009 5:12 pm**

This thread is meant for discussion of http://apod.nasa.gov/apod/ap090217.html titled "Unusual Red Glow Over Minnesota" that appeared on APOD on Monday, 2009 February 17. Thoughtful comments and ideas about what created the red glow in the image are encouraged. This is another attempt to use the collective intelligence of APOD readers as a "problem solving engine."

- RJN

Posted: **Tue Feb 17, 2009 5:24 am**

FWIW, 9/23/02 was a wet, windy day in that part of the Twin Cities. There wasn't a soaking rain - only about .02 precip all day - but average humidity was 75%.

Of course, this is from surface data - may have no bearing at all. Looks like some sort of reflection to me.

Posted: **Tue Feb 17, 2009 5:29 am**

Sunset reflected by atmospheric moisture works for me. It also looks like there is a thin gray cloud layer between the camera and some areas of the glow, which would not be the case if the glow were on the window.

Posted: **Tue Feb 17, 2009 5:34 am**

These would have to be clouds, but the unusual density is a mystery. The reason I say clouds is because if you look at the edges they are what you’d expect clouds to look like. I have seen many small red clouds at sunset, often mixed in with some darker gray clouds at the same altitude, so as far as I’m concerned red clouds aren’t that much of a mystery. The cloud on the left appears to be of greater density near it’s edges, almost like it’s rolling upward like a fireball would.

Posted: **Tue Feb 17, 2009 5:36 am**

I think it's obvious that it's just an unusual perspective on a sunset. The lucky plane-borne photographer here just happens to have a vantage point above some beautifully colored cloud tops--albeit thin clouds and/or virga. Very nice looking, though!

Posted: **Tue Feb 17, 2009 5:43 am**

My first thought was also that this is a simple sunset reflection. I don't know the orientation of the photograph, but my suspicion is that the photo was taken with the sun very low on the horizon, west being toward the lower right hand side of the photo.

Posted: **Tue Feb 17, 2009 5:57 am**

MikeAtHRI wrote:My first thought was also that this is a simple sunset reflection. I don't know the orientation of the photograph, but my suspicion is that the photo was taken with the sun very low on the horizon, west being toward the lower right hand side of the photo.

Explanation: the phenomenon could just be a peculiar window reflection. the image was captured on 2002 September 23 at about 8:07 pm in the evening (local time), and that the camera was reported to be pointing north of west at that time.

I go for the starboard window reflection of a sunset streaming through two forward port windows
(with seats obstructing the bottom of the port window sunset reflections and
a window shade obstructing the top of the left most [i.e., forward most] port window sunset reflection.)

Posted: **Tue Feb 17, 2009 6:05 am**

neufer wrote:
MikeAtHRI wrote:My first thought was also that this is a simple sunset reflection. I don't know the orientation of the photograph, but my suspicion is that the photo was taken with the sun very low on the horizon, west being toward the lower right hand side of the photo.

Explanation: the phenomenon could just be a peculiar window reflection. the image was captured on 2002 September 23 at about 8:07 pm in the evening (local time), and that the camera was reported to be pointing north of west at that time.
I go for the starboard window reflection of a sunset streaming through two forward port windows
(with seats obstructing the bottom of the port window sunset reflections and
a window shade obstructing the top of the left most [i.e., forward most] port window sunset reflection.)

----------------------------------------------------------------
Art (I'm Good Enough, I'm Smart Enough, and Doggone It, People Like Me!) Neuendorffer

Posted: **Tue Feb 17, 2009 6:19 am**

I think unusual perspective on a particularly beautiful sunset--note that in the upper right of the photo is a body of water reflecting a cloudscape with a mixture of pink and gray clouds, so there are reddish clouds in the area. The difference in angle of the observer might account for the difference in color saturation. I also almost think the foreground at the lower right looks like it is basking in more reddish light than the ground further away, but it is hard to tell, and easy to make yourself think so, with that orange patch immediately adjacent. Also, if you examine the edges of the spots of color, they have the diffuse, "foggy" appearance one would expect of clouds, especially on the upper side--not really what you would expect from a window reflection.

Posted: **Tue Feb 17, 2009 6:22 am**

I would vote for the effect being caused by red sunset light reflecting off or shining through rain or fog

Posted: **Tue Feb 17, 2009 6:28 am**

It could be both an atmospheric effect and a reflection, the latter overlaying the former.

I have one question. Are we looking at the entire photograph, or is this only a section of it? If for example, this is a section of a larger photo which included even the smallest slice of the setting sun, the reflection we might be seeing could be internal to the lens.

Posted: **Tue Feb 17, 2009 6:31 am**

Clearly this is a case of alien invaders attempting to destroy Minnesota because of it's cold, harsh environment. Either that, or a great light refraction from the clouds. Fabulous picture Tyler!
I think that the water in the clouds caught the refracted red spectrum of the setting sun, but from a much different angle than the average person is used to. Just much two cents that is worth every penny.
I don't believe that it is a phenomenon caused by the window, but I could be wrong.
Phatso420

Posted: **Tue Feb 17, 2009 6:49 am**

I just put the EXIF date and time in Starry Night and at 8:07PM, the Sun is too low below the horizon. Maybe it was 7:07PM but then the Sun is already 11 deg below and at 6:07PM, then it is close to sunset (6:13PM that day for the location). So the time as suggested by the EXIF data is highly suspect. Now, of course, being Sept 22, the equinox is just around the corner so the Sun was setting due West.
The plane looks like it is not higher than 3000'. At that altitude the Sun is 0 deg 40 minute above the horizon (3000' high, 6:07PM)
Google Maps indeed shows the photo pointing North West. The Sun direction is virtually to the continuation of the road which goes from the bottom of the picture and disappear toward the upper left corner
Clouds are definitely seen near the top of the photo. So the Sun is shining nearly horizontally and going through clouds that are not too thick.
I think that clearing in the clouds are allowing the very red Sun light to illuminate the borders of clouds. At the same time, other farther clouds are not permitting the Sun light to go through.
I do not think that the Sun is shining above the clouds, if we can trust the 6:07PM time. The illumination appears to come through or from (partially) below.

Posted: **Tue Feb 17, 2009 6:58 am**

I'm convinced that the intial explation given by the photographer- light from a sunset striking rain- is correct. Here is why:

- As an earlier poster mentioned, the clouds at the top of the scene seem to "cut off" the orange light. The orange illuminated whatever-it-is must be behind these clouds. Also, the border between the two is quite sharp. If this were a photo out of an airplane window, it is likely the that the depth of field of the image would not be great enough to encompass both the ground and illuminated mateterial on the window. This rules out illuminated particles on the glass.

- However, if this were a reflected image, the "window" that the image was transmitted through would likely be visible in the photograph. Moreover, the angle of the photo is somewhat "down" indicating that any reflected image would have had to originiate higher than the camera, and, since the the plane does not seem to be banking appreciably, this is almost certainly not the case.

- Rain often falls in "sheets" that look very much like the linear features in this orange glow:

http://coosacreek.org/amputated/wp-cont ... nstorm.jpg
http://specieslist.com/images/yucatan/p ... CT0002.JPG
http://lh5.ggpht.com/_bQ1C3J9yiHk/Rs2GT ... Sheets.jpg

- There appears to be one bluish sheet in the foreground that is not illuminated. This is clearly a narrow "shaft" of light being projected through a gap in the clouds. It is likely that the area where there is no illumination in the lower right hand corner is a shadow of a cloud.

Posted: **Tue Feb 17, 2009 7:00 am**

I agree with the sunset theory as this is two days after the equinox and the timing would be about right if the camera was on Standard time or Eastern Daylight time. Sunset is 7:08 CDT for that date in 2009. I would also say there has been recent storm activity or there is about to be storm activity. I venture to say this for the following reasons. When at this time of year and time of day, the plentiful lakes of Minnesota usually appear black with clear or even partly cloudy skies. In this picture they are all reflecting white, especially the cluster in the upper right. The clouds are stratified such that the setting sun on the horizon is hitting the lowest clouds and turning them bright red. To understand the angles I created almost the exact view and vantage point using Google Earth and noted that the horizon is only a few degrees above the top of this picture and the sun would be just to the left of center on that horizon. This tells me the angle of the Sun’s rays are different enough that they are bouncing of clouds at say 20-40,000 feet and the resulting reflection does not get any of the red cast as those at the lower elevation. I also see that the bank of gray just above the red clouds are gray clouds at a slightly higher elevation but they are being kept in the shadow, yet the camera is pointing almost due west at the sunset.

Posted: **Tue Feb 17, 2009 7:04 am**

I live on a low foothill where I can see the sun setting on low mountains 60 miles to the west. I can also see the suns coloring effects on clouds against the Sierra Nevada Mountains 20 miles to the east. I have seen similiar coloring in low clouds many times.

Posted: **Tue Feb 17, 2009 7:23 am**

pkcyll wrote:I just put the EXIF date and time in Starry Night and at 8:07PM, the Sun is too low below the horizon. Maybe it was 7:07PM but then the Sun is already 11 deg below and at 6:07PM, then it is close to sunset (6:13PM that day for the location). So the time as suggested by the EXIF data is highly suspect.

Judging from the visibility of the ground I would guess that it was close to sunset (~ 7:07 CDT).

Code: Select all

Tue 2002 Sep 24 0:07 UT From 44°47'24"N 93°28'48"W:

_____         Altitude    Azimuth
Sun            -0.374      89.936     Setting

[/b]

pkcyll wrote:Now, of course, being Sept 22, the equinox is just around the corner so the Sun was setting due West.
The plane looks like it is not higher than 3000'. At that altitude the Sun is 0 deg 40 minute above the horizon (3000' high, 6:07PM)
Google Maps indeed shows the photo pointing North West. The Sun direction is virtually to the continuation of the road which goes from the bottom of the picture and disappear toward the upper left corner
Clouds are definitely seen near the top of the photo. So the Sun is shining nearly horizontally and going through clouds that are not too thick.
I think that clearing in the clouds are allowing the very red Sun light to illuminate the borders of clouds. At the same time, other farther clouds are not permitting the Sun light to go through.
I do not think that the Sun is shining above the clouds, if we can trust the 6:07PM time. The illumination appears to come through or from (partially) below.

Why would a cloud be nearly opaque as observed from above but apparently not at all opaque when illuminated horizontally?

The illumination is too uniform to be a nearly opaque cloud illuminated horizontally.

Posted: **Tue Feb 17, 2009 7:28 am**

kmatt20 wrote:... not really what you would expect from a window reflection.

Agreed (with all due respect to Neufer's theory - he's been right before). Most airplanes I've been in had terrible foggy scratchy windows. I would put my camera close to the window to take this picture so the terrible window itself would completely disappear out of focus. I think doing so would also put the glow sufficiently out of focus (if it were a reflection on the inside of the window) that we wouldn't see the wispy details at the edges of the glow like we do in this picture.

---

When I was a kid, people gave me a lot of jigsaw puzzles. I think this picture would make a good one.

Posted: **Tue Feb 17, 2009 8:14 am**

I just signed up to The Asterisk* so I could comment about this interesting picture but really after reading all the various posts I think we all know what it is and what's caused it, having said that, I'm therefore in agreement that it is simply the Setting Sun either right on or just below the Horizon but at the height the Aircraft was, the photographer was lucky enough to catch the last rays of Sun Light scattering through the atmosphere where wavelength is longer i.e more Red not to mention the normal amount of dust particles, and I agree with another poster's observation that you can see the colour of the sky in the lakes in the upper right-hand side of the picture with one lake reflecting the same colour of the clouds of the setting Sun, a good "one in a thousand" type of picture!

Cheers.
Clint
Melbourne, (Aust)

Posted: **Tue Feb 17, 2009 8:40 am**

Is it the Tyndall Effect?

Posted: **Tue Feb 17, 2009 9:23 am**

Hello to every one here.
Reffering to Google Earth image with the same direction and view angle.
The sun light can be reflected by the water surface of the river in the front. The sun light became a flat light source due to none perfect surface condition of the river. The reflected light may shin the edge of cloud on the left-up side and reflected again to the camera. The evidence on the photo is the center portion of the lake-like object on the right side appears orange color. This lake-like object is a section of the river and the river has much more water surface across the the picture, it just overlap with the most bright portion of the unusual red glow.
I have no idea about the time because I living in Taiwan.

Glarysun

Taichung, Taiwan

Posted: **Tue Feb 17, 2009 11:43 am**

I go for the starboard window reflection of a sunset streaming through two forward port windows
(with seats obstructing the bottom of the port window sunset reflections and
a window shade obstructing the top of the left most [i.e., forward most] port window sunset reflection.)

Neufer nailed it. The reflection looks two dimensional, not some huge sky-to-ground structure. I'm always suspicious of one passenger's take on something, and wonder if anyone else on the airplane commented on this 'strange phenomenon.'

Posted: **Tue Feb 17, 2009 11:46 am**

If you look at the lake on the right-hand side of the photograph, you'll notice that there are red reflections in the water. That alone suggests that there are red lit clouds/rain showers in the sky. However that doesn't disprove Neufer's idea.

Posted: **Tue Feb 17, 2009 11:51 am**

As for the time and date data on the camera, disregard it. The plane may have taken off from the Eastern time zone, which would be an hour later than Minnesota. Few people have a reliably accurate time in their camera, and some never set it at all.

Posted: **Tue Feb 17, 2009 11:56 am**

If you look at the lake on the right-hand side of the photograph, you'll notice that there are red reflections in the water. That alone suggests that there are red lit clouds/rain showers in the sky. However that doesn't disprove Neufer's idea.bornyesterday

Based on what I know about reflections, I think you'd only see a red reflection off of that lake if the red cloud was on the other side of the lake, out the upper right corner of the photo.

Starship Asterisk*

APOD: Unusual Red Glow Over Minnesota (2009 Feb 17)

APOD: Unusual Red Glow Over Minnesota (2009 Feb 17)

Re: Unusual Red Glow Over Minnesota (2009 February 17)

Re: Unusual Red Glow Over Minnesota (2009 February 17)

Re: Unusual Red Glow Over Minnesota (2009 February 17)

It's a sunset...

Re: Unusual Red Glow Over Minnesota (2009 February 17)

Re: Unusual Red Glow Over Minnesota (2009 February 17)

Re: Unusual Red Glow Over Minnesota (2009 February 17)

Re: Unusual Red Glow Over Minnesota (2009 February 17)

Re: Unusual Red Glow Over Minnesota (2009 February 17)

Re: Unusual Red Glow Over Minnesota (2009 February 17)

Re: Unusual Red Glow Over Minnesota (2009 February 17)

Re: Unusual Red Glow Over Minnesota (2009 February 17)

Re: Unusual Red Glow Over Minnesota (2009 February 17)

Re: Unusual Red Glow Over Minnesota (2009 February 17)

Re: Unusual Red Glow Over Minnesota (2009 February 17)

Re: Unusual Red Glow Over Minnesota (2009 February 17)

Re: Unusual Red Glow Over Minnesota (2009 February 17)

Re: Unusual Red Glow Over Minnesota (2009 February 17)

Re: Unusual Red Glow Over Minnesota (2009 February 17)

Re: Unusual Red Glow Over Minnesota (2009 February 17)

Re: Unusual Red Glow Over Minnesota (2009 February 17)

Re: Unusual Red Glow Over Minnesota (2009 February 17)

Re: Unusual Red Glow Over Minnesota (2009 February 17)

Re: Unusual Red Glow Over Minnesota (2009 February 17)