APOD: Zodiacal Light and the False Dawn (2012 Jan 16)

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APOD: Zodiacal Light and the False Dawn (2012 Jan 16)

Post by APOD Robot » Mon Jan 16, 2012 5:06 am

Image Zodiacal Light and the False Dawn

Explanation: Is it dawn or false dawn? During certain times of the year, the horizon near the rising Sun will begin to glow unusually early. This early glow does not originate directly from the Sun, but rather from sunlight reflected by interplanetary dust. Called zodiacal light, the glowing triangle of light may be mistaken, for a while, for a sunrise, and so may be called a false dawn. Pictured above, two false dawns were recorded in time lapse movies each spanning about five hours from the perch of the highest observatory in the world: Mount Saraswati near Hanle, India. At its brightest, the rising zodiacal triangle on the left glows brighter than even the central disk of our Milky Way Galaxy -- visible as the diagonal band moving left to right across the frame.

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Re: APOD: Zodiacal Light and the False Dawn (2012 Jan 16)

Post by geckzilla » Mon Jan 16, 2012 6:09 am

Big video is big.
Just call me "geck" because "zilla" is like a last name.

islader2

Re: APOD: Zodiacal Light and the False Dawn (2012 Jan 16)

Post by islader2 » Mon Jan 16, 2012 7:02 am

What a great video! The music is superb==reminds me of the other tall mountains, the Andes where I heard Incas playing this type of music on cuadros and Pan pipes.
The calendar being given for the survey is a treasure trove of pictures worthy of framing {so be it}. Thanx everyone who made this possible. Alas==We need a smilie for "I AM NOT WORTHY". Clapping hands will not do==when a standing ovation befits.

Vincent Pinto

Re: APOD: Zodiacal Light and the False Dawn (2012 Jan 16)

Post by Vincent Pinto » Mon Jan 16, 2012 8:55 am

Fabulous music! Marvellous! Thank you!

"The heavens declare the glory of God; and the firmament sheweth his handywork.
Day unto day uttereth speech, and night unto night sheweth knowledge.
There is no speech nor language, where their voice is not heard."

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Re: APOD: Zodiacal Light and the False Dawn (2012 Jan 16)

Post by orin stepanek » Mon Jan 16, 2012 1:42 pm

Is it the highest observatory in the world?
spanning about five hours from the perch of the highest observatory in the world:

from Wiki!
Highest astronomical observatories
Main article: List of highest astronomical observatories
Since the mid-20th century, a number of astronomical observatories have been constructed at very high altitudes, above 4000–5000 m (13,000-16,000 ft). The largest and most notable of these is the Mauna Kea Observatory, located near the summit of a 4205 m (13,796 ft) volcano in Hawaii. The Chacaltaya Astrophysical Observatory in Bolivia, at 5230 m (17,160 ft), was the world's highest permanent astronomical observatory from the time of its construction during the 1940s until 2009. It has now been surpassed by the new University of Tokyo Atacama Observatory, an optical-infrared telescope on a remote 5640 m (18,500 ft) mountaintop in the Atacama Desert of Chile.
[edit]
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Re: APOD: Zodiacal Light and the False Dawn (2012 Jan 16)

Post by eltodesukane » Mon Jan 16, 2012 3:07 pm


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Re: APOD: Zodiacal Light and the False Dawn (2012 Jan 16)

Post by neufer » Mon Jan 16, 2012 3:29 pm

orin stepanek wrote:
spanning about five hours from the perch of the highest observatory in the world:

Is it the highest observatory in the world?
Highest astronomical observatories wrote:
Since the mid-20th century, a number of astronomical observatories have been constructed at very high altitudes, above 4000–5000 m (13,000-16,000 ft). The largest and most notable of these is the Mauna Kea Observatory, located near the summit of a 4205 m (13,796 ft) volcano in Hawaii. The Chacaltaya Astrophysical Observatory in Bolivia, at 5230 m (17,160 ft), was the world's highest permanent astronomical observatory[4] from the time of its construction during the 1940s until 2009. It has now been surpassed by the new University of Tokyo Atacama Observatory,[5] an optical-infrared telescope on a remote 5640 m (18,500 ft) mountaintop in the Atacama Desert of Chile.
The Indian Astronomical Observatory (IAO) is currently the highest astronomical observatory
1) with an optical telescope larger than 1 meter in aperture and
2) in the Northern Hemisphere.

1) 5640 m University of Tokyo Atacama Observatory (miniTAO) [2009]
Cerro Chajnantor Atacama Desert, Chile 22°59′12″S 67°44′32″W
Highest Optical, Highest infrared

2) 5230 m Chacaltaya Astrophysical Observatory [1946]
Chacaltaya Andes, Bolivia 16°21′12″S 68°07′53″W
Highest Cosmic ray, Highest gamma ray

3) 5190 m Atacama Cosmology Telescope [2007]
Cerro Toco Atacama Desert, Chile 22°57′31″S 67°47′16″W
Highest Microwave

4) 5104 m Llano de Chajnantor Observatory [1999]
Llano de Chajnantor Atacama Desert, Chile 23°01′22″S 67°45′17″W
Highest Millimeter wave, Highest submillimeter [CBI, APEX, ALMA]

5) 4800 m Atacama Submillimeter Telescope Experiment (ASTE) [2002}
Pampa La Bola Atacama Desert, Chile 22°58′17″S 67°42′10″W
Highest Submillimeter

6) 4580 m Large Millimeter Telescope [2006]
Sierra Negra Puebla, Mexico 18°59′06″N 97°18′53″W
Microwave

7) 4500 m Indian Astronomical Observatory [2001]
Mount Saraswati Hanle, Ladakh, India 32°46′46″N 78°57′51″E
2nd Highest: Infrared, gamma ray, Optical [Himalayan Chandra Telescope, HAGAR]

8) 4312 m Meyer-Womble Observatory [1996]
Mount Evans Colorado, United States 39°35′12″N 105°38′24″W
3rd Highest Optical
Art Neuendorffer

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Re: APOD: Zodiacal Light and the False Dawn (2012 Jan 16)

Post by orin stepanek » Mon Jan 16, 2012 4:40 pm

Thanks Art! That clears up any confusion! 8-) :D
Orin

Smile today; tomorrow's another day!

Byork

Re: APOD: Zodiacal Light and the False Dawn (2012 Jan 16)

Post by Byork » Mon Jan 16, 2012 4:43 pm

It is fortunate that the issue of the highest and largest telescopes has been discussed here. A site for the Thirty Meter ground based optical telescope was sought for quite some time until it was agreed that the telescope should be built atop Mt Kea in Hawii - currently the site of another high calibre observatory. While the work of the Mt Kea Observatory is outstanding for clarity and detail, the images are generally tinted bluish green owing to the immense water vapor content in the upper atmosphere. The tinting problem can be corrected through computer image processing. Even so, an observatory high on a mountain in the middle of an ocean will always experience imaging limitation due to the water vapor content of the upper atmosphere.
I believe the Thirty Meter Telescope should be built in the continental United States far from any ocean and above 4000 meters.
The Meyer-Womble Observatory at Mt Evans Colorado is interesting. At an elevation of 4312 m the Meyer-Womble Observatory should be able to image with a precision comparable to the Hubble Space Telescope.
The Brigham Young University telescope in Utah has excellent imaging capability. And the Mt Lemmon Observatory in Arizona deserves attention.
Private observatories in Arizona and California have also supplied material for apod. I would not regard them as amateur-these are observatories armed with solid state imaging devices which allow people to see and understand. Once upon a time all that a professional astronomer had were black and white shots of the celestia - an entire field of science was built upon those faint but imposing images.
There i still time to decide upon an appropriate site for the Thirty Meter Telescope. A potential site which deserves consideration is northern Nevada. The place is high and dry and really far away from city lights..ufo traffic irrelevant.

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Re: APOD: Zodiacal Light and the False Dawn (2012 Jan 16)

Post by eltodesukane » Mon Jan 16, 2012 5:06 pm

Byork wrote:It is fortunate that the issue of the highest and largest telescopes has been discussed here. A site for the Thirty Meter ground based optical telescope was sought for quite some time until it was agreed that the telescope should be built atop Mt Kea in Hawii - currently the site of another high calibre observatory. While the work of the Mt Kea Observatory is outstanding for clarity and detail, the images are generally tinted bluish green owing to the immense water vapor content in the upper atmosphere. The tinting problem can be corrected through computer image processing. Even so, an observatory high on a mountain in the middle of an ocean will always experience imaging limitation due to the water vapor content of the upper atmosphere.
I believe the Thirty Meter Telescope should be built in the continental United States far from any ocean and above 4000 meters.
The Meyer-Womble Observatory at Mt Evans Colorado is interesting. At an elevation of 4312 m the Meyer-Womble Observatory should be able to image with a precision comparable to the Hubble Space Telescope.
The Brigham Young University telescope in Utah has excellent imaging capability. And the Mt Lemmon Observatory in Arizona deserves attention.
Private observatories in Arizona and California have also supplied material for apod. I would not regard them as amateur-these are observatories armed with solid state imaging devices which allow people to see and understand. Once upon a time all that a professional astronomer had were black and white shots of the celestia - an entire field of science was built upon those faint but imposing images.
There i still time to decide upon an appropriate site for the Thirty Meter Telescope. A potential site which deserves consideration is northern Nevada. The place is high and dry and really far away from city lights..ufo traffic irrelevant.
I don't think China or India would have favored a US location.

China and India are catapulting to the forefront of astronomy research with their decision to join as partners in a Hawaii telescope that will be the world's largest when it's built later this decade.
China and India will pay a share of the construction cost — expected to top $1 billion — for the Thirty Meter Telescope at the summit of Mauna Kea volcano.
They will also have a share of the observation time.

The University of California system, the California Institute of Technology and the Association of Canadian Universities for Research in Astronomy founded the telescope,
which is expected to be finished in 2018.
China joined as an observer in 2009, followed by India the next year.
Both are now partners, with representatives on the TMT board.
Japan, which has its own large telescope at Mauna Kea, the 8.3-meter Subaru, is also a partner.
http://cnsnews.com/news/article/china-i ... -telescope

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Re: APOD: Zodiacal Light and the False Dawn (2012 Jan 16)

Post by Chris Peterson » Mon Jan 16, 2012 5:58 pm

Byork wrote:It is fortunate that the issue of the highest and largest telescopes has been discussed here. A site for the Thirty Meter ground based optical telescope was sought for quite some time until it was agreed that the telescope should be built atop Mt Kea in Hawii - currently the site of another high calibre observatory. While the work of the Mt Kea Observatory is outstanding for clarity and detail, the images are generally tinted bluish green owing to the immense water vapor content in the upper atmosphere. The tinting problem can be corrected through computer image processing. Even so, an observatory high on a mountain in the middle of an ocean will always experience imaging limitation due to the water vapor content of the upper atmosphere.
I believe the Thirty Meter Telescope should be built in the continental United States far from any ocean and above 4000 meters.
The Meyer-Womble Observatory at Mt Evans Colorado is interesting. At an elevation of 4312 m the Meyer-Womble Observatory should be able to image with a precision comparable to the Hubble Space Telescope.
Atmospheric water vapor does not visibly alter the color of any images made from the surface of the Earth. It is an important factor for IR, radio, and submillimeter astronomy, which is why instruments that operate in these regimes are ideally located at high altitudes. The key metric is known as precipitable water vapor, or sometimes total column water vapor, and is substantially determined by altitude. PWV values are about the same (~3-5 mm) for sites around 4000 m, including those in Hawaii and Colorado. The fact that Hawaii is oceanic and Colorado is continental doesn't change these values. Mt Evans suffers from poorer seeing and more light pollution issues than Mauna Kea. I believe it also has fewer clear nights.
Chris

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Re: APOD: Zodiacal Light and the False Dawn (2012 Jan 16)

Post by neufer » Mon Jan 16, 2012 6:40 pm

Byork wrote:
An observatory high on a mountain in the middle of an ocean will always experience imaging limitation due to the water vapor content of the upper atmosphere.
Actually, some of the best places for high mountain observatories would be in the middle of subtropical oceans because of the low water vapor content of the upper atmosphere over subtropical ridges. Unfortunately, there are not enough high mountains there. (Mauna Loa is OK but it would do somewhat better if it were located about 5º further south.) :arrow:

However, Mount Saraswati and the Andes are quite well placed in this regard. (The top of Mount Damāvand should also be good.)
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Re: APOD: Zodiacal Light and the False Dawn (2012 Jan 16)

Post by TNT » Mon Jan 16, 2012 6:49 pm

I like the part at :30 with the full star trails.
The following statement is true.
The above statement is false.

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Re: APOD: Zodiacal Light and the False Dawn (2012 Jan 16)

Post by bystander » Mon Jan 16, 2012 6:53 pm

neufer wrote:(The top of Mount Damāvand should also be good.)
Somehow, it doesn't seem to me that a potentially active volcano is the ideal place to locate a expensive new telescope.
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Re: APOD: Zodiacal Light and the False Dawn (2012 Jan 16)

Post by Chris Peterson » Mon Jan 16, 2012 7:19 pm

Chris

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Re: APOD: Zodiacal Light and the False Dawn (2012 Jan 16)

Post by Ann » Mon Jan 16, 2012 7:25 pm

Today's video is very beautiful. It was almost hypnotic to see the individual stars suddenly turn into long, colorful star trails. And I was very happy to see the constellations being named at the end of the video, too.

Personally I was also very happy to see our resident Quotidian Quotationist return to the good Starship Asterisk*! :D
APOD Robot wrote:
Tomorrow's picture: head witch
I'm going to make a guess again, and predict that the witchy head will suffer from the blues. She will be beige, brown and gray too, and just possibly an itty bitty tad of pink, although rosy hues don't really become such a lady of black magic. She will owe her presence to a mighty "Foot of the Central One", a real super giant as stars go!

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Re: APOD: Zodiacal Light and the False Dawn (2012 Jan 16)

Post by neufer » Mon Jan 16, 2012 8:54 pm

The most opaque TOVS infrared water vapor sounding channel sees down to about the level of the first precipitable millimeter of water vapor. This is normally at around 400 millibars (= an altitude of ~7.5 kilometers) where the temperature is generally about 239K almost everywhere. Where the upper air is much dryer than normal the TOVS channel can see a kilometer lower down than that (~ altitude of the highest permanent astronomical observatories) where the temperature is (~ 7º) warmer than 239K. When the upper air is much moister than normal (up to 100% RH) the TOVS channel can only see down to a kilometers higher where the temperature is (~ 7º) colder than 239K.

Note that none of this is particularly relevant for SOFIA which flies way up at an altitude of ~12 kilometers or to dry Antarctica where surface temperatures can be below 239K.
Last edited by neufer on Tue Jan 17, 2012 4:22 am, edited 2 times in total.
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Re: APOD: Zodiacal Light and the False Dawn (2012 Jan 16)

Post by neptunium » Tue Jan 17, 2012 12:43 am

The music drove me crazy.

Hornet

Re: APOD: Zodiacal Light and the False Dawn (2012 Jan 16)

Post by Hornet » Tue Jan 17, 2012 4:20 am

I like the song, where can I get it? I want to play it.

Ricardo

Re: APOD: Zodiacal Light and the False Dawn (2012 Jan 16)

Post by Ricardo » Tue Jan 17, 2012 7:28 pm

The highest observatory in the world is NOT in India. It is the Llano de Chajnantor at 5100 m in northern Chile. It consists of several radio-telescopes (CBI, ALMA, APEX, ACT, ASTE, NANTEN2) in the area in which the mini-TAO 1.5 m infrared telescope is the highest, at 5650 m on top of Cerro Chajnantor.

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Re: APOD: Zodiacal Light and the False Dawn (2012 Jan 16)

Post by DavidLeodis » Tue Jan 17, 2012 7:44 pm

The date above the APOD video image states "2011 January 16". That of course should be "2012 January 16". :)

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Re: APOD: Zodiacal Light and the False Dawn (2012 Jan 16)

Post by neufer » Tue Jan 17, 2012 10:19 pm

Ricardo wrote:
The highest observatory in the world is NOT in India...
the mini-TAO 1.5 m infrared telescope is the highest,
at 5650 m on top of Cerro Chajnantor.
The HCT is twice the size of the miniTAO:
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Re: APOD: Zodiacal Light and the False Dawn (2012 Jan 16)

Post by DavidLeodis » Fri Jan 20, 2012 10:21 pm

DavidLeodis wrote:The date above the APOD video image states "2011 January 16". That of course should be "2012 January 16". :)
I notice that the date has since been corrected. I thought I could add an edit to my original post to note that but I was unable to edit that post, so I have posted this new one.