APOD: Noctilucent Clouds Over Edmonton (2011 Jul 20)

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Expand view Topic review: APOD: Noctilucent Clouds Over Edmonton (2011 Jul 20)

Re: APOD: Noctilucent Clouds Over Edmonton (2011 Jul 20)

by DavidLeodis » Wed Sep 14, 2011 7:41 pm

gscratch wrote:
I hope I'm wrong but I seem to detect a touch of irritation and incredulity in your reply that anyone would have been confused over the date. I apologise if I have in any way upset you about that. I did of course also say that it was "a nice video and APOD picture", which they are. :)
Not at all David! Sorry if I gave that impression, in fact, the irritation was my own. I'm VERY new to imaging the sky on purpose and I have to learn that even when we are talking about images that are aesthetically pleasing - we're often still photographing something with a scientific purpose and value, and that any ambiguity can minimize the value of an observation. I should have been much more specific in my notes when I submitted the image, and ensuing video. :)

As I said - I never thought it would be confusing - and I should have. I'll do better with documenting that in future because it DOES make a difference!

Cheers!
Thanks Greg. :)

I've never knowingly seen Noctilucent Clouds but from what I've read they are being seen further south than they used to be so I may one day be lucky enough to see them, though in my heavily light polluted area I'm lucky if I can see more than the brightest stars even in a clear night sky. Something though that I am seeing more than I used to (in daylight) are interesting cloud formations, such as herringbone clouds. In the morning of August 18 2011 the sky was full of very many hundreds (possibly thousands) of small light grey clouds with narrow bright bits between, with the result that the scene resembled a massive quilt cover. It was a gorgeous sight for the 20 minutes I saw them from 7:20 before they dispersed. :)

Re: APOD: Noctilucent Clouds Over Edmonton (2011 Jul 20)

by gscratch » Wed Sep 14, 2011 5:56 pm

I hope I'm wrong but I seem to detect a touch of irritation and incredulity in your reply that anyone would have been confused over the date. I apologise if I have in any way upset you about that. I did of course also say that it was "a nice video and APOD picture", which they are. :)
Not at all David! Sorry if I gave that impression, in fact, the irritation was my own. I'm VERY new to imaging the sky on purpose and I have to learn that even when we are talking about images that are aesthetically pleasing - we're often still photographing something with a scientific purpose and value, and that any ambiguity can minimize the value of an observation. I should have been much more specific in my notes when I submitted the image, and ensuing video. :)

As I said - I never thought it would be confusing - and I should have. I'll do better with documenting that in future because it DOES make a difference!

Cheers!

Re: APOD: Noctilucent Clouds Over Edmonton (2011 Jul 20)

by DavidLeodis » Mon Sep 12, 2011 11:11 am

gscratch wrote:
DavidLeodis wrote:I am confused as to the date when the image was taken. The "above" link in the explanation brings up a video from which the APOD seems to have been captured. The video is titled 'Noctilucent Cloud over Edmonton, Canada July 1, 2011' and other information with it states it was on Canada Day, which I have found is held on July 1st each year. However, just after the start of the video it gives the date 07 02 2011 (presumably July 2 2011) and at about 5 seconds into the video it states "1 hour (12:11am to 1:15am)". I'm unsure therefore if the event was in the very early hours of July 1st (which was Canada Day) or the very early hours of July 2nd (which was not Canada Day). It is a nice video and APOD picture but spoiled somewhat (at least to me) by the confusing dates. :?

To answer your question -

The images were shot starting at 11:43pm on July 1st, and ended at 2:15am *ish* July 2nd. The still in question was 'taken' on the second, 2 hours after I left Canada Day celebrations. Therefore - it was a 'Canada Day' photo that happened to be taken after midnight. Never thought that confusion would have been a big problem. I'll try to be more specific in future.
Thank you Greg for answering, which is appreciated.

I hope I'm wrong but I seem to detect a touch of irritation and incredulity in your reply that anyone would have been confused over the date. I apologise if I have in any way upset you about that. I did of course also say that it was "a nice video and APOD picture", which they are. :)

Re: APOD: Noctilucent Clouds Over Edmonton (2011 Jul 20)

by Beyond » Mon Sep 12, 2011 4:46 am

Wow. This planet has some of the strangest places :!:

Re: APOD: Noctilucent Clouds Over Edmonton (2011 Jul 20)

by gscratch » Mon Sep 12, 2011 4:39 am

According to the description, it's supposed to be the sun setting. It looks like somebody didn't check with the picture-taker. But it still looks really neat!
I wonder how come the "light-pollution" came out in that shape, and in that color?
Shape can be attributed to:
a) shooting the central core of the city of Edmonton, particularly the 'densest' part of the city with orange sodium vapour lighting.
b) shooting with a Canon EF-S 18-55 which has some corner darkening that is more noticeable in low light, low contrast scenes.

[EDIT - ADDED C]
c) The foreground is an un-lit segment of the park - taken on a hill. The park runs E-W along the whitemud, so nothing in the foreground for illumination, and nothing in the sky above about 55 degrees - means a strip of light across the middle... :)

Color can be attributed to:
a) summer skyglow from the north (remember, just 1000km north of this it was daylight. ;))
b) summer dust and smoke in the atmosphere - which is almost always rust / brown coloured (spitballin on this one)

Re: APOD: Noctilucent Clouds Over Edmonton (2011 Jul 20)

by gscratch » Mon Sep 12, 2011 4:33 am

DavidLeodis wrote:I am confused as to the date when the image was taken. The "above" link in the explanation brings up a video from which the APOD seems to have been captured. The video is titled 'Noctilucent Cloud over Edmonton, Canada July 1, 2011' and other information with it states it was on Canada Day, which I have found is held on July 1st each year. However, just after the start of the video it gives the date 07 02 2011 (presumably July 2 2011) and at about 5 seconds into the video it states "1 hour (12:11am to 1:15am)". I'm unsure therefore if the event was in the very early hours of July 1st (which was Canada Day) or the very early hours of July 2nd (which was not Canada Day). It is a nice video and APOD picture but spoiled somewhat (at least to me) by the confusing dates. :?

To answer your question -

The images were shot starting at 11:43pm on July 1st, and ended at 2:15am *ish* July 2nd. The still in question was 'taken' on the second, 2 hours after I left Canada Day celebrations. Therefore - it was a 'Canada Day' photo that happened to be taken after midnight. Never thought that confusion would have been a big problem. I'll try to be more specific in future.

Re: APOD: Noctilucent Clouds Over Edmonton (2011 Jul 20)

by Beyond » Tue Sep 06, 2011 8:29 pm

gscratch wrote:
Beyond wrote:The almost square sunset is really nice. The shape reminds me of the really big fuel storage tanks with the floating tops. Except, they're not orange.
Sadly - no sunset. The bulk of 'orange' visible at the horizon in the image is the light pollution of the city of Edmonton. The image was taken facing nearly due north. (That's Capella to the right...) The Sun sets at WNW during the summer in Edmonton.
According to the description, it's supposed to be the sun setting. It looks like somebody didn't check with the picture-taker. But it still looks really neat!
I wonder how come the "light-pollution" came out in that shape, and in that color?

Re: APOD: Noctilucent Clouds Over Edmonton (2011 Jul 20)

by gscratch » Tue Sep 06, 2011 8:17 pm

Beyond wrote:The almost square sunset is really nice. The shape reminds me of the really big fuel storage tanks with the floating tops. Except, they're not orange.
Sadly - no sunset. The bulk of 'orange' visible at the horizon in the image is the light pollution of the city of Edmonton. The image was taken facing nearly due north. (That's Capella to the right...) The Sun sets at WNW during the summer in Edmonton.

Re: APOD: Noctilucent Clouds Over Edmonton (2011 Jul 20)

by gscratch » Tue Sep 06, 2011 8:14 pm

orin stepanek wrote:I rather like the picture! 8-) :D
Thank you!

Re: APOD: Noctilucent Clouds Over Edmonton (2011 Jul 20)

by gscratch » Tue Sep 06, 2011 8:13 pm

Guest wrote:Hey, great! I joined the RASC (Royal Astronomical Society of Canada) in Edmonton in about 1954 or 1955 - with Earl Milton, Franklin Loehde, Ian McLennan, Art Dalton,... It was WONDERFUL, great people! Dick Henry, Professor, Johns Hopkins University, Baltimore
Franklin is still very much active in the club!

Re: APOD: Noctilucent Clouds Over Edmonton (2011 Jul 20)

by gscratch » Tue Sep 06, 2011 8:12 pm

ssreddy555 wrote:Is it soon after dusk?
The image was taken approximately 3 1/2 hours after sunset. Dusk was effectively over when I began shooting the display at 11:45pm local time.

Re: APOD: Noctilucent Clouds Over Edmonton (2011 Jul 20)

by gscratch » Tue Sep 06, 2011 8:11 pm

Wayne Warren wrote:The image is a good example of terribly unshielded lights as well as noctilucent clouds. If these lights were adequately shielded, their illumination would be seen only on the ground. Clearly, Edmonton needs a light ordinance.
Wayne Warren/Towson University.
Agreed. Hands down. No contest.

Of course - Edmonton City Management is too busy banning swiss army knives, and cutting back on road maintenance expenditures to focus on lights (even if they are cheaper to operate.)

/Greg

Re: APOD: Noctilucent Clouds Over Edmonton (2011 Jul 20)

by owlice » Wed Jul 27, 2011 10:24 am

Sunset in Edmonton on July 1 was after 10 PM (10:06 PM). I can easily believe that the NLC were visible past midnight.

Re: APOD: Noctilucent Clouds Over Edmonton (2011 Jul 20)

by ssreddy555 » Wed Jul 27, 2011 8:47 am

Is it soon after dusk?

Re: APOD: Noctilucent Clouds Over Edmonton (2011 Jul 20)

by DavidLeodis » Thu Jul 21, 2011 2:11 pm

neufer wrote:
DavidLeodis wrote:
I am confused as to the date when the image was taken. The "above" link in the explanation brings up a video from which the APOD seems to have been captured. The video is titled 'Noctilucent Cloud over Edmonton, Canada July 1, 2011' and other information with it states it was on Canada Day, which I have found is held on July 1st each year. However, just after the start of the video it gives the date 07 02 2011 (presumably July 2 2011) and at about 5 seconds into the video it states "1 hour (12:11am to 1:15am)". I'm unsure therefore if the event was in the very early hours of July 1st (which was Canada Day) or the very early hours of July 2nd (which was not Canada Day).
It is pretty obviously the celebration night of Canada Day
which runs into July 2.

(It was still Canada Day in Vancouver.)
Thanks neufer for your help. I respectfully disagree though, as I don't think "It is pretty obviously the celebration night of Canada Day
which runs into July 2". My feeling was that it probably was taken in the early hours of July 1st and that the July 2nd in the video was a mistake. The dates given with the video are confusing, well they are to me! :)

Edit added around 23:00. Having just read the explanation again I noticed that it states the noctilucent clouds event was "after dusk", so the event cannot have been in the early hours of July 1st and thus the video (which had the APOD image) will have been taken on July 2nd. I'm therefore a bit :oops: not to have picked up on that earlier. As normal then I'm :? but still :) ing.

Re: APOD: Noctilucent Clouds Over Edmonton (2011 Jul 20)

by neufer » Thu Jul 21, 2011 11:47 am

DavidLeodis wrote:
I am confused as to the date when the image was taken. The "above" link in the explanation brings up a video from which the APOD seems to have been captured. The video is titled 'Noctilucent Cloud over Edmonton, Canada July 1, 2011' and other information with it states it was on Canada Day, which I have found is held on July 1st each year. However, just after the start of the video it gives the date 07 02 2011 (presumably July 2 2011) and at about 5 seconds into the video it states "1 hour (12:11am to 1:15am)". I'm unsure therefore if the event was in the very early hours of July 1st (which was Canada Day) or the very early hours of July 2nd (which was not Canada Day).
It is pretty obviously the celebration night of Canada Day
which runs into July 2.

(It was still Canada Day in Vancouver.)

Re: APOD: Noctilucent Clouds Over Edmonton (2011 Jul 20)

by DavidLeodis » Thu Jul 21, 2011 11:11 am

I am confused as to the date when the image was taken. The "above" link in the explanation brings up a video from which the APOD seems to have been captured. The video is titled 'Noctilucent Cloud over Edmonton, Canada July 1, 2011' and other information with it states it was on Canada Day, which I have found is held on July 1st each year. However, just after the start of the video it gives the date 07 02 2011 (presumably July 2 2011) and at about 5 seconds into the video it states "1 hour (12:11am to 1:15am)". I'm unsure therefore if the event was in the very early hours of July 1st (which was Canada Day) or the very early hours of July 2nd (which was not Canada Day). It is a nice video and APOD picture but spoiled somewhat (at least to me) by the confusing dates. :?

Re: APOD: Noctilucent Clouds Over Edmonton (2011 Jul 20)

by Chris Peterson » Wed Jul 20, 2011 8:24 pm

neufer wrote:The bulk of the light stops within 3 pole heights of each lamp;
I don't see how one could shield it any more in an economic fashion.
I don't think it is possible to make that determination from this image. However, with a properly shielded light, you should not be able to see the bulb at all from the viewpoint of this shot. The lights should be essentially invisible, except possibly for the poles holding them up.

Re: APOD: Noctilucent Clouds Over Edmonton (2011 Jul 20)

by neufer » Wed Jul 20, 2011 8:15 pm

Wayne Warren wrote:
The image is a good example of terribly unshielded lights as well as noctilucent clouds.
If these lights were adequately shielded, their illumination would be seen only on the ground.
Clearly, Edmonton needs a light ordinance.
The bulk of the light stops within 3 pole heights of each lamp;
I don't see how one could shield it any more in an economic fashion.

Re: APOD: Noctilucent Clouds Over Edmonton (2011 Jul 20)

by Wayne Warren » Wed Jul 20, 2011 7:15 pm

The image is a good example of terribly unshielded lights as well as noctilucent clouds. If these lights were adequately shielded, their illumination would be seen only on the ground. Clearly, Edmonton needs a light ordinance.
Wayne Warren/Towson University.

Re: APOD: Noctilucent Clouds Over Edmonton (2011 Jul 20)

by Guest » Wed Jul 20, 2011 6:25 pm

Hey, great! I joined the RASC (Royal Astronomical Society of Canada) in Edmonton in about 1954 or 1955 - with Earl Milton, Franklin Loehde, Ian McLennan, Art Dalton,... It was WONDERFUL, great people! Dick Henry, Professor, Johns Hopkins University, Baltimore

Re: APOD: Noctilucent Clouds Over Edmonton (2011 Jul 20)

by bystander » Wed Jul 20, 2011 5:18 pm

kaigun wrote:According to the wikipedia link at 61 degrees N I live in the perfect zone to see these clouds, but if I have, I didn't realize what I seeing. I see it also says they are best when the Sun is between 6 and 16 degrees below the horizon. At these latitudes in the early summer, that is going to be after midnight.

Re: APOD: Noctilucent Clouds Over Edmonton (2011 Jul 20)

by Ann » Wed Jul 20, 2011 5:13 pm

neufer wrote:

It's those damn astronomers who to blame. Let's go burn down an observatory :!:
Like the good citizens of Springfield?

Ann

Re: APOD: Noctilucent Clouds Over Edmonton (2011 Jul 20)

by kaigun » Wed Jul 20, 2011 5:01 pm

According to the wikipedia link at 61 degrees N I live in the perfect zone to see these clouds, but if I have, I didn't realize what I seeing. I see it also says they are best when the Sun is between 6 and 16 degrees below the horizon. At these latitudes in the early summer, that is going to be after midnight.

Re: APOD: Noctilucent Clouds Over Edmonton (2011 Jul 20)

by nstahl » Wed Jul 20, 2011 3:25 pm

Information about the Solar System is good, getting men and women generally safely to the asteroids and Mars would be good. Ultimately it will be vital. People who refuse to pay their fair share of taxes are bad.

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