"Puddles" of Water Sighted on Mars 237
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.'"
Re:Well, admittedly, the image is interesting... (Score:5, Interesting)
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.
Yay! Another ad for NewScientist! (Score:1, Interesting)
Re:Why oceans are blue (Score:3, Interesting)
Re:Well, admittedly, the image is interesting... (Score:4, Interesting)
With the rover driving over that area.
http://marsrovers.jpl.nasa.gov/gallery/all/1/n/28
It does look a lot like track prints in mud.
Re:JPL's original pictures (Score:3, Interesting)
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]
Somethings wrong here... (Score:3, Interesting)
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:Not this again (Score:3, Interesting)
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:Why oceans are blue (Score:5, Interesting)
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:Well, admittedly, the image is interesting... (Score:3, Interesting)
Re:Not this again (Score:2, Interesting)
dry powder explanation doesn't work (Score:3, Interesting)
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 definition, created in running water.)
So, while I agree that these pictures don't show liquid water and that we haven't seen any puddles of water on Mars yet, an ultra-dry explanation of Mars doesn't work, and liquid water or salt solutions on the surface of Mars are not just possible, but likely.