Slashdot Mirror
"Puddles" of Water Sighted on Mars
eldavojohn writes "Further reinforcing the theory of a wet Mars, NewScientist is reporting on what appear to be water puddles in newly taken images from the Mars rover. While these results are controversial, the assumption that these blue 'puddles' are water still has to be tested by engineers. They'll try to measure the uniform smoothness of the puddle surfaces. Analysis will also examine their apparent 'opaqueness', where in some areas observers claim to see pebbles underneath the surface of the blue areas. From the article: 'No signs of liquid water have been observed directly from cameras on the surface before. Reports last year pointed to the existence of gullies on crater walls where water appears to have flowed in the last few years, as shown in images taken from orbit, but those are short-lived flows, which are thought to have frozen over almost immediately.'"
Direct link to image: http://space.newscientist.com/data/images/ns/cms/d n12026/dn12026-2_250.jpg
Gotta say, can't think of what it could be besides water. On the other hand, aren't the images artificially colored?
If it is water, then perhaps there is something present that has increased the surface tension of the water.
According to this article
Certain inorganic salts (called strong electrolytes) that readily dissolve and completely dissociate into their separate ions in water can raise the surface tension by modest amounts. For example a 10.5 mass percent solution of sodium chloride in water will have a surface tension that is raised by about 3.3 mN/m from the pure water level (at room temperature). That is, the surface tension goes from about 73 to about 76 mN/m. Some organic solutes can have a similar effect (sucrose, for example). There is also some evidence that some kinds of highly charged particles, when well dispersed, can raise the effective surface tension.
Vintage computer adverts: http://www.vintageadbrowser.com/computers-and-software-ads
It seems that the colored composite picture shown in newscientist's article was derived from these two original left-right pictures from Opportunity's navigation cameras on day 285. There are many more similar pictures around day 285, with these flat paths around the flat stones. In the 'Burns Cliff' Color Panorama (high res), the newscientist's image is just a fraction of the cliff: it's in its very center, where you can see a V and the steepness of where it is located.
1) The surface just seems a bit too steep to me to accumulate any liquid water in such amounts for a pond, since it's facing up the border of the crater in the original pictures. The rover was taking the picture from the bottom up, so also the material wasn't in the lowest part of the terrain.
2) In the original JPL's pictures, you can see the same 'watery' material all way up to the border of the crater: it's distinctly darker. In the panorama, it's interesting to note that it doesn't go all the way down to the bottom of the crater, where you can see a brighter dust covering everything.
Does this darkness means humidity? I fail to see streaming water, maybe flat thin ice sheets from a humid surface but this seems to be explicitely discarded when the author says that "If they were ice or some other material, they'd show wear and tear over the surface, there would be rubble or sand or something." (btw, sand on this steep cliff?) A very thin dark powdery sand looks more likely, but someone needs to go there and poke it to be sure. Any ideas about this? I'm unable to find the original paper to have a look at it.
Can anyone explain how they came up with the bluish hue in the composite picture, since the original pictures do not seem to have any filter information? (the 25th character in their names is 0 instead of some specific filter frequency)
MarsRoverBlog.com is discussing it, this isn't a flat area, but on a 20-30 degree slope. It is part of Burns Cliff in Endurance Crater.There is plenty of evidence for water on Mars, just not in these images. There is evidence of something other than dust, probably water seepage from underground, at Meridiani and Gusev. Orbital images have shown water in the polar caps and probably a frozen sea in Elysium. There are what appear to be ponds and flowing rivers in some images, especially the first Mars Express image released a while ago.
i nds-puddles-on-the-planets-surface.html
http://www.marsroverblog.com/discuss-mars-rover-f
This "puddle" however, doesn't stand the test.
gigantino.tv - Heavy but weighs nothing.
That is an urban myth. The oceans are blue because pure water is very slightly blue. In large quantities, like lakes or oceans, the blue comes out. If it was just due to the reflection of the sky then large bodies of water would by white on overcast days.
http://www.flickr.com/photo_zoom.gne?id=536615119& size=o
Am I really the only one here who actually played in the dirt as a kid?
... let's assume you don't have first hand experience with how liquid-like dry silt can be. Just today I read an article on Nasa's site that got me thinking about this topic. It's about how one of the rovers has again had its solar panels cleaned off by wind. If Martian winds can pull that trick off, clearly wind erosion must be ongoing on Mars, and has been going on for what, BILLIONS of years? Now...
...but with that wind erosion, what would be the lowest limit for particle size on the Martian surface?
... it's nice to dream and all, but what we're dealing with here -- again, at least on the surface -- is one very dry surface that has a heck of a lot of ultra-fine silt lying around in a low gravity environment.
Originally an outwash plain during the final ablation phase of a glacier, the 5+ wild acres I grew up on as a kid had a variety of clay, soil, and silt types. This "OMG, there's water on Mars!" reaction has come up at least once before here on Slashdot, after someone posted a link to a photograph that showed dark plumes spilling down a small incline. Some of the reactions here depressed me back then too. Have so many people really become so disconnected from the earth that they can't recognize ultra-fine silt when they see it?
Ok, so fine
without any liquid water...
without any biological activity...
without any volcanic activity...
Let me put this another way: there has been an erosional force running on that planet for a billion plus years, to this day, and no force (at least on the surface) is present to conglomerate or cement those particles back together. This, to me, means that all surface particles must be being eroded down to some lower limit in silt particle size. I bet there's all kinds of weird and wonderful physics going on down at that level, but I'm digressing.
Folks, as apparently the only person here on Slashdot who's ever played with dry silt, I have some sad news for you: I would be shocked if there weren't patches around that didn't look a heck of a lot like liquid.
Here's another story to contemplate: do you remember when one of the Mars rover's got stuck? The NASA engineers went off to the hardware store to recreate the soil conditions, and picked up things like dry cement powder and diatomaceous earth. And you have to remember that Mars' gravity is what, 1/3 that of Earths? Come on kids
Mars: where a dry surface flows like water.
Whoever designed level 61 in Frozen Bubble is a sadistic bastard.
My red baseball cap looks black in the dark. Does that mean it's not really red? No, of course not. It just means there's not enough light for the color to be seen.
Likewise on overcast days there is not enough light for the blue of the ocean to reveal itself. If you were correct and the ocean was just reflecting the gray of the clouds, it would appear white on many overcast days (when the clouds are white), but it does not.
They're canals!
We've known about the Martian canals for decades!
This is news?
Keep in mind that our pools are also laden with chemicals to keep them "clean"
i ve-lake).jpg
In nature there aren't too many sources of pure H2O, collections of glacial water pools/collections are probably one of the few naturally-occuring sources of relatively pure water, and you'll note that they tend to be quite blue.
http://crevassezone.org/Photos/Graphics/2836L-(Og
http://img407.imageshack.us/img407/594/1n153135181 eff37ljp1950ho2.jpg
u ssion_page/41
from
http://www.marsroverblog.com/dyn/entry/54280/disc
The problem is context. I could build a small scale model of my backyard, dig a hole in it, and pour some bleach into it. From the picture, you would think it is a puddle of water. You would base your decision on your decades of experience seeing how things work on this planet. The problem is that Mars doesn't have the same landscape, materials, temperatures, or pressures that earth does. So you can look at the picture and say it looks like water, but it is really bananna pudding, or bleach, or fine nano-particles of dust that ae so light they flow like water. There's a lot of crazy materials in this world, and you can't base a scientific conclusion on Mars from your Earth-based assumptions.