Page 1 of 1
White Ridges on Mars (APOD 20 Feb 2007)
Posted: Wed Feb 21, 2007 3:30 am
by Al
In the picture of Mar surface (Feb. 20, 2007)--What is it that looks like lakes in the valley between the ridges?? If those are lakes, what are they composed of??
Al
Posted: Wed Feb 21, 2007 3:34 am
by rigelan
personally, i'm having trouble visually decifering the large dark/light line running just above the middle. Is it a shadow because of the ridge? And if it is, what has been done to the photo to make it difficult to interpret?
Hey, does anybody know if this was taken in the visual spectrum? ( as opposed to infrared. If it were not in the visual, and then colorized, it would explain the blue tint.
Posted: Wed Feb 21, 2007 8:19 am
by l3p3r
http://antwrp.gsfc.nasa.gov/apod/ap070220.html
I wouldn't say they were lakes... not many things I can think of that exist in the liquid phase in mars surface conditions. I say your lakes are composed of martian sand dune and/or rock slide
It's difficult to tell without multiple angles of the same site though...
Re: White Ridges on Mars
Posted: Wed Feb 21, 2007 5:51 pm
by orin stepanek
Al wrote:In the picture of Mar surface (Feb. 20, 2007)--What is it that looks like lakes in the valley between the ridges?? If those are lakes, what are they composed of??
Al
I'M not sure; but it looks like shadows to me.
Orin
Posted: Wed Feb 21, 2007 8:29 pm
by BMAONE23
Could they be Limpid pools of Martian BlueBerries???????
Posted: Thu Feb 22, 2007 12:07 am
by rigelan
ooh, sounds exotic
white ridges on Mars
Posted: Thu Feb 22, 2007 6:48 pm
by linx
Hi,
would there be 'ice to go' with these exotics ..or what is the true cause of the deep blue colour, scientifically
Linx
Posted: Fri Feb 23, 2007 5:22 am
by BMAONE23
Well,
I was only half joking. They could be troughs in the surrounding rock that are filled with Hematite nodules (Martian Blue Berries).
Posted: Fri Feb 23, 2007 2:26 pm
by orin stepanek
All the white kind of reminds me of a light snow dusting driven by wind. The dark blue in the crevices looks like it is in too deep an area for the sun to light up. That is why I believe it may be shadows.
Orin
Posted: Fri Feb 23, 2007 9:59 pm
by BMAONE23
Looking at this Full Resolution Image of the area in question (42meg file)
http://mars.jpl.nasa.gov/mro/gallery/pr ... _image.jpg It is clearly shadowing caused by apparent cliffs.
Posted: Sat Feb 24, 2007 11:36 am
by inertnet
I'd say shadows as well.
Do shadows on Mars normally appear blue because of filtering of sunlight in its atmosphere?
Posted: Sat Feb 24, 2007 3:35 pm
by rigelan
I wouldn't think martian atmosphere color would be any different than ours. Its very similar. If it were blue on mars, it would look blue here.
White Ridges on Mars
Posted: Sat Feb 24, 2007 4:54 pm
by linx
Hi,
i dont think that all of the blue colour is caused solely by shadows as the patterns look too inconsistant & sparse in places where it would seem that a shadow should exist
or perhaps i just prefer the idea of the Martian Blue Berries! ..i looked up about them, so thanks BMAONE
Linx
Posted: Sat Feb 24, 2007 7:28 pm
by BMAONE23
It would be interesting to see a 3D pictograph of this area (even Red/blue)
That would show rises, cliffs, and associated shadows better.
Posted: Sun Feb 25, 2007 12:07 am
by inertnet
On Earth the atmosphere is blueish if anything, on Mars it's probably more red. That might result in blue shadows on Mars. So I was wondering if this effect would be enough to account for the blue shadows we're seeing in the image.
contorted layering
Posted: Sun Feb 25, 2007 5:08 am
by rockwiler
I work as a geologist at a mine where the sedimentary rocks underwent extreme soft sediment deformation. As I look at these layers what strikes me is not the white frosting on the rocks so much as the contorted and discordant folding among the layers. This looks like soft sediment slumping to me.
Load the full size version to see more than is shown in the APOD page. What I am talking about is especially apparent in the upper part of the image. See how some gently folded layers are truncated by more strongly folded layers. All through the image the layers are not quite right. In some areas they show ropy compression offsets, in others diverging layers. It all adds up to soft sed.
Posted: Sun Feb 25, 2007 11:45 pm
by Doum
Hey rockwiler,
Interesting! Was wondering, if it is indeed soft sediment formation, then it might be possible to extract organic fossil from it as we do here on earth with our 200 to 500 million years olds sediment that have low temperature and pression formation (These life form are among the first watery life.). We do that with HCl and then with HF(Chloridric acid to remove the carbonate and then fluorhydric acid to remove the silice.) Then we collect the residue and look to it on a microscope or an electron microscope. It might be interesting to do that if human kind go there someday. Just thinking out loud on a may be futur mission.(Robotic may be possible but hard to do.). All that just to see if life did happen on mars in its past. Any comment.
![Smile :)](./images/smilies/icon_smile.gif)
soft sed deformation
Posted: Mon Feb 26, 2007 5:21 am
by rockwiler
Well, sure there is probably life on Mars. It probably got there from Earth from ejecta of meteor strikes. Higher life is pretty doubtful, however. The chemistry was probably never right for that.
This picture and the accompanying text on APOD is really odd. Looking at the detailed version, it is hard to see how any case could be made that the white stuff is related to mineralizing solutions altering the rock. Those subparallel cut-like features clearly cross bedding and are incised into the beds, yet they show little, and in places, no evidence that the white stuff is IN the rock. It looks much more like the white stuff is ON the rocks. To my eye it looks like snow drifts. (Looks like. I'm not saying it is snow.) My guess is that it is some drifted material like snow, that is preferentially accumulated on the texturally rougher surfaces. Maybe it is frost, or dry ice frost, that has blown around.
I can't honestly understand why they still talk about "maybe it was water that did this, and that, and the other." For Pete's sake we've been over that. It is manifest from the evidence that YES, THERE WAS WATER! Let's move on.
Back to this picture. These layers are on edge. There is not much evidence of erosion in this picture, at least not that has left familar erosional features like dendritic drainages. I am wondering where the rest of the material went. Where did the rest of the layers go...the part that originally extended above the current surface but now is gone leaving only what is visible. Some resurfacing process has been at work also - the absence of craters suggests a relatively young surface. Is/Was there a tectonic process that put these layers on edge when they were probably deposited nearly horizontal to begin with?
Here is another thought. Soft sediment deformation on this scale, and a stratigraphic thickness on the order of a couple kilometers suggests a fairly deep and fairly dynamic depositional setting. This almost certainly means water and plenty of it, and also either a) a high deposition rate resulting in oversteepening of the sediment pile, or b) a dynamic, tectonically active depositional basin that resulted in tectonic oversteepening of an unlithified sediment pile.
Movement of massive amounts of sediment also requires movement of surface waters, either via rain, or some major springs system. I'd guess rain. Rain may have been a short lived process however. Just because there was lots of water doesn't mean it stayed around for long. Perhaps the Olympus Mons eruptions served to devolatilize the interior of Mars, pumping lots of water into the atmosphere for some short period (1-100 million years) resulting briefly in an atmosphere capable of producing rain. In the process water was expelled from deep in the planet to the near-surface environment.
Food for thought. javascriptemoticon('8)')
Viewing ridges.
Posted: Mon Feb 26, 2007 11:04 am
by 13 Rabbit
...what has been done to the photo to make it difficult to interpret?...
I copied the image into Paint and rotated it 180 degrees. Then the ridges were very visible.
Posted: Mon Feb 26, 2007 3:14 pm
by Al
You are right!! Rotating the picture 180 degrees makes a BIG difference and the blue areas do look like shadows. Also, I have noticed that if one magnifies the blue areas, they look more like discolored solid than a liquid. That seems to answer my original question that started all of this.
(see the beginning post)
I am glad I asked that question because I have really enjoyed the recent discussions of the probable presence of water on Mars, plus the potential of early life forms there.
thanks, guys.
Al
Posted: Mon Feb 26, 2007 3:18 pm
by BMAONE23
It is a decent thread that you started as it didn't degenerate into vast discussions about unrelated theories.
![Wink :wink:](./images/smilies/icon_wink.gif)