APOD: The Milky Way Over Monument Valley (2012 Aug 01)

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Expand view Topic review: APOD: The Milky Way Over Monument Valley (2012 Aug 01)

"Nothing to see here but a couple of big buttes."

by neufer » Tue Aug 14, 2012 6:23 pm

http://www.foxnews.com/scitech/2012/08/14/long-lost-egyptian-pyramids-found-on-google-earth/ wrote: Long-lost Egyptian pyramids found on Google Earth?
Fox News, August 14, 2012

<<A self-described "satellite archaeology researcher" has garnered widespread media attention with claims that she has found two possible pyramid complexes in Egypt using Google Earth. But experts say her pyramids are nothing more than eroded hills infused with a heavy dose of wishful thinking.

Angela Micol, a North Carolina-based woman who blogs at Google Earth Anomalies, says she discovered the two clusters of mysterious, angular mounds in the Egyptian desert while surveying satellite images of the terrain using Google Earth, the virtual map program. In its coverage, Gizmodo asserts that the desert structures look as if they have been "very deliberately arranged," and that they "bear all the hallmarks of ancient pyramid sites."

If Micol's blog is to be believed, Egyptologists have vetted and are currently investigating her amazing discovery. "The images speak for themselves. It's very obvious what the sites may contain but field research is needed to verify they are, in fact, pyramids," Micol wrote on her blog. Turns out, further field research won't be necessary after all. These mounds are just your common buttes.

"It seems that Angela Micol is one of the so-called 'pyridiots' who see pyramids everywhere," said James Harrell, professor emeritus of archaeological geology at the University of Toledo and a leading expert on the archaeological geology of ancient Egypt. "Her Dimai and Abu Sidhum 'pyramids' are examples of natural rock formations that might be mistaken for archaeological features provided one is unburdened by any knowledge of archaeology or geology. In other words, her pyramids are just wishful thinking by an ignorant observer with an overactive imagination."

The large, three- and four-sided hills Micol chanced upon are geologic features known as buttes, Harrell told Life's Little Mysteries. Commonly seen in the local Faiyum Desert, such buttes form when a mound of sediment contains a difficult-to-erode layer. When the surrounding sediment gradually erodes, that resistant layer gets left on top, making the hill flat. Meanwhile, the smaller hills found in Micol's Google Earth screenshots are circular, and thus nothing like pyramids, Harrell said.

Other geologists attribute the features to the forces of nature as well. "What it looks like to me is an area where a resistant layer of stone is underlain by soft rock, perhaps shales. If that is so, the triangular one looks very much the sort of feature common in the U.S. southwest, and might be called a butte," said Clair Ossian, a geoarcheologist at Tarrant County College who has studied Egypt's sites.

So in summary, sorry folks: nothing to see here but a couple of big buttes. The question is how they garnered so much breathless, and factless, media attention.>>

Re: Relative View point.

by fcmbj » Thu Aug 02, 2012 3:36 pm

Thanks Chris.

Re: APOD: The Milky Way Over Monument Valley (2012 Aug 01)

by saturno2 » Thu Aug 02, 2012 3:56 am

Indeed. The Milky Way Galaxy is very beautiful

Re: APOD: The Milky Way Over Monument Valley (2012 Aug 01)

by NoelC » Thu Aug 02, 2012 1:41 am

What a gorgeous image, Wally! Thank you for taking us all out there along with you. :)

-Noel

Re: APOD: The Milky Way Over Monument Valley (2012 Aug 01)

by neufer » Wed Aug 01, 2012 11:39 pm

Jeeplvr2000 wrote:
Why does the milky way look curved across the sky in this picture?
Why does the International Space Station orbit look curved across the world on this map :?:

Re: APOD: The Milky Way Over Monument Valley (2012 Aug 01)

by Jeeplvr2000 » Wed Aug 01, 2012 8:25 pm

Why does teh milky way look curved across the sky in this picture?

Re: APOD: The Milky Way Over Monument Valley (2012 Aug 01)

by Anthony Barreiro » Wed Aug 01, 2012 6:47 pm

Boomer12k wrote:
ritwik wrote:how many spiral arms does our galaxy have ? 6, 4 or 2 and how many arms are actually observed
what arm is this one ? :?:
what are the locations on earth to see each arm of our galaxy ?

Here is a "YOU ARE HERE" APOD....hold mouse over picture for overlay...
http://apod.nasa.gov/apod/ap080606.html

:---[===] *
This is a very helpful image. It would be even more awesome if the brighter patches were identified on the mouse-over, and if you could tilt the orientation of the disk to get more of a sense of how things look from edge-on. Also, it would help me get oriented to have lines indicating which directions Earth's north celestial and ecliptic poles point relative to the plane of the galaxy.

Re: APOD: The Milky Way Over Monument Valley (2012 Aug 01)

by neufer » Wed Aug 01, 2012 6:41 pm

Chris Peterson wrote:
In some cases buttes may be produced by the material left behind in an extinct volcano, or by magma inclusions. But caprock formations are much more common, and are the cause of the buttes in Monument Valley.
http://en.wikipedia.org/wiki/Butte wrote:
<<A butte is a conspicuous isolated hill with steep, often vertical sides and a small, relatively flat top; buttes are smaller than mesas, plateaus, and table landforms. In some regions, such as the north central and northwestern United States, the word is used for any hill. The word butte comes from a French word meaning "small hill"; its use is prevalent in the western United States, including the southwest, where "mesa" is also used. Because of their distinctive shapes, buttes are frequently key landmarks in both plains and mountainous areas. In differentiating mesas and buttes, geographers use the rule that a mesa has a top wider than its height, while a butte's top is narrower.

Three classic buttes are Scotts Bluff (actually a collection of five bluffs) in Nebraska, Crested Butte in Colorado, and Elephant Butte in New Mexico. Scotts Bluff Scotts Bluff (steep hill), which rises over 830 feet above the plains at its highest point was important 19th century landmark on the Oregon Trail and Mormon Trail.>>
When I was in the Army I used to motorcycle up the Rio Grande to Elephant Butte on weekends.
http://en.wikipedia.org/wiki/Butte wrote:
Click to play embedded YouTube video.
<<Elephant Butte Dam is a concrete gravity dam on the Rio Grande near Truth or Consequences, New Mexico. The river was dammed here, impounding the Elephant Butte Reservoir for recreation and agriculture, lessening the downstream flow from a Rio Bravo to a stream a foot deep. The name "Elephant Butte" refers to a volcanic core similar to Devils Tower in Wyoming. It is now an island in the lake. The butte was said to have the shape of an elephant.

Truth or Consequences is a spa city and the county seat of Sierra County, New Mexico, United States. Originally named Hot Springs, the city changed its name to Truth or Consequences, the title of a popular NBC radio program. In 1950, Ralph Edwards, the host of the radio quiz show Truth or Consequences, announced that he would air the program from the first town that renamed itself after the show. Hot Springs won the honor. Edwards visited the town during the first weekend of May for the next fifty years. This event was called "Fiesta" and included a beauty contest, a parade, and a stage show. The city still celebrates Fiesta each year on the first weekend of May. The parade generally features area celebrities such as the Hatch Chile Queen. Fiesta also features a dance in Ralph Edwards Park.

The dam is part of the Rio Grande Project, a project to provide power and irrigation to south-central New Mexico and west Texas. The United States Congress authorized construction of the dam on February 25, 1905 and it began in 1911. It was completed in 1916 but allowed to begin filling in 1915. Elephant Butte Dam is 301 feet high, 1,674 feet long. The width at the top of the dam is 18 feet and 228 feet at the base. At the time of its construction, the dam was the largest irrigation dam ever built with the exception of the Aswan Dam in Egypt. It was expected that the dam would become the property of the local settlers once a water tax had reimbursed the government for the cost of construction.

Re: APOD: The Milky Way Over Monument Valley (2012 Aug 01)

by Anthony Barreiro » Wed Aug 01, 2012 6:38 pm

Ann wrote:This is a very beautiful picture. We may note that, unlike other pictures taken of this area, this one has been made with a technique that doesn't emphasize the bright stars. That makes it harder to pick out the constellations, but you can more easily see some other features.

One of the easiest deep-sky objects in this picture is the North America Nebula, right above the most obvious "mitten" formation on the ground. Just above the North America Nebula (but not "touching" it) is Deneb, the alpha star in constellation Cygnus. ...

... .

As I said, this is a great picture! I agree that there is something otherworldly about it. It does look like a good landing site for UFOs! :wink:

Ann
I'm rather proud of myself. I have more trouble getting oriented in a picture than when I'm looking at the sky. I tried to find stars and constellations in this picture, but the number of stars visible, the similar brightnesses of stars in the image, and the slight blurring of each star (is this because it's a time lapse picture?) made it hard to identify my familiar first- and second-magnitude friends. Then I saw the North America nebula, and was able to work my way south from there, recognizing the brighter nebulae and clusters. When I read Ann's expertly guided tour, I was pleased that I had correctly identified all the deep sky objects I recognized, mostly Messier objects. It's good to be at home in the sky.

Re: APOD: The Milky Way Over Monument Valley (2012 Aug 01)

by Chris Peterson » Wed Aug 01, 2012 5:32 pm

Devil Particle wrote:When you click on the "far enough" link a map of sky brightness comes up. Does anyone know what the region of sky brightness off the east coast of Argentina is? It thought the Falkland islands were sparsely populated.
From the Night Sky Atlas FAQ:
What's all that light near the Falkland islands? For a small set of islands with more sheep than people, how can they possibly generate so much light?

Satellite data also record the offshore lights where oil and gas production is active (visible e.g. in the North Sea, Chinese Sea and Arabic Gulf), other natural gas flares (visible e.g. in Nigeria) and the fishing fleets (visible e.g. near the coast of Argentina, in Japan Sea and near Malacca). Note that their upward emission functions likely differ from the average emission function of the urban night-time lighting that we use so that the predictions of their effects have some uncertainty.

Re: APOD: The Milky Way Over Monument Valley (2012 Aug 01)

by LocalColor » Wed Aug 01, 2012 5:10 pm

Lovely photo. We can see the milky way from where we live, but the tall mountains block out most of it. So this wide horizon photo is very nice to see.

Re: APOD: The Milky Way Over Monument Valley (2012 Aug 01)

by Devil Particle » Wed Aug 01, 2012 5:08 pm

When you click on the "far enough" link a map of sky brightness comes up. Does anyone know what the region of sky brightness off the east coast of Argentina is? It thought the Falkland islands were sparsely populated.

Re: APOD: The Milky Way Over Monument Valley (2012 Aug 01)

by Chris Peterson » Wed Aug 01, 2012 5:07 pm

guest123456 wrote:If we are in the plane of the Milky Way, why does it appear as an arch?
Projection is everything. The image on your left is what you'd see at midnight (currently) lying on your back and looking straight up. On an image, we see the horizon as a circle. The second image is the same view four hours later. You can see how the band of the Milky Way changes position. The third view is at the same time as the second, but now looking to the north. In this projection, we flatten out the horizon (which is pretty much how we see it visually) and that makes the Milky Way look like an arch. At this time of the night, when the Milky Way is nearly overhead, the arch looks about the same to the north or south, except that the views are mirrored.
views.jpg

Re: APOD: The Milky Way Over Monument Valley (2012 Aug 01)

by Chris Peterson » Wed Aug 01, 2012 4:49 pm

BobbleHeadNed wrote:I believe that buttes are the remains of extinct volcanos - usually composed of the harder, newer rock (i.e. basalt) that was once the magma/lava core of a volcano and the softer, older rock that was the volcano's cone was partially or mostly eroded away. Does that seem right?
No. A butte is typically formed when you have a cap of hard rock (such as basalt) over softer rock (such as sandstone). The caprock protects the underlying material from erosion, so the area outside the caprock erodes faster, leaving behind a columnar or conical structure.

In some cases buttes may be produced by the material left behind in an extinct volcano, or by magma inclusions. But caprock formations are much more common, and are the cause of the buttes in Monument Valley.

Re: APOD: The Milky Way Over Monument Valley (2012 Aug 01)

by BobbleHeadNed » Wed Aug 01, 2012 4:30 pm

APOD Robot wrote:Buttes are composed of hard rock left behind after water has eroded away the surrounding soft rock.
I believe that buttes are the remains of extinct volcanos - usually composed of the harder, newer rock (i.e. basalt) that was once the magma/lava core of a volcano and the softer, older rock that was the volcano's cone was partially or mostly eroded away. Does that seem right?

Re: APOD: The Milky Way Over Monument Valley (2012 Aug 01)

by neufer » Wed Aug 01, 2012 2:22 pm

guest123456 wrote:
If we are in the plane of the Milky Way, why does it appear as an arch?
This wide angle shot really needs to be wrapped around you on half a cylinder.
guest123456 wrote:
Also, is the bright section to the right the direction of the center of the galaxy?
Yes: http://media.skysurvey.org/interactive360/index.html

Re: APOD: The Milky Way Over Monument Valley (2012 Aug 01)

by neufer » Wed Aug 01, 2012 2:06 pm

ritwik wrote:
how many spiral arms does our galaxy have ? 6, 4 or 2
  • 6, 4 or 2 depending upon how one counts.
http://en.wikipedia.org/wiki/Milky_Way wrote:
<<Until recently, there were thought to be four major spiral arms which all start near the Galaxy's center. Two spiral arms, the Scutum–Centaurus Arm and the Carina–Sagittarius Arm, have tangent points inside the Sun's orbit around the center of the Milky Way. If these arms contain an overdensity of stars compared to the average density of stars in the Galactic disk, it would be detectable by counting the stars near the tangent point. Two surveys of near-infrared light, which is sensitive primarily to red giant stars and not affected by dust extinction, detected the predicted overabundance in the Scutum–Centaurus Arm but not in the Carina–Sagittarius Arm. In 2008, Robert Benjamin of the University of Wisconsin–Whitewater used this observation to suggest that the Milky Way possesses only two major stellar arms: the Perseus Arm and the Scutum–Centaurus Arm. The rest of the arms contain excess gas but not excess stars.>>
ritwik wrote:
how many arms are actually observed what arm is this one :?:
what are the locations on earth to see each arm of our galaxy ?
Anytime, like here, that you can observe both Cygnus & Sagittarius then, essentially, you can see all the arms:

The highest part of the Milky Way seen here is towards
Kepler's view of Cygnus in our own Orion–Cygnus Spur

The Perseus Arm is to the left.

And to the right, in order, are:
  • 1) The Carina–Sagittarius Arm
    2) The Scutum–Centaurus Arm and
    3) The Norma Arm.
    4) The Central Bar
Boomer12k wrote:
Here is a "YOU ARE HERE" APOD....hold mouse over picture for overlay...
http://apod.nasa.gov/apod/ap080606.html

Re: APOD: The Milky Way Over Monument Valley (2012 Aug 01)

by StormyKnight » Wed Aug 01, 2012 1:41 pm

Beautiful photo. I remember a time when you couldn't see all those lights/glow on the horizon.

Re: APOD: The Milky Way Over Monument Valley (2012 Aug 01)

by guest123456 » Wed Aug 01, 2012 1:33 pm

If we are in the plane of the Milky Way, why does it appear as an arch? Also, is the bright section to the right the direction of the center of the galaxy?

Thanks

Re: APOD: The Milky Way Over Monument Valley (2012 Aug 01)

by Chris Peterson » Wed Aug 01, 2012 1:33 pm

Boomer12k wrote:It is like a rainbow at night...awesome...what type of camera does that take to get a shot like that?
Nothing special. Any ordinary consumer DSLR made in the last few years can produce an equivalent image. The ability to recognize a photo opportunity, set up a shot, and process it, however, are not so easily purchased <g>.

Re: Relative View point.

by Chris Peterson » Wed Aug 01, 2012 1:26 pm

fcmbj wrote:I understood that our galaxy was a relatively flat disc, yet looking at today's picture of the Milky Way, I get the impression that we are not in the same formation - as though we are at a point well above such a disc. Can anyone please explain why?
Since we are inside the galaxy's disc, we see it as a ring (spanning 360° of sky). Most of the time, part of the ring is below the horizon, so we see what looks like a sort of line of stars going from one part of the horizon to another. If we're outside and can look with our eyes, we really do see what looks linear, but when you map that onto a wide angle image, it almost always appears curved or arch-like. In an image like today's APOD, you have no real reference for where the zenith actually is, or for how many degrees of horizon are actually captured.

Re: APOD: The Milky Way Over Monument Valley (2012 Aug 01)

by orin stepanek » Wed Aug 01, 2012 1:15 pm

When I was a kid; we used to be able to see the Milky Way from our front yard in the small town I grew up in! 8-) Now I'm lucky to see some of the major constellations! Today's APOD is really neat! :thumb_up: :thumb_up: :yes: :clap: :clap:

Re: APOD: The Milky Way Over Monument Valley (2012 Aug 01)

by FloridaMike » Wed Aug 01, 2012 1:10 pm

Ann wrote:... awesomeness...
Thanks Ann, I always appreciate your "guided tours".

Re: APOD: The Milky Way Over Monument Valley (2012 Aug 01)

by biddie67 » Wed Aug 01, 2012 12:12 pm

OMG .... absolutely awesome!!!

Re: APOD: The Milky Way Over Monument Valley (2012 Aug 01)

by Boomer12k » Wed Aug 01, 2012 12:08 pm

ritwik wrote:how many spiral arms does our galaxy have ? 6, 4 or 2 and how many arms are actually observed
what arm is this one ? :?:
what are the locations on earth to see each arm of our galaxy ?

Here is a "YOU ARE HERE" APOD....hold mouse over picture for overlay...
http://apod.nasa.gov/apod/ap080606.html

:---[===] *

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