Comments and questions about the
APOD on the main view screen.
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Chris Peterson
- Abominable Snowman
- Posts: 18610
- Joined: Wed Jan 31, 2007 11:13 pm
- Location: Guffey, Colorado, USA
Post
by Chris Peterson » Tue Apr 03, 2018 4:57 am
APOD Robot wrote: ↑Tue Apr 03, 2018 4:05 am
How these ancient 40-meter high
pillars formed is yet unknown.
I don't think that's really true. Structures like this exist around the world, and their formation is at least broadly understood as the result of weathering and erosion of softer surrounding material. That schists like this form in narrow columns and dikes in not unusual, given the nature of geological metamorphosis.
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S_S
Post
by S_S » Tue Apr 03, 2018 5:10 am
I wonder what's that yellow+orange light on bottom left of the image ?
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Sa Ji Tario
Post
by Sa Ji Tario » Tue Apr 03, 2018 11:19 am
It reminds me of "The Pillars of Creation"
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Chris Peterson
- Abominable Snowman
- Posts: 18610
- Joined: Wed Jan 31, 2007 11:13 pm
- Location: Guffey, Colorado, USA
Post
by Chris Peterson » Tue Apr 03, 2018 1:45 pm
S_S wrote: ↑Tue Apr 03, 2018 5:10 am
I wonder what's that yellow+orange light on bottom left of the image ?
Yellow light on the horizon in long exposure astronomical images is almost always sodium vapor city lighting. Light pollution.
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neufer
- Vacationer at Tralfamadore
- Posts: 18805
- Joined: Mon Jan 21, 2008 1:57 pm
- Location: Alexandria, Virginia
Post
by neufer » Tue Apr 03, 2018 3:38 pm
Chris Peterson wrote: ↑Tue Apr 03, 2018 4:57 am
APOD Robot wrote: ↑Tue Apr 03, 2018 4:05 am
How these ancient 40-meter high
pillars formed is yet unknown.
I don't think that's really true. Structures like this exist around the world, and their formation is at least broadly understood as the result of weathering and erosion of softer surrounding material. That schists like this form in narrow columns and dikes in not unusual, given the nature of geological metamorphosis.
https://en.wikipedia.org/wiki/Hoodoo_(geology) wrote:
.
<<A hoodoo (also called a tent rock, fairy chimney or earth pyramid) is a tall, thin spire of rock that protrudes from the bottom of an arid drainage basin or badland. Hoodoos, which may range from 1.5 to 45 metres,
typically consist of relatively soft rock topped by harder, less easily eroded stone that protects each column from the elements. They generally form within sedimentary rock and volcanic rock formations.
Hoodoos are found mainly in the desert in dry, hot areas. Hoodoos range in size from the height of an average human to heights exceeding a 10-story building. Hoodoo shapes are affected by the erosional patterns of alternating hard and softer rock layers. Minerals deposited within different rock types cause hoodoos to have different colors throughout their height.
Art Neuendorffer
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Chris Peterson
- Abominable Snowman
- Posts: 18610
- Joined: Wed Jan 31, 2007 11:13 pm
- Location: Guffey, Colorado, USA
Post
by Chris Peterson » Tue Apr 03, 2018 3:45 pm
neufer wrote: ↑Tue Apr 03, 2018 3:38 pm
Chris Peterson wrote: ↑Tue Apr 03, 2018 4:57 am
APOD Robot wrote: ↑Tue Apr 03, 2018 4:05 am
How these ancient 40-meter high
pillars formed is yet unknown.
I don't think that's really true. Structures like this exist around the world, and their formation is at least broadly understood as the result of weathering and erosion of softer surrounding material. That schists like this form in narrow columns and dikes in not unusual, given the nature of geological metamorphosis.
https://en.wikipedia.org/wiki/Hoodoo_(geology) wrote:
.
<<A hoodoo (also called a tent rock, fairy chimney or earth pyramid) is a tall, thin spire of rock that protrudes from the bottom of an arid drainage basin or badland. Hoodoos, which may range from 1.5 to 45 metres,
typically consist of relatively soft rock topped by harder, less easily eroded stone that protects each column from the elements. They generally form within sedimentary rock and volcanic rock formations.
Hoodoos are found mainly in the desert in dry, hot areas. Hoodoos range in size from the height of an average human to heights exceeding a 10-story building. Hoodoo shapes are affected by the erosional patterns of alternating hard and softer rock layers. Minerals deposited within different rock types cause hoodoos to have different colors throughout their height.
Yes, but the Manpupuner formations don't appear to be caprock protected columns, but hard metamorphic structures.
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rstevenson
- Quis custodiet ipsos custodes?
- Posts: 2705
- Joined: Fri Mar 28, 2008 1:24 pm
- Location: Halifax, NS, Canada
Post
by rstevenson » Tue Apr 03, 2018 6:42 pm
Chris Peterson wrote: ↑Tue Apr 03, 2018 4:57 am
APOD Robot wrote: ↑Tue Apr 03, 2018 4:05 am
How these ancient 40-meter high
pillars formed is yet unknown.
I don't think that's really true. Structures like this exist around the world, and their formation is at least broadly understood as the result of weathering and erosion of softer surrounding material. That schists like this form in narrow columns and dikes in not unusual, given the nature of geological metamorphosis.
A paragraph from the
Manpupuner Rock Formations wikipedia page seems to address this, at least in part...
About 200 million years ago on the place of stone pillars were high mountains. Rain, snow, wind, frost and heat gradually destroyed mountains and, in the first place, weak rocks. Solid sericite-quartzite schists, from which the remains are composed, were destroyed less and survived to this day, and soft rocks were destroyed by weathering and carried down by water and wind in relief depressions.
Rob
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neufer
- Vacationer at Tralfamadore
- Posts: 18805
- Joined: Mon Jan 21, 2008 1:57 pm
- Location: Alexandria, Virginia
Post
by neufer » Tue Apr 03, 2018 6:58 pm
rstevenson wrote: ↑Tue Apr 03, 2018 6:42 pm
Chris Peterson wrote: ↑Tue Apr 03, 2018 4:57 am
APOD Robot wrote: ↑Tue Apr 03, 2018 4:05 am
How these ancient 40-meter high
pillars formed is yet unknown.
I don't think that's really true. Structures like this exist around the world, and their formation is at least broadly understood as the result of weathering and erosion of softer surrounding material. That schists like this form in narrow columns and dikes in not unusual, given the nature of geological metamorphosis.
A paragraph from the
Manpupuner Rock Formations wikipedia page seems to address this, at least in part...
About 200 million years ago on the place of stone pillars were high mountains. Rain, snow, wind, frost and heat gradually destroyed mountains and, in the first place, weak rocks. Solid sericite-quartzite schists, from which the remains are composed, were destroyed less and survived to this day, and soft rocks were destroyed by weathering and carried down by water and wind in relief depressions.
https://en.wikipedia.org/wiki/United_States_Postal_Service_creed wrote:
<<The words "
Neither snow nor rain nor heat nor gloom of night stays these couriers from the swift completion of their appointed rounds" have long been associated with the American postman. The motto is inscribed on New York's James Farley Post Office in New York City, facing Penn Station, but it has no official status. The phrase was a translation by Prof. George Herbert Palmer, Harvard University, from an ancient Greek work of Herodotus describing the angarium, the ancient Persian system of mounted postal carriers c. 500 B.C.:
It is said that as many days as there are in the whole journey, so many are the men and horses that stand along the road, each horse and man at the interval of a day’s journey; and these are stayed neither by snow nor rain nor heat nor darkness from accomplishing their appointed course with all speed. — Herodotus, Histories (8.98) (trans. A.D. Godley, 1924)>>
Art Neuendorffer
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MarkBour
- Subtle Signal
- Posts: 1377
- Joined: Mon Aug 26, 2013 2:44 pm
- Location: Illinois, USA
Post
by MarkBour » Wed Apr 04, 2018 12:03 am
There is an interesting plan for a visitor center
https://worldarchitecture.org/articles- ... tions.html
I wonder if it will be built ...
About half-way through that document is a diagrammatic description of a theory of the geological formation process (erosion, of course). I wonder if they are growing or shrinking, and whether any of them are going to topple.
Mark Goldfain
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Chris Peterson
- Abominable Snowman
- Posts: 18610
- Joined: Wed Jan 31, 2007 11:13 pm
- Location: Guffey, Colorado, USA
Post
by Chris Peterson » Wed Apr 04, 2018 12:15 am
MarkBour wrote: ↑Wed Apr 04, 2018 12:03 am
There is an interesting plan for a visitor center
https://worldarchitecture.org/articles- ... tions.html
I wonder if it will be built ...
About half-way through that document is a diagrammatic description of a theory of the geological formation process (erosion, of course). I wonder if they are growing or shrinking, and whether any of them are going to topple.
They are surely shrinking, and they will surely erode away. Some will topple during the process.
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MarkBour
- Subtle Signal
- Posts: 1377
- Joined: Mon Aug 26, 2013 2:44 pm
- Location: Illinois, USA
Post
by MarkBour » Wed Apr 04, 2018 7:43 pm
Chris Peterson wrote: ↑Wed Apr 04, 2018 12:15 am
MarkBour wrote: ↑Wed Apr 04, 2018 12:03 am
There is an interesting plan for a visitor center
https://worldarchitecture.org/articles- ... tions.html
I wonder if it will be built ...
About half-way through that document is a diagrammatic description of a theory of the geological formation process (erosion, of course). I wonder if they are growing or shrinking, and whether any of them are going to topple.
They are surely shrinking, and they will surely erode away. Some will topple during the process.
I should clarify what I mean by "growing". The way they could be growing would be if the ground they are embedded in is eroding faster than they are. It looks like a very exposed hilltop. But perhaps you already understood my meaning and have a reason to know that this will not be happening.
Mark Goldfain
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Chris Peterson
- Abominable Snowman
- Posts: 18610
- Joined: Wed Jan 31, 2007 11:13 pm
- Location: Guffey, Colorado, USA
Post
by Chris Peterson » Wed Apr 04, 2018 11:09 pm
MarkBour wrote: ↑Wed Apr 04, 2018 7:43 pm
Chris Peterson wrote: ↑Wed Apr 04, 2018 12:15 am
MarkBour wrote: ↑Wed Apr 04, 2018 12:03 am
There is an interesting plan for a visitor center
https://worldarchitecture.org/articles- ... tions.html
I wonder if it will be built ...
About half-way through that document is a diagrammatic description of a theory of the geological formation process (erosion, of course). I wonder if they are growing or shrinking, and whether any of them are going to topple.
They are surely shrinking, and they will surely erode away. Some will topple during the process.
I should clarify what I mean by "growing". The way they could be growing would be if the ground they are embedded in is eroding faster than they are. It looks like a very exposed hilltop. But perhaps you already understood my meaning and have a reason to know that this will not be happening.
No. It's possible that the erosion around them exceeds the rate their tops are eroding, in essence making them grow. I tend to think not, given the high degree of weathering that has exposed so much surface, which I'd expect to increase the erosion rate (especially as this is a location with strong freeze/thaw cycles). But I don't know for sure.
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MarkBour
- Subtle Signal
- Posts: 1377
- Joined: Mon Aug 26, 2013 2:44 pm
- Location: Illinois, USA
Post
by MarkBour » Thu Apr 05, 2018 9:23 pm
Chris Peterson wrote: ↑Wed Apr 04, 2018 11:09 pm
MarkBour wrote: ↑Wed Apr 04, 2018 7:43 pm
Chris Peterson wrote: ↑Wed Apr 04, 2018 12:15 am
They are surely shrinking, and they will surely erode away. Some will topple during the process.
I should clarify what I mean by "growing". The way they could be growing would be if the ground they are embedded in is eroding faster than they are. It looks like a very exposed hilltop. But perhaps you already understood my meaning and have a reason to know that this will not be happening.
No. It's possible that the erosion around them exceeds the rate their tops are eroding, in essence making them grow. I tend to think not, given the high degree of weathering that has exposed so much surface, which I'd expect to increase the erosion rate (especially as this is a location with strong freeze/thaw cycles). But I don't know for sure.
Ah, yes. Once the pillars themselves have become so etched and "craggy", as these have, the break-down should accelerate. And I have now seen an image that clearly shows rubble near the base of one of them, indicating that it has had a chunk fall off.
In many instances with APOD, I find myself wishing I had a "fast-forward" button. Just as long as it doesn't fast-forward my life along with the scene!
Mark Goldfain