Lakes on Mars today?! - What could they be?

Shaun Barrett · 2002-05-26 23:39:36

Some people claim there are lakes on Mars .... now ...as we speak! At least two New Mars members, rhw007 and rgcarnes, have expressed interest in the photographic evidence for these apparent "pools".
I have seen the photos myself and they do seem to show what look like pools of some kind of liquid (or maybe ice). They even seem to have shorelines. And, when you compare them with aerial photos of lakes in terrestrial deserts, the resemblance is striking.
But there can't possibly be liquid water on Mars, right?
Or can there?
I've noted talk about highly saturated salt solutions being extremely resistant to freezing. What if we imagine a lake of concentrated brine on the Martian surface. Let's assume its freezing point is -60 deg. C. Let's also assume the local daily temperature range is -90 to -30 deg. C.
Could such a lake persist on the surface, alternately freezing and thawing, with surface evaporation being replaced by underground seepage of water into the lake basin?
I've made up all these figures as a wild hypothesis to try to explain the photographic evidence. Perhaps everything I've suggested is totally untenable. But can anyone out there with a better background in chemistry put any of this on a firmer scientific footing?
Who knows ... maybe they'll have to consider taking a canoe on the first expedition!!

C M Edwards · 2002-05-27 08:29:19

Hello Shaun.

This website explains the mathematical relationships between concentration/molality, vapor pressure, freezing point and melting point for aqueous solutions.

http://wine1.sb.fsu.edu/chm1046/notes/S … Collig.htm

The important point to note is that these relationships are roughly linear over broad ranges. The concentration required to lower the vapor pressure of water below the mean atmospheric pressure of Mars is not quite attainable. The brine becomes saturated before that and becomes unable to hold more salt. However, it's very close, and liquid brines could exist in high pressure pockets just inches below the surface if the temperatures ever got high enough.

Some other points to note:

Distilled Water freezes at 0 degrees Celsius even in near vacuum, but will Franklin boil at 0 degrees once the air pressure falls below its vapor pressure. So, once the pressure falls below the vapor pressure of a solution, it can no longer exist as a liquid.

Most chemicals that dissolve in water reach saturation points, beyond which molality cannot be increased just by adding more solute at constant temperature & pressure. However, some chemicals, such as alcohol, have no saturation limits. If you add enough alcohol to water, you reach a point where it's more convenient to talk about water disolved in alcohol.

Freezing salt water concentrates the salt because the salt ions are excluded from the forming water crystals. Thus, the portion that freezes first is relatively pure ice, or at least at a lower concentration than it started. This effect can gradually purify the water out of the solution over time (which is why you can drink water melted off of icebergs). It also means that if you freeze salt water in an ice cube tray, the water pressure in unfrozen portion shrinks rises as more and more salt is forced into it. Ultimately, the internal pressure can rise high enough to force a miniature geyser of water up through the ice cube's surface.

This pressure buildup is a natural consequence of the freezing process and would handily raise the water pressure of a brine above its vapor point.

The same could happen in a frozen salt lake, contaminating the frozen surface with salt. Unfrozen water at the bottom of the lake would become concentrated with salt excluded from the upper layers, raising its pressure and ultimately causing it to burst up through any weaknesses in the ice layers.

Thus, the surface of a frozen lake of brine would likely be contaminated with salt, making it difficult to determine the age or nature of the formation from orbit.

But it would still look like a frozen lake.

CME

C M Edwards · 2002-05-28 11:56:47

Freezing water out of brine can also concentrate it beyond the saturation limits for simple mixing.

It occurs to me that many of the odd formations on Mars that people have tried to explain by ice melting could just as easily be explained by brine freezing.

CME

Phobos · 2002-05-28 14:37:53

I read an article once (don't remember where) that claimed that these areas carved out by water might have been carved out by flowing silicate-like material. The theory sounded a little far fetched, I don't see how dry material could flow with such force like that on its own, but I'm not a geologist, so what do I know.

GOM · 2002-05-29 12:18:21

I read an article once (don't remember where) that claimed that these areas carved out by water might have been carved out by flowing silicate-like material. The theory sounded a little far fetched,

Yes, it sounds mare than a little far fetched. And it doesn't meet the Occam's Razor test that skeptics like to trot out whenever it suits their purposes.

GOM · 2002-05-29 12:21:54

Could such a lake persist on the surface, alternately freezing and thawing, with surface evaporation being replaced by underground seepage of water into the lake basin?

It could. NASA used to claim it was impossible. Now they have had to change their tune.

Or maybe they knew it all along, but this is just another small step in the conditioning process we are being put through.

Almir · 2003-02-17 11:35:22

Hello,

Some links:

Making a Splash on Mars
http://science.msfc.nasa.gov/headlines/ … jun_1m.htm

Use of spacecraft data to derive regions on Mars where liquid water would be stable
http://www.pnas.org/cgi/content/full/98/5/2132

Liquid water and life on Mars
http://www.biospherics.com/mars/spie2/spie98.htm

rgcarnes · 2003-02-18 12:55:04

[color=#000000:post_uid0]The web documents referenced by Almir are, I believe, excellent selections.

In reviewing the previous comments on this topic, people seem to feel that they need to invoke the presence of salts, or soil protection, or substantial ice in order to explain the presence of observable water at, or near, the surface of Mars. Each one of these will, in my opinion, have its place on the red planet.

Indeed, the conventional position, repeated over and over in most of the papers I've seen, is that water would instantly boil away at the atmospheric pressure available on the surface of Mars without them.

I present two fundamental facts about real physical characteristics of gasses, and water including its other phases:

1. Dalton's Law of Partial Pressures--States, as well as I can remember, that the total pressure of a mixture of gasses at equilibrium is the sum of the individual partial pressures, and that each gas is independent of the other components of the mixture. This of course assumes that there are no chemical reactions taking place, hence the "at equilibrium" qualification.

2. The partial pressure of water at its triple point, the point where water vapor, ice, and liquid water can co-exist at equilibrium, is about 6.1 millibars, remarkably equivalent to the atmospheric pressure of Mars as measured by the Pathfinder lander.

If the atmospheric composition at the very surface of Mars is water vapor rather than a preponderance of carbon dioxide, then water would not boil away at all, it would be at equllibrium with it's own vapor!

There are some very valid reasons that early probes may have measured what seemed to be high levels of CO2. Common instrumental errors in mass spectrometers might be one of them. If anyone is interested, I'll explain when I have more time.

Rex G. Carnes

[U][/color:post_uid0]

Palomar · 2003-02-18 16:19:35

Some people claim there are lakes on Mars .... now ...as we speak! At least two New Mars members, rhw007 and rgcarnes, have expressed interest in the photographic evidence for these apparent "pools".
I have seen the photos myself and they do seem to show what look like pools of some kind of liquid (or maybe ice). They even seem to have shorelines.

*I really hate to say this -- all things considered, and all given my enthusiasm in this regard -- but those photos look doctored to me. They don't look real. What's my criteria for "looking real"? Umm....okay, maybe it's because I don't expect to see liquid water standing on Mars (unfrozen) and my mind wants to see it as looking fakey.

But I'm sorry, the photograph (provided via link) submitted in this thread...well, it looks like an artistic conception was added in.

More proof, please. Sorry.

--Cindy

dickbill · 2003-02-18 17:43:56

It looks like somebody else is not convinced by "proof of photographic evidence of presence of mass"... liquid water.

sorry for the joke, just forget it...

Palomar · 2003-02-18 20:57:24

sorry for the joke, just forget it...

*Can't forget something I didn't "get"...what's the joke?

--Cindy

rgcarnes · 2003-02-19 08:52:03

[color=#000000:post_uid0]I was referenced in Shawn's initial post in this topic. Neither he nor anyone else not attending my presentation at the last Mars Society Convention, or the presentation I gave at the 2001 National Space Society Convention has seen any of my evidence.

1. The assumption that the image(s) linked from this forum is/are the one(s) I base my conclusions about water on Mars is not valid. [U]

2. To dismiss the evidence before you've been exposed to it seems a bit cavalier.

3. I appologize for not having the paper, resulting from my presentation last August at the Mars Society Convention, accessable on the web for your review. It's locked up in a computer in the midst of a move. I hope to have it available soon. It was submitted for publication in the proceedings from the Boulder conference, but that will be out "sometime before next August".

Thanks for your patience.

Rex G. Carnes[/color:post_uid0]

dickbill · 2003-02-19 09:38:27

sorry for the joke, just forget it...
*Can't forget something I didn't "get"...what's the joke?
--Cindy

You're not kidding me right ?, I was refering to Colin Powell "proof of mass ..."
Again, just a joke.

I didn't refer at all to the pictures from rgcarnes since I havn't seen them. Maybe they really indicate liquid water, I cannot say.

Palomar · 2003-02-19 10:43:54

dickbill: You're not kidding me right ?,

*Right.

dickbill: I was refering to Colin Powell "proof of mass ..."
Again, just a joke.

*Thanks for the explanation (after all, I can't read your mind).

--Cindy

Palomar · 2003-02-19 10:45:52

2. To dismiss the evidence before you've been exposed to it seems a bit cavalier.

*I wasn't dismissing the evidence you are referring to; I dismissed what appears to me a doctored photograph in a link provided by someone other than you.

--Cindy

Almir · 2003-02-21 13:57:43

The Bell jar experiments and liquid water on Mars

APPROACHES TO RESOLVING THE QUESTION OF LIFE ON MARS
http://www.biospherics.com/mars/2000SPIEFinal.html

What do you know about?

Shaun Barrett · 2003-02-27 01:54:03

Hi Cindy!
I quite understand your reluctance to believe there might be liquid water on the surface of Mars. It's very difficult to judge from the photographs just what some of these features actually are - though I've said some of them do look like pools of clear liquid to my eyes. Certainly NASA hasn't come out in favour of surface liquid, preferring other explanations.
My line of reasoning was to try to establish whether it was even physically possible for bodies of standing water to exist on the Martian surface. Apparently briny water is capable of remaining liquid down to pretty low temperatures, so I pursued that aspect of it. And it seems salty water could conceivably account for some of these 'pools', if pools they be!
It's also interesting to look at what regions of Mars are topographically low enough to experience higher than average atmospheric pressures. Wherever the pressure exceeds 6.1 millibars (the so-called triple point of water, at which pressure it becomes possible for it to exist as a solid, a gas, and a liquid), then liquid water becomes a possibility. It turns out that in places like Hellas Basin, where the pressure can reach 12.4 millibars, and various other places such as the near-equatorial areas of Isidis Planitia, water could, at certain times of the year, form pools. And, presumably, the brinier the water, the longer it could persist as a liquid as the ambient temperatures dropped with the approach of winter.
The only problem is the dryness of the Martian air - far dryer than any on Earth. In theory, this dryness should cause any liquid water to evaporate very fast. But there is apparently a mechanism which might counteract this tendency for extremely rapid evaporation to occur. The Martian air is not only dry but very cold. It is too thin to retain much heat except very close to the ground, which is heated by the sun. This warm layer of air close to the ground would absorb water vapour from a pond and quickly become saturated. But at an altitude of about a metre, the air would be much colder than near the ground, and incapable of absorbing much water vapour from the air below it. Thus, at least in relatively calm conditions, a layer of warm air saturated with water vapour would remain immediately above our imaginary pond, preventing further evaporation from its surface!
Voila!! We now have a theoretically sound basis for ponds and perhaps even lakes on Mars! ( ... At least some parts of Mars, some times of the year, when the weather isn't too windy!)
:;):

And yes Rex!
I would be absolutely delighted to see your evidence for pools on Mars!
I'm only sorry I didn't see your presentations at the two conventions you mentioned.
Will you be at the next Mars Society Convention this year in Oregon? There is some slight chance I might be there myself and would be very interested to speak with you if the opportunity presented itself.

rgcarnes · 2003-02-27 11:41:11

Greetings,

I'm waiting for the arrival of a couple of special network cards to make my previous papers available from the older computer. The're supposed to arrive today, if the delivery vehicle can make it up my snow covered driveway.

The work in the papers was intended to be repeatable by anyone with a home computer and a little motivation. They reference images directly from MSSS.com and the NASA PDS site, so anyone can access the original images for verification.

I haven't made any firm plans to attend the Oregon meeting yet, but would, of course, like to.

Please forgive me if my last post was too harsh. You people have been very gracious. It seems that I may have fired off an elephant gun response when it was't really appropriate.

Shaun Barrett · 2003-02-27 18:23:22

When you send us this stuff, Rex, please bear in mind that not all of us are very good with computers (i.e me! ).
It would be appreciated if the information is as user friendly as possible. I'd hate to get a stack of glorious evidence for standing water on Mars and be unable to bring it up on screen!!

P.S. No need for apologies. I'm sure nobody would have taken
any offence at your comments. You merely stated your
case unequivocally - people who take offence at plain
straight-talking probably need to adjust their sets!

Shaun Barrett · 2003-05-13 19:02:21

I'm not sure if anyone else has posted a reference to this already but, if they have, I apologise in advance!

One of the latest photographs from Mars has been released via Space.com at this site.

The picture shows the floor of a crater in western Arabia Terra and it looks like a geologist/paleontologist's delight to me - so many sedimentary layers!
The lower portion of the photo seems to show lower altitude terrain, judging by the lighting, and some of the ravines there have very dark material in them.
I have had communication with Rex Carnes here at New Mars (and privately) about such features and, as I understand it, he is of the opinion that dark areas like these may possibly be standing bodies of water ... or, at least, concentrated brine.
I have an open mind on the subject but he has put forward intriguing arguments for this hypothesis and I, for one, see no obvious reason why he should not be correct in this.

The physics behind the possibility of standing bodies of brine in certain areas of Mars has been touched on more than once in New Mars threads and I believe the arguments are valid. In low-lying regions, not too far from the equator, such as Isidis Planitia and western Arabia Terra, the atmospheric pressure exceeds the triple point of water - allowing it to exist as a liquid when the temperature is high enough. When you consider the case of very briny water, the 'window of opportunity' for water to exist as a liquid opens much wider. NASA's Chris McKay has published material showing that brine can stay liquid below minus 20 deg.C and at pressures as low as 1 millibar!

It seems that what looks like dark liquid in the low-lying areas of this picture from Arabia Terra, could plausibly be liquid. It's in the right area and physics allows it.

Putting aside the mainstream paradigms and just examining the facts as you see them, what does everyone else here think about these features and others like them?
We know there's lots of water available on Mars.
We know there's no objection in physics to liquid brine on Mars.
Many of these features look just like dark bodies of water.
We know transient dark streaks of liquid flow downhill on certain Martian slopes (we've seen the pictures).
If it looks like a duck, waddles like a duck, and quacks like a duck ... !

I'll stick my neck out and say I think we're dealing with standing bodies of briny water.
What do you think? ???

rgcarnes · 2003-05-14 21:47:18

Good to see this topic come up from a long nap.

My looking has turned up several craters showing features just like you are pointing out. I strongly suspect that the dark areas in such craters are liquid water, but haven't really emphasized them in that the "It sure looks like it" arguement is so easily dismissed, and I haven't really found an extremely compelling visual feature to add to it yet.

That being said, comments are in order regarding the appearance of the layers.
1. They are apparently in the lowest portions of their craters.
2. The apparent uniform spacing between layers appear as if they are very uniform depth contours. This suggests to me that the coutour edges may be seasonal (yearly?) evaporant boundaries, rather than sedimentary layers which were later eroded to the forms we are observing now. After all, where could the material that seems to have been removed have gone, since most of these regions seem to be in the lowest portions of their craters? Identification of the composition of this material as an appropriate evaporant residue would seem to secure this point.

Shaun Barrett · 2003-05-20 21:46:07

Thanks for the reply, Rex. I've been away for a few days which explains why I've taken a while to respond.
You raise interesting points about the layering pattern and the logic seems compelling that perhaps they could be 'high tide' marks of an ever-receding waterline.
I wonder if anyone else has any opinions about this?
???

Josh Cryer · 2003-05-22 01:12:12

rgcarnes, have you managed to put your papers online so that people may view them? I, for one, would be quite interested in the theory.

My main problem with ?liquid water on the surface of Mars? theories is that I honestly don't see anything backing up the whole of such a theory. We can definitely say that liquid water can exist in a mild vaccum, that's physically possible (though I question the significance of this). But can we show how, first, a pool of liquid water clathrate could initally exist on Mars, second, whether or not a pool of liquid water clathrate can still be existing on Mars, and lastly, whether or not a cyclic clathrate is even possible in the conditions of Mars.

Until all of these questions are satisfied, I will continue to be skeptical. And no, ?Films of liquid water in the morning for a short period of time during the triple point? does not impress me, and the implications of such a thing are beyond me, except to show a fundamental of science. One of the worst thing going against ?liquid water on Mars? promoters, is that they almos always mention that NASA claims that liquid water can't exist on Mars, neglecting to mention the triple point phenomena, so there must be a conspiracy. They can't use that argument to push off their paranoia, anymore, though.

Shaun Barrett · 2003-05-22 17:32:29

Hi Josh!
What's "liquid water clathrate"?

Secondly, none of what is discussed here is necessarily anything to do with conspiracies. I think all we're trying to do is look at the pictures, look at the hard science, and make an intelligent assessment of the evidence at hand.

NASA's opinion as to what the photographic evidence actually portrays is simply an informed opinion - not an established fact. You, Rex, I, and anyone else with eyes to see and a brain to think with (and some basic understanding of physics ... not much is needed here), are entitled to examine the same evidence and come to a conclusion. NASA personnel have often stated that many of the landforms on Mars are enigmatic and difficult to analyse. Mars is largely an unknown place and NASA scientists are just human beings like us, not gods - we are permitted to disagree with their conclusions.

As of this particular moment, my personal opinion is that we could very well be looking at standing bodies of salty water on the Martian surface. That opinion may change when new evidence arises.

Josh Cryer · 2003-05-23 00:52:21

Man I lost my post to this thread three times in a row! Okay, let's try this again. This time in notepad. Saving (Control+S) periodically.

Well, Shaun, I think that there is a lot of evidence to suggest that the formations we are seeing, are part of a CO2-clathrate brine-water mixture. A CO2-clathrate mixed with water ice can't really be called liquid water without the brine keeping the water in a more stable state (and we're not sure if a CO2-clathrate could even make the formations without a briney mixture). So I coined the term ?liquid water clathrate.? Sorry if that's not adequate.

The point is, hey, we do know that there are formations which seem to have liquid water in them, they might be really nasty concoctions, but there's some water in there somewhere. But how can we know if these liquid water formations exist elsewhere? We're mostly speculating without any real evidence other than the fact that it's ?physically possible? (I should note that a CO2-clathrate probably wouldn't exist in your standing pools of brine- but has anyone really shown that the pools of brine could actually exist?).

The biggest problem with these theories is that they try to use visual evidence to prove them, knowing that the resolution for the cameras abord MGS and Odyssey aren't nearly adequate to even begin speculating about smaller ground formations. This is specifically why Odyssey carries aboard instruments that get better non-visual measurements. Short of sending a freaking spy satellite, you have to use ?indirect? approaches. I think that if Odyssey detected unusual formations in the images we've recieved, someone would say something. Big discoveries mean more funding, and that's pretty much a fact. So whether we like it or not, the conspiracy theories do mangle themselves within the science.

I take most images of Mars with a grain of salt, especially if they supposedly ?show? something totally unusual. The only visual proof we can really have at this resolution, are clear, obvious, undeniable changes, like the water formations we have discovered.

Pools of standing brine could be interesting, but I need to be convinced that they could last thousands of years, or could be recent. In light of no compelling evidence, I'm not.

New Mars Forums

Announcement

#1 2002-05-26 23:39:36

Re: Lakes on Mars today?! - What could they be?

#2 2002-05-27 08:29:19

Re: Lakes on Mars today?! - What could they be?

#3 2002-05-28 11:56:47

Re: Lakes on Mars today?! - What could they be?

#4 2002-05-28 14:37:53

Re: Lakes on Mars today?! - What could they be?

#5 2002-05-29 12:18:21

Re: Lakes on Mars today?! - What could they be?

#6 2002-05-29 12:21:54

Re: Lakes on Mars today?! - What could they be?

#7 2003-02-17 11:35:22

Re: Lakes on Mars today?! - What could they be?

#8 2003-02-18 12:55:04

Re: Lakes on Mars today?! - What could they be?

#9 2003-02-18 16:19:35

Re: Lakes on Mars today?! - What could they be?

#10 2003-02-18 17:43:56

Re: Lakes on Mars today?! - What could they be?

#11 2003-02-18 20:57:24

Re: Lakes on Mars today?! - What could they be?

#12 2003-02-19 08:52:03

Re: Lakes on Mars today?! - What could they be?

#13 2003-02-19 09:38:27

Re: Lakes on Mars today?! - What could they be?

#14 2003-02-19 10:43:54

Re: Lakes on Mars today?! - What could they be?

#15 2003-02-19 10:45:52

Re: Lakes on Mars today?! - What could they be?

#16 2003-02-21 13:57:43

Re: Lakes on Mars today?! - What could they be?

#17 2003-02-27 01:54:03

Re: Lakes on Mars today?! - What could they be?

#18 2003-02-27 11:41:11

Re: Lakes on Mars today?! - What could they be?

#19 2003-02-27 18:23:22

Re: Lakes on Mars today?! - What could they be?

#20 2003-05-13 19:02:21

Re: Lakes on Mars today?! - What could they be?

#21 2003-05-14 21:47:18

Re: Lakes on Mars today?! - What could they be?

#22 2003-05-20 21:46:07

Re: Lakes on Mars today?! - What could they be?

#23 2003-05-22 01:12:12

Re: Lakes on Mars today?! - What could they be?

#24 2003-05-22 17:32:29

Re: Lakes on Mars today?! - What could they be?

#25 2003-05-23 00:52:21

Re: Lakes on Mars today?! - What could they be?

Board footer