APOD: The Milky Way over Monument Valley (2017 Jul 26)

Comments and questions about the APOD on the main view screen.
User avatar
APOD Robot
Otto Posterman
Posts: 3023
Joined: Fri Dec 04, 2009 3:27 am

APOD: The Milky Way over Monument Valley (2017 Jul 26)

Postby APOD Robot » Wed Jul 26, 2017 4:05 am

Image The Milky Way over Monument Valley

Explanation: You don't have to be at Monument Valley to see the Milky Way arc across the sky like this -- but it helps. Only at Monument Valley USA would you see a picturesque foreground that includes these iconic rock peaks called buttes. Buttes are composed of hard rock left behind after water has eroded away the surrounding soft rock. In the featured image taken a month ago, the closest butte on the left and the butte to its right are known as the Mittens, while Merrick Butte can be seen farther to the right. Green airglow fans up from the horizon. High overhead stretches a band of diffuse light that is the central disk of our spiral Milky Way Galaxy. The band of the Milky Way can be spotted by almost anyone on almost any clear night when far enough from a city and surrounding bright lights, but a sensitive digital camera is needed to capture these colors in a dark night sky.

<< Previous APOD This Day in APOD Next APOD >>

Boomer12k
:---[===] *
Posts: 2117
Joined: Sun Apr 22, 2007 12:07 am

Re: APOD: The Milky Way over Monument Valley (2017 Jul 26)

Postby Boomer12k » Wed Jul 26, 2017 4:14 am

Great image...

So.... is there an East Mitten??? Oh, I see there are several "mittens"... also my old cat's name...

Greetings to Saji... Yes, I am friends with that person...thank you for enjoying my posts... :D
:---[===] *

User avatar
Ann
4725 Å
Posts: 8497
Joined: Sat May 29, 2010 5:33 am

Re: APOD: The Milky Way over Monument Valley (2017 Jul 26)

Postby Ann » Wed Jul 26, 2017 5:46 am

The Milky Way over Monument Valley.
Photo: Tom Masterson.
The Summer Triangle (and the Milky Way) over the Great Wall of China.
Photo: Steed Yu.



















Wow! Is it any wonder that the position of resident Color Commentator at Starship Asterisk* is a busy job?

Compare these two pictures of the Milky Way. Both of them are APODs, the one at left from today, the one at right from July 3 this year. The two images are similar in many ways. We see the same parts of the Milky Way arcing over the landscape in the same way, and Vega is seen "floating" above the Milky Way in almost the same position. The images are similar in many ways, but their colors are so different! :shock:

First things first. The two landscapes are different. The one tall peak in the image from China is interesting and photogenic, making the landscape seem to "rise up" below the Milky Way, almost as if the summit was supporting it. The Colorado landscape is much flatter, and it almost seems to "sink down" under the Milky Way. Of course the amazing "buttes", or "Mittens", are just incredible!

The sky background, disregarding the Milky Way itself, is quite different in the two images. The Chinese sky displays two large yellow-orange patches which are probably signs of light pollution. In a valley, however, blue-green lights can be seen.

Image
Parts of the Colorado plateau is light orange-brown from some sort of illumination. As for the Colorado sky, it is full of green stripes from air glow. The green streaks almost look like the ribs of an umbrella, as if the Milky Way was one giant umbrella opening its canopy over the Earth! Amazing!

All right. But now consider the appearance, and color, of the Milky Way itself and of Vega above it, in the two images. The differences are huge. Look at Vega, shining like a brilliant blue lamp in the picture from China. But in the Colorado picture it is a tiny little white night light in the dark sky.


So what does Vega really look like? To the naked eye, it looks white, in my opinion. Even through a pair of binoculars it often looks white. But through a nice telescope it is definitely, undeniably blue, very similar to what it looks like in the picture at right. Unfortunately I have not been able to find out who took the picture. Also check out Robert Mura's fine picture of Vega and constellation Lyra to see the color of Vega.

Vega is, it must be said, much bluer than the Milky Way. The B-V of Vega is 0.00, but the overall B-V of the Milky Way might be in the region of +0.85. I strongly doubt that there are any extended regions of the Milky Way that are not just as blue as Vega but also large enough to show up prominently in pictures like the two APODs at top. Note in Tom Masterson's image how the left part of the arc of the Milky Way is blue above and below the dust lane, clearly bluer than Vega. That doesn't reflect the true color of extended parts of the Milky Way compared with Vega. In fact, in the picture at right, you can see the beige tint of the faint extended part of the Milky Way, near the left edge of the picture.

Steed Yu's image is a "truer" portrait of the relative color and brightness of Vega and the Milky Way. Yes, the blue color of his Vega is extremely saturated, but the contrast between the blue color of Vega and the basically non-blue color of the Milky Way looks just right to me. Note, too, how bright his Vega is. Because, above all, Vega is bright. It is so, so much brighter than the Milky Way, as seen from our own vantage point. Or, at the very least, the "surface brightness" of Vega is way, way, way brighter than that of the Milky Way!

Does that mean that Tom Masterson's picture is "wrong"? That depends entirely on what you expect it to show you. If you expect to see a brilliant, colorful Milky Way and a tiny, faint Vega floating above it, the way Tom Masterson's skyscape makes it look, you'll never get to see such a sight.

Image

But if you think of Tom Masterson's image as an amazingly colorful, detailed and mostly true-color portrait of the Milky Way, floating above a lot of streaky green airglow, then Tom Masterson's image is like a box of chocolate or mixed candy. It's a joy to behold, as if you want to taste it with your eyes! :D

Ann
Color Commentator

SpookyAstro
Ensign
Posts: 55
Joined: Sat Feb 07, 2015 7:38 pm

Re: APOD: The Milky Way over Monument Valley (2017 Jul 26)

Postby SpookyAstro » Wed Jul 26, 2017 7:33 am

That is an EXCELLENT explanation of what is represented in these images Ann and as I always say, I'm a photographer/astrophotographer/artist. I do my best to try to relay what I think would be possibly seen if say we had camera vision (maybe someday soon right?) and could collect more light with our eyes than biologically possible but it's still always my interpretation and there are a lot of optical/electrical things going on with the lenses used and cameras so almost all of the photography I do I feel is a mix between art and real life.

I would like to shed some light on my thoughts of the difference in appearance of Vega in the two images, full disclosure this is gonna be a lot of conjecture and opinion as I don't have all of the information on how the other astrophotographer shot/assembled/processed that image.

Starting with my image I can firstly explain why Vega is missing it's blue hue, it has to do with the Zeiss 35mm lens I took these images with for this panorama (it is an excellent lens by the way despite the problems I'm going to list about it). It has slight blue chromatic aberration which in my opinion made a lot of the stars in the image have an artificial blue over-saturated hue. If you zoom into my image you can still see some of it in the stars in the Milky Way as I couldn't dodge them without taking out the color of the rest of the area so you can still see the chromatic aberration. To combat the problem in the upper portion of the image I decreased the specific color of the blue saturation in the image so as to take out the weird color in a vast majority of the stars, not just Vega and dodged the entire upper portion of the image. I actually spent some time deciding on whether or not to omit the saturation decrease in Vega since I know it's usually blue but to me the color looked too blue/magenta and was really an artifact of the lens so I just decreased it and said ah well it's art and I wanted to take it out haha :-) As for the rest of the color in the image and the green/red sky glow I was able to pull that out of the raw images because of how little light pollution there is in Monument Valley, in the other image a lot of I'm guessing the dehaze tool in Photoshop was used to pull out detail from light polluted skies which unfortunately takes out a lot of the color and saturation for the benefit of contrast and clarity. Light pollution is a bummer as I'm sure we can all probably agree upon :P

I'm not sure exactly about the other image but to me the size of Vega and the distance that is illuminated and blue away from the center point of the star could probably be because of a couple factors but I'm guessing that possibly it was close to the outside field of view of a wide angle lens maybe a 14mm or 24mm or so lens, so this would create distortions in the color and size and shape of Vega and the light surrounding it. I really like how it looks and if it is because of the distortion caused by the lens so be it, it's kinda a very nice depiction of Vega in the image that in a way does depict how bright it is in the night sky to the naked eye. OPINION AHEAD it is also possible that it is altered 'artificially' in post meaning that in Photoshop the author of that image added in more to Vega and used a lower opacity brush to create the glow around it. This is a possibility because I know that a lot of people do this to add a dramatic effect to their image, and hey just like all of the post processing I did to my image it's all the art of photography and digital imagery no problem and in this image it really works.

For reference these are the technical details of my image in case you or anyone would be interested to know them :)

Technical Info:

Date: 6/14/2017

~66 frame panorama 13 sec @6400 ISO

Camera: Canon 6D Hutech UV/IR Mod
Lens: Zeiss f1.4 Distagon 35mm at f2.5
Reveal Focus Filter by David Lane
Processing: Photoshop CC, PTGui

Also I attached the raw image of the larger portion of the FOV that included Vega as well as a close crop, the larger image is scaled down because of upload file size restrictions. You can see the chromatic aberration I'm talking about or as some people call it color fringing. From how I understand it it's because not all of the wavelengths of light are brought to focus at exactly the same place, technically speaking it's a pretty hard thing to make a true true apochromatic optical system and lenses/telescopes that are apochromatic are expensive for a reason hehe.
You do not have the required permissions to view the files attached to this post.

User avatar
Ann
4725 Å
Posts: 8497
Joined: Sat May 29, 2010 5:33 am

Re: APOD: The Milky Way over Monument Valley (2017 Jul 26)

Postby Ann » Wed Jul 26, 2017 12:04 pm

Tom,

Thanks so much for your detailed description and explanation of the appearance of Vega in your image! :D

Looking at your widefield raw image, I have to agree with you that too many of the stars look unnaturally blue. I like the closeup much better, where many of the stars show many different colors (that extremely red star there might be T Lyrae :D !

But your image isn't a closeup of the constellation Lyra, but a widefield image. I quite agree that it looks better without the overly blue cast to so many of the stars. If Vega had to look white too, then so be it!

Thanks again!

Ann
Color Commentator

User avatar
Chris Peterson
Abominable Snowman
Posts: 13347
Joined: Wed Jan 31, 2007 11:13 pm
Location: Guffey, Colorado, USA

Re: APOD: The Milky Way over Monument Valley (2017 Jul 26)

Postby Chris Peterson » Wed Jul 26, 2017 12:56 pm

Ann wrote:The Colorado landscape is much flatter, and it almost seems to "sink down" under the Milky Way.

FWIW, Monument Valley is located in the geologic region called the Colorado Plateau, but is not itself in Colorado. Confusing, I know.

All right. But now consider the appearance, and color, of the Milky Way itself and of Vega above it, in the two images. The differences are huge. Look at Vega, shining like a brilliant blue lamp in the picture from China. But in the Colorado picture it is a tiny little white night light in the dark sky.

The differences with Vega are not so great as it might appear. In images, Vega is almost always white. Why? Because it's so bright that its core is usually saturated, and saturated images are white. With bright stars like Vega we normally only see their color in their halos- the surrounding light created by scatter or diffraction. The Monument Valley image is much sharper, with much smaller stars and very little in the way of halos. So we don't see much color. If you zoom in on the two pictures, however, approximately the same blue is visible around Vega in both images, even with the color saturation adjustments made by the imager.
Chris

*****************************************
Chris L Peterson
Cloudbait Observatory
http://www.cloudbait.com

User avatar
neufer
Vacationer at Tralfamadore
Posts: 14478
Joined: Mon Jan 21, 2008 1:57 pm
Location: Alexandria, Virginia

Re: APOD: The Milky Way over Monument Valley (2017 Jul 26)

Postby neufer » Wed Jul 26, 2017 1:39 pm

Chris Peterson wrote:
Ann wrote:
The Colorado landscape is much flatter, and it almost seems to "sink down" under the Milky Way.

FWIW, Monument Valley is located in the geologic region called the Colorado Plateau, but is not itself in Colorado. Confusing, I know.

"The Colorado River was named for the reddish color caused by its natural sediment loads, but damming has caused it to acquire a clear green hue"
Art Neuendorffer

User avatar
RJN
Baffled Boffin
Posts: 1399
Joined: Sat Jul 24, 2004 1:58 pm
Location: Michigan Tech

Re: APOD: The Milky Way over Monument Valley (2017 Jul 26)

Postby RJN » Wed Jul 26, 2017 3:27 pm

Great discussion!

This APOD's text has been updated, though, to correctly indicate that this image was taken last month -- in 2017 June, not in 2012. I apologize for the oversight. - RJN

User avatar
neufer
Vacationer at Tralfamadore
Posts: 14478
Joined: Mon Jan 21, 2008 1:57 pm
Location: Alexandria, Virginia

Re: APOD: The Milky Way over Monument Valley (2017 Jul 26)

Postby neufer » Wed Jul 26, 2017 4:55 pm

Click to play embedded YouTube video.
RJN wrote:
Great discussion!

This APOD's text has been updated, though, to correctly indicate that this image was taken last month -- in 2017 June, not in 2012. I apologize for the oversight. - RJN
Art Neuendorffer

De58te
Ensign
Posts: 98
Joined: Mon Sep 30, 2013 6:35 pm

Re: APOD: The Milky Way over Monument Valley (2017 Jul 26)

Postby De58te » Wed Jul 26, 2017 6:38 pm

Is there an East Mitten. I am guessing since I am not personally familiar with Monument Valley that East mitten is the one similar to West Mitten but the mirror image and to the right some 1,000 yards in the background. That is then the east because I figure the camera is pointed more or less to the East. Now I conclude this because Vega is up near the top, and Antares is on the right side, which it would be since it is on the south end of a northern hemisphere.

meadowlark7

Re: APOD: The Milky Way over Monument Valley (2017 Jul 26)

Postby meadowlark7 » Wed Jul 26, 2017 7:08 pm

If the earth is on an outer arm of the Milky Way and the Milky Way is relatively flat, why does it look so arched when we look toward the center? Perhaps our distant vantage point is nevertheless still too close to realize the relative flatness of the whole galaxy.

User avatar
neufer
Vacationer at Tralfamadore
Posts: 14478
Joined: Mon Jan 21, 2008 1:57 pm
Location: Alexandria, Virginia

Re: APOD: The Milky Way over Monument Valley (2017 Jul 26)

Postby neufer » Wed Jul 26, 2017 7:33 pm

meadowlark7 wrote:
If the earth is on an outer arm of the Milky Way and the Milky Way is relatively flat, why does it look so arched when we look toward the center? Perhaps our distant vantage point is nevertheless still too close to realize the relative flatness of the whole galaxy.

Art Neuendorffer

User avatar
Ann
4725 Å
Posts: 8497
Joined: Sat May 29, 2010 5:33 am

Re: APOD: The Milky Way over Monument Valley (2017 Jul 26)

Postby Ann » Wed Jul 26, 2017 9:18 pm

I just want to add something about Steed Yu's picture of the Milky Way and Vega over the Great Wall of China, where Vega looks so very blue. The sky in his image is quite light-polluted with yellow light, and maybe, just maybe, the contrast made Vega look extra blue.

I remember seeing Sirius very early one November morning in downtown Malmö. Dawn was many hours away, but the city was lit up by yellow-tinted street lights. And there, in the south western part of the sky, Sirius floated above a classic Malmö hotel. In this black-and-yellow cityscape, Sirius shone and sparkled like a pale blue sapphire. I had never before seen it look so blue, and I have never seen look so blue again.

Perhaps Steed Yu was struck by the contrast between blue Vega and the yellow-tinted light-polluted sky over the Great Wall of China, in the same way that I was struck by the contrast between the yellow street lights and blue-white Sirius over a classic Malmö hotel. If so, perhaps Steed Yu's experience affected him when he processed his image.

Ann
Color Commentator

SpookyAstro
Ensign
Posts: 55
Joined: Sat Feb 07, 2015 7:38 pm

Re: APOD: The Milky Way over Monument Valley (2017 Jul 26)

Postby SpookyAstro » Wed Jul 26, 2017 11:20 pm

Thanks everyone for the comments and discussion and big THANKS to Robert and Jerry for selecting my image!

Ann, I totally agree this is very possibly the reason it really pops in that image. Like a lot of very nice images out there the drama of the scene is really what makes any panoramic/widefield shot with cool foreground objects, and with the light pollution in that area very bright stars like Vega would stand out a ton more than anything else in the sky. Since I can't say for sure this was what the photographer was going for it really seems that way and if not it is quite serendipitous.

An interesting thing about the topic of light pollution vs dark locations is I remember the first couple times I set up a telescope mount in a dark location and found it was actually more difficult at first to get orientated north and find Polaris. To me it was because from a city the bright stand out stars are more easy to locate because the dimmer ones are more washed out by the light pollution, the first couple times I set up in a dark sky location it for sure took me a minute to figure out where everything was and locate Polaris with all of the stars I could see. Kinda one of those good problems to have :D

Thinking about how much nightscape images really pique the interest of a lot of people I wonder what the common feeling was about the night sky before we put up all of these electric lights everywhere.. Sometimes I wonder if nightscape images would have the same impact on people who live in dark locations vs those that live in urban light polluted ones. Friends and coworkers I've shown this image who all live in urban areas seem to be pretty shocked by this image and others like it, I wonder if people that live in low light polluted areas would look at it and think it's a nice image but not something that is as shocking to them :ssmile: :?

Tom

STARTALKER

Re: APOD: The Milky Way over Monument Valley (2017 Jul 26)

Postby STARTALKER » Thu Jul 27, 2017 12:37 am

I wonder at the names of those buttes prior to white guy names. "Mittens." Right.

STARTALKER

Re: APOD: The Milky Way over Monument Valley (2017 Jul 26)

Postby STARTALKER » Thu Jul 27, 2017 12:44 am

STARTALKER wrote:I wonder at the names of those buttes prior to white guy names. "Mittens." Right.

Not that the locals didn't wear mittens before the Spaniards came. Quite possibly some fancy ones.

SpookyAstro
Ensign
Posts: 55
Joined: Sat Feb 07, 2015 7:38 pm

Re: APOD: The Milky Way over Monument Valley (2017 Jul 26)

Postby SpookyAstro » Thu Jul 27, 2017 2:36 am

I'm not sure if these particular buttes had names given to them by the Navajo or other peoples of this area but the 'area' of Monument Valley does and I think translated it makes a lot of sense, from wikipedia, 'Monument Valley (Navajo: Tsé Biiʼ Ndzisgaii, pronounced [tsʰépìːʔntsɪ̀skɑ̀ìː], meaning valley of the rocks)' https://en.wikipedia.org/wiki/Monument_Valley

FLPhotoCatcher
Science Officer
Posts: 132
Joined: Wed Jul 18, 2012 6:51 am

Re: APOD: The Milky Way over Monument Valley (2017 Jul 26)

Postby FLPhotoCatcher » Thu Jul 27, 2017 4:07 am

RJN wrote:Great discussion!

This APOD's text has been updated....


Yes this has been a good discussion.
I was wondering if anyone else has problems displaying the gif in the June 16th, 1995 APOD (the one in your profile pic)? Maybe you could update the gif to animate correctly, if it needs it?


Return to “The Bridge: Discuss an Astronomy Picture of the Day”

Who is online

Users browsing this forum: CommonCrawl [Bot], Exalead [Bot] and 1 guest