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A question here, behaviour of water on Mars
spdf
post May 24 2007, 12:38 AM
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A question here

There are signs that in the past there was liquid water on Mars. So lets assume thats true.
Since the gravity on Mars is much lower than on Earth, so how does water (waves) behave on Mars compared to Earth?
Someone did say, that waves would have been much higher but also much slower. Is this true? Does anyone have an animation where you can see a waive on Earth in comparsion to a wave on Mars?

Thanks
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nprev
post Nov 16 2007, 01:06 AM
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Mike or HDP Don, how different are the curves for sulfur salts from chlorides? (Hope that wasn't a faux pas; afraid I've forgotten most of my basic chemistry). Martian brines, if any, might be considerably different chemically then their terrestrial counterparts, and the crust is certainly sulfur-rich.


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dburt
post Nov 16 2007, 08:27 PM
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QUOTE (nprev @ Nov 15 2007, 06:06 PM) *
Mike or HDP Don, how different are the curves for sulfur salts from chlorides? (Hope that wasn't a faux pas; afraid I've forgotten most of my basic chemistry). Martian brines, if any, might be considerably different chemically then their terrestrial counterparts, and the crust is certainly sulfur-rich.

Very different, in that common sulfates (e.g., of Mg) can't depress freezing the point more than about 5 degrees C, whereas NaCl (sodium chloride table salt) depresses it about 20 C, MgCl2 about 34 C, and CaCl2 about 50 C. Chloride salt mixtures gain several extra degrees below that (so-called eutectic freezing). Therefore any low temperature brines on or in Mars would have to be dominated by chlorides, a group of salts that can't normally be detected by infrared spectroscopy (TES and THEMIS from orbit, and Mini-TES on the rovers). That is, Mars could be chloride rich, and the salts would be difficult to detect. In this regard, their greater solubility and greater tendency to be frost leached (via freezing point depression) suggests that chloride salts should be less persistent than sulfate salts at the martian surface.

Nevertheless, chloride-rich areas on Mars have recently been inferred by this very lack of an IR signal - they look something like a "black hole" to IR spectrometers. See, e.g., Fall AGU abstract P13D-1563 by M.M. Osterloo et al.
http://www.agu.org/cgi-bin/SFgate/SFgate?&...P13D-1563"
Several of these inferred chloride-rich areas were suggested as possible landing sites for the Mars Science Lander (MSL), but didn't make the semi-final cut a couple of weeks ago.

Gsnorgathon, with regard to cooking with salt, I stand corrected. I perhaps should have said, "among other reasons" or "one reason" and not "the reason". (Adding salt is commonly recommended even for the simplest of recipies such as boiling an egg, where the taste of the salt might be undetectable.)

Ngunn, with regard to Mike Hecht, you could start here:
http://www.lpi.usra.edu/meetings/lpsc2001/pdf/1364.pdf
although he also published longer papers later. Personally, I enjoyed the exciting description of metastable water in an active outflow channel in the novel "Red Mars".

-- HDP Don
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nprev
post Nov 17 2007, 01:17 AM
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QUOTE (dburt @ Nov 16 2007, 12:27 PM) *
Very different, in that common sulfates (e.g., of Mg) can't depress freezing the point more than about 5 degrees C, whereas NaCl (sodium chloride table salt) depresses it about 20 C, MgCl2 about 34 C, and CaCl2 about 50 C. Chloride salt mixtures gain several extra degrees below that (so-called eutectic freezing).


Thanks! smile.gif That's really a dramatic difference. I presume those values are referenced to terrestrial standard temperature & pressure? Has anyone crunched the numbers for average Martian STP (if they've derived that in any meaningful form yet, that is)?


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Posts in this topic
- spdf   A question here   May 24 2007, 12:38 AM
- - tuvas   This is just a guess, but I would guess waves woul...   May 24 2007, 08:19 PM
- - ugordan   I believe the higher-and-slower waves is the corre...   May 24 2007, 08:44 PM
- - nprev   Another major variable would have been atmospheric...   May 24 2007, 11:17 PM
- - dvandorn   Actually, liquid water on Mars would behave consis...   May 25 2007, 07:50 AM
- - AndyG   ...and add bigger drops. Surface tension will play...   May 25 2007, 08:31 AM
- - nprev   Great story, oDoug! Yeah, I should have bee...   May 25 2007, 11:50 AM
- - Juramike   While there would be no really big tides on a Mart...   May 25 2007, 03:41 PM
- - helvick   On earth the average atmospheric pressure of ~101k...   May 25 2007, 04:52 PM
|- - marsbug   I have a question I've not been able to resolv...   Nov 15 2007, 06:14 PM
|- - dburt   QUOTE (marsbug @ Nov 15 2007, 11:14 AM) I...   Nov 15 2007, 11:30 PM
|- - Gsnorgathon   Not to rain (metastably or otherwise) on anyone...   Nov 16 2007, 12:41 AM
|- - Juramike   QUOTE (Gsnorgathon @ Nov 15 2007, 08:41 P...   Nov 16 2007, 08:57 PM
|- - nprev   QUOTE (Juramike @ Nov 16 2007, 12:57 PM) ...   Nov 17 2007, 03:49 PM
|- - Juramike   QUOTE (nprev @ Nov 17 2007, 10:49 AM) .....   Nov 17 2007, 05:02 PM
|- - ElkGroveDan   QUOTE (Juramike @ Nov 17 2007, 09:02 AM) ...   Nov 17 2007, 05:38 PM
- - Greg Hullender   Here's a couple of useful comments from a NASA...   Nov 15 2007, 06:41 PM
- - djellison   And of course, the fact that water can exist, at s...   Nov 15 2007, 07:12 PM
|- - rlorenz   QUOTE (djellison @ Nov 15 2007, 02:12 PM)...   Nov 16 2007, 01:47 AM
|- - ngunn   QUOTE (rlorenz @ Nov 16 2007, 01:47 AM) I...   Nov 16 2007, 01:03 PM
- - Juramike   Both theory and experiment agree that cold brine s...   Nov 15 2007, 10:41 PM
- - nprev   Mike or HDP Don, how different are the curves for ...   Nov 16 2007, 01:06 AM
|- - dburt   QUOTE (nprev @ Nov 15 2007, 06:06 PM) Mik...   Nov 16 2007, 08:27 PM
|- - nprev   QUOTE (dburt @ Nov 16 2007, 12:27 PM) Ver...   Nov 17 2007, 01:17 AM
|- - dburt   QUOTE (nprev @ Nov 16 2007, 06:17 PM) Tha...   Nov 17 2007, 01:40 AM
- - ngunn   Thanks for that Hecht link. Definitely some counte...   Nov 16 2007, 08:51 PM
- - nprev   They don't call ya Herr Doktor Professor for n...   Nov 17 2007, 01:50 AM
|- - dburt   QUOTE (nprev @ Nov 16 2007, 06:50 PM) The...   Nov 17 2007, 03:03 AM
- - marsbug   Thank you very much one and all, I can look foward...   Nov 17 2007, 05:25 PM
- - nprev   Rats...knew I shoulda gone to EGD's alma mater...   Nov 18 2007, 12:15 AM
- - Juramike   Space.com article says that the crust of Mars is c...   May 15 2008, 07:03 PM
|- - dburt   QUOTE (Juramike @ May 15 2008, 12:03 PM) ...   May 17 2008, 01:14 AM
||- - dvandorn   QUOTE (dburt @ May 16 2008, 08:14 PM) ......   May 17 2008, 07:06 AM
||- - Juramike   QUOTE (dburt @ May 16 2008, 08:14 PM) Hop...   May 17 2008, 12:53 PM
||- - dburt   QUOTE (Juramike @ May 17 2008, 05:53 AM) ...   May 19 2008, 02:58 AM
||- - SickNick   QUOTE (Juramike @ May 17 2008, 10:53 PM) ...   Jun 8 2008, 02:38 PM
|- - Juramike   QUOTE (Juramike @ May 15 2008, 02:03 PM) ...   May 18 2008, 06:35 PM
- - dvandorn   As a general comment to the "discovery" ...   May 17 2008, 07:17 AM
- - silylene   QUOTE (spdf @ May 24 2007, 12:38 AM) A qu...   May 24 2008, 03:21 AM
|- - rlorenz   QUOTE (silylene @ May 23 2008, 11:21 PM) ...   May 24 2008, 01:27 PM
|- - Juramike   QUOTE (rlorenz @ May 24 2008, 09:27 AM) M...   May 24 2008, 03:05 PM
|- - silylene   I agree that the problem with resonance waves make...   May 25 2008, 02:05 AM
- - Juramike   A rotovap simulation experiment! That...is......   May 24 2008, 04:28 AM


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