"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.'"

Well, admittedly, the image is interesting...

[Icarus1919]

Direct link to image: http://space.newscientist.com/data/images/ns/cms/d n12026/dn12026-2_250.jpg [newscientist.com]

Gotta say, can't think of what it could be besides water. On the other hand, aren't the images artificially colored?

Re:

[kshade]

Yes they are. And water probably wouldn't look that blue ob the red planet ;)

Re:

[Scynet85]

Actually, the pancam isn't completely black-and-white: http://marsrovers.nasa.gov/mission/spacecraft_inst ru_pancam.html [nasa.gov]

Re:Well, admittedly, the image is interesting...

[MichaelKaiserProScri]

To be more precise, the CCD in the pancam is black and white, but there are a variety of filter they can place in front of it. When they do a "true" color image they use a red, green, and blue filter and take three exposures. However the pretty "true" color images rarely support the science they are doing, so they may, for instance, shoot a picture in infrared, visable green, and UV because that best suits the science they are doing. Sometimes they arbitrarily assign colors to these frequencies of light and make a false color picture. Other times they take a picture of a color reference target attached to the rover using the same filter set they took the picture with. Since the computers on Earth "know" what colors are on the reference chart they can produce a close approximation of the colors in the scene. They photographed the reference chart with ALL of the available filters in a variety of lighting conditions, so they have a pretty good idea that the colors are reasonably accurate. So it would be useful to know if this picture was color corrected or if it is a false color image.

Re:

[oaklybonn]

Thats a great reply; thanks. One question though: is there any possibility that the calibration target chart could fade in either the sunlight or by reaction with the dust/atmosphere? (Just looking out the window at kids toys that have been bleached white...)

Re:

[MichaelKaiserProScri]

I don't know. One would think that they went as durable as possible since the accuracy of the color reference is critical to getting accurate pictures. But the rovers were only supposed to last about 3 months. I think we're going on 5 years now, so who knows.

Re:Well, admittedly, the image is interesting...

[Darkfred]

Here is a picture of it in its original b&w glory from another angle.
With the rover driving over that area.

http://marsrovers.jpl.nasa.gov/gallery/all/1/n/285 /1N153484776EFF37MIP0757R0M1.JPG [nasa.gov]

It does look a lot like track prints in mud.

Re:

[DrVomact]

Here is a picture of it in its original b&w glory from another angle.

What is "it"? A picture of the same area as shown in the article?

Re:

[Myopic]

Is that because water on Mars doesn't have the property of absorbing all but blue light? or is it because on Earth water is blue because of Earth's blue-colored rocky surface?

Re:

[CorSci81]

Actually, the Martian sky frequently has a pinkish hue due to the large quantities of suspended dust grains. If you live anywhere that has wildfires (like SoCal) think of what it's like when the air is full of smoke.

Re:Why oceans are blue

[Anonymous Coward]

That is an urban myth. The oceans are blue because pure water is very slightly blue [lsbu.ac.uk]. 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.

Re:

[MichaelKaiserProScri]

This is true. Glass is also slightly green. Looks transparent when you look from the front, but look into a thick pane of glass from the edge and it's green. Just gotta stack enough of it up to notice. Nothing is perfectly transparent.

Re:

[suv4x4]

[snip].... water is very slightly blue, in large quantities, the blue comes out .... [/snip]

This is true. Glass is also slightly green.

I attest to that. And air is slightly cyan/blue as well. In large quantities (such as a big sky), the cyan/blue comes out.

There's nothing like reading a good piece of science on Slashdot.

There's something I can't figure out: for some reason on sunset and sunrise, water becomes slightly yellow/red, just like the air.

I'm not sure what's with that, maybe as the sun gets ready t

Re:

[MichaelKaiserProScri]

By the time you see the reds and oranges in the sky on a sunset, the sun is actually already just below the horizon. Different wavelengths (colors) or light bend differently through the atmosphere. The blues and greens don't bend as much as the reds and oranges. So when the sun is just under the horizon, the sky turns orange and red because only those wavelengths get through. In this case you actually are seeing the reflection of the sky rather than the inherent color of the water itself.

Re:

[suv4x4]

I was being sarcastic.

Re:

[MichaelKaiserProScri]

This is consistent with the picture. Depending on the filter they took the picture with, it might look VERY blue. They commonly represent the image obtained from the UV filter as "blue" when they want to produce a color image from the pancam, but have not used the true blue filter in the image set. Give the absorption spectrum, that would make it look bluer than usual because water absorbs UV even better than blue. Notice that the lowest point of that graph is just outside the visible range to the left

Why can't it be both?

[Gorimek]

OK, I learned something there. Thank you!

Still, some of the blue color has to come from sky reflection. I mean, the sky clearly is blue, and water clearly does reflect some light. Some percentage of the blueness you see in photos of earth from space has to come from either source. Sadly we can't check what it looks like under clouds in those photos.

Does anyone know how much is from each factor?

Re:Why oceans are blue

[Dunbal]

As a matter of fact, the ocean looks gray on an overcast day. In other words, it's the same color as the sky.

Protip: any SCUBA diver will tell you that water absorbs the red end of the spectrum much faster than the blue end, which is why you lose all the reds at around 40 feet depth, and at 100 feet everything is mostly shades of blue. It has NOTHING to do with the color of the sky which, because of the Compton effect (ie lots of water vapor in our atmosphere) is also blue.

Re:

[Dunbal]

You fail to realize that if water absorbs red light, water will not REFLECT red light, and thus it would look - blue - since the blue light DOES get reflected. Provided the water is deep enough. Amount of red light absorbed is proportional to the distance traveled by the photons. Thus, shallow water is transparent (everything is allowed through so you can see the bottom), and deep water is dark blue. You can still see all the colors of a fish swimming 1 foot beneath the surface, though. You just won't see t

Re:

[sporkme]

They paint the walls of the pool blue (duh). Not arguing against blue water, but hey... the world's largest swimming pool is crap compared to the ocean, and we don't paint the ocean floor... yet.

Re:

[alisson]

Occasionally, but more often green of white.

And who says we don't paint the ocean? Maybe YOU don't.

Re:

[Old Wolf]

They paint the walls of the pool blue (duh).

I used to live in a house with a pool that was painted white; the water looked bluish-green. (Not due to algae!)

Re:

[Yoooder]

Keep in mind that our pools are also laden with chemicals to keep them "clean"

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-(Ogi ve-lake).jpg [crevassezone.org]

Re:

[Evil Pete]

Bad bad analogy. There is plenty of light on an overcast day. But still the sea looks grey. Light is being scattered / reflected from the surface not from underneath. Gees. Basic physics guys. At the angle that we see the surface of a sea then we will usually be seeing reflected / scattered light from the sea. In sunlight where the light has a dominant source then the colour we see may reflect the colour of the water itself if we are at an angle to make the transmitted (back scattered) light from the depths

Re:

[nanosquid]

As for the topic in question. The tracks in the original image do indeed look like they have gone through a puddle. How it could survive in the near vacuum is interesting ... maybe it is very salty

The triple point of water is at 0.01 C and 0.006 atm, which tells you that plain water can, in fact, exist in liquid for in "near vacuum" (salt, of course, probably helps even more). Those conditions are pretty close to what you get on Mars.

Re:

[Old Wolf]

Lakes and oceans look blue on earth mostly because they reflect our blue sky.

That's crap; they're blue because they scatter blue light more, same reason the sky is blue in the first place.

Re:

[DrVomact]

Lakes and oceans look blue on earth mostly because they reflect our blue sky.

Oh yeah? Then why does the sky look blue? Explain that Mr. Smartypants!

To answer my own (rhetorical) question...I always thought that the ocean looks blue for the same reason that the sky looks blue: all those short blue wavelengths get scattered about, and some are reflected back to our eyes. The red light just keeps on going, and doesn't get reflected back. But this is probably one of those "simple" things that aren't so simp

Re:

[Greg_D]

Stop drinking the Tidy-Bowl. Water has no tint of its own.

Re:

[It'sYerMam]

Water absorbs a little visible light in the 760nm region, making it faintly blue. Those small puddles in the picture, though, appear too blue for the apparent depth to be attributable to this blueness.

Re:Well, admittedly, the image is interesting...

[OriginalArlen]

Here's a comprehensive range of responses from a wide selection of informed MER followers at UMSF [unmannedspaceflight.com], ranging from "horsepucky" to "hogwash" via "ludicrous" and "bunk". I'll take UMSF over New Scientist any day.

Sad really, as skipping PE every week when I found that enabled me to skive off to the school library and read the NS (along with the other NS, assorted leftie rags of the 80s, oh and some books) was one of the things that really got me interested in Mars in the first place - that and a big coffee-table atlas with gorgeous repros of Viking Orbiter images of landscapes with obviously terrestrial analogues.

Re:

[aliquis]

Yeah, me to, but for some reason it looks a little blue in indoor pools to? More blue than the white color on the floor, I guess.

Re:

[chanrobi]

Gotta say, can't think of what it could be besides water.

The smoothness and transparency of the features could suggest either water or very clear ice, Levin says. "The surface is incredibly smooth, and the edges are in a plane and all at the same altitude," he says. "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."

Karma whoring? Check

Didn't RTFA? Check

Re:

[buswolley]

Karma is so easy. Why whore it? No one would whore around for pennies? Air? I think I might write a script that will try to gain Karma for me. Candidate rules would include:

1) Use proper html to make lists.

2) Do a google/wikipedia search for the Nouns in TFA and link those into the page.

3) If its a science article use Google Scholar, and use citations.

4)Don't post first, but do post near the top, anytime a noun is close to your topic withing a semantic network dog->mammal->cat.

5) use joke reposi

Re:Well, admittedly, the image is interesting...

[CorSci81]

Yes, they're colored, and lots of things don't look quite normal under the lighting conditions on Mars. Right off the bat I have a lot of reservations about this work.

1. His analysis method is based on stereoscopic image reconstructions of a height field. His claim essentially seems that there was no solution everywhere the picture was blue, so it must be flat. Unfortunately, this technique is pretty lousy for extracting height fields. It's noisy, and contrast issues cause it to fail frequently (I know, I've done it myself).

2. He has no spectral data or any other data to back up his claim. Granted, he's a Lockheed engineer and may not have access. But I have a hard time believing the vast team of scientists analyzing the data overlooked something so obvious.

3. And finally there's Mr. Levin's history of publishing rather dubious claims regarding water on Mars in the Proceedings of the SPIE but never once a full paper in a peer-reviewed journal that covers planetary science. Not that I want to make a personal attack, but this isn't the first time he's made a dubious claim that was never verified.

So, while it's intriguing and might be worth a second look, I'm still firmly in the skeptic category on this one.

Re:

[Unnngh!]

I agree that the images are artificially colored. The liquid looks more like liquid C02 runoff from the underground Katari reactor installed in that region 50,000 years ago by the Zebnor tribe. It should be clear, not bluish in color...

Ice, Ice, baby.

[tverbeek]

Looks like ice to me. The lighter strip along the edge of the left "fork" looks similar to the microfracturing that happens when ice on the surface of a puddle expands and pushes against a steep edge. And in the middle of the photo (the right "fork"), the angular darker lines look like stress lines, also caused by ice expanding as it freezes.

Re:

[suv4x4]

Gotta say, can't think of what it could be besides water. On the other hand, aren't the images artificially colored?

Shoot, it does look like water, a flowing river even, which reflects the blue sky and clouds on Mars.
Which it doesn't have.

Also: "Puddles of Water Sighted on Mars". Damn it, Slashdot! What's wrong with that article title? Tell me.

You forgot the damn question mark is what it is! How many times do I have to repeat: when posting dubious speculative claims that are most likely false, never forget

Re:

[Xyrus]

In other news, apparently a couple of aliens have approached one of the rovers and held up a sign saying: Yes there is f@cking water here. Can you please find something else to talk about?"

Apparently, the sign was targeted at a site called Slashdot. CmdrTaco could not be reached for comment.

~X~

Re:

[xrayspx]

Many replies to this are justifying the "blue" based on "large quantities of water" absorbing more red and thus things become blue tinged, or other such digressions. Remember, this image is not of a "large quantity of water", it's like a couple square meters. From the photo it looks like it could either be a small puddle, or a huge river, since there is no point of reference to judge your distance from the subject, but the article said it's pretty small.

Re:

[MobyDisk]

We finally discovered the tracks of the rovers sent from Venus! With the high carbon-dioxide content and lack of corrosive oxygen in the atmosphere, the Venusians thought it was the best possible planet in the solar system for life to exist.

"True color" version

[AC-x]

Not sure what filters that image used, but this version looks more like NASA's "true color" images

http://www.lyle.org/~markoff/pds/257/1P153927090RA D37MIP2273L257C1.JPG [lyle.org]

Suddenly doesn't look much like water any more does it...

(Cheers to unmannedspaceflight.com for that pic)

Re:

[AC-x]

Now that you mention it I can imagine that central channel as a clear liquid, but I can also imagine it as small ripples on the surface of sand. The features on the left however look a lot more like small pebbles on top of sand to me.

Also don't forget that image is actually taken on a slope (it's at the edge of a crater) so it can't be liquid anything.

My vote is it's just an optical illusion

(of course the most compelling reason is that the giant glass worms [badastronomy.com] would never allow water to exist on their

That's nothing

[Kohath]

We have puddles of water right here.

Re:That's nothing

[naoursla]

Whoa! How did you get on Mars, dude?

Re:

[Glowing Fish]

Fellow Oregonian?

Re:

[Original Replica]

Why oh why, would we take water to Mars? There is no one there to drink it.

Re:

[ZoneGray]

Puddles? My interpretation is that the Martians peed their pants when they saw us coming.

Mirage

[rezac]

Even the Mars rovers are starting to see mirages after 3 years on a desert planet.

Can't be

[Jarjarthejedi]

Isn't the Mars Rover in an area where there couldn't be free flowing water? Last I checked the temperature and pressure were far from the conditions needed for liquid water to flow freely on a surface.

And as someone mentioned earlier the images are artificially colored. It's probably just a mineral deposit or something.

Re:

[mikael]

If it is water, then perhaps there is something present that has increased the surface tension of the water.
According to this article [ucalgary.ca]

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 sur

WTF?

[east coast]

Why did the image in the article have an enlarge feature? They made it about a whole 2% larger. I feel ripped off by shit like that on the web.

In any case, this is an interesting find.

Re:WTF?

[armando_wall]

"They made it about a whole 2% larger. I feel ripped off by shit like that on the web."

Are we still talking about images here?

It's on a slope!!

[EccentricAnomaly]

The article didn't have a larger image because then you'd see that the puddles aren't on the crater floor, but actually on a
huge slope [exploratorium.edu]

Read more in this forum [unmannedspaceflight.com]

Re:

[east coast]

No, you're missing the point, the image in the article had an "enlarge" feature that showed the same image at nearly the same exact size.

Right, be a team player!

[r00t]

Come on you scientist nerds. Keep examining photographs until you find a face -- no, water. That's it, we must find images that match our preconcieved notion of what it'll take to get a bigger budget, more subordinates, etc.

Fuck no.

[r00t]

Well, sadly, war is often useful, but anyway...

How about landers on Venus, Mercury, or any of the dozen interesting moons around Jupiter and Saturn? How about trying the Mars Polar Lander again, getting it right this time, so that we can study the frost?

We might learn quite a bit if we did any of that. But no. We go back to the SAME DAMN PLACE. It's familiar and easy.

Really, we don't get good science payback from YET ANOTHER toy driving around on the warmer/flatter part of Mars. Exploring is about going to

the USSR did it in 1970, 1972, 1975, 1978, 1981

[r00t]

My quick count shows 7 surviving probes on the surface. They got pictures (see wikipedia), a soil probe, gas measurements, temperature measurements, pressure measurements, and spectrometer measurements.

It's been 26 years since the last landing, and a few more since the technology was chosen. Don't you think technology has gotten better in the past 30 years?

At the very minimum, we could set down landers with modern cameras in a few diverse areas.

In some ways, Venus is easy. The atmosphere is so thick that yo

JPL's original pictures

[mrcgran]

It seems that the colored composite picture [newscientist.com] shown in newscientist's article [newscientist.com] was derived from these [nasa.gov] two [nasa.gov] original left-right pictures from Opportunity's navigation cameras on day 285 [nasa.gov]. There are many more similar pictures around day 285, with these flat paths around the flat stones. In the 'Burns Cliff' Color Panorama [nasa.gov] (high res) [nasa.gov], 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 [nasa.gov], 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 [nasa.gov])

Re:

[Ranger]

The original pictures do look like they are on a slope and it does look like sediment in them. Plain water can't stay liquid for very long at Mar's near vacuum. So the question is what water solutions can stay liquid at that temperature and pressure and for how long? Mars is by no means wet. It is mostly dry, but that doesn't mean it's not damp in spots.

Looking at the very hi-res version of the panorama [nasa.gov] reminds me of damp soil. If it were shallow liquid the shadows would look different in them I think. Th

Re:

[nanosquid]

Plain water can't stay liquid for very long at Mar's near vacuum. So the question is what water solutions can stay liquid at that temperature and pressure and for how long?

The triple point of water is around 0.01 C and 0.006 atm, which tells you that even plain water can be liquid at surface conditions that can exist on Mars. Salt solutions can exist in liquid form over a much wider range of conditions.

See also here:

http://mars.spherix.com/spie2/spie98.htm [spherix.com]

Re:

[Ranger]

The triple point of water is around 0.01 C and 0.006 atm

that is very interesting. thanks. I'll check it out.

Re:

[sabernet]

looking at those two left and right camera pics, it doesn't even look like water if viewed stereoscopically. It may look a bit like wet sand, but definitely not water 'puddles'.

Re:

[solitas]

Here's the HUGE version of that panorama: http://marsrovers.jpl.nasa.gov/gallery/press/oppo r tunity/20041213a/Burns_Cliff_L257T-B313R1.jpg [nasa.gov] (just take the "_br" off of http://marsrovers.jpl.nasa.gov/gallery/press/oppor tunity/20041213a/Burns_Cliff_L257T-B313R1_br.jpg [nasa.gov])

Re:

[DrVomact]

Actually, I just realized that the color is ultimately irrelevant. The blue color of the "puddles" helps create the impression of water when you first look at the picture, but if you think about what you're looking at, the color doesn't make sense. The caption says that the area of the picture is 1 square meter. That's a piddle of a puddle. Puddles never look blue (unless you're looking at them at an angle that reflects the blue sky). Puddles are transparent. So the bright blue coloration is either "false c

Re:

[Weeg]

I meant to add: There are more shots of the same scene on the Sol 279 [nasa.gov] page. These are from a different angle, and if you cook up a way to view stereoscopic pairs ( I used MS Paint ) you can see that the "water" surfaces are far from flat, as well as being inclined, of course. Try this left [nasa.gov] and right [nasa.gov] pair, which shows the top part of Levin's image viewed from the right side. The horizontal blue portion of Levin's "puddle" on the upper right is seen to have significant relief in this pair. You can actually s

Re:

[Dunbal]

Calling somebody a crank doesn't excuse you or anybody else from considering evidence.

Yes actually, it does. See, the amount of facts out there is so staggering that no one has enough time to sit around and listen to bullshit crackpot theories anymore. We barely have enough time for the REAL stuff.

Good for you if you have enough time to fill your existence with the "noise", but most of us are concentrating on the "signal". Please stop trying to distract us, and ge

Re:

[Dunbal]

there currently exists no argument that can disqualify Electric Universe Theory

      There's no argument that can disqualify the Great Green Arkleseizure, either. Please prove that this theory is wrong.

      You're falling into the same trap religious nuts fall into when insisting I have to prove that God doesn't exist. Specifically, crackpot pseudo-logic.

not flat, part of Burns Cliff

[J05H]

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.

http://www.marsroverblog.com/discuss-mars-rover-fi nds-puddles-on-the-planets-surface.html [marsroverblog.com]

This "puddle" however, doesn't stand the test.

Re:

[zaydana]

Flowing rivers as in flowing years ago, or flowing currently? I havn't heard anything about that yet. Do you have a link for more details?

the burden of proof

[bwy]

The burden of truth typically lies with the person asserting the positive. However, in this case it would be interesting and useful to hear other explanations for this photo, because it *does* appear to reveal something of interest.

Re:

[symbolset]

Very fine dust.

A very fine dust can settle in depressions and look very much like water in a black and white photo.

Much Better Image

[MorderVonAllem]

http://www.flickr.com/photo_zoom.gne?id=536615119& size=o [flickr.com]

Re:

[alnjmshntr]

Looks like ice to me. But those little ball-like things scattered all over are interesting. Look like molluscs maybe.

Can't they tell?

[khendron]

Does anybody else find it odd that they can't tell whether or not this is water? I mean, were they so positive that they wouldn't find water on Mars that they didn't include any way of testing for it?

Not this again

[orangepeel]

Am I really the only one here who actually played in the dirt as a kid?

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 ... 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 [nasa.gov] 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...

without any liquid water...
without any biological activity...
without any volcanic activity...

...but with that wind erosion, what would be the lowest limit for particle size on the Martian surface?

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 ... 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.

Mars: where a dry surface flows like water.

Re:

[Dunbal]

You just don't get it, do you?

It's WATER (please enclose cheque for $30 million).

Re:

[Evil Pete]

Actually I had these same feelings when I first saw the the images of the landing of the NEAR probe on Eros (note the final image [nasa.gov]). There was silt so fine that it flowed like a liquid and even looked like it had surface tension. This reminded me of when I was a kid I had seen fine silt mud settle out in water with a similar effect. Some very interesting physics must be going on the surface of Mars and the asteroids. Particles the size of colloids interacting like molecules to form a quasi liquid?

Re:

[goeldi]

OK, but how about the opaqueness?

dry powder explanation doesn't work

[nanosquid]

Come on kids ... 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.

It's quite clear that soil surfaces on Mars must regularly be exposed to liquid water. Why? Because we've already pretty much seen it: the Viking lander saw ground frost in its images, and at temperatures and pressures on Mars, that frost can turn liquid.

(Incidentally, silt was, by de

In Soviet Mars...

[toby]

Water flows like dry silt.

Re:

[E++99]

Dude... water.
http://www.flickr.com/photo_zoom.gne?id=536615119& size=o [flickr.com]

cant be water

[Jarik C-Bol]

ok, i'm no trained profesional in hydrophysics, but where i'm from, water obeys the laws of gravity. if you look closely at that picture, you see what is claimed to be "water" in a configuration that it could not hold, and/or would not end up in on any surface. especialy a sloped one. (short runs both up and down the "slope" and runs in oposite direction of what apears to be "primary flow" it looks like extermely fine blown sand to me. blown sand on rock.

This looks really lame

[bl8n8r]

If you look at the colored pic next to the original black and white, it looks like someone was just bored in Gimp and did some coloring. The whole side-hill in the blacknwhite pic must be water if the colored pic is true.

http://img370.imageshack.us/img370/6572/39317433nj 5.jpg [imageshack.us]

Those aren't puddles...

[Anonymous Coward]

They're canals!

We've known about the Martian canals for decades!

This is news?

The place in context ...

[Anonymous Coward]

http://img407.imageshack.us/img407/594/1n153135181 eff37ljp1950ho2.jpg [imageshack.us]

from

http://www.marsroverblog.com/dyn/entry/54280/discu ssion_page/41 [marsroverblog.com]

Somethings wrong here...

[Aerovoid]

There are a number of things wrong with that article.

1) The images are false colour. All images taken by the rovers (or any probe for that matter) are never true colour. They generally take images through various infra red and green and ultraviolet filters. When combined, they create unnatural coloured images. So that blue soil you see wouldn't really be blue if it were to be seen with the naked eye.

2) The specific image shown were taken on the rim of Endurance crater, not at the floor of it. Water can't exactly pool on a slope.

3) Although the summery on slashdot here says "newly taken images...". This is also incorrect. They were taken in 2004.

I don't doubt that there is water on Mars, but I don't think it can pool on the surface (due to the low atmospheric pressure), nor do I think this photo contains any evidence of pooling water either. It may contain evidence of past water how ever.

Re:

[jgoemat]

1) The images are false colour. All images taken by the rovers (or any probe for that matter) are never true colour. They generally take images through various infra red and green and ultraviolet filters. When combined, they create unnatural coloured images. So that blue soil you see wouldn't really be blue if it were to be seen with the naked eye.

Not exactly true. They can create near-real color images in the same way many digital cameras do. They have seven filters for different wavelengths of light.

NASA budget

[Brian Gordon]

Why do they keep sending such crappy cameras to mars? If I took a picture of a puddle of water with my 1 megapixel cellphone camera I could tell it's a puddle of water. Why is it so hard for them to take good pictures?!

Re:NASA budget

[MobyDisk]

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.

Hats off to NASA, this time

[moranar]

For all the fun we poke at them for mixing imperial and metric units, they've done a fantastic job with the Rover, still working so long after its "due date". Congratulations to all people involved.

and one GIANT PUDDLE

[phrostie]

and one GIANT PUDDLE [arizona.edu]

Re:

[Dieppe]

No! That's the real Goatse!!!!

I notice they're not applying their usual filters.

[argent]

As I wrote a few years ago in A Failure of Vision [scarydevil.com] the filtering that NASA has been doing to accurately recreate the actual colors of Mars's surface actually makes it harder to tell what you're looking at. If you were living and working on Mars, before long your eyes and brain would adapt and you wouldn't see the red planet as particularly red.

If you go and adjust the ground to the rusty red in NASA's usual photos with this new photograph [newscientist.com] the water doesn't look nearly so watery any more. But when I lined up

What else could it be?

[TheLazySci-FiAuthor]

I don't ask this implying that it must be water, but rather I ask for more speculations. I wonder, maybe these are massive collections of opalite.

So much is known about mars: but this of course means that so little is known as well. The planet is harsher, and yet less harsh, than anywhere on earth. There is little atmosphere, so the whole breathing situation is much harsher, yet because of this fact 100km winds would fail to move a tent.

I think it's important to guess and wonder about things.

Personally, I h

This is Enlarged Text

[StikyPad]

I love "Enlarge Photo" buttons that open up the photo in the exact same dimensions and resolution as the one in the article. Anyone find a higher quality image?

Also I was under the impression that water is blue on Earth because it reflects our blue atmosphere. Why would water on Mars be blue? Or is that a false-color image?

Drinking Martian Water

[MS-06FZ]

Drinking Martian water is not something to be done without careful consideration... Martians place a very high value on the sharing of water. If you're going to do it, you mustn't do it without understanding the full implications of doing so - the cultural significance and the implicit promises that accompany water ritual.

May you never thirst...

Re:

[MS-06FZ]

That is not water, it's yellow!

Wow... I knew the Church of All Worlds had changed a few of the established traditions over the years but I didn't know that was what they considered "water sharing"...

Re:

[baadger]

Invisible Pink Unicorn farts.

Re:

[HTH NE1]

In one place it says, "...the Mars atmosphere is essentially a vacuum..." In another place it says, "The problem is, there are winds on Mars..."

And in fact both statements are made by the same person: Phil Christensen. But while "the windy vacuum of Mars" has a bit of a giggle factor, the key word in the quote is "essentially", especially when discussing the likelihood of liquid water at Martian air pressure.

There is atmosphere, enough for there to be wind, but for liquid water it might as well be a vacuu

Comment on moderation

[Jesus_666]

Overrated: For when your ego can't handle the chance of someone metamodding your Troll.