Hi,
Perhaps it's mentioned and discussed many times before, anyhow.

There are lots of sites discussnig the tubes of mars (e.g. http://ida.wr.usgs.gov/fullres/divid.../m0400291a.jpg )

I'm not gonna talk about underground irrigation systems, or submerged ufo-rollercoasters.

Could it be that these things are ICE, since they do look 'glassy'? If water, assuming there would be enough water underground, turns into ice as soon it hits the Martian surface, could it than be that the tubes are remainings of water-'geisers', that changed into ice tubes over time?

If so, it could also be a place to find running water inside, wouldnt it?

They're not tubes. They're canyons filled with fine sand, sculpted into rippled dunes by the wind.

The idea behind your thinking is not completely improbable though. Mars having no tectonic movement anymore would render any geysers it did have into barren ice holes that could open up into vast underground caves. :wink:

In a few days, I will have a page up explaining these features. They are valleys with wind blowing down them. The ridges are lines of dunes. The glassy appearance is an illusion due to the way the brightness is displayed in the image.

Which you see in virtually every canyon that MGS has photographed.

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Hmmmm. Moral dilemma, BA says they're dunes, Sir Arthur C. Clarke says they're "glass worms." Who do you believe?

Heres one that looks like it broke open and spilled all over the plains:

http://www.highmars.org/niac/educati...es/blobs01.jpg

The original with context lives here:
http://www.msss.com/moc_gallery/m19_.../M2101816.html

Mighty odd looking. Reminds me of white chocolate chip macadamea cookies...

Yum!

Capthraw the Space Lizard

[-(

I just don't buy it. I've looked at the so-called "canyons with dunes" over and over again and the explanation does not wash. Neither does the argument that they are concave and not convex. I am familiar with lighting and shadow effects through study of art and photography. Just use your eyes for Pete's sake.

I am generally a skeptic about extraterrestrial life. My friends consider me an inveterate debunker, but this explanation I cannot buy into. These formations were either made by some geological process that I cannot fathom, or there is something organic that made them. I have never seen anything that looked like this that wasn't of organic origin.

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8-[ What is the scale of those images???

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I'd be more interested if they didn't seem to show up just about everywhere. They seem to be a commonplace wherever there's any sort of canyon or channel. That makes me think they're the result of winds rather than anything else.

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Mars Global Surveyor MOC Images

The resolution for m0400291 is 3.60 meters. So the image, if my math is correct, is 3.14 km by 4.09 km and the feature at its widest is about 250 meters across and at the narrow point is around 50 to 70 meters. If anyone has a decent graphics program, they should be able to get a better estimate.


Scott

I don't know what your experience with images is, but it is completely obvious that these features are canyons with dunes.

Perhaps you need to read a little more on images taken from orbit.

They are not and cannot possiibly be CONCAVE valleys nor are the high albedo features any sort of aeolian nor fluvial dune form.

In the next 24 hours I will create a new thread here demonstrating why this is not reasonable and contradicts all evidences. The burden of preconceived expectation can be just as misleading and destructive to objective analysis as imagination unbound by technical understanding.

Without a doubt many persons across the Internet have held forth common dune trains constrained in topographic lows as being the same as these convex "Tubes". Certainly there are undeniable correlations betsween those high albedo arcs and transverse dunes, buit only if examined superficially. However the MO4-00291 image is actually an uncommon image in that it has an array of fortunate details which, along with other image details, helps define these contested features as being more unique.

Tripp:

What experience do you have in desert geomorphology, aeolian landforms, and the landscape of Mars that allows you to say that these features are not transverse dunes in canyons? I have seen lots of dunes in terrestrial deserts, and lots of canyons and valley floor deposits. I have even spent a lot of time looking at Martian images. These features are geologic in origin beyond any shadow of doubt.

Jon

I've studied geomorphology and petrology and have empolyed these backgrounds in interpretation of remote geophysical surveys such as GPR, seismic refraction, magnetometer and electromagnetometer. While admittedly I have not spend so much time actually in desert environments, I have examined a vast portion of desert from satellite

Given you're a geologist youself, I gather that you agree that the recognized convex appearance (even acknowledged by NASA) is entirely an optical illusion without any foundation in reality?

Also I am somewhat confused by your concluding statment, "These features are geologic in origin beyond any shadow of doubt". Is the implication that if these features are not aeolian transverse dunes in concave valleys then these features are not geologic in origin?


Do you see nothing at all incongruous to the interpretation of these as transverse dunesl? Keep in mind that the JPL, Media Relations Office made indirect commentary on these features on May 22, 2000:


Even JPL scientists wish they knew what processes are involved to cause these features.

Yes, the convex appearence is entirely an illusion, as far as I can see. OK, if these are not dunes then this does not rule out other geological processes. As to the JPL quote, unless I can read it for myself I can't place it in context. But science by press release is a very dangerous thing. You may (or may not) remember the infamous statement in a popular NASA book after Mariner 2 that spoke of carbonhydrates on Mars, thus giving support to a whole generation of Velikovskyites.

Give a link to the press relase and I can comment. Incidently I have worked on the ground in deserts on Australia (Great Victoria, Simpson, and Strzelecki, the US (southern Utah) and South America (Atacama and the Altiplano). As I child I did travel through Jordan but I am not sure I can include that

Jon

Maybe it is a giant snowboard park... :wink:

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If you go into a program like Photoshop and play around with brightness and contrast options a bit, you can see both canyon walls and in the middle is the "glass worm" or whatever you want to call it.

http://geocities.com/xbck1/canyons.jpg

Copy and paste that link; Geocities hates linking.



Edit: spelling

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Jon,
You are saying that "as far as you can see", the convex appearance is an illusion? But your inclination is to see that illusion youself yet you recognize it as not being real how, by what detail? Many natural forms represent crescent arcs other than dunes, such as glacial crevasses and p-waves or longitudinal pressure waves in pahoehoe-type fluid lava flows, to name a couple.

It would be unfortunate for you to deny the convex nature of this image and force an inverted perspective merely to accomodate what would be the most likely scenario of these arcs being transverse dunes constrainted within narrow valley walls, especially if that convex shape is supported. Is there some other conspicuous detail that indicates these are concave other than expectation?

I have seen a few aerial geologic images that resulted initially in my improperly interpeting lighting resulting in positive and negive reliefs being inverted. One of these images was particularly resilient and I had to actually walk away from it for several hours and approach the image in an upside down, inverted orientation before my mind was freed from its prior prejudice.

These problematic images all had some things in common: they had insufficient or poorly defined detail prohibiting me, personally. from interpreting the terrain properly.



This image under consideration has a wide variety of structural features which serve to clearly indicate the lighting to the mind's eye, not the least of which is an enormous tri-radiate valley system with each of the 3 arms serperated by nearly precise 120 degrees of arc. This 120 degree arc separation between the 3 valley arms ensures that some vectoral aspect of a 360 exposure to light source is represented across the 3 valley arms. Despite this widely varied orientation equally dispersed across the compass, each of these 3 valleys similarly represents the features within as convex in shape. That is a lot of "optical illusion" for even the best of magicians to maintain.

Jon, I