Starship Asterisk*

There are no volcanic rocks in this picture!!!

These buttes are composed of sandstone and mudstone.

They are erosional remnants--quite unusual to be sure, but obviously stratigraphically continuous with the adjacent mesa.

Another minor peeve: either this picture is quite cleverly done with high speed film on a dark night, or it is faked. Could we have details?

CuDubh wrote:There are no volcanic rocks in this picture!!!
...

Very true. Perhaps the photographer thought these buttes were of similar origin to Shiprock, which is volcanic.

CuDubh wrote:Another minor peeve: either this picture is quite cleverly done with high speed film on a dark night, or it is faked. Could we have details?

MV appears to have a FOV of ~70° wide (could be 60), watching east (Google Earth). The night sky in the image appears ~60° wide. By the position of Mars in Gemini, it seems the picture was taken around 11 Dec 2007, when Mars and Orion were just coming up in the east, just after dark. Seems like a good fit. The stars in the image have a slight trail, suggesting the sky was photographed for a short time from a not-rotating mount.
I do not think this is a montage like some other landscapes with the Milky Way, which require much longer exposures.

Does it matter whether the rocks are igneous or sedimentary? The APOD is breathtaking, especially with Mars shining so brightly in a non-light-polluted sky.
Marion

Does it matter whether the rocks are igneous or sedimentary? The APOD is breathtaking, especially with Mars shining so brightly in a non-light-polluted sky.

For people like me who come to this site to find great photography and good science, yes, it does matter.

This site should all ways and always show good science.

Hope all that celebrate these hollidays have safe and great times.

Merry X - Mass
and a Happy New year to all.

Norval

I find the inclusion of pics such as this on APOD problematic.

One of the pleasures of APOD is that most of the pics are at least "quasi-" public domain, i.e., I can download them, send them to friends, etc., so long as I don't seek to profit from them or claim them as my own. (not a lawyer, so this is just a layman's perspective - and, yes, I'm aware of the APOD image permissions policy)

The TWAN website explicitly prohibits "downloading for any purpose" (emphasis mine), etc., etc. The inclusion of pics such as this on the APOD site, in my opinion, crosses (or at least closely approaches) the line of government (nasa.gov) hucksterism for some non-public entity (although self-described as one with possibly admirable goals) that, according to their own site, is a "not for profit corporation" which is seeking to raise money by various means.

This differs from most other non-gov't pics on APOD, as the providers of those pix don't appear to be in the business of raising money, or at least not quite so obviously.

The fact that a co-director of APOD is on the "TWAN team", just reeks of conflict of interest.

Just my 2 cents.

I don't know much about astronomy. I heard mars was close. checked it out in the sky tonight, then went to this site. the picture was awesome. bummer if it is a fake. How long will we be able to see mars?

You will never see Mars at the same apparent size of the Moon without the aid of a telescope. The posted image is, relatively speaking, as large as Mars will ever appear when viewed, unaided, from the Earth. The Internet postings that state Mars will appear to be the same size as the Moon are Hoaxes. This Posted Image from this post is the truth.

Mars will remain visible for some (7 or so) months before it travels around the sun and out of view.

CuDubh wrote:There are no volcanic rocks in this picture!!!

These buttes are composed of sandstone and mudstone.

Buttes are often capped with harder rock of volcanic origin, which is why they erode the way they do.

Thanks APOD for a beautiful Christmas computer screen background !!!
I've been enjoying it all day !

So where did all the cubic miles of dirt that was supposedly eroded go?
And when?

Qev wrote:

CuDubh wrote:There are no volcanic rocks in this picture!!!

These buttes are composed of sandstone and mudstone.

Buttes are often capped with harder rock of volcanic origin, which is why they erode the way they do.

While that is true in other regions, it is not the case in Monument Valley. The capstone rock is a relatively impermeable member of the Chinle Formation, I believe.

The features we see in Monument Valley - like those of the surrounding national parks - are relatively new, geologically speaking. The local uplift is part of the the Laramide orogeny, which began about 60 million years ago. However, the major erosional events are still younger - maybe 2 million years old.

The sediments from this process are generally washed out to sea by rivers. With other uplift features, such as the basin & range (think Death Valley), the erosional sediments fill up the valleys between the ranges, as well as being washed to sea.

The rocks are eroded over millions of years by weathering. Rain and wind are the principal eroding factors. They finally end up in the seas and oceans creating sedimentary formations of the future. In the case of Monument Valley where temperature ranges are high the rate of erosion would be greater, therefore erosion would be faster than say in a temperate climate.
Marion

I'm not saying this was done in this case, but...

If a person were to stand a camera on a tripod and take a long exposure of the landscape. Then they put the camera on a tracking mount and took a long exposure (or multiple long exposures for stacking) and captured the stars and planets to great depth, then combined the images digitally to represent what one would see if one had a camera (or eyes) of incredible sensitivity, how exactly is this a fake?

It is not a fake any more or less than a "photograph" is a "fake" representation of the reality it captures.

-Noel

I've been to Monument Valley, and its limiting magnitude at night is one of the highest in the country (6.7), so I can imagine how even a slightly long exposure could produce a very bright image like the one being discussed.

CuDubh wrote:Another minor peeve: either this picture is quite cleverly done with high speed film on a dark night, or it is faked. Could we have details?

I'm curious why you think it might be a fake? Pictures like this are not at all uncommon in astrophotography.

Yeah, fake was not a good choice of word. I was merely curious whether the image was obtained as you describe (a composite), or whether it is possible to achieve this with a single exposure (short, to avoid streaking of the stars or foreground). In either case it is very well done.

NoelC wrote:I'm not saying this was done in this case, but...

If a person were to stand a camera on a tripod and take a long exposure of the landscape. Then they put the camera on a tracking mount and took a long exposure (or multiple long exposures for stacking) and captured the stars and planets to great depth, then combined the images digitally to represent what one would see if one had a camera (or eyes) of incredible sensitivity, how exactly is this a fake?

It is not a fake any more or less than a "photograph" is a "fake" representation of the reality it captures.

-Noel