Ground Water on Mars? - Opportunity photos - very water-like

Dawg · 2005-01-31 08:58:49

I'm a newby and not too adept at computer and internet stuff. But I have been following the Mars rovers pretty closely. In December, when Opportunity was making its way out of Endurance Crater it took photos of rock slabs, several of which had what looked like muddy water around the base. About the same time the NASA Mars site announced the discovery of conditions that would indicate an ancient site of a sea bed - a conclusion derived from geology, not the current presence of ground water. I have downloaded those photos but I'm not sure how to send them here with a posting. I did not keep the URLs with the photos, only the lengthy NASA/JPL id codes for each one. I would love feedback from an expert on these photos, but never recieved a reply from NASA when I wrote them (Thea ARE a bit busy these days!) I'll be happy to send these photos to this site if someone can tell me how to do it. I have Windows XP. Thanks

Dawg · 2005-01-31 20:42:48

OK, no response yet? I did go back to the Mars site and find one pretty interesting PHOTO! Here's the URL:

http://qt.exploratorium.edu/mars/opport … ...0M1.JPG

It looks even more like water if you can zoom in on it.

RobS · 2005-01-31 21:07:56

That's fine-grained dust, not water. I agree it's hard to tell them apart, but we know Mars is covered by fine-grained dust, and the climate does not permit liquid water.

-- RobS

Dawg · 2005-02-01 08:36:12

Thanks for your reply. I know the temperature on Mars is far too cold to sustain liquid water for any length of time. But if this is dust it settles remarkably like a liquid. I have a half dozen photos the NAVCAM took in this area that look almost as dramatic as the one at the above URL. With each of these photos if you zoom in on them, the visual effect of liquidity gets stronger. I don't know much about chemistry but is there another liquid other than water that could stay liquid in this kind of cold?

RobS · 2005-02-01 21:50:27

Nothing can stay liquid over the temperature range seen daily (freezing to about 80 below Centigrade). Dust should form smooth, flat piles, especially if there's any electrostatic attraction between particles.

-- RobS

Shaun Barrett · 2005-02-01 22:11:25

The picture presented doesn't look like it has any water in it to me, though the smoothness of the dust around the rocks is reminiscent of the smooth mud you sometimes see after water dries up.
Liquid water can exist at certain elevations on Mars, at certain times of the day, in certain parts of the seasonal cycle. I say it can exist but, of course, there's no unequivocal evidence it really does exist.

I suppose it's not entirely impossible, then, that liquid water could actually trickle between the rocks in that picture during brief periods of midday warmth in the summer (?). But we'll need better evidence than this, I think.
???

rgcarnes · 2005-02-02 08:44:22

Rob S,

Why do you invoke electrostatic attraction? It doesn't seem to explain flat piles at all, to me. Totally neutral (at least in the aggregate) material would tend to behave that way under the influence of gravity.

Dawg · 2005-02-03 04:35:01

I agree, Shaun B. that it looks like the kind of mud you see in a puddle as it dries up, especially such a puddle in the red clay of the state of Georgia, where I grew up. I wonder what would happen if you could take a stick and poke at it. Would it make a scar in the surface like in Georgia mud? Would it ridge up like sand? Or would it puff up into a little cloud and then settle back down into a nice smooth surface again?

If someone could tell me how to upload pictures to this site I can send several more. I can go back to NASA and get the URLs, but it takes a lot of time.

Dawg · 2005-02-03 06:03:15

Here's a paper, albeit unpublished, asserting that at least transient water is likely to be found on mars:

Richardson, Mark; Mischna, Michael, — December 2004
The Long-Term Evolution of Transient Liquid Water on Mars

http://www.agu.org/pubs/pip/2004JE00236 … 002367.pdf

RobS · 2005-02-03 23:29:11

I said if there's electrostatic attraction between particles, they'd cling to each other and that might incline them to form flatter surfaces (because anything sticking up would be pulled down). But I am not sure how much electrostatic charge there is on Mars.

Yes, there can be transient liquid water on Mars over about half its surface, especially if it is salty.

-- RobS

Shaun Barrett · 2005-02-04 06:34:50

Thanks, Dawg, for that unpublished paper you linked for us.

What the authors imply, in a nutshell, is that the Transient Liquid Water Potential (TLWP), as they describe it, doesn't increase in a linear or even proportional way as atmospheric pressure rises on Mars.

The present average ambient pressure, about 6 or 7 millibars, allows for relatively unmoderated highs and lows of surface temperature, rather like conditions on airless bodies like the Moon. Since some areas on Mars have pressures routinely in the range of 7 - 10 millibars (or even higher), and since seasonal temperatures can frequently reach as high as 10 - 20 deg.C above freezing, many regions exhibit conditions in which liquid water can exist, at least briefly.
The paper goes on to explain that pressures of up to 50 millibars, not surprisingly, would serve to increase the area of Mars in which liquid water might exist.

But, because of what they call 'atmospheric thermal blanketing', somewhere between 50 and 100 millibars the increasing atmospheric pressure reduces the diurnal temperature range such that the daily maximum in all parts of Mars fails to reach the melting point of water. (They even considered briny water and came to much the same conclusion.)
According to the authors, it's not until the atmospheric pressure reaches 1 bar (1000 millibars) that the mean temperature again becomes high enough, through the greenhouse effect, to allow liquid water on the surface!

If all this is true, it has important ramifications for the history of liquid water on Mars. While many authorities believe it likely that Mars was once warmer and wetter due to perhaps a 5 bar atmosphere of CO2, it's generally accepted that much of that atmosphere was lost relatively early in its history. The remaining Martian 'air' has thinned gradually through various means, it's suggested, including leakage to space, formation of carbonate rocks, and sequestering in reservoirs such as the polar caps and the regolith.
Whichever way the process occurred, it's obvious that the atmospheric pressure must have entered the range of 1000 millibars to 100 millibars, sooner or later, on its way down to its present-day figure, and it's not difficult to imagine the pressure remaining in that range for an extended period. In fact, I suppose it could have taken over a billion years to lose those 900 millibars, in which time there was no possibility of liquid water at all!

This is something I admit I'd never considered before. I had always imagined the extent and persistence of liquid water on Mars as having decreased in proportion to the decreasing density of its atmosphere, in a roughly linear relationship over time.
Now it appears Mars' surface was first wet, then completely dry for perhaps a very long time, and only relatively recently able to support transient surface water once more.
The possible consequences of that for any early life-forms on Mars probably haven't been considered yet. ???

As a corollary to all this, almost every terraforming plan I've seen put forward for Mars involves an atmosphere of somewhere between about 350 and 500 millibars, with the higher of these two figures being the preferred option.
As you'll have noticed, 500 millibars is smack-dab in the middle of that 'dry range' we've been discussing!
Fortunately for us terraformers, we won't have to rely on CO2 alone to keep the average surface temperature high enough for liquid water. Unlike Mars herself, we can add a nice cocktail of perfluorocarbons to the air to enhance the greenhouse effect.
But the above paper helps to underline the fact that those super greenhouse gases will be a permanent necessity on a terraformed Mars. We'll have to keep pumping 'em out, no matter what!

[P.S. I have serious doubts about the paper, by the way. As I understand it, there is considerable evidence that liquid water has flowed on Mars at regular intervals throughout most of its history, though the amounts may have varied greatly. To the best of my knowledge, there isn't a well-documented lengthy epoch during which Mars is believed to have been totally dry.
But still, there's such a lot about that place we don't know yet!]

extrasense · 2005-03-10 06:12:02

never recieved a reply from NASA when I wrote them

I agree with you, some pictures have water/mud/ice on them.
The thing is that NASA is deranged, totally incompetent bureaucracy, full of imbeciles and saboteurs.

e :band: s

extrasense · 2005-03-10 06:24:26

I'll be happy to send these photos to this site if someone can tell me how to do it.

The way to "send" pictures depend wheather a picture is on your computer, or on an Internet.

If it is on your computer, the first step is to upload it to some Internet site.

When/if it is on the Internet, you can:

(1) include 'http full link' to it in your message
(2) use tags around 'http full link' in your message

es

dicktice · 2005-03-10 09:16:39

How about giving us elderly members a step by step "worked example" of what you mean, so we can send pictures unerringly?

Earthfirst · 2005-03-10 14:04:20

I my self have never found out how to send pictures on the internet. I think that the internet moniters yours dreams at night so that it can send you spam in the morning.

dicktice · 2005-03-10 22:02:56

Not Melatonin dreams, since they're closed circuit.

srmeaney · 2005-03-18 09:14:44

the iron oxide is purely a result of permafrost glacier breaking up and reacting with the iron on a chemical level. The amount of energy involved in the iron stealing the oxygen from the hydrogen is much lower than melting and evaporation.

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#1 2005-01-31 08:58:49

Re: Ground Water on Mars? - Opportunity photos - very water-like

#2 2005-01-31 20:42:48

Re: Ground Water on Mars? - Opportunity photos - very water-like

#3 2005-01-31 21:07:56

Re: Ground Water on Mars? - Opportunity photos - very water-like

#4 2005-02-01 08:36:12

Re: Ground Water on Mars? - Opportunity photos - very water-like

#5 2005-02-01 21:50:27

Re: Ground Water on Mars? - Opportunity photos - very water-like

#6 2005-02-01 22:11:25

Re: Ground Water on Mars? - Opportunity photos - very water-like

#7 2005-02-02 08:44:22

Re: Ground Water on Mars? - Opportunity photos - very water-like

#8 2005-02-03 04:35:01

Re: Ground Water on Mars? - Opportunity photos - very water-like

#9 2005-02-03 06:03:15

Re: Ground Water on Mars? - Opportunity photos - very water-like

#10 2005-02-03 23:29:11

Re: Ground Water on Mars? - Opportunity photos - very water-like

#11 2005-02-04 06:34:50

Re: Ground Water on Mars? - Opportunity photos - very water-like

#12 2005-03-10 06:12:02

Re: Ground Water on Mars? - Opportunity photos - very water-like

#13 2005-03-10 06:24:26

Re: Ground Water on Mars? - Opportunity photos - very water-like

#14 2005-03-10 09:16:39

Re: Ground Water on Mars? - Opportunity photos - very water-like

#15 2005-03-10 14:04:20

Re: Ground Water on Mars? - Opportunity photos - very water-like

#16 2005-03-10 22:02:56

Re: Ground Water on Mars? - Opportunity photos - very water-like

#17 2005-03-18 09:14:44

Re: Ground Water on Mars? - Opportunity photos - very water-like

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