APOD: Night and Day above Almost Planet Sounio (2011 Jan 17)

Comments and questions about the APOD on the main view screen.
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APOD: Night and Day above Almost Planet Sounio (2011 Jan 17)

Post by APOD Robot » Mon Jan 17, 2011 5:12 am

Image Night and Day above Almost Planet Sounio

Explanation: Has a new planet been discovered? What is pictured above is a remarkable 24 hour mosaic surrounding a spot on Sounio, Greece, right here on planet Earth. Images taken at night compose the top half of the picture, with star trails lasting as long as 11 hours visible. Contrastingly, images taken during the day compose the bottom of the image, with the Sun being captured once every 15 minutes. The image center shows a Little Prince wide angle projection centered on the ground but including gravel, grass, trees, Saint John's church, clouds, crepuscular rays, and even a signature icon of the photographer -- the Temple of Poseidon. Meticulous planning as well as several transition shots and expert digital processing eventually culminated in this image documenting half of the final two days of last year.

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Re: APOD: Night and Day above Almost Planet Sounio (2011 Jan

Post by owlice » Mon Jan 17, 2011 7:13 am

Oh, that's great!! Congratulations to Chris!!
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Re: APOD: Night and Day above Almost Planet Sounio (2011 Jan

Post by Astrostitcher » Mon Jan 17, 2011 9:01 am

Thank you , very lovely and interesting composition. But why is the Polaris startrail a semi-circle ? instead of a dot or an almost complete circle ...

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Re: APOD: Night and Day above Almost Planet Sounio (2011 Jan

Post by Czerno » Mon Jan 17, 2011 9:52 am

Good day !
Astrostitcher wrote:Thank you , very lovely and interesting composition. But why is the Polaris startrail a semi-circle ? instead of a dot or an almost complete circle ...
Because Polaris doesn't outshine the Sun !

From the picture's legend : "Images taken at night compose the top half of the picture, with star trails lasting as long as 11 hours visible."

11 hours/(24 hours/day) x 1 circle/day = 11/24 circle or slightly less than a semi-circle ;=)
Czerno

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Re: APOD: Night and Day above Almost Planet Sounio (2011 Jan

Post by Puddock » Mon Jan 17, 2011 10:14 am

Stunning image - lots to take in but artistically inspiring too - thanks and congrats to Chris!

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Re: APOD: Night and Day above Almost Planet Sounio (2011 Jan

Post by Astrostitcher » Mon Jan 17, 2011 12:30 pm

Czerno wrote:
11 hours/(24 hours/day) x 1 circle/day = 11/24 circle or slightly less than a semi-circle ;=)
Gottch'a & thanks, just not on my toes and a bit lazy at the hour I looked at the photo :oops: :oops: :wink:
Still I am surprised to see what a relatively large diameter there is for the Polaris trail. How much error would this contribute to navigational calculations if you assume the dia=0?

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Re: APOD: Night and Day above Almost Planet Sounio (2011 Jan

Post by neufer » Mon Jan 17, 2011 1:49 pm

Astrostitcher wrote:
I am surprised to see what a relatively large diameter there is for the Polaris trail.
How much error would this contribute to navigational calculations if you assume the dia=0?
Declination of Polaris = +89° 16′

Ergo, one could be off in latitude by ± 44′
Art Neuendorffer

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Re: APOD: Night and Day above Almost Planet Sounio (2011 Jan

Post by Astrostitcher » Mon Jan 17, 2011 2:23 pm

thank you neufer. is that a big error ? like, would you miss say : Easter Island??

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Re: APOD: Night and Day above Almost Planet Sounio (2011 Jan

Post by moonstruck » Mon Jan 17, 2011 2:29 pm

All I can say is WOW! Thanks Chris.

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Re: APOD: Night and Day above Almost Planet Sounio (2011 Jan

Post by rmsparks » Mon Jan 17, 2011 2:38 pm

Photo was nice but thoroughly enjoyed "meticulous planning" link!

Thanks to who ever came up with it.

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Re: APOD: Night and Day above Almost Planet Sounio (2011 Jan

Post by neufer » Mon Jan 17, 2011 3:15 pm

Astrostitcher wrote:
thank you neufer. is that a big error ? like, would you miss say : Easter Island??
One could easily miss hitting Easter Island at night.

However, one would probably be able to see Easter Island during the day from the deck or crow's nest of a ship.

With a maximum altitude of 507 meters Easter Island would be visible during the day
from the ocean surface from a distance of 43' latitude north or south.
.....................................................................................
Note, however, that navigators would always have corrected for
the varying position of Polaris at least to first order (i.e., within 4' latitude)
Art Neuendorffer

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Re: APOD: Night and Day above Almost Planet Sounio (2011 Jan

Post by Astrostitcher » Mon Jan 17, 2011 4:25 pm

Thanks again Art, very interesting ! I'll remember that the next time talk to my seafaring friends as it's unlikely that navigational job will ever fall to me :-)

Brad

Re: APOD: Night and Day above Almost Planet Sounio (2011 Jan

Post by Brad » Mon Jan 17, 2011 4:42 pm

Am I the only one who immediately flashed back to Le Petit Prince, by Antoine de Saint-Exupéry? http://en.wikipedia.org/wiki/The_Little_Prince

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Re: APOD: Night and Day above Almost Planet Sounio (2011 Jan

Post by mexhunter » Mon Jan 17, 2011 6:08 pm

It is an scandalously beautiful composition.
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Re: APOD: Night and Day above Almost Planet Sounio (2011 Jan

Post by ChrisKotsiopoulos » Mon Jan 17, 2011 6:45 pm

Thank you all so much for your kind words!
This was the most demanding photo for me so far but I enjoyed every minute of it!
:mrgreen:

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Re: APOD: Night and Day above Almost Planet Sounio (2011 Jan

Post by neufer » Mon Jan 17, 2011 7:10 pm

Brad wrote:
Am I the only one who immediately flashed back to Le Petit Prince, by Antoine de Saint-Exupéry?
http://en.wikipedia.org/wiki/The_Little_Prince
:tree: You must have read the Explanation:
APOD Robot wrote:
Explanation: The image center shows a Little Prince wide angle projection centered on the ground but including gravel, grass, trees, Saint John's church, clouds, crepuscular rays, and even a signature icon of the photographer -- the Temple of Poseidon.
Art Neuendorffer

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Re: APOD: Night and Day above Almost Planet Sounio (2011 Jan

Post by flash » Mon Jan 17, 2011 7:27 pm

Astrostitcher wrote:thank you neufer. is that a big error ? like, would you miss say : Easter Island??
Easter Island is at 27 degrees south. I think if you could see Polaris you'd miss Easter Island by alot.

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Re: APOD: Night and Day above Almost Planet Sounio (2011 Jan

Post by Astrostitcher » Mon Jan 17, 2011 8:21 pm

flash wrote: Easter Island is at 27 degrees south. I think if you could see Polaris you'd miss Easter Island by alot.
Ah ha ! Thank you for your comment. Shows I've never been there and am not thinking. This raises yet another question : so if you can't see Polaris, what do you use to navigate by ?

bigrbigr

Re: APOD: Night and Day above Almost Planet Sounio (2011 Jan

Post by bigrbigr » Mon Jan 17, 2011 9:22 pm

ChrisKotsiopoulos wrote:Thank you all so much for your kind words!
This was the most demanding photo for me so far but I enjoyed every minute of it!
:mrgreen:
Hi Chris,
well done, a very nice marage of art and science. bravo!! :b: :b:

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Re: APOD: Night and Day above Almost Planet Sounio (2011 Jan

Post by luigi » Tue Jan 18, 2011 3:03 am

Astrostitcher wrote:
flash wrote: Easter Island is at 27 degrees south. I think if you could see Polaris you'd miss Easter Island by alot.
Ah ha ! Thank you for your comment. Shows I've never been there and am not thinking. This raises yet another question : so if you can't see Polaris, what do you use to navigate by ?
Canopus is (was) used a lot for Navigation to the south. Some spaceships have a "Canopus Tracker" Canopus is bright, isolated and far away from the ecliptic.

In a more informal way we use the constellation of Crux to find the celestial south pole and without pollution the Magellan clouds can be used too as the south pole would form an equilateral triangle with the Magellan Clouds

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Re: APOD: Night and Day above Almost Planet Sounio (2011 Jan

Post by Astrostitcher » Tue Jan 18, 2011 8:50 am

Thank you Luigi, I have seen Crux and Canopus. Gonna go try this on my Redshift program.

germiNateJ

Re: APOD: Night and Day above Almost Planet Sounio (2011 Jan

Post by germiNateJ » Fri Jan 21, 2011 4:31 pm

Anybody younger than 30 here that watched Dragon Ball Z?

http://images2.wikia.nocookie.net/__cb2 ... Planet.png

Coincidence??
..probably.